1
|
Kumar S, Song R, Mishra JS. Elevated gestational testosterone impacts vascular and uteroplacental function. Placenta 2023:S0143-4004(23)00598-2. [PMID: 37977936 PMCID: PMC11087376 DOI: 10.1016/j.placenta.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
Maternal vascular adaptations to establish an adequate blood supply to the uterus and placenta are essential for optimal nutrient and oxygen delivery to the developing fetus in eutherian mammals, including humans. Numerous factors contribute to maintaining appropriate hemodynamics and placental vascular development throughout pregnancy. Failure to achieve or sustain these pregnancy-associated changes in women is strongly associated with an increased risk of antenatal complications, such as preeclampsia, a hypertensive disorder of pregnancy. The precise etiology of preeclampsia is unknown, but emerging evidence points to a potential role for androgens. The association between androgens and maternal cardiovascular and placental function merits particular attention due to the notable 2- to 3-fold elevated plasma testosterone (T) levels observed in preeclampsia. T levels in preeclamptic women positively correlate with vascular dysfunction, and preeclampsia is associated with increased androgen receptor (AR) levels in placental tissues. Moreover, animal studies replicating the pattern and magnitude of T increase observed in preeclamptic pregnancies have reproduced key features of preeclampsia, including gestational hypertension, endothelial dysfunction, heightened vasoconstriction to angiotensin II, impaired spiral artery remodeling, placental hypoxia, reduced nutrient transport, and fetal growth restriction. Collectively, these findings suggest that AR-mediated activity plays a significant role in the clinical presentation of preeclampsia. This review critically evaluates this hypothesis, considering both clinical and preclinical evidence.
Collapse
Affiliation(s)
- Sathish Kumar
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706, USA; Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53792, USA.
| | - Ruolin Song
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706, USA
| | - Jay S Mishra
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706, USA
| |
Collapse
|
2
|
Firman RC, Ellis CM, Thorn S, Mawson PR. Parental effects on offspring sex ratio in the Numbat ( Myrmecobius fasciatus): does captivity influence paternal sex allocation? J Mammal 2023; 104:1036-1046. [PMID: 38033358 PMCID: PMC10682968 DOI: 10.1093/jmammal/gyad067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 06/03/2023] [Indexed: 12/02/2023] Open
Abstract
Sex allocation theories predict that under different ecological conditions the production of sons and daughters will affect parental fitness differently. Skewed offspring sex ratios often occur under captive conditions where individuals are exposed to nutritional and social conditions that differ from nature. Here, we analyzed 29 years of offspring sex ratio data from a captive population of an endangered marsupial, the Numbat (Myrmecobius fasciatus). We partitioned variation in offspring sex ratio based on parental origin (captive- vs. wild-bred), parental weight, maternal age, and maternal reproductive history. Our analyses revealed no effect of parental weight or maternal origin on offspring sex ratio-however, there was a significant effect of paternal origin. Data visualization indicated that captive-bred males tended to produce male-biased litters. We discuss the result in relation to recent studies that have shown that male mammals have the capacity to be arbiters of sex allocation and highlight candidate mechanisms, but consider it with caution due to the small sample size from which the result was derived. We performed a population viability analysis (PVA) to explore the potential impact of a sex ratio skew on the sustainability of the captive Numbat population under hypothetical scenarios. Our PVA revealed that supplementation with wild individuals is critical to the persistence of the captive Numbat population and that a biased sex ratio will lead to extinction of the captive colony under certain conditions. Overall, our study demonstrates that covert sex ratio skews can persist undetected in captive populations, which have the potential to become impactful and compromise population sustainability under changed management processes.
Collapse
Affiliation(s)
- Renée C Firman
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
- School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
| | - Connor M Ellis
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
- School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
| | - Sian Thorn
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
| | - Peter R Mawson
- School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
- Perth Zoo, Department of Biodiversity, Conservation and Attractions, 20 Labouchere Road, South Perth, Western Australia 6151, Australia
| |
Collapse
|
3
|
Evidence that Murciano-Granadina does with longer anogenital distance are more fertile and prolific and produce heavier and male-biased litters. Anim Reprod Sci 2022; 244:107047. [DOI: 10.1016/j.anireprosci.2022.107047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 06/13/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022]
|
4
|
Naidu SJ, Arangasamy A, Selvaraju S, Binsila BK, Reddy IJ, Ravindra JP, Bhatta R. Maternal influence on the skewing of offspring sex ratio: a review. ANIMAL PRODUCTION SCIENCE 2022. [DOI: 10.1071/an21086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
5
|
OUP accepted manuscript. J Mammal 2022. [DOI: 10.1093/jmammal/gyac041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
6
|
Haines BA, Barradale F, Dumont BL. Patterns and mechanisms of sex ratio distortion in the Collaborative Cross mouse mapping population. Genetics 2021; 219:6355587. [PMID: 34740238 DOI: 10.1093/genetics/iyab136] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/09/2021] [Indexed: 11/12/2022] Open
Abstract
In species with single-locus, chromosome-based mechanisms of sex determination, the laws of segregation predict an equal ratio of females to males at birth. Here, we show that departures from this Mendelian expectation are commonplace in the 8-way recombinant inbred Collaborative Cross (CC) mouse population. More than one-third of CC strains exhibit significant sex ratio distortion (SRD) at wean, with twice as many male-biased than female-biased strains. We show that these pervasive sex biases persist across multiple breeding environments, are stable over time, and are not mediated by random maternal effects. SRD exhibits a heritable component, but QTL mapping analyses fail to nominate any large effect loci. These findings, combined with the reported absence of sex ratio biases in the CC founder strains, suggest that SRD manifests from multilocus combinations of alleles only uncovered in recombined CC genomes. We explore several potential complex genetic mechanisms for SRD, including allelic interactions leading to sex-biased lethality, genetic sex reversal, chromosome drive mediated by sex-linked selfish elements, and incompatibilities between specific maternal and paternal genotypes. We show that no one mechanism offers a singular explanation for this population-wide SRD. Instead, our data present preliminary evidence for the action of distinct mechanisms of SRD at play in different strains. Taken together, our work exposes the pervasiveness of SRD in the CC population and nominates the CC as a powerful resource for investigating diverse genetic causes of biased sex chromosome transmission.
