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Wallage AL, Lees AM, Lisle AT, Lees JC, Johnston SD, Gaughan JB. Thermoregulation of the bovine scrotum 2: simulated acute and chronic heat waves reduces the scrotal thermoregulatory capability of Wagyu bulls. Int J Biometeorol 2022; 66:251-262. [PMID: 33733303 DOI: 10.1007/s00484-021-02108-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 01/12/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
The objective of this study was to investigate the effect of acute and chronic heat load events on scrotal temperature (ST), body temperature (BT) and bull behaviour, and to examine the interrelationship between these parameters; the underlying hypothesis was that adverse heat treatments delivered in a temperature controlled environment will lead to thermoregulatory dysfunction of the bull scrotum. Six sexually mature Wagyu bulls were used in this study with data loggers surgically implanted into the abdominal cavity and scrotum. Body temperate and ST were recorded at 30-min intervals for the duration of the study. There were two housing locations used throughout the study, outdoor pens and climate control rooms. The study was designed as a four-phase crossover design with two heat treatments: (1) a 5-day acute challenge, and (2) a 14-day chronic challenge. The study was also blocked by phase to control for systematic change between phases with a thermoneutral (TN) phase in outdoor pens between each heat challenge. Observations within the climate rooms were conducted at 1-h intervals and data on panting scores (PS), respiration rate (RR), posture (standing or lying) and general behaviours (feeding, drinking, ruminating) recorded. Ambient temperature (AT, °C) and relative humidity (RH, %) were obtained at 10-min intervals and used to calculate the temperature humidity index (THI). Multiple models were conducted using a linear mixed effects model that contained different permutations of date and time factors and interactions as well as inclusion of an autoregressive parameter. The strongest model based on Akaike's information criterion (AIC) was selected and further analysed. Ambient conditions during heat treatments were consistent with heat load and bulls showed typical physiological symptoms of the same. Maximum ST for acute and chronic treatments occurred once AT had exceeded 34 °C for at least 3 h (acute 35.59 °C at 1500 h; chronic 35.18 °C at 1400 h), whereas during TN conditions, maximum ST was at 2100 h. All phases showed variation in ST throughout the day. There were strong cross correlations between ST and RR during the heat treatments (acute r = 0.918, P < 0.0001; chronic r = 0.916, P < 0.0001), but not during TN (r = 0.411, P < 0.05). Our results confirmed that the ST of the bulls used in this study was not held at a constant temperature and that there was a possible connection between ST and RR. We have shown that during a period of heat load, the thermoregulatory mechanisms thought responsible for maintaining bovine ST appear to breakdown.
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Affiliation(s)
- Andrea L Wallage
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia.
| | - A M Lees
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2350, Australia
| | - A T Lisle
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - J C Lees
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2350, Australia
| | - S D Johnston
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - J B Gaughan
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
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McAuley C, McCullagh D, Johnston SD. MELANOMA: MORE THAN SKIN DEEP. Ulster Med J 2022; 91:58-59. [PMID: 35169347 PMCID: PMC8835426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- C McAuley
- Gastroenterology Department, Belfast City Hospital
| | | | - SD Johnston
- Gastroenterology Department, Belfast City Hospital
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3
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Adam D, Johnston SD, Beard L, Nicolson V, Lisle AT, Gaughan JB, Larkin R, Theilemann P, Ellis W. Temporal effect of feeding on the body temperature and behaviour of captive koalas (Phascolarctos cinereus). Aust Mammalogy 2022. [DOI: 10.1071/am20024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Free-ranging koalas generally feed at night; however, captive koalas are usually fed during the day in order to encourage activity for display purposes. We studied the temporal effect of feeding on body temperature of captive koalas in Queensland, to determine whether nocturnal feeding may be beneficial for koalas in warmer climates. Six adult koalas were implanted with thermal transmitters and data loggers, waxed together as a single package, to record internal body temperature. Koalas were exposed to two treatments: koalas were fed in the morning (between 0730 and 0830 hours) during the AM treatment or late afternoon (between 1700 and 1800 hours) for the PM treatment. The body temperature of koalas fed in the mornings was on average 0.5°C higher at its peak (P ≤ 0.01) when compared to koalas fed in the evening. Furthermore, the body temperature maxima of morning-fed koalas was reached ~2 h earlier in the afternoon, compared with those fed in the evening. There was no significant difference between behaviours associated with the two feeding regimes: inactivity (P = 0.840), feeding (P = 0.472) and activity (P = 0.634). We postulate that nocturnal feeding by koalas may be an adaptive mechanism that reduces diurnal heat load during times of high environmental temperatures.
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Miller RR, Beranek F, Anderson AL, Johnston SD, Nixon B. Plasma and acrosomal membrane lipid content of saltwater crocodile spermatozoa. Reprod Fertil Dev 2021; 33:RD21007. [PMID: 33941311 DOI: 10.1071/rd21007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/01/2021] [Indexed: 11/23/2022] Open
Abstract
This study describes the chemical lipid composition of the sperm plasma and acrosomal membranes of the saltwater crocodile Crocodylus porosus with the aim of providing new insights into sperm physiology, particularly that associated with their preservation ex vivo . The specific fatty acid composition of the sperm plasma and acrosomal membranes is documented. The mean (±s.d.) ratio of unsaturated to saturated membrane fatty acids within the plasma membrane was 2.57±0.50, and was determined to be higher than a similar analysis of the lipids found in the acrosomal membrane (0.70±0.10). The saltwater crocodile sperm plasma membrane also contained remarkably high levels of cholesterol (mean (±s.d.) 40.7±4.5 nmol per 106 sperm cells) compared with the spermatozoa of other amniote species that have so far been documented. We suggest that this high cholesterol content could be conferring stability to the crocodile sperm membrane, allowing it to tolerate extreme osmotic fluxes and rapid changes in temperature. Our descriptive analysis now provides those interested in reptile and comparative sperm physiology an improved baseline database for interpreting biochemical changes associated with preservation pathology (e.g. cold shock and cryoinjury), epididymal sperm maturation and capacitation/acrosome reaction.
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Affiliation(s)
- R R Miller
- Department of Biology, Hillsdale College, 33 E. College Street, Hillsdale, MI 49242, USA
| | - F Beranek
- Department of Biology, Hillsdale College, 33 E. College Street, Hillsdale, MI 49242, USA; and Controls Group, Limbach Company, 926 Featherstone Street, Pontiac, MI 48342, USA
| | - A L Anderson
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - S D Johnston
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Qld 4343, Australia; and Corresponding author
| | - B Nixon
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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Johnston SD, López-Fernández C, Arroyo F, Roy R, Holt WV, Gosálvez J. Protamine composition of koala and wombat spermatozoa provides new insights into DNA stability following cryopreservation. Reprod Fertil Dev 2020; 31:1558-1566. [PMID: 31167697 DOI: 10.1071/rd18512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/02/2019] [Indexed: 11/23/2022] Open
Abstract
To investigate differences in the post-thaw DNA stability of koala and wombat spermatozoa, protamine amino acid sequences were compared and it was found that there were three more arginine residues for the wombat. Koala and wombat spermatozoa, cryopreserved using identical protocols, were examined for changes in sperm DNA fragmentation (SDF) dynamics over 24h of post-thaw incubation. Following validation of a wombat sperm chromatin dispersion test, wombat DNA showed a rate of SDF that was 6-fold higher than for koala spermatozoa (P=0.038). Finally, we examined whether expected differences in chromatin compactness, associated with protamine sequence, had an effect on restriction site accessibility of sperm DNA. Thawed spermatozoa were exposed to Alu I and EcoR1 endonuclease restriction enzymes and the SDF dynamics were observed. Koala spermatozoa exposed to Alu I showed a greater rate of SDF (P=0.01), whereas wombat spermatozoa exposed to EcoR1 showed a greater rate of SDF (P=0.032). We conclude that restriction sites in these species are differentially present or exposed and potentially account for differences in SDF dynamics. Although differences in the arginine composition of protamine may explain relative differences in SDF following cryopreservation, they do not support the hypothesis that increased arginine composition increases DNA stability; rather, increased arginine composition in the wombat may reduce post-thaw chromatin swelling.
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Affiliation(s)
- S D Johnston
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Qld 4343, Australia; and Corresponding author.
| | - C López-Fernández
- Department of Biology, Autonomous University of Madrid, Cantoblanco, Madrid, 28049, Spain
| | - F Arroyo
- Department of Biology, Autonomous University of Madrid, Cantoblanco, Madrid, 28049, Spain
| | - R Roy
- Department of Biology, Autonomous University of Madrid, Cantoblanco, Madrid, 28049, Spain
| | - W V Holt
- Academic unit of Reproductive and Developmental Medicine, University of Sheffield, Sheffield, S10 2TN, UK
| | - J Gosálvez
- Department of Biology, Autonomous University of Madrid, Cantoblanco, Madrid, 28049, Spain
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Adam D, Johnston SD, Beard L, Nicolson V, Gaughan JB, Lisle AT, FitzGibbon S, Barth BJ, Gillett A, Grigg G, Ellis W. Body temperature of free-ranging koalas (Phascolarctos cinereus) in south-east Queensland. Int J Biometeorol 2020; 64:1305-1318. [PMID: 32388686 DOI: 10.1007/s00484-020-01907-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 02/17/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
The distribution of the koala (Phascolarctos cinereus) in Queensland is predicted to contract as a result of climate change, driven by the frequency, intensity and duration of heatwaves and drought. However, little is known about the physiological responses of this species to environmental extremes under field conditions. This study aimed to establish the efficacy of surgically implanted thermal radio transmitters and data loggers to measure the body temperature of free-ranging koalas across a range of environmental conditions and ambient temperatures. Five free-ranging koalas in southeast Queensland were implanted with thermal transmitters and data loggers waxed together as a single package. Body temperatures were recorded for variable periods ranging from 3 to 12 months. Diurnal rhythms in body temperature were detected irrespective of season. The long-term diurnal body temperature peak for all koalas occurred between 16:00 and 17:00 h and body temperature was 36.7-36.9 °C, the long-term nadir occurred between 07:00 and 08:00 h and body temperature was 35.4-35.7 °C. Koala body temperatures as low as 34.2 °C and as high as 39.0 °C were recorded. Thermolability became apparent when ambient temperatures were outside the deduced thermal neutral zone for koalas (14.5-24.5 °C): heat was accumulated during the day and dissipated during the cool of the night. While this study is the first to report on body temperature of free-ranging koalas in their normal behavioural context, further investigations are necessary to determine the physiological boundaries of the thermal niche for this species, in order to better equip models that will more accurately predict the impacts of climate change on koalas.
