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López-Pérez JE, Goessling JM, Murray CM. Testing androgen-induced immunosuppression: Environmental androgens as a model system for steroid-immune interaction. J Exp Zool A Ecol Integr Physiol 2024; 341:431-439. [PMID: 38374761 PMCID: PMC10994726 DOI: 10.1002/jez.2795] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 01/05/2024] [Accepted: 02/02/2024] [Indexed: 02/21/2024]
Abstract
It is well known that hormones influence and direct most facets of physiology; however, there is still contention regarding the directions of certain relationships, for example, between gonadal hormones and immunity. Among the many proposed relationships relating to gonadal-immune interactions, support for immunosuppressive effects of androgens remains prominent within physiological literature. Although ample study has been directed toward the immunosuppressive effects of androgens, considerable disagreement remains regarding their influence on immune function. In this study, we test the hypothesis that androgens inhibit immunocompetence in the American alligator (Alligator mississippiensis). Developing alligators were incubated at female-producing temperatures with a subset of individuals being exposed to 17-α-methyltestosterone (MT) before sexual determination. 17-α-methyltestosterone is a potent androgen, not aromatizable by crocodilians, that has been found to exert masculinizing effects in exposed crocodilian populations in vivo and in vitro. Additionally, a subset of animals was exposed to a novel antigen to quantify innate and acquired immune function. We recovered no significant differences in leukocyte ratios or proportions between groups and found no significant differences in innate immune function as measured by hemolysis-hemagglutination. However, we did find significant differences in acquired immune function, where masculinized individuals expressed greater antibody titers. Our findings reject the hypothesis that androgens suppress immune function; rather, androgens may be immunoenhancing to acquired humoral responses and neutral to innate humoral immunity in crocodilians.
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Affiliation(s)
- Jorge E. López-Pérez
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana, 70402, USA
| | - Jeffrey M. Goessling
- Natural Sciences Collegium, Eckerd College, Saint Petersburg, Florida, 33711, USA
| | - Christopher M. Murray
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana, 70402, USA
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2
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Coleman TS, Gabel W, Easter M, McGreal M, Marin MS, Garrigos DB, Murray CM. The Spatial Ecology of Nuisance Crocodiles: Movement Patterns of Relocated American Crocodiles ( Crocodylus acutus) in Guanacaste, Costa Rica. Animals (Basel) 2024; 14:339. [PMID: 38275799 PMCID: PMC10812618 DOI: 10.3390/ani14020339] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024] Open
Abstract
Anthropogenic alterations of the environment have increased, highlighting the need for human-wildlife coexistence and conflict mitigation. Spatial ecology, and the use of passive satellite movement technology in particular, has been used to identify patterns in human-wildlife conflict as a function of shared resources that present potential for dangerous situations. Here, we aim to remotely identify patterns indicative of human-crocodile conflict in Guanacaste, Costa Rica by exploring site fidelity and diverse modes of movement (i.e., land and water) across space between nuisance (relocated) and non-nuisance (wild) crocodiles. Advanced satellite remote sensing technology provided near-constant movement data on individuals at the regional scale. Telonics Iridium SeaTrkr-4370-4 transmitters were used with modified crocodilian fitting. Results indicate that relocated crocodiles exhibited large-scale movements relative to wild crocodiles. Nuisance relocated crocodiles either returned to the area of nuisance or potentially attempted to in short time frames. The results presented here highlight the need for alternative management strategies that facilitate relocation efficacy.
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Affiliation(s)
- Tyler Steven Coleman
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA 70401, USA (M.M.)
| | - Wray Gabel
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA 70401, USA (M.M.)
| | | | - Maggie McGreal
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA 70401, USA (M.M.)
| | - Mahmood Sasa Marin
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San Jose 11403, Costa Rica;
- Centro Investigaciones en Biodiversidad y Biologia Tropical, Universidad de Costa Rica, San Jose 11501, Costa Rica
| | | | - Christopher M. Murray
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA 70401, USA (M.M.)
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Valli FE, Simoncini MS, González MA, Piña CI. How do maternal androgens and estrogens affect sex determination in reptiles with temperature-dependent sex? Dev Growth Differ 2023; 65:565-576. [PMID: 37603030 DOI: 10.1111/dgd.12887] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/22/2023]
Abstract
Temperature sex determination (TSD) in reptiles has been studied to elucidate the mechanisms by which temperature is transformed into a biological signal that determines the sex of the embryo. Temperature is thought to trigger signals that alter gene expression and hormone metabolism, which will determine the development of female or male gonads. In this review, we focus on collecting and discussing important and recent information on the role of maternal steroid hormones in sex determination in oviparous reptiles such as crocodiles, turtles, and lizards that possess TSD. In particular, we focus on maternal androgens and estrogens deposited in the egg yolk and their metabolites that could also influence the sex of offspring. Finally, we suggest guidelines for future research to help clarify the link between maternal steroid hormones and offspring sex.