Collapse
Affiliation(s)
| | | | - Beth L Dumont
- The Jackson Laboratory, Bar Harbor, ME 04609, USA.,Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| |
Collapse
|
7
|
Brandimarti ME, Gray R, Coulson G, Cripps JK, Wilson ME, Death C, Snape M, Wimpenny C, Silva FRO, Miller EJ, Scanes E, Spielman D, Thomas G, Herbert CA. Reference intervals for parameters of health of eastern grey kangaroos Macropus giganteus and management implications across their geographic range. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Maquel E. Brandimarti
- M. E. Brandimarti (https://orcid.org/0000-0002-4055-6623) ✉ , G. Thomas, C. A. Herbert (https://orcid.org/0000-0003-0174-0898), F. R. O. Silva and E. Scanes (https://orcid.org/0000-0001-7520-3804), School of Life and
| | - Rachael Gray
- R. Gray and D. Spielman, Sydney School of Veterinary Science, The Univ. of Sydney, Camperdown, New South Wales, Australia
| | - Graeme Coulson
- G. Coulson (https://orcid.org/0000-0001-9873-8203), J. K. Cripps (https://orcid.org/0000-0003-3049-5510) and M. E. Wilson, School of BioSciences, The Univ. of Melbourne, Melbourne, Victoria, Australia. JKC also at: Dept of Environment, Land, Water an
| | - Jemma K. Cripps
- G. Coulson (https://orcid.org/0000-0001-9873-8203), J. K. Cripps (https://orcid.org/0000-0003-3049-5510) and M. E. Wilson, School of BioSciences, The Univ. of Melbourne, Melbourne, Victoria, Australia. JKC also at: Dept of Environment, Land, Water an
| | - Michelle E. Wilson
- G. Coulson (https://orcid.org/0000-0001-9873-8203), J. K. Cripps (https://orcid.org/0000-0003-3049-5510) and M. E. Wilson, School of BioSciences, The Univ. of Melbourne, Melbourne, Victoria, Australia. JKC also at: Dept of Environment, Land, Water an
| | - Clare Death
- C. Death, Faculty of Veterinary and Agricultural Sciences, The Univ. of Melbourne, Werribee, Victoria, Australia
| | - Melissa Snape
- M. Snape and C. Wimpenny, Conservation Research, Environment, Planning and Sustainable Development Directorate, ACT Government, Canberra, ACT, Australia
| | - Claire Wimpenny
- M. Snape and C. Wimpenny, Conservation Research, Environment, Planning and Sustainable Development Directorate, ACT Government, Canberra, ACT, Australia
| | - Fabiola Rodrigues Oliveira Silva
- M. E. Brandimarti (https://orcid.org/0000-0002-4055-6623) ✉ , G. Thomas, C. A. Herbert (https://orcid.org/0000-0003-0174-0898), F. R. O. Silva and E. Scanes (https://orcid.org/0000-0001-7520-3804), School of Life and
| | - Emily J. Miller
- E. J. Miller, The Univ. of Sydney, Camperdown, New South Wales, Australia
| | - Elliot Scanes
- M. E. Brandimarti (https://orcid.org/0000-0002-4055-6623) ✉ , G. Thomas, C. A. Herbert (https://orcid.org/0000-0003-0174-0898), F. R. O. Silva and E. Scanes (https://orcid.org/0000-0001-7520-3804), School of Life and
| | - Derek Spielman
- R. Gray and D. Spielman, Sydney School of Veterinary Science, The Univ. of Sydney, Camperdown, New South Wales, Australia
| | - Georgia Thomas
- M. E. Brandimarti (https://orcid.org/0000-0002-4055-6623) ✉ , G. Thomas, C. A. Herbert (https://orcid.org/0000-0003-0174-0898), F. R. O. Silva and E. Scanes (https://orcid.org/0000-0001-7520-3804), School of Life and
| | - Catherine A. Herbert
- M. E. Brandimarti (https://orcid.org/0000-0002-4055-6623) ✉ , G. Thomas, C. A. Herbert (https://orcid.org/0000-0003-0174-0898), F. R. O. Silva and E. Scanes (https://orcid.org/0000-0001-7520-3804), School of Life and
| |
Collapse
|
8
|
Firman RC. Exposure to high male density causes maternal stress and female-biased sex ratios in a mammal. Proc Biol Sci 2020; 287:20192909. [PMID: 32370673 PMCID: PMC7282911 DOI: 10.1098/rspb.2019.2909] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/14/2020] [Indexed: 12/29/2022] Open
Abstract
A shift from the traditional perspective that maternal stress is invariably costly has instigated recent interest into its adaptive role in offspring sex allocation. Stress generated by social instability has been linked to offspring sex ratio biases that favour the production of female offspring, which converges with the theoretical prediction that mothers in the poor condition are better off investing in daughters rather than sons. However, previous research has failed to disentangle two different processes: the passive consequence of maternal stress on sex-specific mortality and the adaptive effect of maternal stress at the time of conception. Here, I show that exposure to high male density social conditions leads to elevated stress hormone levels and female-biased in utero offspring sex ratios in house mice (Mus musculus domesticus), and identify that sex-specific offspring production-not sex-specific mortality-is the mechanism accounting for these sex ratio skews. This outcome reflects the optimal fitness scenario for mothers in a male-dominated environment: the production of daughters, who are guaranteed high mate availability, minimizes male-male competition for their sons. Overall, this study supports the idea that maternal stress has the potential to be adaptive and advances our understanding of how exposure to different social conditions can influence sex allocation in mammals.
