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Lin JC, Daigle CL, Tang PC, Wang CK. Influence of sex hormones on the aggressive behavior during peck order establishment and stabilization in meat and egg type chickens. Poult Sci 2024; 103:103669. [PMID: 38603931 PMCID: PMC11017360 DOI: 10.1016/j.psj.2024.103669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/10/2024] [Accepted: 03/12/2024] [Indexed: 04/13/2024] Open
Abstract
In the poultry industry, broiler and layer strains are genetically selected for different purposes (e.g., high meat-yield and high egg-production). Genetic selection for productivity can have unintended consequences on the behavioral repertoire of the birds, including aggression. Alongside the increasing societal concern regarding the welfare of animal in agriculture, the number of countries that are advocating the prohibition of using battery cages for laying hens has resulted in the transition and adoption of cage-free or free-range systems. Thus, both broiler and layer chickens are housed in large flocks rather than housed individually in cages. Housing birds in groups increases the opportunity for birds to engage in social behaviors, including aggression, that are used to establish social status. Aggressive interactions are associated with the risk of injury and the potential for a subordinate animal to have unmet needs (e.g., access to feed). The aim of this study was to characterize the relationships among aggressive behavior, neurobiology, and hormones during peck order establishment and social hierarchy stabilization of 2 divergently selected strains (meat- and egg-type chicken). Meat-type strains performed more male on male (P < 0.001), male on female (P < 0.0001), and female on female (P < 0.0001) non-reciprocal aggression behavior (NRA) than egg-type strains. Greater serum testosterone and estradiol concentrations in the weeks after the peck order establishment were observed in meat-type birds compared those in egg-type birds for both males and females (all P < 0.05). Greater (P < 0.05) cellular densities of androgen receptors, but not estrogen receptors, were observed in the hypothalamus of meat-type birds compared to egg-type birds. These findings suggest that greater sex hormone concentrations in the meat-type birds may be a consequence of genetic selection for rapid growth resulting in more sex hormones-induced aggressive behavior.
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Affiliation(s)
- Jou-Ching Lin
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan
| | - Courtney Lynd Daigle
- Department of Animal Science, Texas A&M University, Kleberg Center, College Station, TX 77843, USA
| | - Pin-Chi Tang
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Chien-Kai Wang
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
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Wang LQ, Liu ZT, Wang JJ, Fang YH, Zhu H, Shi K, Zhang FS, Shuai LY. Complex effects of testosterone level on ectoparasite load in a ground squirrel: an experimental test for the immunocompetence handicap hypothesis. Parasit Vectors 2024; 17:164. [PMID: 38555448 PMCID: PMC10981293 DOI: 10.1186/s13071-024-06261-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND The immunocompetence handicap hypothesis suggests that males with a higher testosterone level should be better at developing male secondary traits, but at a cost of suppressed immune performance. As a result, we should expect that males with an increased testosterone level also possess a higher parasite load. However, previous empirical studies aimed to test this prediction have generated mixed results. Meanwhile, the effect of testosterone level on parasite load in female hosts remains poorly known. METHODS In this study, we tested this prediction by manipulating testosterone level in Daurian ground squirrels (Spermophilus dauricus), a medium-sized rodent widely distributed in northeast Asia. S. dauricus is an important host of ticks and fleas and often viewed as a considerable reservoir of plague. Live-trapped S. dauricus were injected with either tea oil (control group) or testosterone (treatment group) and then released. A total of 10 days later, the rodents were recaptured and checked for ectoparasites. Fecal samples were also collected to measure testosterone level of each individual. RESULTS We found that testosterone manipulation and sex of hosts interacted to affect tick load. At the end of the experiment, male squirrels subjected to testosterone implantation had an averagely higher tick load than males from the control group. However, this pattern was not found in females. Moreover, testosterone manipulation did not significantly affect flea load in S. dauricus. CONCLUSIONS Our results only lent limited support for the immunocompetence handicap hypothesis, suggesting that the role of testosterone on regulating parasite load is relatively complex, and may largely depend on parasite type and gender of hosts.