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Affiliation(s)
- Florencia E Valli
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Melina S Simoncini
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
| | - Marcela A González
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Carlos I Piña
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
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Honan C, Murray CM. The effect of androgen exposure on cerebral lateralization in the American alligator (Alligator mississippiensis). Gen Comp Endocrinol 2023; 336:114248. [PMID: 36848983 PMCID: PMC10071487 DOI: 10.1016/j.ygcen.2023.114248] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/15/2023] [Accepted: 02/23/2023] [Indexed: 02/27/2023]
Abstract
The division of the brain manifests in lateralized physical behaviors, where specific tasks originate from one side of the body. Previous studies have shown that birds and reptiles mediate aggression in their right hemisphere and focus on opponents with their left eye. Degree of lateralization varies between sexes, likely due to androgen inhibition of lateralization in mammals, birds, and fish, but remains untested in herpetofauna. In this experiment, we investigated the effect of androgen exposure on cerebral lateralization in the American Alligator, Alligator mississippiensis. Alligator eggs were collected and incubated at female producing temperature with a subset dosed with methyltestosterone in ovo. Dosed hatchlings were randomly paired with control individuals and their interactions were recorded. The number of bites initiated by focus from each eye and the number of times an animal was bitten on each side of the body was recorded for each individual to elucidate cerebral lateralization in aggression. Control alligators had a significant bias towards left-eye bite initiation whereas androgen exposed alligators used both eyes indiscriminately. No significance was found in injury patterns. This study suggests that androgen exposure inhibits cerebral lateralization in alligator brains and corroborates right-hemisphere mediation of aggression, something previously unstudied in crocodilians.
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Affiliation(s)
- Caroline Honan
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - Christopher M Murray
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA 70402, USA
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Smaga CR, Bock SL, Johnson JM, Parrott BB. Sex Determination and Ovarian Development in Reptiles and Amphibians: From Genetic Pathways to Environmental Influences. Sex Dev 2022; 17:99-119. [PMID: 36380624 DOI: 10.1159/000526009] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 07/08/2022] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND Reptiles and amphibians provide untapped potential for discovering how a diversity of genetic pathways and environmental conditions are incorporated into developmental processes that can lead to similar functional outcomes. These groups display a multitude of reproductive strategies, and whereas many attributes are conserved within groups and even across vertebrates, several aspects of sexual development show considerable variation. SUMMARY In this review, we focus our attention on the development of the reptilian and amphibian ovary. First, we review and describe the events leading to ovarian development, including sex determination and ovarian maturation, through a comparative lens. We then describe how these events are influenced by environmental factors, focusing on temperature and exposure to anthropogenic chemicals. Lastly, we identify critical knowledge gaps and future research directions that will be crucial to moving forward in our understanding of ovarian development and the influences of the environment in reptiles and amphibians. KEY MESSAGES Reptiles and amphibians provide excellent models for understanding the diversity of sex determination strategies and reproductive development. However, a greater understanding of the basic biology of these systems is necessary for deciphering the adaptive and potentially disruptive implications of embryo-by-environment interactions in a rapidly changing world.
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Affiliation(s)
- Christopher R Smaga
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Samantha L Bock
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Josiah M Johnson
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Benjamin B Parrott
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
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Barraza AD, Finlayson KA, Leusch FDL, van de Merwe JP. Systematic review of reptile reproductive toxicology to inform future research directions on endangered or threatened species, such as sea turtles. Environ Pollut 2021; 286:117470. [PMID: 34438481 DOI: 10.1016/j.envpol.2021.117470] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/28/2021] [Accepted: 05/24/2021] [Indexed: 06/13/2023]
Abstract
Threatened or endangered reptiles, such as sea turtles, are generally understudied within the field of wildlife toxicology, with even fewer studies on how contaminants affect threatened species reproduction. This paper aimed to better inform threatened species conservation by systematically and quantitatively reviewing available research on the reproductive toxicology of all reptiles, threatened and non-threatened. This review found 178 studies that matched our search criteria. These papers were categorized into location conducted, taxa studied, species studied, effects found, and chemicals investigated. The most studied taxa were turtles (n = 87 studies, 49%), alligators/crocodiles (n = 54, 30%), and lizards (n = 37, 21%). Maternal transfer, sex steroid alterations, sex reversal, altered sexual development, developmental abnormalities, and egg contamination were the most common effects found across all reptile taxa, providing guidance for avenues of research into threatened species. Maternal transfer of contaminants was found across all taxa, and taking into account the foraging behavior of sea turtles, could help elucidate differences in maternal transfer seen at nesting beaches. Sex steroid alterations were a common effect found with contaminant exposure, indicating the potential to use sex steroids as biomarkers along with traditional biomarkers such as vitellogenin. Sex reversal through chemical exposure was commonly found among species that exhibit temperature dependent sex determination, indicating the potential for both environmental pollution and climate change to disrupt population dynamics of many reptile species, including sea turtles. Few studies used in vitro, DNA, or molecular methodologies, indicating the need for more research using high-throughput, non-invasive, and cost-effective tools for threatened species research. The prevalence of developmental abnormalities and altered sexual development and function indicates the need to further study how anthropogenic pollutants affect reproductive output in threatened reptiles.