Collapse
Affiliation(s)
- Renée C. Firman
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
| |
Collapse
|
9
|
Perret M. Litter sex composition affects first reproduction in female grey mouse lemurs (Microcebus murinus). Physiol Behav 2019; 208:112575. [DOI: 10.1016/j.physbeh.2019.112575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/05/2019] [Accepted: 06/05/2019] [Indexed: 01/25/2023]
|
10
|
Fishman R, Vortman Y, Shanas U, Koren L. Non-model species deliver a non-model result: Nutria female fetuses neighboring males in utero have lower testosterone. Horm Behav 2019; 111:105-109. [PMID: 30790563 DOI: 10.1016/j.yhbeh.2019.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 01/06/2019] [Accepted: 02/14/2019] [Indexed: 12/15/2022]
Abstract
Neighboring fetuses may impact their siblings in various respects, depending on their in utero location and sex. The effects of the intrauterine position (IUP) are widely studied in model organisms, especially laboratory bred murine strains that are characterized by short gestations and altricial offspring. In some species, the proximity to a male fetus and its higher circulating testosterone masculinizes neighboring female fetuses. In utero testosterone exposure might be manifested as higher testosterone concentrations, which contribute to a variation in morphology, reproductive potential and behavior. In this study, we examined the influence of neighboring an opposite sex fetus on testosterone levels in a feral animal model characterized by a long gestation and precocious offspring. Using necropsies of culled nutria (Myocastor coypus), we accurately determined the IUP and quantified testosterone immunoreactivity in fetal hair. We found that as expected, both male and female fetuses neighboring a male in utero had longer anogenital distance. However, females adjacent to males in utero showed lower testosterone levels than male fetuses, while testosterone levels of females without a male neighbor did not differ from those of males. This surprising result suggests an alternative mode by which local exogenous steroids may modify the local fetal environment. Our study emphasizes the importance of examining known phenomena in species with different life histories, other than the traditional murine models, to enhance our understanding of the evolutionary mechanisms that are driving sexual differentiation.
Collapse
Affiliation(s)
- Ruth Fishman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yoni Vortman
- Hula Research Center, Department of Animal Sciences, Tel-Hai College, Upper Galilee 1220800, Israel
| | - Uri Shanas
- Faculty of Life Sciences, University of Haifa-Oranim, Tivon 3600600, Israel
| | - Lee Koren
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| |
Collapse
|
11
|
The Adaptive Sex in Stressful Environments. Trends Ecol Evol 2019; 34:628-640. [PMID: 30952545 DOI: 10.1016/j.tree.2019.02.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/18/2019] [Accepted: 02/19/2019] [Indexed: 01/10/2023]
Abstract
The impact of early stress on juvenile development has intrigued scientists for decades, but the adaptive significance of such effects remains an ongoing debate. This debate has largely ignored some characteristics of the offspring, such as their sex, despite strong evolutionary and demographic implications of sex-ratio variation. We review recent studies that examine associations between glucocorticoids (GCs), the main class of stress hormones, and offspring sex. Whereas exposure to GCs at around the time of sex determination in fish consistently produces males, the extent and direction of sex-ratio bias in response to stress vary in reptiles, birds, and mammals. We propose proximate and ultimate explanations for most of these trends.
Collapse
|
12
|
Female-biased sex ratios are associated with higher maternal testosterone levels in nutria (Myocastor coypus). Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2517-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
13
|
Wells C, Van Vuren D. Female kin density affects offspring sex ratio in an asocial mammal, the golden-mantled ground squirrel, Callospermophilus lateralis. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
14
|
Affiliation(s)
- Mathieu Douhard
- Département de Biologie; Université de Sherbrooke; 2500 boulevard de l’ Université Sherbrooke QC J1K 2R1 Canada
| |
Collapse
|
15
|
|
16
|
Douhard M. Offspring sex ratio in mammals and the Trivers-Willard hypothesis: In pursuit of unambiguous evidence. Bioessays 2017; 39. [DOI: 10.1002/bies.201700043] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Mathieu Douhard
- Département de Biologie; Université de Sherbrooke; Sherbrooke Québec Canada
| |
Collapse
|
17
|
Cameron EZ, Edwards AM, Parsley LM. Developmental sexual dimorphism and the evolution of mechanisms for adjustment of sex ratios in mammals. Ann N Y Acad Sci 2016; 1389:147-163. [PMID: 27862006 DOI: 10.1111/nyas.13288] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/28/2016] [Accepted: 10/05/2016] [Indexed: 12/15/2022]
Abstract
Sex allocation theory predicts biased offspring sex ratios in relation to local conditions if they would maximize parental lifetime reproductive return. In mammals, the extent of the birth sex bias is often unpredictable and inconsistent, leading some to question its evolutionary significance. For facultative adjustment of sex ratios to occur, males and females would need to be detectably different from an early developmental stage, but classic sexual dimorphism arises from hormonal influences after gonadal development. Recent advances in our understanding of early, pregonadal sexual dimorphism, however, indicate high levels of dimorphism in gene expression, caused by chromosomal rather than hormonal differences. Here, we discuss how such dimorphism would interact with and link previously hypothesized mechanisms for sex-ratio adjustment. These differences between males and females are sufficient for offspring sex both to be detectable to parents and to provide selectable cues for biasing sex ratios from the earliest stages. We suggest ways in which future research could use the advances in our understanding of sexually dimorphic developmental physiology to test the evolutionary significance of sex allocation in mammals. Such an approach would advance our understanding of sex allocation and could be applied to other taxa.
Collapse
Affiliation(s)
- Elissa Z Cameron
- School of Biological Sciences, University of Tasmania, Hobart, Australia.,School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Amy M Edwards
- School of Biological Sciences, University of Tasmania, Hobart, Australia
| | - Laura M Parsley
- School of Biological Sciences, University of Tasmania, Hobart, Australia
| |
Collapse
|
18
|
Edwards AM, Cameron EZ, Pereira JC, Wapstra E, Ferguson-Smith MA, Horton SR, Thomasson K. Gestational experience alters sex allocation in the subsequent generation. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160210. [PMID: 27493776 PMCID: PMC4968468 DOI: 10.1098/rsos.160210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/08/2016] [Indexed: 06/06/2023]
Abstract
Empirical tests of adaptive maternal sex allocation hypotheses have presented inconsistent results in mammals. The possibility that mothers are constrained in their ability to adjust sex ratios could explain some of the remaining variation. Maternal effects, the influence of the maternal phenotype or genotype on her developing offspring, may constrain sex allocation through physiological changes in response to the gestational environment. We tested if maternal effects constrain future parental sex allocation through a lowered gestational stress environment in laboratory mice. Females that experienced lowered stress as embryos in utero gave birth to female-biased litters as adults, with no change to litter size. Changes in offspring sex ratio was linked to peri-conceptual glucose, as those females that had increasing blood glucose peri-conceptionally gave birth to litters with a higher male to female sex ratio. There was, however, no effect of the lowered prenatal stress for developing male embryos and their sperm sex ratio when adult. We discuss the implications of maternal effects and maternal stress environment on the lifelong physiology of the offspring, particularly as a constraint on later maternal sex allocation.