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Affiliation(s)
- D Adam
- Wildlife Science Unit, School of Agriculture & Food Science, The University of Queensland, Gatton, Queensland, 4343, Australia.
| | - S D Johnston
- Wildlife Science Unit, School of Agriculture & Food Science, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - L Beard
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - V Nicolson
- Dreamworld Veterinary Clinic, Dreamworld, Coomera, Queensland, 4209, Australia
| | - J B Gaughan
- School of Agriculture & Food Sciences, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - A T Lisle
- School of Agriculture & Food Sciences, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - S FitzGibbon
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - B J Barth
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - A Gillett
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - G Grigg
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - W Ellis
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
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Adam D, Beard L, Johnston SD, Nicolson V, Lisle A, McKinnon A, Larkin R, Theilemann P, Gillett A, Brackin K, FitzGibbon S, Barth B, Ellis W. Recording body temperature in koalas (Phascolarctos cinereus
): a comparison of techniques. Aust Vet J 2018; 96:308-311. [DOI: 10.1111/avj.12719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 02/04/2018] [Accepted: 03/05/2018] [Indexed: 12/01/2022]
Affiliation(s)
- D Adam
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - L Beard
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - SD Johnston
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | | | - A Lisle
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - A McKinnon
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - R Larkin
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - P Theilemann
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - A Gillett
- Australia Zoo Wildlife Hospital; Beerwah QLD Australia
| | - K Brackin
- Bellbowrie Veterinary Surgery; Bellbowrie QLD Australia
| | - S FitzGibbon
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
| | - B Barth
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
| | - W Ellis
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
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Johnston SD, López-Fernández C, Arroyo F, Fernández JL, Gosálvez J. The assessment of sperm DNA fragmentation in the saltwater crocodile (Crocodylus porosus). Reprod Fertil Dev 2018; 29:630-636. [PMID: 26462595 DOI: 10.1071/rd15300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/05/2015] [Indexed: 11/23/2022] Open
Abstract
Herein we report a method of assessing DNA fragmentation in the saltwater crocodile using the sperm chromatin dispersion test (SCDt) after including frozen-thawed spermatozoa in a microgel (Halomax; Halotech DNA, Madrid, Spain). Following controlled protein depletion, which included a reducing agent, sperm nuclei with fragmented DNA showed a homogeneous and larger halo of chromatin dispersion with a corresponding reduced nucleoid core compared with sperm with non-fragmented DNA. The presence of DNA damage was confirmed directly by incorporation of modified nucleotides using in situ nick translation (ISNT) and indirectly by studying the correlation of the SCDt with the results of DNA damage visualisation using a two-tailed comet assay (r=0.90; P=0.037). Results of the SCDt immediately following thawing and after 5h incubation at 37°C in order to induce a range of DNA damage revealed individual crocodile differences in both the baseline level of DNA damage and DNA longevity.
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Affiliation(s)
- S D Johnston
- School of Agriculture and Food Science, The University of Queensland, Gatton, Qld 4070, Australia
| | - C López-Fernández
- Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, 20849 Madrid, Spain
| | - F Arroyo
- Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, 20849 Madrid, Spain
| | - J L Fernández
- Genetics Unit, The Institute of Biomedical Research (INIBIC)-Complejo Hospitalario Universitario A Coruña (CHUAC), As Xubias, 84, 15006 A Coruña, Spain
| | - J Gosálvez
- Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, 20849 Madrid, Spain
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Du Z, Johnston SD, Janssen T, Phillips CJC, Lisle A, Keeley T. Behavioral and endocrine responses to season and social dynamics of captive male southern hairy-nosed wombats (Lasiorhinus latifrons). Gen Comp Endocrinol 2018; 261:40-50. [PMID: 29373814 DOI: 10.1016/j.ygcen.2018.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 12/29/2017] [Accepted: 01/22/2018] [Indexed: 11/16/2022]
Abstract
Although southern hairy-nosed wombats (SHN wombats; Lasiorhinus latifrons) rarely breed in captivity, further knowledge of their reproductive physiology and behavior is likely to improve their breeding potential. This study examined the effect of seasonal variation and changes in social dynamics on the physiology and behavior of a captive population of male SHN wombats (n = 6). Seasonal changes in urinary testosterone metabolites (UTM), urinary cortisol metabolites (UCM), qualitative estimates of spermatorrhoea (QS), aggressive behavior and reproductive behavior were measured over an 11-month period. While there was no effect of month on QS (GLM ANOVA, P = 0.27), reproductive behavior (GLM ANOVA, P = 0.19) or aggressive behavior (Tukey pairwise comparisons), the secretion of UTM (GLM ANOVA, P = 0.051) was only marginally affected by season, compared to that reported for wild male SHN wombats. Mean UCM concentrations of July and August 2016 were significantly higher than those between October 2015 and January 2016 (Tukey pairwise comparisons). To examine social dynamics, two trials of animal positioning exchange with the enclosure system were implemented and behavioral data were examined for each trial over a six week period; UTM, UCM and general behaviors (n = 27) were measured for each trial. Neither UTM nor UCM concentration varied significantly (P ≥ 0.45) before and after the exchanges. "Scratching" decreased at the group level following the animal exchange in both trials, suggesting reduction in self-grooming may be a behavioral response to novel stimuli. UCM and UTM concentrations were both positively correlated with "standing still" and "body rub" behaviors. This may be evidence of a hormonal control of a "freezing behavioral response" to external stimuli and marking behavior, respectively. As there was no evidence that changing the social dynamics affected reproductive or agonistic behavior or hormone concentrations, it was concluded that captive male wombats in this study showed reduced reproductive seasonality compared to wild wombats and that animal exchange resulted in a behavioral response to novel stimuli but was not sufficient to affect testosterone or cortisol secretion, within the context of our study.
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Affiliation(s)
- Z Du
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia.
| | - S D Johnston
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia
| | - T Janssen
- Australian Animal Care and Education, Mount Larcom 4695, Queensland, Australia
| | - C J C Phillips
- Centre for Animal Welfare and Ethics, The University of Queensland, Gatton 4343, Queensland, Australia
| | - A Lisle
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia
| | - T Keeley
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia
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Swinbourne AM, Johnston SD, Janssen TM, Lisle A, Keeley T. Validation of techniques to measure reproductive hormones in the urine of female southern hairy-nosed wombats (Lasiorhinus latifrons). Gen Comp Endocrinol 2017; 252:130-141. [PMID: 28826813 DOI: 10.1016/j.ygcen.2017.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/30/2017] [Accepted: 08/02/2017] [Indexed: 10/19/2022]
Affiliation(s)
- A M Swinbourne
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia.
| | - S D Johnston
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - T M Janssen
- Australian Animals Care and Education, Mount Larcom, Queensland, Australia
| | - A Lisle
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - T Keeley
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
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11
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Du Z, Keeley T, Janssen T, Nicolson V, Johnston SD. Measurement of testosterone and cortisol metabolites and luteinising hormone in captive southern hairy-nosed wombat (Lasiorhinus latifrons) urine. Gen Comp Endocrinol 2017; 250:70-79. [PMID: 28599837 DOI: 10.1016/j.ygcen.2017.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/17/2017] [Accepted: 06/04/2017] [Indexed: 10/19/2022]
Abstract
This study reports the validation and use of enzyme immunoassays (EIA) to measure changes in plasma and urinary luteinizing hormone, testosterone metabolites (UTM) and cortisol metabolites (UCM) in captive southern hairy-nosed wombats (Lasiorhinus latifrons). GnRH agonist and ACTH agonist challenges were conducted to validate urinary testosterone (male wombat only) and cortisol (male and female wombats) EIAs. Following intra-muscular injection of 8-12μg buserelin (n=4 males), there was a significant increase in both plasma (P<0.001) and urinary testosterone concentrations (P<0.001) 60min and 21h after administration, respectively. Plasma LH levels were elevated (p<0.05) at 20min but there was no significant increase found in urinary LH concentrations after injection. Intra-muscular injection of Synacthen® Depot (250μg) (n=3 males, 3 females) resulted in a significant increase (p<0.05) in plasma cortisol secretion 15min and in urinary cortisol concentrations 3h post injection, respectively. Sex-related differences in cortisol secretion were also reported in this study. These findings indicate that (1) urinary LH might not be an appropriate index for describing the reproductive status in captive male L. latifrons, and (2) the UTM and UCM assays appear to be suitable for the assessment of the testicular steroidogenic capacity and the adrenocortical activity in captive southern hairy-nosed wombats, respectively.
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Affiliation(s)
- Z Du
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia.
| | - T Keeley
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia
| | - T Janssen
- Australian Animal Care and Education, Mount Larcom 4695, Queensland, Australia
| | - V Nicolson
- Dreamworld, Coomera, 4209 Qld, Australia
| | - S D Johnston
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Queensland, Australia
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12
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Wallage AL, Johnston SD, Lisle AT, Beard L, Lees AM, Collins CW, Gaughan JB. Thermoregulation of the bovine scrotum 1: measurements of free-range animals in a paddock and pen. Int J Biometeorol 2017; 61:1381-1387. [PMID: 28280936 DOI: 10.1007/s00484-017-1315-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 01/21/2017] [Accepted: 01/24/2017] [Indexed: 06/06/2023]
Abstract
The bull's scrotum and scrotal cord vasculature has traditionally been regarded as a thermoregulatory device for maintaining optimal testicular temperature for normal spermatogenesis. This assumption has mostly been derived from discrete measurements using thermocouples with limited data correlating continuous scrotal temperature (ST) to body temperature (BT). From mid-summer to early autumn, four Wagyu bulls (9-18 months) were surgically implanted with two data loggers (DL) logging at 30 min intervals: one on the right hand side flank and the other was attached to the visceral vaginal tunic of the mid-testis. Bulls were firstly housed in a paddock (PK) for 13 days and then moved to individual pens (IP), again for 13 days. Repeated measures analysis modelled the long-term and diurnal trends in BT and ST. While both day and time of day (TOD) were significant effects for ST at both housing locations (P < 0.005), only TOD showed significance for BT at both locations (P < 0.0001). Significant effects were seen between bulls with ST (F = 167.2, P < 0.001) but not BT (F = 0.03, P = 0.863), suggestive of variation in individual bull thermoregulatory capacity. Dual peaks were observed in ST at 0500 and 2130 h when housed in PK but not IP, suggesting ST may be influenced by external stimuli such as postural or behavioural changes. Reporting concurrent and continuous BT and ST will allow further investigation into factors influencing bovine ST and should be useful in selecting bulls with high degrees of thermoregulation capacity.
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Affiliation(s)
- Andrea L Wallage
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia.
| | - S D Johnston
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - A T Lisle
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - L Beard
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - A M Lees
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - C W Collins
- School of Veterinary Science, The University of Queensland, Brisbane, 4343, Australia
| | - J B Gaughan
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
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Wallage AL, Gaughan JB, Lisle AT, Beard L, Collins CW, Johnston SD. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography. Int J Biometeorol 2017; 61:1309-1321. [PMID: 28337635 DOI: 10.1007/s00484-017-1309-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/03/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT (r > 0.94, P < 0.001) and ST (r > 0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.