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Affiliation(s)
- Li-Qing Wang
- Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, China
| | - Zhi-Tao Liu
- College of Life Sciences, Harbin Normal University, Harbin, China
| | - Jian-Jun Wang
- Inner Mongolia Autonomous Region Comprehensive Center for Disease Control and Prevention, Hohhot, China
| | - Yu-Han Fang
- College of Life Sciences, Huaibei Normal University, Huaibei, China
| | - Hao Zhu
- College of Life Sciences, Huaibei Normal University, Huaibei, China
| | - Ke Shi
- College of Life Sciences, Huaibei Normal University, Huaibei, China
| | - Fu-Shun Zhang
- Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, China
| | - Ling-Ying Shuai
- College of Life Sciences, Huaibei Normal University, Huaibei, China.
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3
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Drea CM, Davies CS. Meerkat manners: Endocrine mediation of female dominance and reproductive control in a cooperative breeder. Horm Behav 2022; 145:105245. [PMID: 35988450 DOI: 10.1016/j.yhbeh.2022.105245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/18/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022]
Abstract
This article is part of a Special Issue (Hormones and Hierarchies). To gain more balanced understanding of sexual selection and mammalian sexual differentiation processes, this review addresses behavioral sex differences and hormonal mediators of intrasexual competition in the meerkat (Suricata suricatta) - a cooperative breeder unusual among vertebrates in its female aggression, degree of reproductive skew, and phenotypic divergence. Focused on the evolution, function, mechanism, and development of female dominance, the male remains a key reference point throughout. Integrated review of endocrine function does not support routine physiological suppression in subordinates of either sex, but instead a ramp up of weight, reproduction, aggression, and sex steroids, particularly androgens, in dominant females. Important and timely questions about female competition are thus addressed by shifting emphasis from mediators of reproductive suppression to mediators of reproductive control, and from organizational and activational roles of androgens in males to their roles in females. Unusually, we ask not only how inequity is maintained, but how dominance is acquired within a lifetime and across generations. Antiandrogens administered in the field to males and pregnant dominant females confirm the importance of androgen-mediated food competition. Moreover, effects of maternal endocrine milieu on offspring development reveal a heritable, androgenic route to female aggression, likely promoting reproductive priority along dominant matrilines. Integrating endocrine measures with long-term behavioral, ecological, morphological, and life-history data on normative and experimental individuals, across life stages and generations, provides better appreciation of the role of naturally circulating androgens in regulating the female phenotype, and sheds new light on the evolution of female dominance, reproductive inequity, and cooperative breeding.
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Affiliation(s)
- Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708-0383, USA; Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.
| | - Charli S Davies
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708-0383, USA; Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
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4
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Drea CM, Davies CS, Greene LK, Mitchell J, Blondel DV, Shearer CL, Feldblum JT, Dimac-Stohl KA, Smyth-Kabay KN, Clutton-Brock TH. An intergenerational androgenic mechanism of female intrasexual competition in the cooperatively breeding meerkat. Nat Commun 2021; 12:7332. [PMID: 34921140 PMCID: PMC8683399 DOI: 10.1038/s41467-021-27496-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 11/22/2021] [Indexed: 12/27/2022] Open
Abstract
Female intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testosterone, but in females, there has been little systematic investigation of androgen-mediated behaviour within and across generations. In 22 clans of wild meerkats (Suricata suricatta), we show that matriarchs 1) express peak androgen concentrations during late gestation, 2) when displaying peak feeding competition, dominance behaviour, and evictions, and 3) relative to subordinates, produce offspring that are more aggressive in early development. Late-gestation antiandrogen treatment of matriarchs 4) specifically reduces dominance behaviour, is associated with infrequent evictions, decreases social centrality within the clan, 5) increases aggression in cohabiting subordinate dams, and 6) reduces offspring aggression. These effects implicate androgen-mediated aggression in the operation of female sexual selection, and intergenerational transmission of masculinised phenotypes in the evolution of meerkat cooperative breeding.
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Affiliation(s)
- Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA.
- Department of Biology, Duke University, Durham, NC, 27708, USA.