Collapse
Affiliation(s)
- A. M. Edwards
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - E. Z. Cameron
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - J. C. Pereira
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
- Cytocell Ltd., Cambridge Technopark, Newmarket Road, Cambridge, UK
| | - E. Wapstra
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | | | - S. R. Horton
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - K. Thomasson
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| |
Collapse
|
19
|
Arnon L, Hazut N, Tabachnik T, Weller A, Koren L. Maternal testosterone and reproductive outcome in a rat model of obesity. Theriogenology 2016; 86:1042-1047. [PMID: 27125699 DOI: 10.1016/j.theriogenology.2016.03.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/15/2016] [Accepted: 03/19/2016] [Indexed: 01/22/2023]
Abstract
Global sex differences in obesity rates are persistent, suggesting the involvement of sex steroids. In addition, adipose tissue is a metabolic site for steroidogenesis. Here, we compared female reproductive parameters in a rat model of obesity, with the same parameters in its lean control strain, and tested for an association with integrated measures of corticosterone and testosterone. Steroids were extracted and quantified from 17 Otsuka Long Evans Tokushima Fatty (OLETF; an animal model for obesity) and 13 Long Evans Tokushima Otsuka (LETO; the lean control strain) hair samples that were collected after weaning offspring. The obese OLETF mothers had higher hair testosterone levels than the control LETO strain. Overall, testosterone, but not corticosterone, predicted litter sex ratios. Younger mothers with large litters and older mothers with small litters tended to have the highest sex ratios (i.e., male-biased litters). In the lean LETO strain, but not in the obese OLETF, maternal testosterone was positively associated with litter size and number of male pups. Corticosterone did not differ between the two strains and was not associated with testosterone or with reproductive parameters. This study suggests that long-term circulating testosterone is associated with female reproduction in multiple ways. The possible trade-off between litter size and sex ratio may be mediated by testosterone and influenced by body fat and composition, which influence the individual's well-being. Exploring the multiple roles of testosterone in females may also help explain the complex relationship between obesity and reproduction.
Collapse
Affiliation(s)
- Liat Arnon
- Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Noa Hazut
- Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel; Gonda Brain Research Center, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Tzlil Tabachnik
- Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel; Gonda Brain Research Center, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Aron Weller
- Gonda Brain Research Center, Bar Ilan University, Ramat-Gan 5290002, Israel; Department of Psychology, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Lee Koren
- Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel.
| |
Collapse
|
20
|
Are there physiological constraints on maternal ability to adjust sex ratios in mammals? J Zool (1987) 2016. [DOI: 10.1111/jzo.12327] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
21
|
Gaukler SM, Ruff JS, Potts WK. Paroxetine exposure skews litter sex ratios in mice suggesting a Trivers-Willard process. Behav Ecol 2016; 27:1113-1121. [PMID: 27418753 DOI: 10.1093/beheco/arw017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 12/10/2015] [Accepted: 01/23/2016] [Indexed: 12/26/2022] Open
Abstract
While conducting a toxicity assessment of the antidepressant paroxetine (Paxil®), in wild-derived mice (Mus musculus), we observed that exposed dams (P0) produced female biased litters (32:68 M:F). Though numerous experimental manipulations have induced sex ratio bias in mice, none have assessed the fitness of the offspring from these litters relative to controls. Here, we retrospectively analyze experimentally derived fitness data gathered for the purpose of toxicological assessment in light of 2 leading hypothesis (Trivers-Willard hypothesis [TWH] and cost of reproduction hypothesis [CRH]), seeking to test if this facultative sex ratio adjustment fits into an adaptive framework. Control F1 males were heavier than F1 females, but no differences in mass were detected between exposed F1 males and females, suggesting that exposed dams did not save energy by producing fewer males, despite producing 29.2% lighter litters relative to controls. F1 offspring of both treatments were released into seminatural enclosures where fitness was quantified. In enclosures, the relative reproductive success of F1-exposed males (compared with controls) was reduced by ~20% compared with the relative reproductive success of F1-exposed females. Thus, exposed dams increased their fitness by adjusting litters toward females who were less negatively affected by the exposure than males. Collectively, these data provide less support that the observed sex ratio bias results in energetic savings (CRH), and more support for the TWH because fitness was increased by biasing litters toward female offspring. These mammalian data are unique in their ability to support the TWH through the use of relevant fitness data.