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Affiliation(s)
- A L Wallage
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia.
| | - J B Gaughan
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - A T Lisle
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
| | - L Beard
- School of Biological Science, The University of Queensland, St. Lucia, 4072, Australia
| | - C W Collins
- School of Veterinary Science, The University of Queensland, Gatton, 4343, Australia
| | - S D Johnston
- School of Agriculture and Food Sciences, Animal Science Group, The University of Queensland, Gatton, QLD, 4343, Australia
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14
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Johnston SD, Qualischefski E, Cooper J, McLeod R, Lever J, Nixon B, Anderson AL, Hobbs R, Gosálvez J, López-Fernández C, Keeley T. Cryopreservation of saltwater crocodile (Crocodylus porosus) spermatozoa. Reprod Fertil Dev 2017; 29:2235-2244. [DOI: 10.1071/rd16511] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 02/21/2017] [Indexed: 11/23/2022] Open
Abstract
The aim of the present study was to develop a protocol for the successful cryopreservation of Saltwater crocodile spermatozoa. Sperm cells were frozen above liquid nitrogen vapour in phosphate-buffered saline (PBS) containing either 0.3 M trehalose, 0.3 M raffinose or 0.3 M sucrose and compared with glycerol (0.3–2.7 M). Although the highest levels of mean post-thaw motility were observed following cryopreservation in 0.3 M trehalose (7.6%) and 0.3 M sucrose (7.3%), plasma membrane integrity (PI) was best following cryopreservation in 2.7 M glycerol (52.5%). A pilot study then assessed the cytotoxicity of glycerol and sucrose prior to cryopreservation and revealed no loss of survival when spermatozoa were diluted in 0.68 M glycerol or 0.2–0.3 M sucrose once cryoprotectants were washed out with PBS or Biggers, Whitten and Whittingham medium containing sperm capacitation agents (BWWCAP). A final study refined the combined use of permeating (0.68 or 1.35 M glycerol) and non-permeating (0.2 or 0.3 M sucrose) cryoprotectants. Spermatozoa were cryopreserved in liquid nitrogen vapour at rates of approximately −21°C min−1 (fast freeze) or −6.0°C min−1 (slow freeze). Post-thaw survival was highest with a combination of 0.2 M sucrose and 0.68 M glycerol and when these cryoprotectants were washed out with BWWCAP, regardless of whether spermatozoa were frozen using a fast (motility 14.2 ± 4.7%; PI 20.7 ± 2.0%) or slow (motility 12.0 ± 2.7%; PI 22 ± 4%) cryopreservation rate.
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Nixon B, Ecroyd H, Dacheux JL, Dacheux F, Labas V, Johnston SD, Jones RC. Formation and Dissociation of Sperm Bundles in Monotremes. Biol Reprod 2016; 95:91. [DOI: 10.1095/biolreprod.116.140491] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 08/22/2016] [Indexed: 11/01/2022] Open
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16
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Schultz BK, Palmieri C, Nicolson V, Larkin R, Keeley T, McGowan M, Johnston SD. First report of a spermatic granuloma and varicocele in a marsupial: A Koala (Phascolarctos cinereus) Case Study. Res Vet Sci 2016; 107:30-33. [PMID: 27473971 DOI: 10.1016/j.rvsc.2016.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/24/2016] [Accepted: 05/07/2016] [Indexed: 11/18/2022]
Abstract
This study reports the first documented clinical case of a spermatic granuloma and varicocele in a marsupial. Initial clinical presentation included gross morphological changes in the left scrotal cord, epididymis and testis. Ultrasonography of the scrotum and spermatic cord, and gross and histopathological examination after hemicastration, confirmed the condition as a spermatic granuloma affecting the left caput epididymis, with a varicocele in the left proximal spermatic cord, which was causing azoospermia and infertility. Semen quality and serum testosterone secretion following a GnRH challenge was assessed prior to, and following surgery. After hemi-castration, an increase in androgen secretion to within normal reference ranges for the koala was observed with a subsequent increase in semen production and sperm quality resulting in the sire of a pouch young, 12months later.
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Affiliation(s)
- B K Schultz
- Wildlife Science Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Australia; School of Veterinary Science, The University of Queensland, Gatton 4343, Australia.
| | - C Palmieri
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia
| | | | - R Larkin
- Moggill Koala Hospital, Queensland Department of Environment Heritage, Moggill 4070, Australia
| | - T Keeley
- Wildlife Science Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Australia
| | - M McGowan
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia
| | - S D Johnston
- Wildlife Science Unit, School of Agriculture and Food Science, The University of Queensland, Gatton 4343, Australia
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Adam D, Johnston SD, Beard L, Nicholson V, Lisle A, Gaughan J, Larkin R, Theilemann P, Mckinnon A, Ellis W. Surgical implantation of temperature-sensitive transmitters and data-loggers to record body temperature in koalas (Phascolarctos cinereus). Aust Vet J 2016; 94:42-7. [DOI: 10.1111/avj.12393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 06/01/2015] [Accepted: 06/01/2015] [Indexed: 11/26/2022]
Affiliation(s)
- D Adam
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | - SD Johnston
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | - L Beard
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | | | - A Lisle
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | - J Gaughan
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | - R Larkin
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - P Theilemann
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
| | - A Mckinnon
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - W Ellis
- University of Queensland; School of Agriculture and Food Science; Gatton Campus Gatton Queensland 4343 Australia
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton QLD Australia
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18
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Abstract
Although it has been thirty years since publication of one of the most influential papers on the value of assessing sperm DNA damage, andrologists have yet to reach a general consensus about how to apply this seminal parameter to improve or predict reproductive outcomes. Studies that have attempted to establish a causal relationship between sperm DNA damage and pregnancy success have often resulted in conflicting findings, eroding the practitioner’s confidence to incorporate this phenomenon into their appraisal of fertility. In this review we have identified and answered ten important unresolved questions commonly asked by andrologists with respect to the relationship between sperm DNA damage and fertility. We answer questions ranging from a basic comprehension of biological mechanisms and external factors that contribute to increased levels of sperm DNA damage in the ejaculate to what type of DNA lesions we might be expect to occur and what are some of the consequences of DNA damage on early embryonic development. We also address some of the fundamental technical issues associated with the most appropriate measurement of sperm DNA damage and the need to attenuate the confounding impacts of iatrogenic damage. We conclude by asking whether it is possible to reduce elevated levels of sperm DNA damage therapeutically.
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Affiliation(s)
- J Gosálvez
- Genetics Unit, Department of Biology, Autonomous University of Madrid, Madrid, Spain
| | - C López-Fernández
- Genetics Unit, Department of Biology, Autonomous University of Madrid, Madrid, Spain
| | - JL Fernández
- Laboratory of Molecular Genetics and Radiobiology, Oncology Center of Galicia, A Coruña, Galicia, Spain
| | - SC Esteves
- Androfert, Andrology and Human Reproduction Clinic, Campinas, São Paulo, Brazil
| | - SD Johnston
- School of Agriculture and Food Science, The University of Queensland, Gatton, Queensland, Australia
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Sánchez-Calabuig MJ, de la Fuente J, Laguna-Barraza R, Beltrán-Breña P, Martínez-Nevado E, Johnston SD, Rizos D, Gutiérrez-Adán A, Pérez-Gutiérrez JF. Heterologous murine and bovine IVF using bottlenose dolphin (Tursiops truncatus) spermatozoa. Theriogenology 2015; 84:983-94. [PMID: 26149074 DOI: 10.1016/j.theriogenology.2015.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 06/04/2015] [Accepted: 06/04/2015] [Indexed: 11/29/2022]
Abstract
Assisted reproductive technologies are of great importance for increasing the genetic diversity in captive animals. The use of bovine or murine oocytes in heterologous IVF provides advantages compared to homologous IVF in nondomestic animals, such as the accessibility to oocytes and the availability of well-developed in vitro maturation systems. The aim of this study was to determine the heterologous IVF parameters using cryopreserved dolphin spermatozoa and zona-intact bovine or murine oocytes and to examine the nuclear chromatin status of the dolphin spermatozoa. All the processes involved in the fertilization including embryo cleavage were observed by confocal microscopy and hybrid embryo formation was confirmed by polymerase chain reaction. Heterologous bovine IVF showed no polyspermy, lower percentages of pronuclear formation, and a lower cleavage rate compared to homologous IVF group (34.8% vs. 89.3%). Heterologous murine IVF showed a lower cleavage rate than homologous IVF (9.6% vs. 77.1%). With respect to dolphin sperm chromatin, it was more stable, i.e. more resistant to EDTA-SDS decondensation than the bovine sperm chromatin. This study revealed the stability of the dolphin sperm chromatin and the ability of the dolphin spermatozoa to penetrate zona-intact bovine and murine oocytes, leading to hybrid embryo formation.
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Affiliation(s)
- M J Sánchez-Calabuig
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - J de la Fuente
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - R Laguna-Barraza
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - P Beltrán-Breña
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | | | - S D Johnston
- Wildlife Science Unit, School of Agriculture and Food Science, University of Queensland, Gatton, Australia
| | - D Rizos
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - A Gutiérrez-Adán
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - J F Pérez-Gutiérrez
- Department of Animal Medicine and Surgery, School of Veterinary Medicine, Universidad Complutense de Madrid, Madrid, Spain.
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Ballantyne K, Anderson ST, Mucci A, Nicolson V, Johnston SD. Plasma prolactin concentrations during lactation, pouch young development and the return to behavioural oestrus in captive koalas (Phascolarctos cinereus). Reprod Fertil Dev 2015; 28:RD14384. [PMID: 26020798 DOI: 10.1071/rd14384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 04/27/2015] [Indexed: 02/28/2024] Open
Abstract
Plasma prolactin (PRL) concentrations in captive koalas during lactation were determined by serial blood sampling. PRL concentrations were low (1.3 ± 0.1 ng mL-1; n = 5) during early lactation until pouch young (PY) began to emerge from the pouch (around Day 130) before significantly (P < 0.05) increasing between Day 161 and Day 175 (5.3 ± 1.0 ng mL-1). A significant (P < 0.001) peak in PRL (7.7 ± 0.6 ng mL-1) coincided with maturing young between Day 189 and Day 231. All females failed to exhibit any signs of oestrous behaviour until Day 268.8 ± 8.5 (n = 4), some 102 ± 19 days before PY were weaned following achieving target weights of 2.5-2.7 kg. Throughout lactation, plasma LH concentrations were relatively high (range 4.9-8.7 ng mL-1) and LH responses to exogenous gonadotrophin-releasing hormone were observed in all koalas at all times during lactation.
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21
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Ballantyne K, Anderson ST, Pyne M, Nicolson V, Mucci A, Lisle A, Johnston SD. Use of the gonadotrophin-releasing hormone antagonist azaline B to control the oestrous cycle in the koala (Phascolarctos cinereus). Reprod Fertil Dev 2015; 28:RD14349. [PMID: 25929179 DOI: 10.1071/rd14349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 03/25/2015] [Indexed: 02/28/2024] Open
Abstract
The present study examined the effectiveness of the gonadotrophin-releasing hormone (GnRH) antagonist azaline B to suppress plasma LH and 17β-oestradiol concentrations in koalas and its potential application for oestrous synchronisation. In Experiment 1, single subcutaneous injections of azaline B successfully blocked the LH response to exogenous mammalian (m) GnRH in a dose-dependent manner; specifically, 0 mg (n = 4) did not suppress the LH response, 1 mg azaline B (n = 6) suppressed the LH response for 24 h (P < 0.05), 3.3 mg azaline B (n = 8) suppressed the LH response significantly in all animals only for 3 h (P < 0.05), although in half the animals LH remained suppressed for up to 3 days, and 10 mg azaline B (n = 4) suppressed the LH response for 7 days (P < 0.05). In Experiment 2, daily 1 mg, s.c., injections of azaline B over a 10-day period during seasonal anoestrus (June-July; n = 6) suppressed (P < 0.01) the LH response to mGnRH consecutively over the 10-day treatment period and, 4 days after cessation of treatment, the LH response had not recovered. Experiment 3 was designed to test the efficacy of daily 1 mg, s.c., azaline B over 10 days to suppress plasma LH and 17β-oestradiol concentrations and ultimately synchronise timed return to oestrus during the breeding season. Although azaline B treatment did not suppress basal LH or 17β-oestradiol, oestrus was delayed in all treated females by 24.2 days, but with high variability (range 9-39 days). Overall, the present study demonstrates that the GnRH antagonist azaline B is able to inhibit the LH response in koalas to exogenous mGnRH and successfully delay the return to oestrus. However, although azaline B clearly disrupts folliculogenesis, it has not been able to effectively synchronise return to oestrus in the koala.