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.
| | - Charli S Davies
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Lydia K Greene
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- Duke Lemur Center, Duke University, Durham, NC, 27705, USA
| | - Jessica Mitchell
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- Nuffield Centre for International Health and Development, University of Leeds, Leeds, West Yorkshire, LS2 9JT, UK
| | - Dimitri V Blondel
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- Department of Biology, North Carolina Wesleyan College, Rocky Mount, NC, 27804, USA
| | - Caroline L Shearer
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
| | - Joseph T Feldblum
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Department of Anthropology and Society of Fellows, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kristin A Dimac-Stohl
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Kendra N Smyth-Kabay
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- Boston Consulting Group, Bethesda, MD, 20814, USA
| | - Tim H Clutton-Brock
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
- Mammal Research Institute, University of Pretoria, 0002, Pretoria, South Africa
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Vernasco BJ, Moore IT. Testosterone as a mediator of the tradeoff between cooperation and competition in the context of cooperative reproductive behaviors. Gen Comp Endocrinol 2020; 288:113369. [PMID: 31857075 DOI: 10.1016/j.ygcen.2019.113369] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/18/2019] [Accepted: 12/13/2019] [Indexed: 11/20/2022]
Abstract
Behavioral tradeoffs occur when the expression of one behavior detracts from the expression of another. Understanding the proximate mediators of behavioral tradeoffs is important as these tradeoffs can act as potential constraints on evolutionary responses to selection. Here, we describe the tradeoff between cooperation and competition faced by species that exhibit cooperative reproductive behaviors and propose that testosterone is a key hormonal mediator of the tradeoff. Cooperative reproductive behaviors occur when multiple individuals coordinate their efforts to gain a reproductive advantage over other individuals and/or those individuals attempting to reproduce in absence of cooperation. We propose that testosterone, a sex steroid known to mediate a number of physiological and behavioral actions associated with reproductive competition, is involved in mediating the tradeoff between cooperation and competition. To support this proposition, we first describe the importance of individual variation in behavior to the evolution of cooperative behaviors. We then describe how proximate mechanisms represent a prominent source of individual variation in social behaviors and highlight evidence suggesting testosterone mediates variation in cooperative behaviors. Two case studies in which the relationship between testosterone and cooperative behaviors have been investigated in detail are then summarized. Throughout we highlight the importance of studying individual variation to understand the mechanistic basis of behaviors, behavioral tradeoffs, and the evolution of cooperative reproductive behaviors more broadly.
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Affiliation(s)
- Ben J Vernasco
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA; School of Biological Sciences, Washington State University, Pullman, WA, USA.
| | - Ignacio T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
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6
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Grebe NM, Fitzpatrick C, Sharrock K, Starling A, Drea CM. Organizational and activational androgens, lemur social play, and the ontogeny of female dominance. Horm Behav 2019; 115:104554. [PMID: 31276664 DOI: 10.1016/j.yhbeh.2019.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/06/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022]
Abstract
The role of androgens in shaping "masculine" traits in males is a core focus in behavioral endocrinology, but relatively little is known about an androgenic role in female aggression and social dominance. In mammalian models of female dominance, including the ring-tailed lemur (Lemur catta), links to androgens in adulthood are variable. We studied the development of ring-tailed lemurs to address the behavioral basis and ontogenetic mechanisms of female dominance. We measured behavior and serum androgen concentrations in 24 lemurs (8 males, 16 females) from infancy to early adulthood, and assessed their 'prenatal' androgen milieu using serum samples obtained from their mothers during gestation. Because logistical constraints limited the frequency of infant blood sampling, we accounted for asynchrony between behavioral and postnatal hormone measurements via imputation procedures. Imputation was unnecessary for prenatal hormone measurements. The typical sex difference in androgen concentrations in young lemurs was consistent with adult conspecifics and most other mammals; however, we found no significant sex differences in rough-and-tumble play. Female (but not male) aggression increased beginning at approximately 15 months, coincident with female puberty. In our analyses relating sexually differentiated behavior to androgens, we found no relationship with activational hormones, but several significant relationships with organizational hormones. Notably, associations of prenatal androstenedione and testosterone with behavior were differentiated, both by offspring sex and by type of behavior within offspring sexes. We discuss the importance of considering (1) missing data in behavioral endocrinology research, and (2) organizational androgens other than testosterone in studies of female dominance.