Collapse
Affiliation(s)
- Shannon Marie Gaukler
- Department of Biology, University of Utah , 257 South 1400 East, Salt Lake City, UT 84112 , USA
| | - James Steven Ruff
- Department of Biology, University of Utah , 257 South 1400 East, Salt Lake City, UT 84112 , USA
| | - Wayne K Potts
- Department of Biology, University of Utah , 257 South 1400 East, Salt Lake City, UT 84112 , USA
| |
Collapse
|
22
|
Douhard M, Festa-Bianchet M, Coltman DW, Pelletier F. Paternal reproductive success drives sex allocation in a wild mammal. Evolution 2016; 70:358-68. [DOI: 10.1111/evo.12860] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/10/2016] [Indexed: 01/08/2023]
Affiliation(s)
- Mathieu Douhard
- Département de biologie and Centre d’Études Nordiques; Université de Sherbrooke; 2500 boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada
| | - Marco Festa-Bianchet
- Département de biologie and Centre d’Études Nordiques; Université de Sherbrooke; 2500 boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada
| | - David W. Coltman
- Department of Biological Sciences; University of Alberta; Edmonton Alberta T6G 2E9 Canada
| | - Fanie Pelletier
- Département de biologie and Centre d’Études Nordiques; Université de Sherbrooke; 2500 boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada
| |
Collapse
|
23
|
Kim TB, Oh JK, Kim KT, Yoon SJ, Kim SW. Does the Mother or Father Determine the Offspring Sex Ratio? Investigating the Relationship between Maternal Digit Ratio and Offspring Sex Ratio. PLoS One 2015; 10:e0143054. [PMID: 26575995 PMCID: PMC4648576 DOI: 10.1371/journal.pone.0143054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 10/30/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE In mammals, high parental testosterone levels present around the time of conception are thought to skew offspring sex ratio toward sons. The second to fourth digit ratio (digit ratio) is now widely accepted as a negative correlate of prenatal testosterone. Thus, we investigated the association between digit ratio and offspring sex ratio. METHODS A total of 508 Korean patients (257 males and 251 females) less than 60 years old who had one or more offspring were prospectively enrolled. The lengths of the 2nd and 4th digits of the right hand were measured by a single investigator using a digital vernier calliper. Next, the patients' lifetime offspring birth sex ratios were investigated. RESULTS Maternal (rather than paternal) digit ratio was significantly associated with the number of sons (r = -0.153, p = 0.015), number of daughters (r = 0.130, p = 0.039), and offspring sex ratio (r = -0.171, p = 0.007). And, the maternal digit ratio was a significant factor for predicting offspring sex ratio (B = -1.620, p = 0.008) on multiple linear regression analysis. The female patients with a lower digit ratio (< 0.95) were found to have a higher offspring sex ratio (0.609 versus 0.521, p = 0.046) compared to those with a higher digit ratio (≥ 0.95). Furthermore, females in the low digit ratio group have a probability 1.138 greater of having sons than females in the high digit ratio group. CONCLUSIONS Maternal digit ratio was negatively associated with offspring sex ratio. Females with a lower digit ratio were more likely to have more male offspring compared to those with a higher digit ratio. Thus, our results suggest that the sex of offspring might be more influenced by maternal rather than paternal factors.
Collapse
Affiliation(s)
- Tae Beom Kim
- Department of Urology, Gachon University Gil Hospital, Incheon, Republic of Korea
| | - Jin Kyu Oh
- Department of Urology, Gachon University Gil Hospital, Incheon, Republic of Korea
| | - Kwang Taek Kim
- Department of Urology, Gachon University Gil Hospital, Incheon, Republic of Korea
| | - Sang Jin Yoon
- Department of Urology, Gachon University Gil Hospital, Incheon, Republic of Korea
| | - Soo Woong Kim
- Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea
- * E-mail:
| |
Collapse
|
24
|
Booksmythe I, Mautz B, Davis J, Nakagawa S, Jennions MD. Facultative adjustment of the offspring sex ratio and male attractiveness: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2015; 92:108-134. [DOI: 10.1111/brv.12220] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 08/09/2015] [Accepted: 08/28/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Isobel Booksmythe
- Division of Evolution, Ecology & Genetics; Research School of Biology, The Australian National University; Daley road Canberra Australian Capital Territory 2601 Australia
- Department of Animal Ecology; Evolutionary Biology Centre, Uppsala University; Norbyvägen 18D SE-75236 Uppsala Sweden
- Institute of Evolutionary Biology and Environmental Studies; University of Zürich; Winterthurerstrasse 190 CH-8057 Zürich Switzerland
| | - Brian Mautz
- Division of Evolution, Ecology & Genetics; Research School of Biology, The Australian National University; Daley road Canberra Australian Capital Territory 2601 Australia
- Department of Animal Ecology; Evolutionary Biology Centre, Uppsala University; Norbyvägen 18D SE-75236 Uppsala Sweden
| | - Jacqueline Davis
- Division of Evolution, Ecology & Genetics; Research School of Biology, The Australian National University; Daley road Canberra Australian Capital Territory 2601 Australia
- Department of Psychology; University of Cambridge; Downing Street CB2 3EB Cambridge U.K
| | - Shinichi Nakagawa
- Department of Zoology; University of Otago; PO Box 56 Dunedin 9054 New Zealand
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences; University of New South Wales; Sydney New South Wales 2052 Australia
| | - Michael D. Jennions
- Division of Evolution, Ecology & Genetics; Research School of Biology, The Australian National University; Daley road Canberra Australian Capital Territory 2601 Australia
| |
Collapse
|
25
|
Moore EPB, Hayward M, Robert KA. High density, maternal condition, and stress are associated with male-biased sex allocation in a marsupial. J Mammal 2015. [DOI: 10.1093/jmammal/gyv129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
26
|
Setchell JM, Smith TE, Knapp LA. Androgens in a female primate: Relationships with reproductive status, age, dominance rank, fetal sex and secondary sexual color. Physiol Behav 2015; 147:245-54. [DOI: 10.1016/j.physbeh.2015.04.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 11/25/2022]
|
27
|
Rezagholizadeh A, Gharagozlou F, Akbarinejad V, Youssefi R. Left-Sided Ovulation Favors More Male Foals Than Right-Sided Ovulation in Thoroughbred Mares. J Equine Vet Sci 2015. [DOI: 10.1016/j.jevs.2014.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
28
|
Schnettler S, Klüsener S. Economic stress or random variation? Revisiting German reunification as a natural experiment to investigate the effect of economic contraction on sex ratios at birth. Environ Health 2014; 13:117. [PMID: 25533777 PMCID: PMC4391084 DOI: 10.1186/1476-069x-13-117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 12/04/2014] [Indexed: 06/04/2023]
Abstract
BACKGROUND The economic stress hypothesis (ESH) predicts decreases in the sex ratio at birth (SRB) following economic decline. However, as many factors influence the SRB, this hypothesis is difficult to test empirically. Thus, researchers make use of quasi-experiments such as German reunification: The economy in East, but not in West Germany, underwent a rapid decline in 1991. A co-occurrence of a decline in the East German SRB in 1991 has been interpreted by some as support for the ESH. However, another explanation might be that the low SRB in 1991 stems from increased random variation in the East German SRB due to a drastically reduced number of births during the crisis. We look into this alternative random variation hypothesis (RVH) by re-examining the German case with more detailed data. METHODS Our analysis has two parts. First, using aggregate-level birth register data for all births in the period between 1946 and 2011, we plot the quantum and variance of the SRB and the number of births and unemployment rates, separately for East and West Germany, and conduct a time series analysis on the East German SRB over time. Second, we model the odds for a male birth at the individual level in a multiple logistic regression (1991-2010, ~13.9 million births). Explanatory variables are related to the level of the individual birth, the mother of the child born, and the regional economic context. RESULTS The aggregate-level analysis reveals a higher degree of variation of the SRB in East Germany. Deviations from the time trend occur in several years, seemingly unrelated to economic development, and the deviation in 1991 is not statistically significant. The individual-level analysis confirms that the 1991-drop in the East German SRB cannot directly be attributed to economic development and that there is no statistically significant effect of economic development on sex determination in East or West Germany. CONCLUSION Outcomes support the RVH but not the ESH. Furthermore, our results speak against a statistically significant effect of the reunification event itself on the East German SRB. We discuss the relative importance of behavioral and physiological responses to macro-level stressors, a distinction that may help integrate previously mixed findings.
