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Arrieta RS, Cornejo P, Mahler B, Llambías PE. A possible case of offspring sex manipulation as result of a biased adult sex ratio. Sci Rep 2024; 14:819. [PMID: 38191894 PMCID: PMC10774364 DOI: 10.1038/s41598-023-51131-y] [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: 09/17/2023] [Accepted: 12/31/2023] [Indexed: 01/10/2024] Open
Abstract
Although random meiosis should prevent the facultative adjustment of offspring sex ratio, theory predicts that females should produce more of the sex with the higher reproductive value. We reported a case of offspring sex ratio manipulation in grass wrens Cistothorus platensis. Males in better body condition would have higher reproductive value than females due to the potential for social polygyny and extra-pair fertilizations. On the other hand, local demography influences reproductive strategies in grass wrens as male abundance affects both social polygyny and extra-pair paternity frequencies. We evaluated whether females bias their brood sex ratio in response to adult sex ratio and nestling body condition (a proxy for female's prospects of producing high-quality males). Females raised more male offspring when males were less abundant in the population (female-biased adult sex ratio). However, we found no relationship between nestling body condition and brood sex ratio, suggesting that females did not bias the brood sex ratio towards males when able to raise nestlings in better body condition. Taken together, our results provide the first suggestive evidence that female birds can manipulate their offspring sex ratio in response to the adult sex ratio.
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Affiliation(s)
- Ramiro S Arrieta
- Instituto Argentino de Investigaciones de Zonas Áridas, CONICET, Mendoza, Argentina.
| | - Paula Cornejo
- Instituto Argentino de Investigaciones de Zonas Áridas, CONICET, Mendoza, Argentina
| | - Bettina Mahler
- Departamento de Ecología, Genética y Evolución, IEGEBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paulo E Llambías
- Instituto Argentino de Investigaciones de Zonas Áridas, CONICET, Mendoza, Argentina
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Boersma J, Jones JA, Enbody ED, Welklin JF, Ketaloya S, Nason D, Karubian J, Schwabl H. Male White-shouldered Fairywrens (Malurus alboscapulatus) elevate androgens greater when courting females than during territorial challenges. Horm Behav 2022; 142:105158. [PMID: 35378335 DOI: 10.1016/j.yhbeh.2022.105158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/02/2022] [Accepted: 03/11/2022] [Indexed: 11/25/2022]
Abstract
Androgens like testosterone mediate suites of physical and behavioral traits across vertebrates, and circulation varies considerably across and within taxa. However, an understanding of the causal factors of variation in circulating testosterone has proven difficult despite decades of research. According to the challenge hypothesis, agonistic interactions between males immediately prior to the breeding season produce the highest levels of testosterone measured during this period. While many studies have provided support for this hypothesis, most species do not respond to male-male competition by elevating testosterone. As a result, a recent revision of the hypothesis ('challenge hypothesis 2.0') places male-female interactions as the primary cause of rapid elevations in testosterone circulation in male vertebrates. Here, we offer a test of both iterations of the challenge hypothesis in a tropical bird species. We first illustrate that male White-shouldered Fairywrens (Malurus alboscapulatus) differ by subspecies in plasma androgen concentrations. Then we use a social network approach to find that males of the subspecies with higher androgens are characterized by greater social interaction scores, including more time aggregating to perform sexual displays. Next, we use a controlled experiment to test whether males respond to simulated territorial intrusion and/or courtship competition contexts by elevating androgens. We found that males elevated androgens during territorial intrusions relative to flushed controls, however, males sampled during courtship competitions had greater plasma androgens both relative to controls and males sampled while defending territories. Ultimately, our results are consistent with challenge hypothesis 2.0, as sexual interactions with extra-pair females were associated with greater elevation of androgens than territorial disputes.
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Affiliation(s)
- Jordan Boersma
- School of Biological Sciences, Washington State University, Pullman, WA, USA; Department of Neurobiology and Behavior, Cornell University, USA; Cornell Lab of Ornithology, Ithaca, NY, USA.
| | - John Anthony Jones
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - Erik D Enbody
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA; Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Joseph F Welklin
- Department of Neurobiology and Behavior, Cornell University, USA; Cornell Lab of Ornithology, Ithaca, NY, USA
| | - Serena Ketaloya
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA; Porotona Village, Milne Bay Province, Papua New Guinea
| | - Doka Nason
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA; Porotona Village, Milne Bay Province, Papua New Guinea
| | - Jordan Karubian
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - Hubert Schwabl
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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Wrobel ER, Bentz AB, Lorenz WW, Gardner ST, Mendonça MT, Navara KJ. Corticosterone and testosterone treatment influence expression of gene pathways linked to meiotic segregation in preovulatory follicles of the domestic hen. PLoS One 2020; 15:e0232120. [PMID: 32407351 PMCID: PMC7224459 DOI: 10.1371/journal.pone.0232120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/07/2020] [Indexed: 01/25/2023] Open
Abstract
Decades of work indicate that female birds can control their offspring sex ratios in response to environmental and social cues. In laying hens, hormones administered immediately prior to sex chromosome segregation can exert sex ratio skews, indicating that these hormones may act directly on the germinal disc to influence which sex chromosome is retained in the oocyte and which is discarded into an unfertilizable polar body. We aimed to uncover the gene pathways involved in this process by testing whether treatments with testosterone or corticosterone that were previously shown to influence sex ratios elicit changes in the expression of genes and/or gene pathways involved in the process of meiotic segregation. We injected laying hens with testosterone, corticosterone, or control oil 5h prior to ovulation and collected germinal discs from the F1 preovulatory follicle in each hen 1.5h after injection. We used RNA-sequencing (RNA-seq) followed by DESeq2 and gene set enrichment analyses to identify genes and gene pathways that were differentially expressed between germinal discs of control and hormone-treated hens. Corticosterone treatment triggered downregulation of 13 individual genes, as well as enrichment of gene sets related to meiotic spindle organization and chromosome segregation, and additional gene sets that function in ion transport. Testosterone treatment triggered upregulation of one gene, and enrichment of one gene set that functions in nuclear chromosome segregation. This work indicates that corticosterone can be a potent regulator of meiotic processes and provides potential gene targets on which corticosterone and/or testosterone may act to influence offspring sex ratios in birds.