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Affiliation(s)
- Nicholas M Grebe
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
| | | | - Katherine Sharrock
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Anne Starling
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biology, Duke University, Durham, NC, USA; University Program in Ecology, Duke University, Durham, NC, USA
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7
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Van den Berghe F, Paris MCJ, Sarnyai Z, Vlamings B, Millar RP, Ganswindt A, Cozzi A, Pageat P, Paris DBBP. Dog appeasing pheromone prevents the androgen surge and may reduce contact dominance and active submission after stressful interventions in African wild dogs (Lycaon pictus). PLoS One 2019; 14:e0212551. [PMID: 30917139 PMCID: PMC6436694 DOI: 10.1371/journal.pone.0212551] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 02/05/2019] [Indexed: 11/20/2022] Open
Abstract
The endangered African wild dog (AWD; Lycaon pictus) is a highly social canid living in packs with a separate male and female hierarchy. Immobilisation, handling and translocations are acute stressors for AWDs, however such interventions are often needed for species management. In addition, new pack formation or temporary pack separation can lead to an increase in intra-pack aggression. The goal of this double-blinded placebo-controlled study conducted in captive zoo populations was to evaluate whether dog appeasing pheromone (DAP) reduces behavioural stress and faecal glucocorticoid metabolite levels (fGCM) normally associated with pack separation, immobilisation and reintroduction (SIR), and to assess whether this reduces aggressive behaviours and faecal androgen metabolite levels (fAM). Four packs (n = 11 males) were treated with DAP and 4 packs (n = 12 males) were treated with a placebo solution, applied at the end of anaesthesia. Behavioural interactions as well as fGCM and fAM were determined from 3 days before until 4-6 days after SIR. No effect of DAP on fGCM was observed, however, fAM increased after SIR in placebo but not DAP treated animals. Moreover, on the day of reintroduction, DAP treated packs tended to have lower rates of contact-dominance and active-submission behaviour, but higher rates of non-contact dominance behaviour. As these effects could decrease the risk of agonistic interactions, DAP may be a useful tool to help manage new pack formations and temporary pack separation.
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Affiliation(s)
- Femke Van den Berghe
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
| | - Monique C. J. Paris
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Wageningen Livestock Research, Wageningen, The Netherlands
| | - Zoltan Sarnyai
- Laboratory of Psychiatric Neuroscience, Australian Institute of Tropical Health and Medicine (AITHM) and College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Bart Vlamings
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
| | - Robert P. Millar
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Andre Ganswindt
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Alessandro Cozzi
- Institut de Recherche en Sémiochimie et Ethologie Appliquée, Apt, France
| | - Patrick Pageat
- Institut de Recherche en Sémiochimie et Ethologie Appliquée, Apt, France
| | - Damien B. B. P. Paris
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Centre for Tropical Environmental & Sustainability Science, James Cook University, Townsville, QLD, Australia
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de Bruin PR, Ganswindt A, Laver P, le Roux A. Friendly foxes: the relationship between steroid hormones and social behaviour in a monogamous African canid. J Zool (1987) 2018. [DOI: 10.1111/jzo.12574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. R. de Bruin
- Department of Zoology and Entomology Faculty of Natural and Agricultural Science Mammalian Cognition Research Group University of the Free State ‐ Qwaqwa Campus Phuthaditjhaba South Africa
| | - A. Ganswindt
- Department of Anatomy and Physiology Faculty of Veterinary Science Endocrine Research Laboratory University of Pretoria Pretoria South Africa
- Department of Zoology and Entomology Faculty of Natural and Agricultural Sciences Mammal Research Institute University of Pretoria Pretoria South Africa
| | - P. Laver
- Department of Anatomy and Physiology Faculty of Veterinary Science Endocrine Research Laboratory University of Pretoria Pretoria South Africa
| | - A. le Roux
- Department of Zoology and Entomology Faculty of Natural and Agricultural Science Mammalian Cognition Research Group University of the Free State ‐ Qwaqwa Campus Phuthaditjhaba South Africa
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Incidence and biomarkers of pregnancy, spontaneous abortion, and neonatal loss during an environmental stressor: Implications for female reproductive suppression in the cooperatively breeding meerkat. Physiol Behav 2018; 193:90-100. [PMID: 29730033 DOI: 10.1016/j.physbeh.2017.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/11/2017] [Accepted: 11/11/2017] [Indexed: 11/22/2022]
Abstract