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Ballantyne K, Anderson ST, Pyne M, Nicolson V, Mucci A, Lisle A, Johnston SD. The use of a synthetic progesterone, levonorgestrel (LNG), to control the oestrous cycle in the koala. Reprod Fertil Dev 2015; 28:RD14387. [PMID: 25929260 DOI: 10.1071/rd14387] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 02/09/2015] [Indexed: 02/28/2024] Open
Abstract
This study investigated the efficacy of a synthetic progestogen, levonorgestrel (LNG), to control koala ovarian activity for the purposes of oestrous synchronisation. Captive koalas were administered either saline control or a 70-mg LNG implant on Day 2 of oestrus. Urogenital cytology, oestrous behaviour and plasma oestradiol-17β and LH concentrations were monitored over a 6-week period. After LNG implant removal females were monitored to determine if the return to oestrus was synchronised. LNG-treated koalas immediately ceased displaying oestrous behaviour, showed no evidence of cornified epithelial cells in smears of urogenital cytology and exhibited low plasma oestradiol-17β concentrations throughout the implantation period. In contrast, oestradiol-17β levels in control koalas showed evidence of continued cyclic activity associated with behavioural oestrus and increased cornified epithelial cells in urogenital smears on Days 33 to 35 after saline injection. After implant removal, LNG-treated koalas exhibited oestrus at 13, 14, 17 and 30 days after implant removal. Plasma LH concentrations varied throughout the study period with no significant time (P = 0.49) or treatment (P = 0.13) effect. Overall results from this study suggest that LNG implants in koalas can inhibit oestrous behaviour and reduce circulating oestradiol-17β levels before oestrus, most likely by preventing development of the pre-ovulatory follicle. However, there was no evidence of LH suppression by the LNG implants. Removal of LNG implants resulted in the synchronous return to oestrus in three of the four treated koalas. Further studies on a larger population are required to validate these findings.
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Johnston SD, López-Fernández C, Arroyo F, Fardell S, Roy R, Gosálvez J. Spermatozoa of Sminthopsis murina (Mammalia: Metatheria) exhibit an unusually high degree of chromatin stability in the absence of disulphide bonding in protamine 1. Reprod Fertil Dev 2015; 28:RD14504. [PMID: 25714780 DOI: 10.1071/rd14504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/05/2015] [Indexed: 11/23/2022] Open
Abstract
Although all but a single genus (Planigale) of the metatheria so far examined contain no cysteine residues in protamine 1, we report a remarkable level of chromatin stability in the spermatozoa of the common dunnart, Sminthopsis murina. S. murina cauda epididymal spermatozoa and somatic epithelial cells were exposed to a combination of graded treatments to lyse sperm protein and induce sperm DNA damage via standard freeze-thaw protocols and post-thaw incubation at 37°C for 48h, exposure to sodium nitroprusside (SNP) and the enzyme AluI restriction endonuclease. Sperm DNA fragmentation was assessed using the comet assay and sperm chromatin dispersal test. Although S. murina somatic cells showed DNA fragmentation following protein lysis and after treatment with all the protocols specifically designed to induce chromatin damage, sperm DNA fragmentation was only observed following moderate to severe proteolytic exposure and treatment with the restriction endonuclease; there was also an increase in the baseline halo of spermatozoa treated with an aggressive reducing agent, but no corresponding evidence of fragmented DNA, suggesting that cysteine residues may be functioning to conform tertiary and/or quaternary chromatin structure. Given that the protamine 1 of S. murina contains no cysteine, we suggest that the source of these residues is possibly the histone fraction of the chromatin and that the high level of stability is potentially related to prolonged sperm survival in the female's reproductive tract.
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Johnston SD, Deif HH, McKinnon A, Theilemann P, Griffith JE, Higgins DP. Orchitis and Epididymitis in Koalas (Phascolarctos cinereus) Infected With Chlamydia pecorum. Vet Pathol 2015; 52:1254-7. [PMID: 25637084 DOI: 10.1177/0300985815570069] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although Chlamydia causes disease of the urethra and prostate of male koalas, its impact on the testis and epididymis has not been examined. This study describes chronic-active and granulomatous orchitis and epididymitis with interstitial fibrosis associated with infection by Chlamydia pecorum in 2 of 18 adult male koalas being euthanized at a koala hospital, 8 of which also had chlamydial prostatitis. By immunohistochemistry and transmission electron microscopy, chlamydial inclusions were demonstrated within Sertoli cells directly associated with mild inflammation surrounding intact seminiferous and epididymal tubules, marked pyogranulomatous inflammation around disrupted tubules, replacement of tubules by interstitial fibrosis, and aspermia. The presence of C. pecorum but not Chlamydia pneumoniae was detected by quantitative polymerase chain reaction of formalin-fixed tissues of the left and right testes and right epididymis in 1 animal. This is the first report of orchitis and epididymitis in a koala infected with C. pecorum.
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Affiliation(s)
- S D Johnston
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Australia
| | - H H Deif
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Australia
| | - A McKinnon
- Environmental Protection Agency, Queensland, Australia
| | - P Theilemann
- Environmental Protection Agency, Queensland, Australia
| | - J E Griffith
- Faculty of Veterinary Science, The University of Sydney, Australia
| | - D P Higgins
- Faculty of Veterinary Science, The University of Sydney, Australia
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Sánchez-Calabuig MJ, López-Fernández C, Johnston SD, Blyde D, Cooper J, Harrison K, de la Fuente J, Gosálvez J. Effect of cryopreservation on the sperm DNA fragmentation dynamics of the bottlenose dolphin (Tursiops truncatus). Reprod Domest Anim 2015; 50:227-235. [PMID: 25604784 DOI: 10.1111/rda.12474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/02/2014] [Indexed: 11/29/2022]
Abstract
Sperm DNA fragmentation is one of the major causes of infertility; the sperm chromatin dispersion test (SCDt) evaluates this parameter and offers the advantage of species-specific validated protocol and ease of use under field conditions. The main purpose of this study was to evaluate sperm DNA fragmentation dynamics in both fresh and post-thaw bottlenose dolphin sperm using the SCDt following different cryopreservation protocols to gain new information about the post-thaw differential sperm DNA longevity in this species. Fresh and cryopreserved semen samples from five bottlenose dolphins were examined for sperm DNA fragmentation dynamics using the SCDt (Halomax(®)). Sperm DNA fragmentation was assessed immediately at collection and following cryopreservation (T0) and then after 0.5, 1, 4, 8, 24, 48 and 72 h incubation at 37°C. Serially collected ejaculates from four dolphins were frozen using different cryopreservation protocols in a TES-TRIS-fructose buffer (TTF), an egg-yolk-free vegetable lipid LP1 buffer (LP1) and human sperm preservation medium (HSPM). Fresh ejaculated spermatozoa initially showed low levels of DNA fragmentation for up to 48 h. Lower Sperm DNA fragmentation (SDF) was found in the second fresh ejaculate compared to the first when more than one sample was collected on the same day (p < 0.05); this difference was not apparent in any other seminal characteristic. While there was no difference observed in SDF between fresh and frozen-thawed sperm using the different cryopreservation protocols immediately after thawing (T0), frozen-thawed spermatozoa incubated at 37°C showed an increase in the rate of SDF after 24 h. Sperm frozen in the LP1(℗) buffer had higher levels (p < 0.05) of DNA fragmentation after 24- and 48-h incubation than those frozen in TTF or HSPM. No correlation was found between any seminal characteristic and DNA fragmentation in either fresh and/or frozen-thawed samples.
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Affiliation(s)
- M J Sánchez-Calabuig
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - C López-Fernández
- Department of Genetics, Autonomous University of Madrid, Cantoblanco, Spain
| | - S D Johnston
- School of Agriculture and Food Science, University of Queensland, Gatton, Qld, Australia
| | - D Blyde
- School of Agriculture and Food Science, University of Queensland, Gatton, Qld, Australia.,Sea World, Gold Coast, Qld, Australia
| | - J Cooper
- Just Genes Artificial Breeding Service, Brisbane, Qld, Australia
| | - K Harrison
- Queensland Fertility Group, Brisbane, Qld, Australia
| | - J de la Fuente
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - J Gosálvez
- Department of Genetics, Autonomous University of Madrid, Cantoblanco, Spain
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26
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Ballantyne K, Lisle A, Mucci A, Johnston SD. Seasonal oestrous cycle activity of captive female koalas in south-east Queensland. Aust Mammalogy 2015. [DOI: 10.1071/am14018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study investigated the seasonality of behavioural oestrus in a captive koala population in south-east Queensland. A total of 33 sexually mature koalas were examined over a 4-year period (2009–12) to determine the possible influence of temperature, photoperiod and rainfall on the incidence of expression of behavioural oestrus without the confounding effect of lactation or limiting food resource availability. Although signs of behavioural oestrus were detected throughout the year, an obvious seasonality was apparent, with significantly fewer females displaying behavioural oestrus in late autumn and winter (May–August) than September to April (P < 0.0001). While average monthly photoperiod (P < 0.0001) and average monthly temperature (P < 0.0001) were significantly related to oestrous behaviour, rainfall was not (P > 0.05). A better understanding of the seasonality of reproductive function in the female koala will facilitate the use of reproductive management-assisted breeding technology to enable improved genetic management in captive populations.
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Pollock K, Gosálvez J, Arroyo F, López-Fernández C, Guille M, Noble A, Johnston SD. Validation of the sperm chromatin dispersion (SCD) test in the amphibian Xenopus laevis using in situ nick translation and comet assay. Reprod Fertil Dev 2015; 27:1168-74. [DOI: 10.1071/rd14070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 04/13/2014] [Indexed: 11/23/2022] Open
Abstract
The integrity of sperm DNA is becoming increasingly recognised as an important parameter of semen quality, but there are no published reports of this procedure for any amphibian. The primary aim of this study was to apply a modified sperm chromatin dispersion (SCD) test (Halomax) to an amphibian sperm model (African clawed frog; Xenopus laevis) and to validate the assay against in situ nick translation (ISNT) and the double-comet assay procedure. Inactivated spermatozoa were collected from fresh testes (n = 3). Sperm DNA fragmentation (SDF) for each sperm sample was conducted immediately following activation (T0) and again after 1 h (T1) and 24 h (T24) of incubation at room temperature in order to produce a range of spermatozoa with differing levels of DNA damage. The SCD procedure resulted in the production of three nuclear morphotypes; amphibian sperm morphotype 1 (ASM-1) and ASM-2 showed no evidence of DNA damage, whereas ASM-3 spermatozoa were highly fragmented with large halos of dispersed DNA fragments and a reduced nuclear core. ISNT confirmed that ASM-3 nuclei contained damaged DNA. There was a significant correlation (r = 0.9613) between the levels of ASM-3 detected by the SCD test and SDF revealed by the double-comet assay.