Collapse
Affiliation(s)
- Sebastian Schnettler
- Department of Sociology, University of Konstanz, Box 40, Universitätsstr. 10, 78457, Konstanz, Germany.
| | - Sebastian Klüsener
- Max Planck Institute for Demographic Research, Konrad-Zuse-Str. 1, 18057, Rostock, Germany.
| |
Collapse
|
29
|
Emadi SR, Rezaei A, Bolourchi M, Hovareshti P, Akbarinejad V. Administration of estradiol benzoate before insemination could skew secondary sex ratio toward males in Holstein dairy cows. Domest Anim Endocrinol 2014; 48:110-8. [PMID: 24906936 DOI: 10.1016/j.domaniend.2014.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 11/21/2022]
Abstract
The present study was conducted to investigate the effect of estradiol benzoate administration before insemination on secondary sex ratio (proportion of male calves at birth) in Holstein dairy cows. Cows (n = 1,647) were randomly assigned to 2 experimental groups by parity over a 1-yr period. Cows in the control group (n = 827; 232 primiparous and 595 multiparous cows) received 2 administrations of PGF2α (500 μg) 14 d apart, started at 30 to 35 d postpartum. Twelve d after the second PGF2α injection, cows received GnRH (100 μg), followed by administration of PGF2α 7 d later. Cows in the treatment group (n = 820; 238 primiparous and 582 multiparous cows) received the same hormonal administrations as the cows in the control group. Additionally, cows in the treatment group received estradiol benzoate (1 mg) 1 d after the third PGF2α injection. Estrus detection by visual observation was started 1 d after the third PGF2α injection and after estradiol administration in the control (for 6 d) and treatment (for 36 h) groups, respectively. Artificial insemination was carried out 12 h after observation of standing estrus. Exposure of cows to heat stress at conception was determined based on temperature-humidity index. Estrus detection rate was lower in primiparous than in multiparous cows (P < 0.05), but conception rate was higher in primiparous vs multiparous cows (P < 0.05). Estradiol administration improved estrus detection rate and fertility (P < 0.05); moreover, it increased secondary sex ratio (adjusted odds ratio: 1.645; P = 0.017). Exposure to heat stress diminished heat detection rate and fertility (P < 0.05), and altered secondary sex ratio toward males (adjusted odds ratio: 2.863; P = 0.012). In conclusion, the present study revealed that estradiol administration before insemination could improve fertility and increase the probability of calves being male in Holstein dairy cows. Moreover, the results showed that cows exposed to heat stress around conception had diminished fertility and increased secondary sex ratio.
Collapse
Affiliation(s)
- S R Emadi
- Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran; Theriogenology Association, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - A Rezaei
- Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - M Bolourchi
- Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - P Hovareshti
- Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - V Akbarinejad
- Young Researchers and Elites Club, North Tehran Branch, Islamic Azad University, Tehran, Iran.
| |
Collapse
|
30
|
Law PR, Fike B, Lent PC. Birth sex in an expanding black rhinoceros (Diceros bicornis minor) population. J Mammal 2014. [DOI: 10.1644/13-mamm-a-175] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
31
|
Schwanz LE, Robert KA. Proximate and ultimate explanations of mammalian sex allocation in a marsupial model. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1720-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
Gharagozlou F, Vojgani M, Akbarinejad V, Niasari-Naslaji A, Hemmati M, Youssefi R. Parallel distribution of sexes within left and right uterine horns in Holstein dairy cows: Evidence that the effect of side of pregnancy on sex ratio could be breed-specific in cattle. Anim Reprod Sci 2013; 142:101-5. [DOI: 10.1016/j.anireprosci.2013.09.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 09/22/2013] [Accepted: 09/30/2013] [Indexed: 11/17/2022]
|
33
|
Szenczi P, Bánszegi O, Groó Z, Altbäcker V. Anogenital distance and condition as predictors of litter sex ratio in two mouse species: a study of the house mouse (Mus musculus) and mound-building mouse (Mus spicilegus). PLoS One 2013; 8:e74066. [PMID: 24069268 PMCID: PMC3777973 DOI: 10.1371/journal.pone.0074066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/30/2013] [Indexed: 11/23/2022] Open
Abstract
The Trivers - Willard hypothesis (1973) suggests that the maternal condition may affect the female's litter size and sex ratio. Since then other factors had been found. Previous findings revealed in the case of some mammalian species, that females with larger anogenital distance have smaller litters, while the sex ratio is male-biased. That has only been demonstrated in laboratory animals, while the genetic diversity of a wild population could mask the phenomenon seen in laboratory colonies. We examined the connection between morphological traits (weight and anogenital distance) and the reproductive capacity of two wild mice species, the house mouse and the mound-building mice. We showed in both species that anogenital distance and body weight correlated positively in pre-pubertal females, but not in adults. Neither the house mouse nor the mound-building mouse mothers' weight had effect on their litter's size and sex ratio. Otherwise connection was found between the mothers' anogenital distance and their litters' sex ratio in both species. The results revealed that females with larger anogenital distance delivered male biased litter in both species. The bias occurred as while the number of female pups remained the same; mothers with large anogenital distance delivered more male pups compared to the mothers with small anogenital distance. We concluded that a female's prenatal life affects her reproductive success more than previously anticipated.