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Affiliation(s)
- Arthur D Barraza
- Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, 4222, Qld, Australia.
| | - Kimberly A Finlayson
- Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, 4222, Qld, Australia
| | - Frederic D L Leusch
- Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, 4222, Qld, Australia
| | - Jason P van de Merwe
- Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, 4222, Qld, Australia
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Ciocan H, Leiva PM, Simoncini MS. Sexual Identification of Caiman latirostris Hatchlings by Cloacal Inspection. South American Journal of Herpetology 2020. [DOI: 10.2994/sajh-d-18-00075.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Hernán Ciocan
- Proyecto Yacaré, Laboratorio de Zoología Aplicada: Anexo Vertebrados (Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral/ Ministerio de Medio Ambiente), Aristóbulo del Valle 8700, CP 3000 Santa Fe, Santa Fe, Argentina
| | - Pamela M.L. Leiva
- Proyecto Yacaré, Laboratorio de Zoología Aplicada: Anexo Vertebrados (Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral/ Ministerio de Medio Ambiente), Aristóbulo del Valle 8700, CP 3000 Santa Fe, Santa Fe, Argentina
| | - Melina S. Simoncini
- Proyecto Yacaré, Laboratorio de Zoología Aplicada: Anexo Vertebrados (Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral/ Ministerio de Medio Ambiente), Aristóbulo del Valle 8700, CP 3000 Santa Fe, Santa Fe, Argentina
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8
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Martínez-Juárez A, Moreno-Mendoza N. Mechanisms related to sexual determination by temperature in reptiles. J Therm Biol 2019; 85:102400. [PMID: 31657741 DOI: 10.1016/j.jtherbio.2019.102400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 09/17/2018] [Revised: 08/12/2019] [Accepted: 08/21/2019] [Indexed: 01/08/2023]
Abstract
A number of strategies have emerged that appear to relate to the evolution of mechanisms for sexual determination in vertebrates, among which are genetic sex determination caused by sex chromosomes and environmental sex determination, where environmental factors influence the phenotype of the sex of an individual. Within the reptile group, some orders such as: Chelonia, Crocodylia, Squamata and Rhynchocephalia, manifest one of the most intriguing and exciting environmental sexual determination mechanisms that exists, comprising temperature-dependent sex determination (TSD), where the temperature of incubation that the embryo experiences during its development is fundamental to establishing the sex of the individual. This makes them an excellent model for the study of sexual determination at the molecular, cellular and physiological level, as well as in terms of their implications at an evolutionary and ecological level. There are different hypotheses concerning how this process is triggered and this review aims to describe any new contributions to particular TSD hypotheses, analyzing them from the "eco-evo-devo" perspective.
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Affiliation(s)
- Adriana Martínez-Juárez
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228 México, D.F. 04510, Mexico
| | - Norma Moreno-Mendoza
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228 México, D.F. 04510, Mexico.