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Affiliation(s)
- Elizabeth R. Wrobel
- Department of Poultry Science, The University of Georgia, Athens, GA, United States of America
| | - Alexandra B. Bentz
- Department of Biology, Indiana University, Bloomington, IN, United States of America
| | - W. Walter Lorenz
- Institute of Bioinformatics and Georgia Genomics and Bioinformatics Core, The University of Georgia, Athens, GA, United States of America
| | - Stephen T. Gardner
- Department of Biological Sciences, Auburn University, Auburn, AL, United States of America
| | - Mary T. Mendonça
- Department of Biological Sciences, Auburn University, Auburn, AL, United States of America
| | - Kristen J. Navara
- Department of Poultry Science, The University of Georgia, Athens, GA, United States of America
- * E-mail:
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Wrobel ER, Molina E, Khan NY, Akingbemi BT, Mendonca MT, Navara KJ. Androgen and mineralocorticoid receptors are present on the germinal disc region in laying hens: Potential mediators of sex ratio adjustment in birds? Gen Comp Endocrinol 2020; 287:113353. [PMID: 31809721 DOI: 10.1016/j.ygcen.2019.113353] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 11/26/2019] [Accepted: 12/01/2019] [Indexed: 11/21/2022]
Abstract
Female birds skew offspring sex ratios based on environmental and social stimuli; however, the mechanism mediating this phenomenon remains unknown. Growing evidence suggests that testosterone and corticosterone may influence meiosis, as they skew sex ratios when given immediately before chromosomal segregation. It is unclear if these hormones act on the germinal disc (GD) or through a downstream mediator. It is also unknown whether the GD contains receptors for these hormones. If testosterone and/or corticosterone act on the GD to skew sex ratios, then the GD should have receptors for them and that receptor levels should be higher in the GD regions compared to other follicular regions. Furthermore, fluctuations of receptor levels should occur near meiotic segregation. We collected ovarian follicles at 5 h pre-ovulation (just before meiotic segregation) and 20 h pre-ovulation (when sex chromosomes are arrested), and measured androgen receptor (AR) and mineralocorticoid receptor (MR) protein levels via Western blot. ARs and MRs were on the follicle in the GD and non-GD regions, and at 5 h and 20 h pre-ovulation. Both AR and MR protein levels were higher in the GD region than the non-GD region at both time points, but did not differ between time points. These results suggest that hen ovarian follicles have receptors for testosterone and corticosterone, and that the ability for testosterone to respond may be specifically higher in the GD-region, providing further support for the role of testosterone in the alteration of meiotic segregation.
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Affiliation(s)
- Elizabeth R Wrobel
- Poultry Science Department, University of Georgia, 203 Poultry Science Bldg., Athens, GA 30602, USA.
| | - Erica Molina
- Biological Sciences Department, Auburn University, 331 Funchess Hall, Auburn, AL 36849, USA
| | - Nicola Y Khan
- School of Psychology and Neuroscience, University of St. Andrews, South Street, St. Andrews KY16 9JP, Scotland, UK
| | - Benson T Akingbemi
- Department of Anatomy, Physiology and Pharmacology, Auburn University, 109 Greene Hall, College of Veterinary Medicine, Auburn, AL 36849, USA
| | - Mary T Mendonca
- Biological Sciences Department, Auburn University, 331 Funchess Hall, Auburn, AL 36849, USA
| | - Kristen J Navara
- Poultry Science Department, University of Georgia, 203 Poultry Science Bldg., Athens, GA 30602, USA
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Parolini M, Possenti CD, Romano A, Caprioli M, Rubolini D, Saino N. Physiological increase of yolk testosterone level does not affect oxidative status and telomere length in gull hatchlings. PLoS One 2018; 13:e0206503. [PMID: 30365552 PMCID: PMC6203383 DOI: 10.1371/journal.pone.0206503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 10/15/2018] [Indexed: 02/01/2023] Open
Abstract
Conditions experienced during early-life can cause the onset of oxidative stress, resulting in pervasive effects on diverse life-history traits, including lifespan. In birds, maternally-transferred egg substances may exert positive or negative influence over the offspring phenotype. Among these, testosterone can upregulate the bioavailability of certain antioxidants but simultaneously promotes the production of pro-oxidants, leading to an oxidative stress situation, which is one of the main forces causing telomere attrition However, no study has investigated the role of this androgen on telomere dynamics in birds and little is known about the effects of yolk testosterone on oxidative status in early-life of these species. We physiologically increased the levels of yolk testosterone by in ovo injections in yellow-legged gull (Larus michahellis) to evaluate the effects induced by this androgen on hatchlings plasma total antioxidant capacity, amount of pro-oxidant molecules and telomere length at hatching. Testosterone supplementation did not increase hatchling body growth, did not result in the overproduction of pro-oxidant molecules nor a reduction of antioxidant capacity. Accordingly, telomere length at hatching was not affected by testosterone treatment, although hatchlings from the third-laid eggs showed shorter telomeres than their siblings from first- and second-laid eggs, independently of testosterone treatment. Our results suggest that injection of physiological levels of testosterone does not induce oxidative stress to hatchlings and, consequently do not affect telomere dynamics during early post-natal periods.
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Affiliation(s)
- Marco Parolini
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
- * E-mail:
| | | | - Andrea Romano
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Manuela Caprioli
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Diego Rubolini
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Nicola Saino
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
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Langen EMA, von Engelhardt N, Goerlich-Jansson VC. No evidence for sex-specific effects of the maternal social environment on offspring development in Japanese quail (Coturnix japonica). Gen Comp Endocrinol 2018; 263:12-20. [PMID: 29684400 DOI: 10.1016/j.ygcen.2018.04.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/26/2018] [Accepted: 04/12/2018] [Indexed: 01/25/2023]
Abstract
The social environment of reproducing females can cause physiological changes, with consequences for reproductive investment and offspring development. These prenatal maternal effects are often found to be sex-specific and may have evolved as adaptations, maximizing fitness of male and female offspring for their future environment. Female hormone levels during reproduction are considered a potential mechanism regulating sex allocation in vertebrates: high maternal androgens have repeatedly been linked to increased investment in sons, whereas high glucocorticoid levels are usually related to increased investment in daughters. However, results are not consistent across studies and therefore still inconclusive. In Japanese quail (Coturnix japonica), we previously found that pair-housed females had higher plasma androgen levels and tended to have higher plasma corticosterone levels than group-housed females. In the current study we investigate whether these differences in maternal social environment and physiology affect offspring sex allocation and physiology. Counter to our expectations, we find no effects of the maternal social environment on offspring sex ratio, sex-specific mortality, growth, circulating androgen or corticosterone levels. Also, maternal corticosterone or androgen levels do not correlate with offspring sex ratio or mortality. The social environment during reproduction therefore does not necessarily modify sex allocation and offspring physiology, even if it causes differences in maternal physiology. We propose that maternal effects of the social environment strongly depend upon the type of social stimuli and the timing of changes in the social environment and hormones with respect to the reproductive cycle and meiosis.
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Affiliation(s)
- Esther M A Langen
- Department of Animal Behaviour, Bielefeld University, Morgenbreede 45, 33615 Bielefeld, Germany; Department of Animals in Science and Society, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands.
| | - Nikolaus von Engelhardt
- Department of Animal Behaviour, Bielefeld University, Morgenbreede 45, 33615 Bielefeld, Germany.
| | - Vivian C Goerlich-Jansson
- Department of Animal Behaviour, Bielefeld University, Morgenbreede 45, 33615 Bielefeld, Germany; Department of Animals in Science and Society, Utrecht University, Yalelaan 2, 3508 TD Utrecht, The Netherlands.