Collapse
Affiliation(s)
- Péter Szenczi
- Department of Ethology, Eötvös Loránd University, Göd, Hungary
| | - Oxána Bánszegi
- Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zita Groó
- Department of Ethology, Eötvös Loránd University, Göd, Hungary
| | | |
Collapse
|
34
|
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.
Collapse
Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
35
|
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.
Collapse
Affiliation(s)
- M Aamir Aslam
- Animal Breeding and Genomics Centre, Wageningen UR Livestock Research, PO Box 65, 8200 AB Lelystad, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Maner JK, Miller SL, Coyle JM, Kaschak MP. Confronting Intrasexual Rivals. SOCIAL PSYCHOLOGICAL AND PERSONALITY SCIENCE 2013. [DOI: 10.1177/1948550613488948] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The current research sheds light on a physiological mechanism potentially underlying confrontational responses to infidelity. Findings suggest that responses to infidelity threats in adulthood are shaped by hormonally mediated masculinization of the brain in utero. 2D:4D digit ratio (widely regarded as an index of prenatal testosterone exposure) moderated behavioral and endocrinological responses to infidelity threat. After an infidelity prime (but not a control prime), lower (more masculine) 2D:4D was associated with a greater tendency to approach attractive same-sex targets (intrasexual rivals) and with heightened increases in circulating testosterone, a hormone related to a variety of aggressive and confrontational behaviors.
Collapse
|
37
|
Helle S, Laaksonen T, Huitu O. Sex-specific offspring growth according to maternal testosterone, corticosterone, and glucose levels. Behav Ecol 2012. [DOI: 10.1093/beheco/ars155] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
38
|
Influence of selected (pre-)maturational parameters on in vitro development and sex distribution of bovine embryos. ZYGOTE 2012; 22:41-9. [PMID: 22784675 DOI: 10.1017/s0967199412000275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The objectives of this research were to study the influence of a reduced oxygen concentration during in vitro maturation (IVM) and examine the effect of follicular glucose concentration on bovine in vitro development and sex distribution. In the first experiment, abattoir-derived cumulus-oocyte complexes (COC) were matured under 5% O2 or 20% O2. Secondly, COC were isolated and the glucose (G) concentration of each follicle was determined. COC were pooled in groups (G (< 1.1 mMol) or G (≥ 1.1 mMol)) according to the glucose content before being subjected to in vitro production (IVP). Cleavage and development rates were assessed on days 3, 7 and 8 post insemination. Blastocysts of each group were sexed by polymerase chain reaction (PCR). Expanded blastocysts were stained to assess total cell numbers and live-dead cell ratio. Cleavage and development rates stayed similar after reducing the O2 concentration during IVM. The sex ratio of embryos generated from oocytes matured under 5% O2 was shifted in favour of the female (♀: 61.9%), whereas the sex ratio of embryos belonging to the IVM 20% O2 group did not differ significantly from the expected 50:50 ratio. Neither a 'higher' nor a 'lower' intrafollicular glucose concentration influenced cleavage and development rates, cell numbers or live-dead cell ratio. Eighty five per cent (G (<1.1)) and 63.6% (G (≥ 1.1)) of the analysed embryos were female. In summary, neither a reduced O2 concentration during IVM nor selection based on follicular glucose concentrations affected the morphological quality of embryos. Although the sex distribution was shifted in favour of female embryos in all three experimental groups, more male embryos could be seen in the G (≥ 1.1) group compared with the G(<1.1) group.
Collapse
|
39
|
Ryan CP, Anderson WG, Gardiner LE, Hare JF. Stress-induced sex ratios in ground squirrels: support for a mechanistic hypothesis. Behav Ecol 2011. [DOI: 10.1093/beheco/arr169] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
40
|
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]
|
41
|
Marealle WN, Fossøy F, Holmern T, Stokke BG, Røskaft E. Does illegal hunting skew Serengeti wildlife sex ratios? WILDLIFE BIOLOGY 2010. [DOI: 10.2981/10-035] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
|
42
|
ROBERT KA, SCHWANZ LE. Emerging sex allocation research in mammals: marsupials and the pouch advantage. Mamm Rev 2010. [DOI: 10.1111/j.1365-2907.2010.00168.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]
|
43
|
Grant VJ, Chamley LW. Can mammalian mothers influence the sex of their offspring peri-conceptually? Reproduction 2010; 140:425-33. [PMID: 20591970 DOI: 10.1530/rep-10-0137] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Although controversial, growing evidence from evolutionary biology suggests that the mammalian mother may have a role in influencing the sex of her offspring. However, there is competing information on the molecular mechanisms by which such influence could be manifested. The new initiatives are based on hypotheses from evolutionary biology: the 'good condition' hypothesis, which suggests that post conception, higher levels of maternal glucose may differentially promote the development of male embryos; and the 'maternal dominance' hypothesis, which proposes that before conception, higher follicular testosterone may influence the development of the ovum so that it emerges already adapted to receive an X- or a Y-chromosome-bearing spermatozoon. Now, it seems these hypothesised mechanisms could be operating in synchrony, each complementing and reinforcing the other. On the other hand, there are continuing problems in identifying a precise sequence of mechanisms as evidenced from research in sperm-sorting. Research on high-fat diets and the sex ratio in polytocous species may indicate important differences in proximate mechanisms for sex allocation between polytocous and monotocous mammals.