Meerkats are group-living, insectivorous herpestids in which subordinate members provide extensive care for the dominant female's young. In contrast to some cooperative breeders, subordinate female meerkats are physiologically able to reproduce and occasionally do so successfully; their attempts are more frequently 'suppressed' via eviction or infanticide by the dominant female. Spontaneous abortion and neonatal loss occur with some regularity, further negatively impacting reproductive success. Here, we compared the reproductive outcomes and endocrine profiles, including of serum progesterone (P4), serum estradiol (E2), and fecal glucocorticoid metabolites (fGCm), of dominant and subordinate dams residing within their clans in the Kalahari Desert of South Africa. Our study spanned years of drought, which reduced insect abundance and represented a substantial environmental stressor. Meerkat pregnancies were identified at mid-term and culminated either in spontaneous abortions or full-term deliveries, after which pups were either lost prior to emergence from the natal den (usually within 2days of birth) or emerged at 2-3weeks. Neonatal loss exceeded fetal loss for all females, and contributed to narrowing the status-related disparity in female reproductive output seen during less arid periods. Although E2 concentrations were significantly lower in subordinate than dominant females, they were sufficient to support gestation. Absolute E2 concentrations may owe to androgenic precursors that also attain highest concentrations in dominant dams and may mediate aggression underlying female reproductive skew. Pregnancies terminating in fetal loss were marked by significantly lower P4 concentrations in mid-gestation and modestly lower E2 concentrations overall. Consistently high fGCm concentrations further increased across trimesters, particularly (but not consistently) in subordinates and in aborted pregnancies. Environmental stressors may modulate reproductive outcomes in meerkats through their influence on sex steroids and their effects on intragroup competition. The social and eco-physiological factors affecting intraspecific variation in reproductive output, even in obligate cooperative breeders, may be most apparent during extreme conditions, reflecting the benefits of long-term studies for assessing the impact of climate change.
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Mršić G, Ozretić P, Crnjac J, Merkaš S, Sukser V, Račić I, Rožić S, Barbarić L, Popović M, Korolija M. Expanded Croatian 12 X-STR loci database with an overview of anomalous profiles. Forensic Sci Int Genet 2018; 34:249-256. [PMID: 29573605 DOI: 10.1016/j.fsigen.2018.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/16/2018] [Accepted: 03/02/2018] [Indexed: 02/08/2023]
Abstract
In order to implement X-chromosome short tandem repeat (X-STR) typing into routine forensic practice, reference database of a given population should be established. Therefore we extended already published data with additional 397 blood samples from unrelated Croatian citizens, and analyzed the total of 995 samples (549 male and 446 female) typed by Investigator® Argus X-12 Kit. To test genetic homogeneity of consecutively processed five historic-cultural regions covering the entire national territory, we calculated pairwise Fst genetic distances between regions based on allele and full haplotype frequencies. Since the comparison did not yield any statistically significant difference, we integrated STR profile information from all regions and used the whole data set to calculate forensic parameters. The most informative marker is DXS10135 (polymorphism information content (PIC = 0.929) and the most informative linkage group (LG) is LG1 (PIC = 0.996). We confirmed linkage disequilibrium (LD) for seven marker pairs belonging to LG2, LG3 and LG4. By including LD information, we calculated cumulative power of discrimination that amounted to 0.999999999997 in females and 0.999999005 in males. We also compared Croatia with 13 European populations based on haplotype frequencies and detected no statistically significant Fst values after Bonferroni correction in any LG. Multi-dimensional scaling plot revealed tight grouping of four Croatian regions amongst populations of southern, central and northern Europe, with the exception of northern Croatia. In this study we gave the first extensive overview of aberrant profiles encountered during Investigator® Argus X-12 typing. We found ten profiles consistent with single locus duplication followed by tetranucleotide tract length polymorphism. Locus DXS10079 is by far the most frequently affected one, presumably mutated in eight samples. We also found four profiles consistent with X-chromosome aneuploidy (three profiles with XXX pattern and one profile with XXY pattern). In conclusion, we established integral forensic Croatian X-chromosome database, proved forensic pertinence of Investigator® Argus X-12 Kit for the entire Croatian population and identified locus DXS10079 as a potential duplication hotspot.
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Affiliation(s)
- Gordan Mršić
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Petar Ozretić
- Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Josip Crnjac
- University Department for Forensic Sciences, University of Split, Ruđera Boškovića 31, 21000 Split, Croatia
| | - Siniša Merkaš
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Viktorija Sukser
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Ivana Račić
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Sara Rožić
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Lucija Barbarić
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia
| | - Maja Popović
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova ulica 55, 10000 Zagreb, Croatia
| | - Marina Korolija
- Forensic Science Centre "Ivan Vučetić", Ilica 335, 10000 Zagreb, Croatia; Forensic Science Office, University of Zagreb, Ulica Ivana Lučića 5-6, 10000 Zagreb, Croatia.