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Bowling M, Forder R, Hughes RJ, Weaver S, Hynd PI. Effect of restricted feed intake in broiler breeder hens on their stress levels and the growth and immunology of their offspring. Transl Anim Sci 2018; 2:263-271. [PMID: 32704710 PMCID: PMC7200449 DOI: 10.1093/tas/txy064] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/30/2018] [Indexed: 01/05/2023] Open
Abstract
The prenatal environment has been shown to have significant effects on the lifelong health of offspring in humans and other species. Such effects have not been studied extensively in avian species but could prove important, especially in the case of severe feed restriction imposed on broiler breeder hens to prevent obesity and reduce rate of lay. Feed restriction can potentially affect not only nutrient supply to the embryo but stress hormone levels within the hen. This study investigated the impact of nutrient restriction of the breeder hen on growth rate and immune responses in the progeny with the objective to measure the impact of feed restriction of broiler breeder hens on growth and immune response of the progeny. Broiler breeder hens were feed restricted from 24 wk of age and maintained at three bodyweights; 3.4, 3.6, and 4.0 kg until 43 wk of age and behavioral and physiological measures of stress recorded. Chicks were hatched from each hen treatment and at day 7 vaccinated for infectious bronchitis virus (IBV) and at 16, 18, and 20 d old given an immune challenge of lipopolysaccharide. Growth and immune responses of these birds were then recorded. Sex ratio was affected by hen bodyweight, with a significantly increased proportion of males hatched from heavy hens. Growth rate from 35 to 42 d of age was reduced in male progeny from low bodyweight hens. Female progeny from heavy hens responded to an immune challenge by reduced live weight and increased heterophil: lymphocyte ratio, suggesting a more robust immune response in these birds than in the progeny from lower bodyweight hens. Overall, progeny from heavy hens had increased antibodies at day 35 to the vaccination of IBV compared with progeny of low bodyweight hens, also suggesting an improved immune response in these birds. Breeder hens restricted to the lowest feed level showed behaviors indicative of increased stress (object pecking) and an increased heterophil: lymphocyte ratio. Feed restriction of broiler breeder hens increased indices of stress in hens and resulted in offspring that have reduced growth rate and immune response in a sex-dependent way.
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Affiliation(s)
- Mandy Bowling
- Poultry CRC, University of New England, Armidale, NSW, Australia.,School of Animal and Veterinary Science, The University of Adelaide, Roseworthy Campus, Adelaide, SA, Australia
| | - Rebecca Forder
- School of Animal and Veterinary Science, The University of Adelaide, Roseworthy Campus, Adelaide, SA, Australia
| | - Robert J Hughes
- South Australian Research and Development Institute, Roseworthy Campus, South Australia, Australia
| | - Sarah Weaver
- School of Animal and Veterinary Science, The University of Adelaide, Roseworthy Campus, Adelaide, SA, Australia
| | - Philip Ian Hynd
- School of Animal and Veterinary Science, The University of Adelaide, Roseworthy Campus, Adelaide, SA, Australia
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Podmokła E, Drobniak SM, Rutkowska J. Chicken or egg? Outcomes of experimental manipulations of maternally transmitted hormones depend on administration method - a meta-analysis. Biol Rev Camb Philos Soc 2018; 93:1499-1517. [PMID: 29573376 DOI: 10.1111/brv.12406] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 01/28/2018] [Accepted: 02/13/2018] [Indexed: 12/25/2022]
Abstract
Steroid hormones are important mediators of prenatal maternal effects in animals. Despite a growing number of studies involving experimental manipulation of these hormones, little is known about the impact of methodological differences among experiments on the final results expressed as offspring traits. Using a meta-analytical approach and a representative sample of experimental studies performed on birds, we tested the effect of two types of direct hormonal manipulations: manipulation of females (either by implantation of hormone pellets or injection of hormonal solutions) and manipulation of eggs by injection. In both types of manipulation we looked at the effects of two groups of hormones: corticosterone and androgens in the form of testosterone and androstenedione. We found that the average effect on offspring traits differed between the manipulation types, with a well-supported positive effect of egg manipulation and lack of a significant effect of maternal manipulation. The observed average positive effect for egg manipulation was driven mainly by androgen manipulations, while corticosterone manipulations exerted no overall effect, regardless of manipulation type. Detailed analyses revealed effects of varying size and direction depending on the specific offspring traits; e.g., egg manipulation positively affected physiology and behaviour (androgens), and negatively affected future reproduction (corticosterone). Effect size was negatively related to the dose of androgen injected into the eggs, but unrelated to timing of manipulation, offspring developmental stage at the time of measuring their traits, solvent type, the site of egg injection and maternal hormone delivery method. Despite the generally acknowledged importance of maternal hormones for offspring development in birds, the overall effect of their experimental elevation is rather weak, significantly heterogeneous and dependent on the hormone and type of manipulation. We conclude by providing general recommendations as to how hormonal manipulations should be performed in order to standardize their impact and the results achieved. We also emphasize the need for research on free-living birds with a focus on fitness-related and other long-term effects of maternal hormones.
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Affiliation(s)
- Edyta Podmokła
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Szymon M Drobniak
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Joanna Rutkowska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
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Pikus AE, Guindre-Parker S, Rubenstein DR. Testosterone, social status and parental care in a cooperatively breeding bird. Horm Behav 2018; 97:85-93. [PMID: 29054796 DOI: 10.1016/j.yhbeh.2017.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 10/14/2017] [Accepted: 10/16/2017] [Indexed: 01/14/2023]
Abstract
The steroid hormone testosterone not only plays an important role in gamete production, but also influences social and aggressive behavior. Testosterone varies seasonally, peaking when competition for mates is high and declining during parental care. Surprisingly, little is known about how testosterone mediates social conflict and parental care behavior in highly social species like cooperative breeders, where group members compete for breeding opportunities and provide parental or alloparental care. We examined how testosterone differs across breeding roles in the tropical cooperatively breeding superb starling, Lamprotornis superbus. We determined whether testosterone was elevated in larger groups, and whether testosterone was negatively related to total levels of parental and alloparental care. We found that male breeders had higher testosterone than male helpers and female breeders and helpers during incubation. However, breeding males exhibited a significant decline in testosterone from incubation to chick rearing, and all individuals had similar levels during the chick rearing stage. Additionally, helpers-but not breeders-in large social groups had higher testosterone than those in small groups. Finally, testosterone was not correlated with nestling provisioning rates during chick rearing, suggesting that natural variation in the low levels of testosterone observed during periods of high parental care does not affect nestling provisioning. Together, these results offer insight into how testosterone is related to breeding roles, intra-group conflict, and parental care in a highly social species.