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Melville DF, Crichton EG, Johnston SD. Semen collection, ejaculate characteristics and in vitro manipulation of spermatozoa from six species of captive flying-fox (Pteropus spp.). Reprod Fertil Dev 2015; 27:1233-41. [DOI: 10.1071/rd13391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 05/08/2014] [Indexed: 11/23/2022] Open
Abstract
Seminal characteristics are described in six Pteropus species including the critically endangered P. rodricensis. Spermic ejaculates (~40 μL) were collected using electro-ejaculation on 406 of 413 attempts. All flying-fox species had mean percentages of acrosome- and plasma-membrane (PM)-intact spermatozoa of >66% and >73%, respectively; the predominant sperm abnormalities found across all species were damaged, folded or missing acrosomes, bent midpieces and coiled tails. Seminal pH ranged from a low of 7.5 in P. giganteus to a high of 8.2 in P. alecto with the other species in between. Electro-ejaculates recovered in short succession from P. alecto revealed no differences in sperm quality, allowing spermatozoa to be utilised for multi-treatment experiments that evaluated the effects of transportation, incubation temperature and in vitro physico-chemical environments on acrosome and PM integrity. Pteropus alecto spermatozoa were successfully held at ~27°C and 37°C for up to 6 h before a reduction in PM integrity (P = 0.003) was observed. Acrosome and PM integrity decreased (P < 0.000) when P. alecto spermatozoa were incubated at 37°C for 30 min in a Tris–citrate buffer of pH 9.0 but remained stable at pH 5.0 to 8.0. Pteropus alecto mean (± s.e.m.) seminal osmolality was 307.0 ± 2.5 mOsm kg–1; nevertheless, spermatozoa were tolerant of media ranging from 160 to 1190 mOsm kg–1 but exposure to media of ≤160 mOsm kg–1 resulted in increased acrosome damage (P < 0.000).
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Busby ER, Soeta S, Sherwood NM, Johnston SD. Molecular analysis of the koala reproductive hormones and their receptors: gonadotrophin-releasing hormone (GnRH), follicle-stimulating hormone β and luteinising hormone β with localisation of GnRH. J Neuroendocrinol 2014; 26:870-87. [PMID: 25200132 DOI: 10.1111/jne.12208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 07/31/2014] [Accepted: 08/31/2014] [Indexed: 10/24/2022]
Abstract
During evolution, reproductive hormones and their receptors in the brain-pituitary-gonadal axis have been altered by genetic mechanisms. To understand how the neuroendocrine control of reproduction evolved in mammals, it is important to examine marsupials, the closest group to placental mammals. We hypothesised that at least some of the hormones and receptors found in placental mammals would be present in koala, a marsupial. We examined the expression of koala mRNA for the reproductive molecules. Koala cDNAs were cloned from brain for gonadotrophin-releasing hormones (GnRH1 and GnRH2) or from pituitary for GnRH receptors, types I and II, follicle-stimulating hormone (FSH)β and luteinising hormone (LH)β, and from gonads for FSH and LH receptors. Deduced proteins were compared by sequence alignment and phylogenetic analysis with those of other vertebrates. In conclusion, the koala expressed mRNA for these eight putative reproductive molecules, whereas at least one of these molecules is missing in some species in the amniote lineage, including humans. In addition, GnRH1 and 2 are shown by immunohistochemistry to be expressed as proteins in the brain.
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Affiliation(s)
- E R Busby
- Department of Biology, University of Victoria, Victoria B.C., Canada
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Sánchez-Calabuig MJ, López-Fernández C, Martínez-Nevado E, Pérez-Gutiérrez JF, de la Fuente J, Johnston SD, Blyde D, Harrison K, Gosálvez J. Validation of a Field Based Chromatin Dispersion Assay to Assess Sperm DNA Fragmentation in the Bottlenose Dolphin(Tursiops truncatus). Reprod Domest Anim 2014; 49:761-8. [DOI: 10.1111/rda.12364] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/29/2014] [Indexed: 11/29/2022]
Affiliation(s)
- M-J Sánchez-Calabuig
- Department of Animal Reproduction; Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA); Madrid Spain
| | - C López-Fernández
- Department of Genetics; Autonomous University of Madrid; Cantoblanco Spain
| | | | - JF Pérez-Gutiérrez
- School of Veterinary Medicine; Universidad Complutense de Madrid; Madrid Spain
| | - J de la Fuente
- Department of Animal Reproduction; Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA); Madrid Spain
| | - SD Johnston
- School of Agriculture and Food Science; University of Queensland; Gatton Qld Australia
| | - D Blyde
- School of Agriculture and Food Science; University of Queensland; Gatton Qld Australia
- Seaworld; Gold Coast Qld Australia
| | - K Harrison
- Queensland Fertility Group; Brisbane Qld Australia
| | - J Gosálvez
- Department of Genetics; Autonomous University of Madrid; Cantoblanco Spain
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Johnston SD, Booth RA, Pyne M, Keeley T, Mackie JT, Hulse L, Ellis W. Preliminary study of faecal cortisol and corticosterone as an index of acute cortisol secretion in the koala (Phascolarctos cinereus). Aust Vet J 2013; 91:534-537. [PMID: 31027400 DOI: 10.1111/avj.12125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Stress can play a role in disease incidence in all species via immunosuppression and has been implicated as a contributing factor in significant infectious diseases of koalas. Faecal cortisol measurement may represent a non-invasive methodology for quantifying stress in koalas. METHODS We used an ACTH (adrenocorticotropic hormone) stimulation test (10 IU) to induce sustained secretion of cortisol, which was measured in serum samples from four koalas and subsequently it was attempted to locate a corresponding elevation in either cortisol or corticosterone measurements within the faeces. RESULTS Although ACTH administration resulted in an elevation of serum cortisol for at least 4 h post injection, it was not possible to identify a corresponding peak in corticosterone or cortisol concentrations in extracts from the faeces, consistent with the known gut transit time of the koala. CONCLUSION Faecal cortisol and corticosterone metabolites may not be reliable indices of acute changes in cortisol secretion in the koala and studies that attempt to use faecal cortisol as an index of stress will need to be interpreted with caution.
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Affiliation(s)
- S D Johnston
- Wildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton, 4343, Australia
| | - R A Booth
- Manly Road Veterinary Hospital, Manly West, NSW, Australia
| | - M Pyne
- Currumbin Wildlife Sanctuary, Currumbin, Queensland, Australia
| | - T Keeley
- Wildlife Reproduction Centre, Taronga Conservation Society Australia, Dubbo, NSW, Australia
| | - J T Mackie
- Gribbles Veterinary Pathology, Clayton, Victoria, Australia
| | - L Hulse
- Gribbles Veterinary Pathology, Clayton, Victoria, Australia
| | - W Ellis
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, St Lucia, Australia
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Crespo F, Gutiérrez-Cepeda L, Gosalvez J, Serres C, Johnston SD. Colloidal Centrifugation of Stallion Semen Results in a Reduced Rate of Sperm DNA Fragmentation. Reprod Domest Anim 2012; 48:e23-5. [DOI: 10.1111/j.1439-0531.2012.02140.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Melville DF, Johnston SD, Miller RR. Flying-fox (Pteropus spp.) sperm membrane fatty acid composition, its relationship to cold shock injury and implications for cryopreservation success. Cryobiology 2012; 65:224-9. [PMID: 22771758 DOI: 10.1016/j.cryobiol.2012.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/09/2012] [Accepted: 06/26/2012] [Indexed: 11/26/2022]
Abstract
The very large acrosome of Pteropus species spermatozoa is prone to damage during cooling procedures. Cryogenic succuss has been linked to membrane composition, therefore the lipid composition of five Pteropus species sperm acrosomal and plasma membranes were investigated to provide insight into reasons for cold shock susceptibility. Rapid chilling and re-warming of spermatozoa from three Pteropus species resulted in a decrease (P<0.05) in acrosomal integrity. Biochemical analysis of lipids revealed that stearic acid (18:0) was the predominant saturated fatty acid and oleic acid (18:1, n-9) the predominant unsaturated fatty acid in both acrosomal and plasma membranes. Linolenic acid (18:3, n-3) was only detected in plasma membranes of Pteropus hypomelanus and was detected in acrosomal membranes of all Pteropus spp. studied (except Pteropus giganteus). Although detected in both plasma and acrosomal membranes of Pteropus vampyrus, docosahexaenoic acid (22:6) was not detected at all in Pteropus poliocephalus, only in trace levels in the acrosomal and plasma membranes of P. giganteus and P. hypomelanus and not in acrosomal membranes of Pteropus rodricensis. No difference was seen in the levels of polyunsaturated fatty acids (PUFAs) within plasma membranes, however PUFAs were lower (P<0.05) in acrosomal membranes of P. giganteus compared with P. vampyrus. Pteropus spp. spermatozoa have a very low ratio of unsaturated/saturated membrane fatty acids (<0.5). Membranes containing more PUFAs are more fluid, so the use of cryogenic media which improves membrane fluidity should improve Pteropus spp. spermatozoal viability post-thaw.
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Affiliation(s)
- D F Melville
- School of Agriculture and Food Science, University of Queensland, Gatton, Qld 4343, Australia.
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Johnston SD, Satake N, Zee Y, López-Fernández C, Holt WV, Gosálvez J. Osmotic stress and cryoinjury of koala sperm: an integrative study of the plasma membrane, chromatin stability and mitochondrial function. Reproduction 2012; 143:787-97. [DOI: 10.1530/rep-11-0436] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study investigated whether cryopreservation-induced injury to koala spermatozoa could be explained using an experimental model that mimics the structural and physiological effects of osmotic flux. DNA labelling after in situ nick translation of thawed cryopreserved spermatozoa revealed a positive correlation (r=0.573; P<0.001; n=50) between the area of relaxed chromatin in the nucleus and the degree of nucleotide labelling. While the chromatin of some spermatozoa increased more than eight times its normal size, not all sperm nuclei with relaxed chromatin showed evidence of nucleotide incorporation. Preferential staining associated with sperm DNA fragmentation (SDF) was typically located in the peri-acrosomal and peripheral regions of the sperm head and at the base of the spermatozoa where it appear to be ‘hot spots’ of DNA damage following cryopreservation. Results of the comparative effects of anisotonic media and cryopreservation on the integrity of koala spermatozoa revealed that injury induced by exposure to osmotic flux, essentially imitated the results found following cryopreservation. Plasma membrane integrity, chromatin relaxation and SDF appeared particularly susceptible to extreme hypotonic environments. Mitochondrial membrane potential (MMP), while susceptible to extreme hypo- and hypertonic environments, showed an ability to rebound from hypertonic stress when returned to isotonic conditions. Koala spermatozoa exposed to 64 mOsm/kg media showed an equivalent, or more severe, degree of structural and physiological injury to that of frozen–thawed spermatozoa, supporting the hypothesis that cryoinjury is principally associated with a hypo-osmotic effect. A direct comparison of SDF of thawed cryopreserved spermatozoa and those exposed to a 64 mOsm/kg excursion showed a significant correlation (r=0.878; P<0.05; n=5); however, no correlation was found when the percentage of sperm with relaxed chromatin was compared. While a cryo-induced osmotic injury model appears to explain post-thaw changes in koala SDF, the mechanisms resulting in relaxed chromatin require further study. A lack of correlation between the percentage of sperm with relaxed chromatin and SDF suggests that the timing of these pathologies are asynchronous. We propose an integrative model of cryo-induced osmotic injury that involves a combination of structural damage (rupture of membrane) and oxidative stress that first leads to the reduction of MMP and the relaxation of chromatin, which is then ultimately followed by an increase in DNA fragmentation.