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12
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Smyth KN, Greene LK, Clutton-Brock T, Drea CM. Androgens predict parasitism in female meerkats: a new perspective on a classic trade-off. Biol Lett 2017; 12:rsbl.2016.0660. [PMID: 28120802 DOI: 10.1098/rsbl.2016.0660] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022] Open
Abstract
The immunocompetence handicap hypothesis posits that androgens in males can be a 'double-edged sword', actively promoting reproductive success, while also negatively impacting health. Because there can be both substantial androgen concentrations in females and significant androgenic variation among them, particularly in species portraying female social dominance over males or intense female-female competition, androgens might also play a role in mediating female health and fitness. We examined this hypothesis in the meerkat (Suricata suricatta), a cooperatively breeding, social carnivoran characterized by aggressively mediated female social dominance and extreme rank-related reproductive skew. Dominant females also have greater androgen concentrations and harbour greater parasite loads than their subordinate counterparts, but the relationship between concurrent androgen concentrations and parasite burdens is unknown. We found that a female's faecal androgen concentrations reliably predicted her concurrent state of endoparasitism irrespective of her social status: parasite species richness and infection by Spirurida nematodes, Oxynema suricattae, Pseudandrya suricattae and coccidia were greater with greater androgen concentrations. Based on gastrointestinal parasite burdens, females appear to experience the same trade-off in the costs and benefits of raised androgens as do the males of many species. This trade-off presumably represents a health cost of sexual selection operating in females.
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Affiliation(s)
- Kendra N Smyth
- University Program in Ecology, Duke University, Durham NC 27708, USA .,Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.,Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa
| | - Lydia K Greene
- University Program in Ecology, Duke University, Durham NC 27708, USA.,Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.,Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa
| | - Tim Clutton-Brock
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa.,Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.,Mammal Research Institute, University of Pretoria, Pretoria 0028, South Africa
| | - Christine M Drea
- University Program in Ecology, Duke University, Durham NC 27708, USA.,Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA.,Department of Biology, Duke University, Durham NC 27708, USA.,Kalahari Research Trust, Kuruman River Reserve, Northern Cape 8467, South Africa
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Davies CS, Smyth KN, Greene LK, Walsh DA, Mitchell J, Clutton-Brock T, Drea CM. Exceptional endocrine profiles characterise the meerkat: sex, status, and reproductive patterns. Sci Rep 2016; 6:35492. [PMID: 27752129 PMCID: PMC5067592 DOI: 10.1038/srep35492] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/30/2016] [Indexed: 11/17/2022] Open
Abstract
In vertebrates, reproductive endocrine concentrations are strongly differentiated by sex, with androgen biases typifying males and estrogen biases typifying females. These sex differences can be reduced in female-dominant species; however, even the most masculinised of females have less testosterone (T) than do conspecific males. To test if aggressively dominant, female meerkats (Suricata suricatta) may be hormonally masculinised, we measured serum androstenedione (A4), T and estradiol (E2) in both sexes and social classes, during both ‘baseline’ and reproductive events. Relative to resident males, dominant females had greater A4, equivalent T and greater E2 concentrations. Males, whose endocrine values did not vary by social status, experienced increased T during reproductive forays, linking T to sexual behaviour, but not social status. Moreover, substantial E2 concentrations in male meerkats may facilitate their role as helpers. In females, dominance status and pregnancy magnified the unusual concentrations of measured sex steroids. Lastly, faecal androgen metabolites replicated the findings derived from serum, highlighting the female bias in total androgens. Female meerkats are thus strongly hormonally masculinised, possibly via A4’s bioavailability for conversion to T. These raised androgen concentrations may explain female aggressiveness in this species and give dominant breeders a heritable mechanism for their daughters’ competitive edge.
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Affiliation(s)
- Charli S Davies
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Kendra N Smyth
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA
| | - Lydia K Greene
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA
| | - Debbie A Walsh
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Jessica Mitchell
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Tim Clutton-Brock
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Mammal Research Institute, University of Pretoria, Pretoria, South Africa.,Department of Zoology, University of Cambridge, Cambridge, UK
| | - Christine M Drea
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA.,Department of Biology, Duke University, Durham, USA
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