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Affiliation(s)
- Alyxandra E Pikus
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
| | - Sarah Guindre-Parker
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA; Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Dustin R Rubenstein
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA; Center for Integrative Animal Behavior, Columbia University, New York, NY 10027, USA.
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12
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Paul SC, Pell JK, Blount JD. Reproduction in Risky Environments: The Role of Invasive Egg Predators in Ladybird Laying Strategies. PLoS One 2015; 10:e0139404. [PMID: 26488753 PMCID: PMC4619405 DOI: 10.1371/journal.pone.0139404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/12/2015] [Indexed: 12/04/2022] Open
Abstract
Reproductive environments are variable and the resources available for reproduction are finite. If reliable cues about the environment exist, mothers can alter offspring phenotype in a way that increases both offspring and maternal fitness (‘anticipatory maternal effects’—AMEs). Strategic use of AMEs is likely to be important in chemically defended species, where the risk of offspring predation may be modulated by maternal investment in offspring toxin level, albeit at some cost to mothers. Whether mothers adjust offspring toxin levels in response to variation in predation risk is, however, unknown, but is likely to be important when assessing the response of chemically defended species to the recent and pervasive changes in the global predator landscape, driven by the spread of invasive species. Using the chemically defended two-spot ladybird, Adalia bipunctata, we investigated reproductive investment, including egg toxin level, under conditions that varied in the degree of simulated offspring predation risk from larval harlequin ladybirds, Harmonia axyridis. H. axyridis is a highly voracious alien invasive species in the UK and a significant intraguild predator of A. bipunctata. Females laid fewer, larger egg clusters, under conditions of simulated predation risk (P+) than when predator cues were absent (P-), but there was no difference in toxin level between the two treatments. Among P- females, when mean cluster size increased there were concomitant increases in both the mass and toxin concentration of eggs, however when P+ females increased cluster size there was no corresponding increase in egg toxin level. We conclude that, in the face of offspring predation risk, females either withheld toxins or were physiologically constrained, leading to a trade-off between cluster size and egg toxin level. Our results provide the first demonstration that the risk of offspring predation by a novel invasive predator can influence maternal investment in toxins within their offspring.
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Affiliation(s)
- Sarah C. Paul
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, United Kingdom
| | - Judith K. Pell
- J. K. Pell Consulting, Luton, Bedfordshire, United Kingdom
| | - Jonathan D. Blount
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, United Kingdom
- * E-mail:
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DeVries MS, Winters CP, Jawor JM. Testosterone might not be necessary to support female aggression in incubating northern cardinals. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Cantarero A, Laaksonen T, Järvistö PE, Gil D, López-Arrabé J, Redondo AJ, Moreno J. Nest Defence Behaviour and Testosterone Levels in Female Pied Flycatchers. Ethology 2015. [DOI: 10.1111/eth.12407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Toni Laaksonen
- Department of Biology; University of Turku; Turku Finland
| | | | - Diego Gil
- Museo Nacional de Ciencias Naturales - CSIC; Dpto Ecología Evolutiva; Madrid Spain
| | - Jimena López-Arrabé
- Museo Nacional de Ciencias Naturales - CSIC; Dpto Ecología Evolutiva; Madrid Spain
| | | | - Juan Moreno
- Museo Nacional de Ciencias Naturales - CSIC; Dpto Ecología Evolutiva; Madrid Spain
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Aslam MA, Schokker D, Groothuis TG, de Wit AA, Smits MA, Woelders H. Association of Egg Mass and Egg Sex: Gene Expression Analysis from Maternal RNA in the Germinal Disc Region of Layer Hens (Gallus gallus)1. Biol Reprod 2015; 92:157. [DOI: 10.1095/biolreprod.114.123380] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 03/19/2015] [Indexed: 11/01/2022] Open
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van der Westhuizen D, Solms M. Social dominance and the Affective Neuroscience Personality Scales. Conscious Cogn 2015; 33:90-111. [DOI: 10.1016/j.concog.2014.12.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 11/04/2014] [Accepted: 12/07/2014] [Indexed: 11/17/2022]
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Pinson SE, Wilson JL, Navara KJ. Timing matters: corticosterone injections 4 h before ovulation bias sex ratios towards females in chickens. J Comp Physiol B 2015; 185:539-46. [DOI: 10.1007/s00360-015-0897-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 02/10/2015] [Accepted: 03/01/2015] [Indexed: 10/23/2022]
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Aslam MA, Groothuis TG, Smits MA, Woelders H. Effect of Corticosterone and Hen Body Mass on Primary Sex Ratio in Laying Hen (Gallus gallus), Using Unincubated Eggs1. Biol Reprod 2014; 90:76. [DOI: 10.1095/biolreprod.113.115352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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19
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Grenna M, Avidano L, Malacarne G, Leboucher G, Cucco M. Influence of Male Dominance on Egg Testosterone and Antibacterial Substances in the Egg of Grey Partridges. Ethology 2013. [DOI: 10.1111/eth.12189] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marco Grenna
- DISIT; University of Piemonte Orientale; Alessandria Italy
| | - Lorena Avidano
- DISIT; University of Piemonte Orientale; Alessandria Italy
| | | | | | - Marco Cucco
- DISIT; University of Piemonte Orientale; Alessandria Italy
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20
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Cain KE, Ketterson ED. Individual variation in testosterone and parental care in a female songbird; the dark-eyed junco (Junco hyemalis). Horm Behav 2013; 64:685-92. [PMID: 24060498 PMCID: PMC4013145 DOI: 10.1016/j.yhbeh.2013.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/11/2013] [Accepted: 09/13/2013] [Indexed: 10/26/2022]
Abstract
When competition for sex-specific resources overlaps in time with offspring production and care, trade-offs can occur. Steroid hormones, particularly testosterone (T), play a crucial role in mediating such trade-offs in males, often increasing competitive behaviors while decreasing paternal behavior. Recent research has shown that females also face such trade-offs; however, we know little about the role of T in mediating female phenotypes in general, and the role of T in mediating trade-offs in females in particular. Here we examine the relationship between individual variation in maternal effort and endogenous T in the dark-eyed junco, a common songbird. Specifically, we measure circulating T before and after a physiological challenge (injection of gonadotropin releasing hormone, GnRH), and determine whether either measure is related to provisioning, brooding, or the amount of T sequestered in egg yolk. We found that females producing more T in response to a challenge spent less time brooding nestlings, but provisioned nestlings more frequently, and deposited more T in their eggs. These findings suggest that, while T is likely important in mediating maternal phenotypes and female life history tradeoffs, the direction of the relationships between T and phenotype may differ from what is generally observed in males, and that high levels of endogenous T are not necessarily as costly as previous work might suggest.
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Affiliation(s)
- Kristal E Cain
- Research School of Biology, The Australian National University, ACT 0200, Australia; Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Bloomington, IN 47405, USA.