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Lovas EM, Johnston SD, Filippich LJ. Using a GnRH agonist to obtain an index of testosterone secretory capacity in the cockatiel (Nymphicus hollandicus) and sulphur-crested cockatoo (Cacatua galerita). Aust Vet J 2010; 88:52-6. [PMID: 20148828 DOI: 10.1111/j.1751-0813.2009.00533.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Validation of a stimulation test for determining the steroidogenic capacity of the parrot testis. The major aim was to characterise testosterone secretion after injection of a gonadotropin-releasing hormone agonist (GnRHa), then use the test to investigate seasonal reproduction in the male cockatiel. PROCEDURE A synthetic GnRHa (buserelin; 8.0 microg of peptide/kg bodyweight) was injected IM into male cockatiels (n = 7) and sulphur-crested cockatoos (n = 3) and serial blood samples collected at 0, 30, 60, 90 and 120 min after administration. Once validated, the technique was subsequently used to examine seasonal changes (23 months) in the testosterone profile of a captive cockatiel population. RESULTS Injection of buserelin resulted in a significant increase in the testosterone concentration of cockatiel plasma, with maximal concentrations occurring at approximately 60 (1.33 +/- 0.08 ng/mL) to 90 min (1.22 +/- 0.08 ng/mL) after injection. Although no clear pattern of seasonal variation in testosterone secretion was detected in cockatiel plasma, samples taken 60 and 90 min after administration showed a significant increase in all seasons. Injection of buserelin in the sulphur-crested cockatoo also resulted in increased testosterone secretion, with maximal concentrations obtained after 90 min. CONCLUSION Buserelin can be used to obtain a reliable index of the prevailing testosterone capacity of the cockatiel and cockatoo testis. With further studies, this test may be incorporated into clinical assessment of reproductive status.
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Affiliation(s)
- E M Lovas
- School of Veterinary Science, The University of Queensland, St Lucia, Queensland, Australia
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Johnston SD, López-Fernández C, Gosálbez A, Holt WV, Gosálvez J. Directional mapping of DNA nicking in ejaculated and cauda epididymidal spermatozoa of the short-beaked echidna (Tachyglossus aculeatus: Monotremata). Reprod Fertil Dev 2010; 21:1008-14. [PMID: 19874725 DOI: 10.1071/rd09079] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 06/07/2009] [Indexed: 11/23/2022] Open
Abstract
Prototherian spermatozoa are unique amongst the Mammalia in terms of their filiform morphology, tandem arrangement of chromosomes and formation of sperm bundles. In the present study, we provide observations of echidna spermatozoa and note that the superstructure of the bundle is engineered around the shape of the individual sperm head and that this in turn may be a consequence of the unusual circumferential and helicoidal condensation of the DNA during spermiogenesis. Frozen-thawed ejaculated echidna spermatozoa were incubated and examined for the presence of non-typical DNA conformation by means of in situ labelling of DNA breaks using Klenow polymerase and via alkaline single-cell comet assays for detection of fragmented DNA. Both techniques successfully revealed the presence of what appeared to be directional DNA nicking, co-localised with the presence of highly sensitive alkali sites along the length of the sperm nucleus. It was not possible to define whether these alternative DNA configurations were associated with a failure of the sperm nucleus to condense appropriately during spermiogenesis or were evidence of DNA fragmentation following post-thaw incubation or a sequential structural chromatin rearrangement necessary for fertilisation.
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Affiliation(s)
- S D Johnston
- School of Animal Studies, The University of Queensland, Gatton, Qld 4343, Australia.
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Johnston SD, McGowan MR, Carrick FN, Cameron RD, Tribe A. Seminal characteristics and spermatozoal morphology of captive Queensland koalas (Phascolarctos cinereus adustus). Theriogenology 2009; 42:501-11. [PMID: 16727557 DOI: 10.1016/0093-691x(94)90688-f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/1991] [Accepted: 07/05/1994] [Indexed: 10/26/2022]
Abstract
Viable koala spermatozoa were successfully collected from 8 of 11 captive Queensland koalas on 52 of 76 attempts using electroejaculation under general anesthesia. Semen characteristics, including sperm concentration, percent progressive sperm motility and nuclear heterogeneity appeared to be similar to those of free-ranging Victoria koalas (P.c . victor). Two new head morphotypes (Type XI and teratoid) were identified, and the incidence of midpiece and principal piece spermatozoal abnormalities were recorded.
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Affiliation(s)
- S D Johnston
- Department of Farm Animal Medicine and Production, The University of Queensland, St. Lucia, 4072 Queensland, Australia
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Portas T, Johnston SD, Hermes R, Arroyo F, López-Fernadez C, Bryant B, Hildebrandt TB, Göritz F, Gosalvez J. Frozen-thawed rhinoceros sperm exhibit DNA damage shortly after thawing when assessed by the sperm chromatin dispersion assay. Theriogenology 2009; 72:711-20. [PMID: 19560805 DOI: 10.1016/j.theriogenology.2009.05.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 05/02/2009] [Accepted: 05/03/2009] [Indexed: 11/29/2022]
Abstract
This study reports on the successful validation (via in situ nick translation and neutral comet assay) of the equine Sperm-Halomax kit as an appropriate methodology for the assessment of sperm DNA fragmentation in three species of rhinoceros. Rhinoceros sperm nuclei with fragmented DNA (validated using in situ nick translation) were evident as large halos with dispersed DNA fragments, whereas those with nonfragmented DNA displayed small halos of nondispersed DNA within the microgel. There was a high correlation (r) of 0.974 (R(2) value=0.949; P<0.01; n=16) between the respective assessments of the Sperm Chromatin Dispersion test (SCDt) and the neutral comet assay. Application of the SCDt to determine the DNA fragmentation dynamics of rhinoceros (n=6) sperm frozen in liquid nitrogen vapor and incubated postthaw at 37 degrees C for up to 48 h to mimic in vitro conditions in the female reproductive tract, revealed an increase (P=0.001) in DNA damage, as soon as 4h after the start of incubation. Linear regression equations were calculated for all six rhinoceroses over the first 6h of incubation and revealed individual animal variation. Freshly collected and incubated (37 degrees C) rhinoceros (n=3) sperm had no increase in the basal level of DNA fragmentation for up to 48 h, indicating that the cryopreservation of rhinoceros sperm in liquid nitrogen vapor, as used in this study, appeared to result in freeze-thaw DNA damage.
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Affiliation(s)
- T Portas
- Taronga Western Plains Zoo, Dubbo, NSW 2830, Australia
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Johnston SD, Gosalvez J, Holt WV. 046. FUTURE PROOFING AUSTRALIA'S MAMMALIAN BIODIVERSITY USING GENOME RESOURCE BANKING AND ART: WHERE ARE WE UP TO? Reprod Fertil Dev 2009. [DOI: 10.1071/srb09abs046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The establishment of a functional genome resource bank for the genetic management and future proofing of Australian native mammals sounds great in theory, but what is the reality of this idea. In order to understand the current rate of progress in this area, we will present an overview of the inherent structural and physiological limitations of non-eutherian mammalian reproduction in terms of gamete biology and ART. For the male, these include (1) an unique mode of spermatid condensation that imparts the need for major structural changes to sperm morphology during epididymal transit, (2) a lack of cysteine protamines and disulphide bonds in the sperm chromatin that predisposes the nucleus to post-thaw chromatin relaxation, (3) an extremely stable acrosome, which to date, has not been possible to experimentally react in vitro, (4) unusual lipid composition in the plasma membrane that potentially makes the sperm cell resistant to cold shock trauma and (5) the need, in some species, for extremely high concentrations of cryoprotectant, that paradoxically, appear to be cytotoxic to the spermatozoon. Female limitations include, (1) the production of a large yolky oocyte and resulting embryo, making it difficult to cryopreserve, (2) a small and technically challenging complex reproductive tract that makes gamete recovery and artificial insemination problematic and (3) a general lack of information on marsupial reproductive physiology and behaviour that has hindered the development of protocols for timed induction of oestrus and ovulation. We shall also identify, socio-political and ethical limitations holding back the application of assisted breeding technology in these species.
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Ballantyne K, Matson P, Noakes N, Nicolson V, Johnston SD. Reproductive physiology of the female greater bilby (Macrotis lagotis Thylacomyidae): evidence for a male-induced luteal phase. Reprod Fertil Dev 2009; 21:274-82. [DOI: 10.1071/rd08134] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 08/11/2008] [Indexed: 11/23/2022] Open
Abstract
Endocrinology of the oestrous cycle, pregnancy and early lactation was investigated in captive Western Australian greater bilbies (Macrotis lagotis). Initially, six females were monitored for changes in urogenital cytology, plasma progestogen, pericloacal and pouch morphology in the absence of a male. This was followed by the introduction of a male and a reproductive assessment through mating, gestation and early lactation. In the absence of a male, there was no cyclical pattern of urogenital cytology, pericloacal or pouch development, and progestogen concentrations remained basal. Within 5 days of the introduction of a male, all females had a karyopycnotic index of 100%. Spermatozoa were present in the urogenital smear within 3 days of male introduction in all five females that gave birth. Five to 9 days after the introduction of a male, there was an increase in plasma progestogen concentration that remained elevated for 14–19 days. Six of the seven females gave birth approximately 3 days after reaching peak plasma progestogen concentrations. Gestation length ranged between 14 and 17 days. Plasma progestogen concentrations of the postpartum and early lactation period were lower (P < 0.0001) than during gestation, but greater (P < 0.0001) than those recorded before the introduction of a male. One female that gave birth early in the study that was examined until weaning of the pouch young showed a cyclical pattern of plasma progestogen secretion that ended at weaning. This study provides evidence that the luteal phase in the greater bilby is induced by the presence of a male. Similar to female reproductive physiology in the Peramelidae, elevated progestogen concentration in the greater bilby was extended into lactation.
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Abstract
Koala sperm chromatin has a tendency to relax following incubation and thawing but the background incidence and dynamics of DNA fragmentation during semen processing at 35°C and following chilled and frozen preservation has not been investigated. This study (n = 10) was designed to establish the fragmentation dynamics of koala sperm DNA at body temperature (35°C), after chilling (4°C) for upward of 16 days, and following a standard freeze–thaw protocol (Johnston SD et al. 2006 Cryobiology 53, 218–228). Sperm DNA fragmentation index (sDFI) was determined using a Halomax kit (ChromaCell SL, Madrid, Spain), which had been customized and validated for koalas (Johnston SD et al. 2007 J. Androl. 28, 891–899). All semen was assessed for sDFI over a 48-h incubation period (T0, T2, T6, T24, and T48) at 35°C. After incubation at 35°C for 48 h, the sDFI and rate of DNA degradation of freshly diluted spermatozoa were highly variable between individuals; the sDFI for 2 koalas remained consistently low (≤2%) whereas the other 8 had sDFI of 8 to 12% after incubation. Chilled storage increased sDFI in all animals, but the rate of increase and the time at which the DNA started to fragment also varied between koalas; sDFI for 1 koala increased immediately upon rewarming after being chilled for 4 h, whereas that of another koala did not increase until after 8 days of chilling and 24 h of incubation at 35°C. Animals also responded to cryopreservation differently; sDFI increased after thawing for 2 of the koalas but did not increase in the others. Subsequent evaluation of frozen–thawed spermatozoa from a greater number of captive koalas (n = 22), and under extended conditions of post-thaw incubation (up to 17 days at 35°C) permitted categorization of the koalas into 3 distinctive groups based on their DNA fragmentation dynamics and rate of DNA degradation. For 7 of the animals, sDFI remained close to the basal level when incubated at 35°C over 7 days, whereas 2 of the koalas had sDFI ranging from 40 to 70% after 24 h of incubation. This study confirmed the occurrence of inter-animal variability in the dynamics of DNA fragmentation, a finding that was apparent whether or not the spermatozoa had been subjected to chilling or cryopreservation.