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Hale MD, McCoy JA, Doheny BM, Galligan TM, Guillette LJ, Parrott BB. Embryonic estrogen exposure recapitulates persistent ovarian transcriptional programs in a model of environmental endocrine disruption†. Biol Reprod 2018; 100:149-161. [DOI: 10.1093/biolre/ioy165] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/12/2018] [Indexed: 11/15/2022] Open
Affiliation(s)
- Matthew D Hale
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
- Odum School of Ecology, University of Georgia, Athens, Georgia, USA
| | | | - Brenna M Doheny
- School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Thomas M Galligan
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, USA
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina, USA
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
- Odum School of Ecology, University of Georgia, Athens, Georgia, USA
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Murray CM, Merchant M, Easter M, Padilla S, Garrigós DB, Sasa Marin M, Guyer C. Detection of a synthetic sex steroid in the American crocodile (Crocodylus acutus): Evidence for a novel environmental androgen. Chemosphere 2017; 180:125-129. [PMID: 28399454 DOI: 10.1016/j.chemosphere.2017.04.020] [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: 12/05/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 06/07/2023]
Abstract
Endocrine-disrupting contaminants (EDC's) are well known to alter sexual differentiation among vertebrates via estrogenic effects during development, particularly in organisms characterized by temperature-dependent sex determination. However, substances producing androgenic effects typically lack potency when tested in laboratory settings and are virtually unstudied in field settings. Here, we assay levels of a synthetic androgen, 17α-methyltestosterone (MT), in a heavily male-biased population of American crocodiles in the Tempisque River Basin of Costa Rica based on the recent hypothesis that this chemical is an EDC in developing crocodilian embryos. The presence of MT was documented in all field-collected samples of egg yolk and in plasma of all age classes in among population of crocodiles. Hatchlings exhibited higher plasma MT concentrations (102.1 ± 82.8 ng/mL) than juveniles (33.8 ± 51.5) and adults (25.9 ± 20.8 ng/mL). Among populations, crocodiles captured in the Tempisque River (62.9 ± 73.7 ng/mL) were higher in MT concentration than those from Tarcoles (13.3 ± 11.4 ng/mL) and negative controls (0.001 ± 0.0002 ng/mL). A mechanism for the bio-transport of MT and its subsequent effects is proposed.
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Affiliation(s)
- Christopher M Murray
- Department of Biology, Tennessee Technological University, PO Box 5063, Cookeville, TN 38505, USA.
| | - Mark Merchant
- Department of Chemistry, McNeese State University, Lake Charles, LA, USA.
| | | | - Sergio Padilla
- Palo Verde Biological Station, Organization for Tropical Studies, Guanacaste, Costa Rica.
| | - Davinia B Garrigós
- Biodiversity and Evolutionary Biology "Cavanilles" Institute, University of Valencia, Valencia, Spain.
| | - Mahmood Sasa Marin
- Palo Verde Biological Station, Organization for Tropical Studies, Guanacaste, Costa Rica; Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
| | - Craig Guyer
- Department of Biological Sciences, Auburn University, 331 Funchess Hall, Auburn, AL 36849, USA.
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Lin T, Liu X, Xiao D, Zhang D. Plasma levels of immune factors and sex steroids in the male seahorse Hippocampus erectus during a breeding cycle. Fish Physiol Biochem 2017; 43:889-899. [PMID: 28197868 DOI: 10.1007/s10695-017-0343-6] [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: 08/08/2016] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
To better understand the endocrine- and immune-response pattern during reproduction in a fish species having parental care behaviors and also to accumulate the endocrine- and immune-related data for future explanations of the low reproductive efficiency in seahorse species, the variations of immune factors and sex steroids in the plasma of the male lined seahorse Hippocampus erectus at different breeding stages, i.e., pre-pregnancy, pregnancy (early, middle, and late periods), and post-pregnancy, were investigated in the present study. The immune factors included monocytes/leucocytes (M/L), leucocyte phagocytic rate (LPR), immunoglobulin M (Ig M), interleukin-2 (IL-2), interferon-α (IFN-α), and lysozyme (LZM). The sex steroids included testosterone (T), 11-ketotestosterone (11-KT), 11β-hydroxytestosterone (11β-OHT), 17α-methyltestosterone (17α-MT), 17β-estradiol (E2), and 17α-hydroxy-20β-dihydroprogesterone (17α-20β-P). Moreover, the immune metabolic activity of epithelium cells in the brood pouch at different breeding stages was also analyzed through ultrastructural observations of the abundance of cytoplasmic granules, mitochondria, endoplasmic reticulum, lysosomes, and exocytosis. The results show that a higher immune level was observed during pregnancy, particularly in the early and middle periods, and a lower immune level was noted during pre-pregnancy. Correspondingly, the epithelium cells in the brood pouch also showed a stronger immune metabolic activity during pregnancy and weaker activity during pre-pregnancy. Four sex steroids of T, 11β-OHT, 17α-MT, and E2 were higher during pre-pregnancy and lower during post-pregnancy, whereas 11-KT and 17α-20β-P, which were positively correlated with part immune factors, were higher during pregnancy. No negative correlations between sex steroids and immune factors were observed. In conclusion, the higher immune competence during pregnancy may indicate that parental care could improve immunity, which may be the major factor for no immunosuppressive effect of sex steroids during reproduction in the seahorse H. erectus, unlike noncaregiving fishes in which inhibitions of sex steroids on immunity are frequently observed. Moreover, higher 11-KT and 17α-20β-P during pregnancy than during pre-pregnancy and post-pregnancy may suggest that these two steroids are also involved in parental care regulation.
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Affiliation(s)
- Tingting Lin
- Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Xin Liu
- Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Dongxue Xiao
- Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Dong Zhang
- Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China.
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