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21
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O'Neal DM. Eco-endo-immunology across avian life history stages. Gen Comp Endocrinol 2013; 190:105-11. [PMID: 23707379 DOI: 10.1016/j.ygcen.2013.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 11/28/2022]
Abstract
Broadly distributed songbirds, particularly those that migrate, encounter a wide range of pathogens. Both pathogen exposure and energy available for immune responses are expected to be affected by environmental variation in climate, habitat quality, and social interactions as well as hormonal mechanisms. Comparisons of Aves in the field have begun to build the framework for understanding how such environmental variation interacts with disease environments as reflected in endocrine and immune responses. In this review, the roles of hormones and immune function across the various life history stages that make up the avian annual cycle are considered with an emphasis on free-living songbirds and the various hormones known to mediate the innate and acquired immune systems including melatonin, prolactin, growth hormone, and several neuroendocrine hormones. Finally, hormone-immune interactions are considered within the framework of disease ecology.
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Affiliation(s)
- Dawn M O'Neal
- Huyck Preserve and Biological Research Station, P.O. Box 189, Rensselaerville, NY 12147, USA.
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22
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Navara KJ. The role of steroid hormones in the adjustment of primary sex ratio in birds: compiling the pieces of the puzzle. Integr Comp Biol 2013; 53:923-37. [PMID: 23900275 DOI: 10.1093/icb/ict083] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
There is ample evidence that birds have the ability to adjust their offsprings' sex ratios before fertilization occurs. Recent work has focused on pinpointing when during the process of oocyte maturation adjustment of sex ratio takes place. Additionally, there is growing support for the idea that there is hormonal control over the process of adjustment of sex ratio in birds. Whether steroid hormones represent direct mediators of the process, however, remains unclear. This review outlines the precise points during maturation of ovarian follicles during which adjustment of primary sex ratios could potentially occur, compiles the evidence for hormonal involvement in the process of primary adjustment of sex ratio, and discusses potential hormonal targets during maturation and fertilization of oocytes where hormones may trigger adjustment of sex ratio in birds.
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Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
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23
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Abstract
The ability to adjust sex ratios at the individual level exists among all vertebrate groups studied to date. In many cases, there is evidence for facultative adjustment of sex ratios in response to environmental and/or social cues. Because environmental and social information must be first transduced into a physiological signal to influence sex ratios, hormones likely play a role in the adjustment of sex ratio in vertebrates, because the endocrine system acts as a prime communicator that directs physiological activities in response to changing external conditions. This symposium was developed to bring together investigators whose work on adjustment of sex ratio represents a variety of vertebrate groups in an effort to draw comparisons between species in which the sex-determination process is well-established and those in which more work is needed to understand how adjustments in sex ratio are occurring. This review summarizes potential hormone targets that may underlie the mechanisms of adjustment of sex ratio in humans, non-human mammals, birds, reptiles, and fishes.
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Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
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24
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Aslam MA, Hulst M, Hoving-Bolink RAH, Smits MA, de Vries B, Weites I, Groothuis TGG, Woelders H. Yolk concentrations of hormones and glucose and egg weight and egg dimensions in unincubated chicken eggs, in relation to egg sex and hen body weight. Gen Comp Endocrinol 2013; 187:15-22. [PMID: 23510857 DOI: 10.1016/j.ygcen.2013.02.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 02/13/2013] [Accepted: 02/24/2013] [Indexed: 11/15/2022]
Abstract
Birds can manipulate offspring sex ratio under natural and experimental conditions and maternal hormones have been shown to be involved in this process. Studies also provided evidence for the presence of sex specific concentrations of yolk hormones in avian eggs. These findings led to the suggestion that yolk hormones could influence genetic sex determination in birds. However, in previous studies, yolk hormone concentrations and egg sex were studied in incubated eggs, although incubation of the eggs and embryonic development can alter yolk hormone concentrations and measured sex ratio. This study is the first to determine a wide array of egg components and hen body weight in relation to the sex of the egg in unincubated eggs. Egg parameters studied were yolk concentrations of testosterone, estradiol, androstenedione, progesterone, dihydrotestosterone, and glucose, and egg weight and dimensions. In addition, we studied the associations among all measured parameters. Associations were found between a number of yolk hormones (progesterone associated with testosterone, estradiol and androstenedione; androstenedione with testosterone; dihydrotestosterone with estradiol and androstenedione) as well as between yolk testosterone and egg length and egg weight. There were no significant overall differences between male and female chicken eggs in any of the measured egg parameters. However, there were a few interactions such as the interaction of egg sex with dihydrotestosterone and with hen body weight which predicted estradiol levels and an interaction of estradiol levels with egg width for predicting sex of egg. Their biological relevance need, however, further study.
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Affiliation(s)
- M Aamir Aslam
- Animal Breeding and Genomics Centre, Wageningen UR Livestock Research, PO Box 65, 8200 AB Lelystad, The Netherlands
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Goerlich-Jansson VC, Muller MS, Groothuis TGG. Manipulation of Primary Sex Ratio in Birds: Lessons from the Homing Pigeon (Columba livia domestica). Integr Comp Biol 2013; 53:902-12. [DOI: 10.1093/icb/ict056] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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26
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Gerlach NM, Ketterson ED. Experimental elevation of testosterone lowers fitness in female dark-eyed juncos. Horm Behav 2013; 63:782-90. [PMID: 23523740 DOI: 10.1016/j.yhbeh.2013.03.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 03/05/2013] [Accepted: 03/07/2013] [Indexed: 11/16/2022]
Abstract
Testosterone (T) is often referred to as the "male hormone," but it can influence aggression, parental behavior, and immune function in both males and females. By experimentally relating hormone-induced changes in phenotype to fitness, it is possible to ask whether existing phenotypes perform better or worse than alternative phenotypes, and hence to predict how selection might act on a novel or rare phenotype. In a songbird, the dark-eyed junco (Junco hyemalis), we have examined the effects of experimentally elevated T in females on fitness-related behaviors such as parental care. In this study, we implanted female juncos with exogenous T and examined its effect on fitness (survival, reproduction, and extra-pair mating) to assess whether T-altered phenotypes would prove to be adaptive or deleterious for females. Experimental elevation of T decreased the likelihood that a female would breed successfully, and T-implanted females had lower total reproductive success at every stage of the reproductive cycle. They did not, however, differ from control females in fledgling quality, extra-pair offspring production, survival, or reproduction in the following year. Previous work in this system has shown that experimental elevation of T in males alters behavior and physiology and decreases survival but increases the production of extra-pair offspring, leading to higher net fitness relative to control animals. Our results suggest that increased T has divergent effects on male and female fitness in this species, and that prevailing levels in females may be adaptive for them. These findings are consistent with sexual conflict.