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Allen CD, de Villiers DL, Manning BD, Dique DS, Burridge M, Chafer ML, Nicolson VM, Jago SC, McKinnon AJ, Booth RJ, McKee JJ, Pyne MJ, Zee YP, Wilson RJ, Johnston SD. 151 SEASONAL REPRODUCTION IN WILD AND CAPTIVE MALE KOALA POPULATIONS IN SOUTH-EAST QUEENSLAND. Reprod Fertil Dev 2009. [DOI: 10.1071/rdv21n1ab151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Seasonal changes in male reproductive function were assessed in a wild free-range population (n = 10; obtained every six weeks from January to November 2005), a deceased wild free-range population (n = 84; obtained monthly from September to August 2005) and a captive population (n = 7; obtained monthly from October 2005 to October 2006) of koalas in south-east Queensland. This study also determined the practicality of using free-range wild male koalas as potential semen donors for genome resource banks. Examination of a range of reproductive variables initially revealed no significant seasonal change in the 3 koala populations; however, when the data were adjusted to account for individual koalas, their size and/or their health status, the majority of reproductive parameters showed evidence of seasonal variation that was supported by statistical modeling. Relationships between variables were based on simple polynomials, up to a cubic for some variables. Total testicular volume changed throughout the year in the wild and captive populations with an increase over spring and summer and a decrease in autumn and winter; no such change was detected in the deceased population. Maximum area of the sternal gland stain occurred in spring in both the deceased and captive populations but in winter for the wild free-range population. Total bulbo-urethral gland volume in the deceased population showed an increase over spring, a decrease over summer and autumn and then an increase towards the end of winter. The steroidogenic capacity of the koala testis (testosterone secretion) in both the wild free-range (live) and captive populations showed a peak during spring and a nadir in autumn. The quality of semen samples collected by electroejaculation from the wild (live) and captive koala populations showed evidence of being influenced by season. Initial percentage motility of the wild population decreased marginally throughout the study and initial rate of sperm movement was highest in winter. Motility of spermatozoa after thawing from the wild koala population was also highest in winter as was the percentage of cryopreserved spermatozoa with intact plasma membranes collected from the captive population. This study has shown that male koala reproduction in south-east Queensland is seasonal and that it is possible to repeatedly collect semen from free-range koalas as potential genetic donors. Nevertheless, semen quality from captive and wild caught animals appears to be susceptible to seasonal change and winter appears to be the optimal season in which to collect such samples.
We are grateful to the veterinary staff, zookeepers, and volunteers at Dreamworld for their assistance with general animal husbandry. We also sincerely thank the many veterinarians, volunteers, and Queensland Parks and Wildlife Service staff that assisted with this project whose help was invaluable for the accomplishment of this project. This project was funded by an Australian Research Council (ARC) Grant, the School of Animal Studies (SAS) The University of Queensland, and the Queensland Government’s Koala Enhanced Genetic Exchange Program (KEGEP).
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Melville DF, Crichton EG, O'Brien GM, Johnston SD. 12 PHARMACOLOGICAL STIMULATION OF OVULATION IN THE BLACK FLYING-FOX (PTEROPUS ALECTO). Reprod Fertil Dev 2009. [DOI: 10.1071/rdv21n1ab12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Artificial insemination (AI) involves the accurate detection of oestrus, the ability to pharmacologically induce ovulation, or both. This is particularly important in flying-foxes (Pteropus spp.) that do not have an overt behavioural oestrus. Pregnant mare serum gonadotropin (PMSG) stimulates folliculogenesis and ovulation in the Little Red Flying-fox (P. scapulatus; Towers PA and Martin L 1985 Proc. Aust. Soc. Reprod. Biol. 17, 115). In this study, a dose rate of 15 IU PMSG was used. Our study investigated if 15 IU PMSG would sufficiently induce ovulation in the larger, Black Flying-fox (P. alecto) or if a higher dose (30 IU) would be necessary. Before the mating season, a single injection of PMSG (Folligon®, Intervet Australia Pty Ltd, Bendigo East, Australia) was administered i.m. to eight adult females at 15 IU (n = 4) or 30 IU (n = 4) on Day 0. On Day 4, semen was collected by electro-ejaculation from adult males and inseminated intravaginally into females under isoflurane (Forthane®, Abbott Australasia Pty Ltd, Sydney, Australia) anaesthesia. Ovaries and reproductive tracts were surgically removed on Day 6, fixed, serially sectioned and stained using Gomori’s Stain. Histological sections were examined for evidence of ovarian activity and the presence of ova and spermatozoa in the reproductive tracts. Preliminary observations showed evidence of ovulation in both groups in the form of at least one CL in either ovary and an ovum in the ipsilateral oviduct or uterine horn. Ovaries of females stimulated with 30 IU PMSG differed noticeably from those treated with 15 IU in containing multiple, large, collapsed luteinized follicles with retained oocytes. Vascularization and glandular hypertrophy of the endometrium was also more evident in the higher dose group. No spermatozoa were observed in any of the excised tracts. These results suggest that whereas both doses of PMSG induce ovulation, the administration of 30 IU PMSG may over-stimulate the ovaries. This, in turn, could lead to an unphysiological environment for successful fertilization and embryonic development. A dose level of 15 IU or slightly above may be sufficient for subsequent attempts to stimulate folliculogenesis and ovulation in P. alecto. The absence of spermatozoa suggests that the site of insemination, the number of spermatozoa inseminated, or both requires further investigation if AI is to be successfully implemented in these species. We conclude that the ovarian responses to PMSG indicate that pharmacological induction of ovulation can be successfully achieved and thereby utilized in AI programs of endangered Pteropus species.
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Satake N, Johnston SD, Holt WV. 231 SPERM SUBPOPULATIONS IN THE KOALA (PHASCOLARCTOS CINEREUS) EJACULATE. Reprod Fertil Dev 2009. [DOI: 10.1071/rdv21n1ab231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Koala semen contains a heterogeneous mixture of sperm morphotypes, mainly attributable to extreme degree of shape variability displayed by the hooked sperm head. By analogy with other species, we anticipate that the morphotypes may exhibit correspondingly different sperm-motility behaviors, largely caused by the differences in hydrodynamic interactions with the suspending media. This trend has been shown in human spermatozoa where motility behavior was demonstrably correlated with the sperm head morphology (Overstreet et al. 1981). In this study, we have investigated the heterogeneity of koala sperm motility profiles in semen in an effort to determine whether distinct sperm subpopulations within ejaculates are recognizable by the use of computer-assisted sperm motility analysis. Ejaculates from 5 males were collected by electroejaculation, then diluted and transported in Tris-citrate-glucose (TCG) diluent. Spermatozoa were washed through a 35–60% Percoll gradient to separate seminal plasma and the majority of the prostatic bodies from spermatozoa. Spermatozoa from the washed pellet were then diluted in TCG at 35°C, incubated for 10 min, and video recorded using a negative phase ×10 objective. Sperm motion parameters were then analyzed using the Hobson sperm tracker (Hobson Vision Systems, UK: Holt et al. 1996 J. Androl. 17, 587–596). Multivariate pattern analysis (PATN; CSIRO Australia; Abaigar 1999 Biol. Reprod. 60, 32–41) was used to distinguish 3 sperm subgroups, consistently shown in each ejaculate, within the data (1936 tracks × 6 kinetic parameters; VCL, VAP, MAD, BCF, ALH, LIN). After group allocation by PATN, all parameters showed significant differences between each of the groups (P < 0.0001). Group 1, approximately 25% of the sperm tracks, showed profiles of spermatozoa with fast, non-linear motility (VCL 106.88 ± 28.15; BCF 3.23 ± 3.81; LIN 14.08 ± 10.20). Group 2, approximately 27% of sperm tracks, showed profiles of fast, linear motility (VCL 63.92 ± 13.50; BCF 7.90 ± 3.42; LIN 28.10 ± 12.15). Group 3, 48% of sperm tracks, showed profiles of slow, non-linear or circular patterns of motility (VCL 39.05 ± 11.92; BCF 0.02 ± 0.35; LIN 5.15 ± 4.88). The recognition of 3 clearly identifiable subgroups supports our hypothesis that heterogeneity of sperm motility patterns exists within koala ejaculates. These may be a reflection of the heterogeneity in sperm-head morphotypes in koala semen, but that remains to be investigated in more detail. The clear distinctions between these groups, and the observation that all 3 subpopulations exist in each of the ejaculates, also suggest that the spermatozoa exhibit functional differences, possibly related to biochemical or maturational status.
Many thanks to Dr. Michael Pyne and Dr. Vere Nicholson and their teams and animals at Currumbin Wildlife Sanctutary and Dreamwolrd QLD for all their help and support for the collection of samples.
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Johnston SD, Camacho FC, Carrillo L, Guy N, Govea J, Martinez O, Parãs A, Lisle AT, D'Occhio M. The development of a testosterone stimulation test in the Virginia opossum (Didelphis virginiana) and its use in evaluating deslorelin contraception. Reprod Fertil Dev 2008; 20:563-9. [PMID: 18577353 DOI: 10.1071/rd07215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Accepted: 03/04/2008] [Indexed: 11/23/2022] Open
Abstract
The aims of the present study were to examine the variability of testosterone secretion in the Virginia Opossum over a 24 h period and to develop a testosterone stimulation test that would provide an index of the prevailing testosterone biosynthetic capacity of the testes; the latter was used to clinically evaluate the efficacy of a gonadotrophin-releasing hormone agonist contraceptive. Sexually-mature captive opossums (n = 12) located in Africam Safari (Mexico) sampled every 12 h over 24 h consistently showed basal (<0.21 ng mL(-1)) blood testosterone concentrations. Intra-muscular injection of buserelin (2 microg mL(-1)) and human chorionic gonadotrophin (hCG; 1000 IU) resulted in an increase (P < 0.05) of plasma testosterone concentrations with maximal concentrations (3.9 ng mL(-1) and 5.8 ng mL(-1) respectively) occurring 120 min after injection. Plasma testosterone declined relatively rapidly to basal concentrations after 240 min with hCG but remained elevated after the same period of time with buserelin. Male opossums treated with (n = 6) and without (n = 6) a controlled-release deslorelin implant (Suprelorin; 4.7 mg deslorelin) were evaluated over a 10-week period for changes in testosterone secretion (hCG stimulation test) and sperm production (spermatorrhea). At the end of this period, the animals were hemi-castrated and their relative testicular quantitative histology compared. Testosterone concentration decreased over the course of the study in both treated and control animals (P < 0.0001) but there was no apparent effect of deslorelin on testosterone secretion, testicular histology (relative proportions of testicular cell types and seminiferous tubule diameter), or sperm production (presence of sperm in the cauda epididymis or urine).