Collapse
Affiliation(s)
- Valerie J Grant
- Department of Psychological Medicine Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | | |
Collapse
|
44
|
Navara KJ. Programming of offspring sex ratios by maternal stress in humans: assessment of physiological mechanisms using a comparative approach. J Comp Physiol B 2010; 180:785-96. [PMID: 20544204 DOI: 10.1007/s00360-010-0483-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 05/18/2010] [Accepted: 05/20/2010] [Indexed: 01/23/2023]
Abstract
Sex ratio adjustment has become a hot topic in ecology and evolutionary biology, as documentations of sex ratio skews are numerous, and include examples in diverse animal species. Over the past several decades, scientists have repeatedly debated whether human sex ratios also significantly deviate toward one sex or the other based on environmental or social conditions. An increasing number of studies supports the idea that exposure to stressful conditions can influence the sexes of offspring produced by humans, a majority of which document significantly fewer males after exposure to adverse conditions such as severe life events, economic disruption, or natural disasters. From a comparative standpoint, these findings are similar to studies in non-human mammals and other vertebrate species showing a bias toward females during times of stress. However, the mechanisms by which stress-related biases in the offspring sex ratio may occur remain elusive, and the involvement of glucocorticoids indicating a true influence of stress itself remains unstudied. Here, I review the evidence that stressful events induce sex ratio adjustment in humans. Additionally, I discuss the possibility for glucocorticoid mediation of sex ratio adjustment and the potential reproductive stages during which stress-induced sex ratio adjustment may occur in humans and other mammals.
Collapse
Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, 203 Poultry Science Building, 110 Cedar Street, Athens, GA 30605, USA.
| |
Collapse
|
45
|
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]
|
46
|
Sex determines the expression level of one third of the actively expressed genes in bovine blastocysts. Proc Natl Acad Sci U S A 2010; 107:3394-9. [PMID: 20133684 DOI: 10.1073/pnas.0913843107] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although genetically identical for autosomal Chrs (Chr), male and female preimplantation embryos could display sex-specific transcriptional regulation. To illustrate sex-specific differences at the mRNA level, we compared gene-expression patterns between male and female blastocysts by DNA microarray comparison of nine groups of 60 bovine in vitro-produced blastocysts of each sex. Almost one-third of the transcripts detected showed sexual dimorphism (2,921 transcripts; false-discovery rate, P < 0.05), suggesting that in the absence of hormonal influences, the sex Chrs impose an extensive transcriptional regulation upon autosomal genes. Six genes were analyzed by qPCR in in vivo-derived embryos, which displayed similar sexual dimorphism. Ontology analysis suggested a higher global transcriptional level in females and a more active protein metabolism in males. A gene homolog to an X-linked gene involved in network interactions during spliceosome assembly was found in the Y-Chr. Most of the X-linked-expressed transcripts (88.5%) were up-regulated in females, but most of them (70%) exhibited fold-changes lower than 1.6, suggesting that X-Chr inactivation is partially achieved at the blastocyst stage. Almost half of the transcripts up-regulated in female embryos exhibiting more than 1.6-fold change were present in the X-Chr and eight of them were selected to determine a putative paternal imprinting by gene expression comparison with parthenogenetic embryos. Five (BEX, CAPN6, BEX2, SRPX2, and UBE2A) exhibited a higher expression in females than in parthenotes, suggesting that they are predominantly expressed by the paternal inherited X-Chr and that imprinting may increase the transcriptional skew caused by double X-Chr dosage.
Collapse
|
47
|
Grant VJ. Wartime sex ratios: Stress, male vulnerability and the interpretation of atypical sex ratio data. ACTA ACUST UNITED AC 2009. [DOI: 10.1556/jep.7.2009.4.5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
48
|
Lilley T, Laaksonen T, Huitu O, Helle S. Maternal corticosterone but not testosterone level is associated with the ratio of second-to-fourth digit length (2D:4D) in field vole offspring (Microtus agrestis). Physiol Behav 2009; 99:433-7. [PMID: 19958785 DOI: 10.1016/j.physbeh.2009.11.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 09/07/2009] [Accepted: 11/23/2009] [Indexed: 01/23/2023]
Abstract
The steroid environment encountered by a foetus can strongly affect its post-natal physiology and behaviour. It has been proposed that steroid concentrations experienced in utero could be estimated from adults by measuring their second-to-fourth digit length ratio (2D:4D). However, there is still little direct evidence that intra-uterine steroid levels affect individual 2D:4D. We examined whether maternal pre-pregnancy testosterone and corticosterone levels (as estimates of intra-uterine testosterone and corticosterone exposure) affected the 2D:4D of pups in non-domesticated field voles (Microtus agrestis), measured by X-rays at the age of weaning (21 days). Furthermore, for the first time in a non-human species, we studied whether testosterone and corticosterone levels correlated with 2D:4D in adult females. We found that the maternal pre-pregnancy level of testosterone was not associated with offspring 2D:4D in either the left or the right paw. Instead, maternal pre-pregnancy corticosterone level was positively correlated with offspring 2D:4D in the right paw, but unrelated to 2D:4D in the left paw. In addition, the 2D:4D of adult females was not associated with either their circulating testosterone or corticosterone levels. Our results suggest that in field voles maternally administered testosterone is not a major determinant of offspring 2D:4D, whereas maternal stress appears to account for some of the variation in the 2D:4D of their offspring.
Collapse
Affiliation(s)
- Thomas Lilley
- Section of Ecology, Department of Biology, University of Turku, FI-20014, Turku, Finland.
| | | | | | | |
Collapse
|
49
|
Johannessen LE, Kristiansen L, Hansen BT, Slagsvold T. Facultative Adjustment of Brood Sex Ratio in Response to Indirect Manipulation of Behaviour. Ethology 2009. [DOI: 10.1111/j.1439-0310.2009.01695.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
50
|
Nováková M, Vašáková B, Kutalová H, Galeštoková K, Průšová K, Šmilauer P, Šumbera R, Frynta D. Secondary sex ratios do not support maternal manipulation: extensive data from laboratory colonies of spiny mice (Muridae: Acomys). Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0853-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|