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Affiliation(s)
- Nicole M Gerlach
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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27
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Increased exposure to yolk testosterone has feminizing effects in chickens, Gallus gallus domesticus. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Tagirov M, Rutkowska J. Chimeric embryos—potential mechanism of avian offspring sex manipulation. Behav Ecol 2013. [DOI: 10.1093/beheco/art007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Marteinson SC, Letcher RJ, Graham L, Kimmins S, Tomy G, Palace VP, Ritchie IJ, Gauthier LT, Bird DM, Fernie KJ. The flame retardant β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane: fate, fertility, and reproductive success in American kestrels (Falco sparverius). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8440-8447. [PMID: 22775271 DOI: 10.1021/es301032a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Captive American kestrels (Falco sparverius) were exposed via diet during reproduction to an environmentally relevant concentration of β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (β-TBECH). The β-TBECH isomer was injected into the food source at a daily dosing concentration of 0.239 ng/g kestrel/day (22 pairs); control birds were exposed via diet to the safflower oil vehicle only (24 pairs). Eight pairs in each group were exposed for four weeks and sacrificed for tissue analysis; the remaining pairs completed their breeding cycle, with exposure ceasing at the end of incubation (82 days). α- and β-TBECH appeared to be rapidly metabolized and/or eliminated from fat, liver, and plasma; both isomers and potential hydroxylated metabolites of β-TBECH (plasma) were undetected. Notwithstanding, compared to controls, pairs exposed to β-TBECH laid fewer eggs (p = 0.019) and laid lighter eggs (successful eggs: p = 0.009). Exposed pairs also demonstrated poorer egg fertility (p = 0.035) although testis mass and histology were similar among males. Reductions in egg production and fertility resulted in decreased hatchling success (p = 0.023). The β-TBECH-exposed pairs also produced fewer males overall (p = 0.009), which occurred concurrently with increased estradiols maternally deposited in eggs (p = 0.039). These findings demonstrate that β-TBECH may be detrimental for breeding in wild birds receiving similar exposure levels.
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Affiliation(s)
- Sarah C Marteinson
- Ecotoxicology & Wildlife Health Division, Science & Technology Branch, Environment Canada, Burlington, Ontario, Canada
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30
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Ruuskanen S, Doligez B, Pitala N, Gustafsson L, Laaksonen T. Long-term fitness consequences of high yolk androgen levels: sons pay the costs. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.01994.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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DeVries MS, Holbrook AL, Winters CP, Jawor JM. Non-breeding gonadal testosterone production of male and female northern cardinals (Cardinalis cardinalis) following GnRH challenge. Gen Comp Endocrinol 2011; 174:370-8. [PMID: 21986087 DOI: 10.1016/j.ygcen.2011.09.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 09/18/2011] [Accepted: 09/25/2011] [Indexed: 10/17/2022]
Abstract
Yearly, testosterone (T) levels fluctuate as many vertebrates cycle through reproductive and non-reproductive periods. Among many temperate birds, it is well established that levels of T peak as gonads recrudesce for breeding and then fall as gonads regress prior to the non-breeding season. While the tissues producing breeding season T are well studied, the tissues responsible for non-breeding T have received less investigative attention. We examined the ability of male and female Northern Cardinals (Cardinalis cardinalis) to elevate gonadal T following standardized injections of gonadotropin-releasing hormone (GnRH) across three non-breeding seasons. Males and females were capable of significantly elevating gonadal T production following GnRH injections during periods of reproductive quiescence. The magnitude of T elevation varied across the non-breeding season, but not between sexes. To our knowledge, this is the first report of a significant increase in gonadal T production following GnRH injections administered in the non-breeding season.
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Affiliation(s)
- M Susan DeVries
- Department of Biological Sciences, The University of Southern Mississippi, 118 College Drive # 5018, Hattiesburg, MS 39406, USA.
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Pinson SE, Wilson JL, Navara KJ. Elevated testosterone during meiotic segregation stimulates laying hens to produce more sons than daughters. Gen Comp Endocrinol 2011; 174:195-201. [PMID: 21925503 DOI: 10.1016/j.ygcen.2011.08.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 08/22/2011] [Accepted: 08/24/2011] [Indexed: 11/25/2022]
Abstract
Biases in avian sex ratios have been documented in relation to a variety of social and environmental conditions. Previous studies suggest that treatment with hormones can stimulate females to manipulate offspring sex, and that this effect occurs before ovulation. For example, acute and chronic treatments with testosterone stimulated significant skews towards male offspring. Hormones may act by influencing which sex chromosome is donated by the heterogametic female bird into the oocyte. However, it is difficult to pinpoint when effects of testosterone on offspring sex occurred in previous experiments because testosterone treatments were given either chronically over the entire period of follicular development or many hours before the critical period of chromosome segregation. We injected laying hens with testosterone injections 5 h prior to ovulation to target this critical period and quantified the sexes of the subsequently ovulated eggs. We hypothesized that an injection of testosterone coincident with segregation of sex chromosomes would stimulate hens to produce more male than female offspring. As hypothesized, hens injected with testosterone produced a significant bias towards male offspring compared to controls, nearly 70%. These results suggest that acute testosterone elevation during meiotic segregation may mediate skews in avian primary sex ratios.
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Affiliation(s)
- Sara E Pinson
- Department of Poultry Science, University of Georgia, Athens, GA 30602, USA.
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Competitive females are successful females; phenotype, mechanism and selection in a common songbird. Behav Ecol Sociobiol 2011; 66:241-252. [PMID: 22345899 DOI: 10.1007/s00265-011-1272-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In a variety of taxa, male reproductive success is positively related to expression of costly traits such as large body size, ornaments, armaments, and aggression. These traits are thought to improve male competitive ability, and thus access to limited reproductive resources. Females of many species also express competitive traits. However, we know very little about the consequences of individual variation in competitive traits and the mechanisms that regulate their expression in females. Consequently, it is currently unclear whether females express competitive traits owing to direct selection or as an indirect result of selection on males. Here we examine females of a mildly dimorphic songbird (Junco hyemalis) to determine whether females, show positive covariance in traits (morphology and behavior) that may be important in a competition. We also examine whether trait expression relates either to testosterone (T) in terms of mechanism or to reproductive success in terms of function. We found that larger females were more aggressive and that greater ability to produce T in response to a physiological challenge consisting of a standardized injection of gonadotropin releasing hormone (GnRH) predicted some measures of female body size and aggression. Finally, we found that aggressive females had greater reproductive success. We conclude that testosterone may influence female phenotype and that females may benefit from expressing a competitive phenotype. We also suggest that the mild dimorphism observed in many species may be due in part to direct selection on females rather than simply a correlated response to selection in males.