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Affiliation(s)
- S D Johnston
- School of Animal Studies, The University of Queensland, Gatton, Queensland 4343, Australia.
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Wells R, Scott PT, Harrison DK, Wreford NG, Duckett R, Johnston SD, D'Occhio MJ. Expression of FGF2 and TGFalpha and testis morphology during testicular hypertrophy subsequent to hemicastration in the neonatal boar. Mol Reprod Dev 2008; 75:961-6. [PMID: 18278782 DOI: 10.1002/mrd.20743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective was to ascertain fibroblast growth factor-2 (FGF2), epidermal growth factor (EGF), and transforming growth factor-alpha (TGFalpha) mRNA expression and testis morphology during accelerated testicular growth after hemicastration in the neonatal boar. On Day 10 after birth (Day 0), boars were assigned to control (n = 28), no treatment; hemicastrated (n = 28), left testis removed. The right testis in both groups (n = 7) was removed on Days 5, 10, 15, and 20. Expression of mRNA for FGF2, EGF, and TGFalpha was determined by qRT-PCR using TaqMan. Testicular morphology was determined on Day 15. On Day 10, hemicastrated boars had a greater (P = 0.01) testis weight (6.2 +/- 0.8 g; mean +/- SEM) than controls (4.3 +/- 0.4 g) and on Day 15 testis weight in hemicastrated boars (8.8 +/- 0.8 g) was twice (P < 0.01) that of control boars (4.2 +/- 0.3 g). Seminiferous tubule volume was approximately doubled in hemicastrated boars (P < 0.01) and was associated with an increase (P < 0.01) in Sertoli cell number. Interstitial compartment volume was greater (P < 0.01) in hemicastrated boars. Leydig cell numbers were similar (P = 0.14) but volume was greater (P < 0.01) for hemicastrates. There were no differences (P > 0.05) between control and hemicastrated boars in TGFalpha or FGF2 expression on Day 5 or Day 10, and EGF was not detected. It was concluded that upregulation of TGFalpha or FGF2 expression is not a pre-requisite for enhanced testicular growth and increased Sertoli cell proliferation that occurs subsequent to hemicastration in the neonatal boar.
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Affiliation(s)
- R Wells
- School of Animal Studies, The University of Queensland, Gatton, Australia
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Phillips DJ, McKinnon A, Keeley T, Johnston SD. Testosterone secretion, testicular histology and the cryopreservation of cauda epididymidal spermatozoa in the common ringtail possum (Pseudocheirus peregrinus). Reprod Fertil Dev 2008; 20:391-401. [DOI: 10.1071/rd07206] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Accepted: 12/13/2007] [Indexed: 11/23/2022] Open
Abstract
The present study reports novel aspects of the reproductive biology of the male common ringtail possum (Pseudocheirus peregrinus). Plasma testosterone was measured through a stimulation test using the gonadotrophin-releasing hormone agonist, buserelin. Following intra-muscular administration of buserelin, there was an increase (P < 0.05) in testosterone concentration in the peripheral circulation 4 h later. Quantitative testicular histology of this species was described for the first time. Eight stages of the seminiferous epithelium cycle were identified in 10 possums and their relative frequency determined. Spermatozoa were recovered from the cauda epididymides of hemi-castrated possums and cryopreservation conducted in straws (6°C min–1) using final glycerol concentrations ranging between 2 and 20% in Tris-citrate egg yolk extender (v/v). Frozen straws were thawed and post-thaw motility, rate of motility, the percentage of live–dead spermatozoa and the percentage of sperm with swollen decondensed nuclei recorded. Similar to other marsupial sperm, common ringtail possum cauda epididymidal spermatozoa required high levels of glycerol (10–16%) in order to maintain post-thaw viability.
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D'Occhio MJ, Hengstberger KJ, Johnston SD. Biology of sperm chromatin structure and relationship to male fertility and embryonic survival. Anim Reprod Sci 2007; 101:1-17. [PMID: 17303352 DOI: 10.1016/j.anireprosci.2007.01.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 01/02/2007] [Accepted: 01/02/2007] [Indexed: 11/19/2022]
Abstract
Embryonic mortality in mammals is typically thought to result from 'female factor' infertility. There is growing evidence, however, that the status of sperm chromatin (DNA) at the time of fertilisation can also influence embryonic survival. During the final stages of spermatogenesis (spermiogenesis) a number of unique biochemical, morphological and physiological processes take place that are associated with marked changes in the structure of sperm chromatin. In early stages of spermatogenesis, sperm DNA is associated with histone nucleoproteins and structured into classical nucleosome core particles similar to other somatic cells. As spermiogenesis proceeds, the histone nucleoproteins are replaced by transition proteins which are subsequently replaced by protamines. At the completion of spermiogenesis the chromatin of mature sperm has a toroidal structure that is tightly compacted and resistant to denaturation. The compaction is necessary to protect sperm chromatin during transit through the epididymis and female reproductive tract. Disruption to chromatin remodelling during spermiogenesis results in chromatin that is susceptible to denaturation. Inappropriate chromatin structure has been shown in a number of mammalian species to be related to male infertility, and specifically the failure of embryonic development. A range of techniques are available to assess chromatin status in sperm but arguably the most informative is the sperm chromatin structure assay (SCSA). The SCSA is a flow cytometric assay that uses the metachromatic properties of acridine orange to measure the susceptibility of sperm chromatin to acid-induced denaturation. A relationship has been demonstrated, primarily in men, between the SCSA outcome and the probability of continued embryonic development and the establishment of pregnancy after fertilisation. The contribution of sperm chromatin instability to reproductive wastage in both natural mating and assisted reproduction warrants further investigation as it may prove valuable as a means of decreasing the incidence of embryonic mortality. In this regard, it is possible that 'male factor' infertility may emerge as an even more important component in embryonic development.
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Affiliation(s)
- M J D'Occhio
- School of Animal Studies, Faculty of Natural Resources, Agriculture and Veterinary Science, The University of Queensland, Gatton Campus, Gatton, Qld 4343, Australia.
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Johnston SD, Ward D, Lemon J, Gunn I, MacCallum CA, Keeley T, Blyde D. Studies of male reproduction in captive African wild dogs (Lycaon pictus). Anim Reprod Sci 2007; 100:338-55. [PMID: 16987622 DOI: 10.1016/j.anireprosci.2006.08.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 08/03/2006] [Accepted: 08/07/2006] [Indexed: 10/24/2022]
Abstract
Implementation of assisted breeding in the captive African wild dog is restricted by a current lack of knowledge on their reproductive physiology and the apparent difficulty of effectively manipulating the complex social dynamic of the pack in order to conduct reproductive procedures. In this study, we describe protocols for the safe and repeated capture and restraint of the African wild dog (n=7) as well as techniques for assessment of male reproductive function, semen collection and preservation. In a serendipitous finding, captive African wild dogs appeared to display significant seasonal change in male reproduction. Testicular volume and tone, spermatorrhea and the ability to collect semen by electroejaculation all increased significantly during late summer and then subsequently declined by early spring. While there were no detectable seasonal changes in testosterone concentration in the population as whole, the alpha-dominant male in both years of the study, had a highly elevated testosterone concentration compared to subordinate males. Semen collection by electroejaculation during the late summer was most effective in peri-pubertal males (15 months) when all seven electroejaculates were of adequate quality for cryopreservation. In the second breeding season (27 months), there were numerous changes in the pack hierarchy and electroejaculation was not as successful (3/7). The characteristics of electroejaculated semen collected in the breeding season are described for seven animals including the first descriptions and incidence of sperm abnormalities in the species. Semen (n=7) was frozen using a Tris-citrate fructose buffer and final egg yolk and glycerol concentration of 20% and 4%, respectively. Sperm were loaded into 0.25 mL straws, frozen in liquid nitrogen vapor and then thawed at 37 degrees C. Initial post-thaw survival of spermatozoa was encouraging (% motile: 31.8+/-5.8%; rate: 2.8+/-0.3; % intact plasma membranes: 33.4+/-5.3% and the % of damaged acrosomes: 4.4+/-1.5%) but following 2 h incubation at 37 degrees C, post-thaw survival declined markedly.
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Affiliation(s)
- S D Johnston
- School of Animal Studies, The University of Queensland, Gatton 4343, Australia.
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Johnston SD, Nicolson V, Madden C, Logie S, Pyne M, Roser A, Lisle AT, D'Occhio M. Assessment of reproductive status in male echidnas. Anim Reprod Sci 2007; 97:114-27. [PMID: 16476529 DOI: 10.1016/j.anireprosci.2005.12.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 12/12/2005] [Accepted: 12/28/2005] [Indexed: 10/25/2022]
Abstract
This study reports the development and application of techniques to assess the reproductive status of male echidnas. The pattern of testosterone secretion over a 24-h period in five echidnas was documented. Testosterone secretion after injection i.m. of either 1000 IU hCG (n=4) or 4 microg GnRH agonist (n=6) was determined to establish whether this could be used as a practical index of the prevailing steroidogenic capacity of the testes. hCG (1000 IU) was also used to assess seasonal changes in testosterone secretion in six echidnas over a 13-month period. Seasonal changes in testicular volume were examined by transabdominal ultrasonography. Electroejaculation was attempted to monitor seasonal changes in sperm production, which was also determined by spermatorrhea. There was no apparent diurnal pattern of testosterone secretion in echidnas and circulating concentrations of testosterone remained relatively low (maximum 1.2 ng/mL) and stable over 24h. Injection of hCG resulted in an increase (P<0.01; n=4) in testosterone concentration with a peak (2.9+/-0.3 ng/mL) approximately 4h after injection. GnRH also induced an increase (P<0.01; n=6) in circulating testosterone that was apparent after 1h (2.6+/-0.3 ng/mL) and concentrations remained elevated (3.4+/-0.3 ng/mL) for up to 8h after injection. Seasonal changes in testosterone secretion determined after injection of hCG, increased (P=0.03; n=6) from late-autumn, peaked in late-winter, and decreased by early-spring. Testicular volume followed a similar seasonal pattern (P<0.01; n=6) with an increase from late-autumn, peak in winter and a decline in mid-spring. There was no seasonal change in live weight. Electroejaculation was attempted throughout two breeding seasons but no semen was obtained. Spermatorrhoea in the echidna was described for the first time and was subsequently used to assess seasonal sperm production. Spermatozoa were found in the urine from June to September. This study has demonstrated that exogenous hormones can be used to obtain an index of the prevailing steroidogenic capacity of the testes in echidnas, which is not apparent with repetitive non-stimulated samples over 24 h. The assessment of testosterone secretion after injection of trophic hormones provides a valuable and practical procedure for the assessment of reproductive status. Testicular ultrasonography and spermatorrhea are useful in assessing reproductive status and in this study were successfully used to determine seasonal reproduction in captive echidnas.
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Affiliation(s)
- S D Johnston
- School of Animal Studies, The University of Queensland, Gatton, 4343 Qld, Australia.
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