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34
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Grant VJ, Konečná M, Sonnweber RS, Irwin RJ, Wallner B. Macaque mothers’ preconception testosterone levels relate to dominance and to sex of offspring. Anim Behav 2011. [DOI: 10.1016/j.anbehav.2011.07.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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GnRH--a missing link between testosterone concentrations in yolk and plasma and its intergenerational effects. PLoS One 2011; 6:e22675. [PMID: 21829476 PMCID: PMC3145665 DOI: 10.1371/journal.pone.0022675] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/30/2011] [Indexed: 12/02/2022] Open
Abstract
Despite the strong interest in hormone-mediated maternal effects two key questions concerning their mechanisms are as yet unanswered: First, whether the deposition of hormones in the egg yolk is coupled with the levels of these hormones in the maternal circulation, and second, whether epigenetic changes as induced by embryonic exposure to maternal yolk hormones impinge on yolk hormone deposition at adulthood. We investigated the responsiveness to gonadotropin-releasing hormone (GnRH) in female canaries whose embryonic exposure to yolk testosterone had been manipulated. This enabled us to study to what extent GnRH interlinks testosterone concentrations in female circulation and egg yolk as well as the intergenerational potential of hormone-mediated maternal effects. As expected, canary females responded to GnRH with a rise in plasma testosterone. The GnRH-responsiveness was positively correlated with the yolk testosterone content. Factors stimulating the release of GnRH will, therefore, lead to an increase of testosterone in both plasma and egg, posing a potential constraint on the yolk hormone deposition due to testosterone related trade-offs within the laying female. Exposure to elevated yolk testosterone levels as embryo reduced the GnRH-responsiveness in adulthood, potentially limiting environmental influences on yolk testosterone deposition, but the concentrations of yolk testosterone itself were not affected.
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Pryke SR, Rollins LA, Buttemer WA, Griffith SC. Maternal stress to partner quality is linked to adaptive offspring sex ratio adjustment. Behav Ecol 2011. [DOI: 10.1093/beheco/arr040] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Correa SM, Horan CM, Johnson PA, Adkins-Regan E. Copulatory behaviors and body condition predict post-mating female hormone concentrations, fertilization success, and primary sex ratios in Japanese quail. Horm Behav 2011; 59:556-64. [PMID: 21376051 DOI: 10.1016/j.yhbeh.2011.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 02/10/2011] [Accepted: 02/11/2011] [Indexed: 11/20/2022]
Abstract
Environmental cues and social interactions are known to influence reproductive physiology and behavior in vertebrates. In female birds, male courtship displays can result in the growth of ovarian follicles, the production of reproductive hormones, and stimulation of oviduct development, all of which have the potential to influence maternal investment. Male Japanese quail follow a typical sequence of copulatory behaviors during a mating interaction and often force copulations with unreceptive females. We hypothesized that female Japanese quail could adjust maternal investment in response to male copulatory behaviors during a single mating interaction. We investigated the relationships between 1) male copulatory behaviors and post-mating concentrations of steroids in the female, 2) female steroid concentrations and fertilization success of inseminations and 3) female steroid concentrations and the offspring sex ratio. We found that male condition and copulatory behaviors predicted female steroid concentrations and maternal investment in eggs laid after a mating trial. The body condition of one or both mates was a significant predictor of the changes in female corticosterone and testosterone concentrations after mating, whereas specific male copulatory behaviors significantly predicted changes in female progesterone concentrations. Male and female body condition, male neck grabs and post-mating concentrations of female corticosterone, progesterone, and testosterone were all significant predictors of egg fertilization rates. Female body condition, male copulation efficiency, and female testosterone concentrations were significant predictors of offspring sex ratios. Our results show that phenotypic and behavioral characteristics of male Japanese quail modulate female steroid concentrations and result in changes in maternal investment.
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Affiliation(s)
- Stephanie M Correa
- Department of Neurobiology & Behavior, Cornell University, Ithaca, NY 14853, USA.
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Dama MS, Singh NMP, Rajender S. High fat diet prevents over-crowding induced decrease of sex ratio in mice. PLoS One 2011; 6:e16296. [PMID: 21283594 PMCID: PMC3026815 DOI: 10.1371/journal.pone.0016296] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 12/20/2010] [Indexed: 12/02/2022] Open
Abstract
Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. In the present study, we tested the effect of housing mice under crowded condition on the sex ratio and whether the fat content of the diet has any influence on the outcome of pregnancies. Three-week-old mice were placed on the control diet (NFD) for 3 weeks. Thereafter the mice were allotted randomly to two groups of 7 cages each with 4, 6, 8, 10, 12, 14, and 16 mice in every cage to create increasing crowding gradient and fed either NFD or high fat diet (HFD). After 4 weeks, dams were bred and outcomes of pregnancy were analyzed. The average dam body weight (DBW) at conception, litter size (LS) and SR were significantly higher in HFD fed dams. Further, male biased litters declined with increasing crowding in NFD group but not in HFD. The LS and SR in NFD declined significantly with increasing crowding, whereas only LS was reduced in HFD group. We conclude that female mice housed under overcrowding conditions shift offspring SR in favor of daughters in consistent with the TW hypothesis and high fat diet reduces this influence of overcrowding.
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Affiliation(s)
- Madhukar Shivajirao Dama
- Division of Endocrinology, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
| | - Negi Mahendra Pal Singh
- Biometry and Statistics Division, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
| | - Singh Rajender
- Division of Endocrinology, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
- * E-mail:
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Erikstad KE, Moum T, Bustnes JO, Reiertsen TK. High levels of organochlorines may affect hatching sex ratio and hatchling body mass in arctic glaucous gulls. Funct Ecol 2010. [DOI: 10.1111/j.1365-2435.2010.01771.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kjell Einar Erikstad
- Norwegian Institute for Nature Research, Department of Arctic Ecology, The Polar Environmental Centre, N‐9286 Tromsø, Norway
| | - Truls Moum
- Faculty of Biosciences and Aquaculture, Bodø University College, N‐8049 Bodø, Norway
| | - Jan O. Bustnes
- Norwegian Institute for Nature Research, Department of Arctic Ecology, The Polar Environmental Centre, N‐9286 Tromsø, Norway
| | - Tone K. Reiertsen
- Department of Natural Sciences, Tromsø University Museum, 9037 Tromsø, Norway
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Goerlich V, Dijkstra C, Boonekamp J, Groothuis T. Change in Body Mass Can Overrule the Effects of Maternal Testosterone on Primary Offspring Sex Ratio of First Eggs in Homing Pigeons. Physiol Biochem Zool 2010; 83:490-500. [DOI: 10.1086/651315] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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41
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Goerlich VC, Dijkstra C, Groothuis TGG. Effects of in vivo testosterone manipulation on ovarian morphology, follicular development, and follicle yolk testosterone in the homing pigeon. ACTA ACUST UNITED AC 2010; 313:328-38. [DOI: 10.1002/jez.600] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Polo V, López-Rull I, Gil D, Veiga JP. Experimental Addition of Green Plants to the Nest Increases Testosterone Levels in Female Spotless Starlings. Ethology 2010. [DOI: 10.1111/j.1439-0310.2009.01724.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Isaksson C, Magrath MJL, Groothuis TGG, Komdeur J. Androgens during development in a bird species with extremely sexually dimorphic growth, the brown songlark, Cinclorhamphus cruralis. Gen Comp Endocrinol 2010; 165:97-103. [PMID: 19539628 DOI: 10.1016/j.ygcen.2009.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 06/06/2009] [Accepted: 06/12/2009] [Indexed: 11/27/2022]
Abstract
In birds, early exposure to androgens has been shown to influence offspring growth and begging behaviour, and has been proposed as a mechanism for the development of sexual size dimorphism (SSD). Sex specific effects during development can occur due to sex-specific allocation of maternal androgens, sensitivity to, or synthesis of, androgens. In addition, maternal hormones have been suggested as a mechanism to skew brood sex ratio. This study uses one of the world's most extreme SSD species, the brown songlark Cinclorhamphus cruralis, to investigate (1) sex-specific differences of androgens in yolk and chick plasma and (2) the relationship between androgens and sex ratio bias. The study reveals no indication of sex-specific maternal allocation, but a modest sex effect during the later stages of incubation when the embryo starts to produce its own androgens. Moreover, there was a strong seasonal sex ratio bias: female-biased early and male-biased later in the season, but yolk testosterone (T) did not show a seasonal trend. Taken together these results suggest that if androgens, from any source, have a significant role in development of SSD in this species it is most likely via sex-specific sensitivity or synthesis rather than differential maternal transfer to the egg.
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Affiliation(s)
- C Isaksson
- Centre for Ecological and Evolutionary Studies, University of Groningen, Haren, The Netherlands.
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Tschirren B, Sendecka J, Groothuis TGG, Gustafsson L, Doligez B. Heritable variation in maternal yolk hormone transfer in a wild bird population. Am Nat 2009; 174:557-64. [PMID: 19737108 DOI: 10.1086/605379] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Differential reproductive investment by the mother can critically influence offspring development and phenotype, and strong selection is therefore expected to act on such maternal effects. Although a genetic basis is a prerequisite for phenotypic traits to respond to selection and thus to evolve, we still know very little about the extent of heritable variation in maternal effects in natural populations. Here, we present the first estimates of intrafemale repeatability across breeding seasons and estimates of heritability of hormone-mediated maternal effects in a wild population of collared flycatchers (Ficedula albicollis). We found that maternal yolk testosterone (T) concentrations, yolk mass, and egg mass were moderately to highly repeatable within females across years, whereas intrafemale consistency of maternal yolk androstenedione (A4) deposition was low yet statistically significant. Furthermore, maternal yolk T transfer, yolk mass, and egg mass were significantly heritable, whereas yolk A4 transfer was not. These results strongly suggest that two major maternal yolk androgens are differentially regulated by genes and the environment. Selection on heritable variation in maternal yolk T deposition has the potential to shape the rate and direction of phenotypic change in offspring traits and can thereby accelerate or impede the response to selection in natural populations.
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Affiliation(s)
- Barbara Tschirren
- Department of Animal Ecology, Lund University, Sölvegatan 37, 22362 Lund, Sweden.
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Elevated testosterone levels affect female breeding success and yolk androgen deposition in a passerine bird. Behav Processes 2009; 82:312-8. [DOI: 10.1016/j.beproc.2009.07.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 07/22/2009] [Accepted: 07/26/2009] [Indexed: 11/21/2022]
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Goerlich VC, Dijkstra C, Schaafsma SM, Groothuis TGG. Testosterone has a long-term effect on primary sex ratio of first eggs in pigeons--in search of a mechanism. Gen Comp Endocrinol 2009; 163:184-92. [PMID: 19344666 DOI: 10.1016/j.ygcen.2009.01.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 12/18/2008] [Accepted: 01/13/2009] [Indexed: 11/19/2022]
Abstract
Despite accumulating evidence that birds, in which females are the heterogametic sex, are able to manipulate primary offspring sex ratio, the underlying mechanism remains elusive. Steroid hormones, which govern female reproduction and are also accumulated by the developing follicle could potentially affect primary sex ratio by differential follicle development in relation to future sex and meiotic drive, or by sex specific influence on oocyte abortion or fertilization. So far, experimental results on the involvement of maternal testosterone (T) in offspring sex manipulation are ambiguous. To investigate the effect of T on primary sex ratio and elucidate underlying mechanisms, we elevated circulating T levels in female homing pigeons (Columba livia). During the course of the experiment females produced three clutches--before and during T implantation, and one year after implant removal. Intriguingly, first eggs, but not second eggs of T females were significantly male biased relative to sham-implanted controls. One year after cessation of the treatment the male bias was still present, indicating long-term effects on female reproductive physiology. T treatment did not affect maternal body condition, nor was body condition correlated with offspring sex ratio. Our data on timing of oviposition, lack of infertile eggs, and yolk weight indicate a possible role for sex specific follicle abortion, perhaps in combination with meiotic drive. However, despite T treatment elevating maternal plasma levels, egg yolk T concentrations did not differ between treatment groups and did not vary with embryo sex, suggesting that yolk T is not involved in meiotic drive.
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Affiliation(s)
- V C Goerlich
- Behavioral Biology, University of Groningen, Kerklaan 30, P.O. Box 14, 9750 AA Haren, The Netherlands.
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Jacot A, Valcu M, van Oers K, Kempenaers B. Experimental nest site limitation affects reproductive strategies and parental investment in a hole-nesting passerine. Anim Behav 2009. [DOI: 10.1016/j.anbehav.2009.01.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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James WH. The variances of the distributions of the combinations of the sexes within mammalian litters: notes to mark the centenary of the problem. J Theor Biol 2009; 259:264-8. [PMID: 19336236 DOI: 10.1016/j.jtbi.2009.03.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2008] [Revised: 02/19/2009] [Accepted: 03/13/2009] [Indexed: 11/16/2022]
Abstract
It is 100 years since Gini noted that in some samples of litters of mice and rabbits, the variances of the distributions of the combinations of the sexes are sub-binomial. In other words, in contrast with binomial expectation, there are too many litters in which the sexes are equally balanced, and there are too few unisexual litters. In the intervening years, this finding has been replicated in a number of further species, but no explanation has become established. Potential explanations are reviewed here, and it is suggested that the most likely cause is that, at the time of formation of the zygotes, p, the probability that a zygote will be male, varies from one zygote to another within litters, thus constituting an example of Poisson variation. And it is a standard result in probability theory that such variation causes sub-binomial variance.
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Affiliation(s)
- William H James
- The Galton Laboratory, Department of Genetics, Evolution and Environment, University College London, Wolfson House, 4 Stephenson Way, London NW 1 2 HE, UK.
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