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Jiang G, Xue Y, Huang X. Temperature-Induced Sex Differentiation in River Prawn ( Macrobrachium nipponense): Mechanisms and Effects. Int J Mol Sci 2024; 25:1207. [PMID: 38279207 PMCID: PMC10816446 DOI: 10.3390/ijms25021207] [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: 11/30/2023] [Revised: 01/14/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024] Open
Abstract
Macrobrachium nipponense is gonochoristic and sexually dimorphic. The male prawn grows faster and usually has a larger size than the female. Therefore, a higher male proportion in stock usually results in higher yield. To investigate the impact of temperature on sexual differentiation in M. nipponense, two temperature treatments (26 °C and 31 °C) were conducted. The results showed that compared to the 31 °C treatment (3.20 ± 0.12), the 26 °C treatment displayed a lower female/male ratio (2.20 ± 0.11), which implied that a lower temperature could induce masculinization in M. nipponense. The temperature-sensitive sex differentiation phase was 25-35 days post hatching (DPH) at 26 °C while 15-20 DPH at 31 °C. Transcriptome and qPCR analysis revealed that a lower temperature up-regulated the expression of genes related to androgen secretion, and down-regulated the expressions of genes related to oogonia differentiation. Thirty-one temperature-regulated sex-differentiation genes were identified and the molecular mechanism of temperature-regulated sex differentiation was suggested. The finding of this study indicates that temperature regulation can be proposed as an innovative strategy for improving the culture yield of M. nipponense.
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Affiliation(s)
- Gang Jiang
- Centre for Research on Environmental Ecology and Fish Nutrition (CREEFN) of the Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; (G.J.); (Y.X.)
| | - Yucai Xue
- Centre for Research on Environmental Ecology and Fish Nutrition (CREEFN) of the Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; (G.J.); (Y.X.)
| | - Xuxiong Huang
- Centre for Research on Environmental Ecology and Fish Nutrition (CREEFN) of the Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; (G.J.); (Y.X.)
- Building of China-ASEAN Belt and Road Joint Laboratory on Mariculture Technology and Joint Research on Mariculture Technology, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
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2
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Valli FE, Simoncini MS, González MA, Piña CI. How do maternal androgens and estrogens affect sex determination in reptiles with temperature-dependent sex? Dev Growth Differ 2023; 65:565-576. [PMID: 37603030 DOI: 10.1111/dgd.12887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/22/2023]
Abstract
Temperature sex determination (TSD) in reptiles has been studied to elucidate the mechanisms by which temperature is transformed into a biological signal that determines the sex of the embryo. Temperature is thought to trigger signals that alter gene expression and hormone metabolism, which will determine the development of female or male gonads. In this review, we focus on collecting and discussing important and recent information on the role of maternal steroid hormones in sex determination in oviparous reptiles such as crocodiles, turtles, and lizards that possess TSD. In particular, we focus on maternal androgens and estrogens deposited in the egg yolk and their metabolites that could also influence the sex of offspring. Finally, we suggest guidelines for future research to help clarify the link between maternal steroid hormones and offspring sex.
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Affiliation(s)
- Florencia E Valli
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Melina S Simoncini
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
| | - Marcela A González
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Carlos I Piña
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
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3
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Yu Y, Chen M, Shen ZG. Molecular biological, physiological, cytological, and epigenetic mechanisms of environmental sex differentiation in teleosts: A systematic review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 267:115654. [PMID: 37918334 DOI: 10.1016/j.ecoenv.2023.115654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/04/2023]
Abstract
Human activities have been exerting widespread stress and environmental risks in aquatic ecosystems. Environmental stress, including temperature rise, acidification, hypoxia, light pollution, and crowding, had a considerable negative impact on the life histology of aquatic animals, especially on sex differentiation (SDi) and the resulting sex ratios. Understanding how the sex of fish responds to stressful environments is of great importance for understanding the origin and maintenance of sex, the dynamics of the natural population in the changing world, and the precise application of sex control in aquaculture. This review conducted an exhaustive search of the available literature on the influence of environmental stress (ES) on SDi. Evidence has shown that all types of ES can affect SDi and universally result in an increase in males or masculinization, which has been reported in 100 fish species and 121 cases. Then, this comprehensive review aimed to summarize the molecular biology, physiology, cytology, and epigenetic mechanisms through which ES contributes to male development or masculinization. The relationship between ES and fish SDi from multiple aspects was analyzed, and it was found that environmental sex differentiation (ESDi) is the result of the combined effects of genetic and epigenetic factors, self-physiological regulation, and response to environmental signals, which involves a sophisticated network of various hormones and numerous genes at multiple levels and multiple gradations in bipotential gonads. In both normal male differentiation and ES-induced masculinization, the stress pathway and epigenetic regulation play important roles; however, how they co-regulate SDi is unclear. Evidence suggests that the universal emergence or increase in males in aquatic animals is an adaptation to moderate ES. ES-induced sex reversal should be fully investigated in more fish species and extensively in the wild. The potential aquaculture applications and difficulties associated with ESDi have also been addressed. Finally, the knowledge gaps in the ESDi are presented, which will guide the priorities of future research.
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Affiliation(s)
- Yue Yu
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan, PR China
| | - Min Chen
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan, PR China
| | - Zhi-Gang Shen
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan, PR China.
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4
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Sloat S, Rockman M. Sexual antagonism evolves when autosomes influence offspring sex ratio. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.14.544982. [PMID: 37398423 PMCID: PMC10312671 DOI: 10.1101/2023.06.14.544982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Sex allocation theory generally assumes maternal control of offspring sex and makes few predictions for populations evolving under paternal control. Using population genetic simulations, we show that maternal and paternal control of the sex ratio lead to different equilibrium sex ratios in structured populations. Sex ratios evolved under paternal control are more female biased. This effect is dependent on the population subdivision; fewer founding individuals leads to both more biased sex ratios and a greater difference between the paternal and maternal equilibria. In addition, sexual antagonism evolves in simulations with both maternally- and paternally-acting loci. Maternally-acting loci continuously accumulate ever more female-biasing effects as male-biasing effects accumulate at paternally-acting loci. The difference in evolved sex-ratio equilibria and the evolution of sexual antagonism can be largely explained by differences in the between-group variance of maternal and paternal effects in the founding generation. These theoretical results apply to any system with biparental autosomal influence over offspring sex, opening up an exciting new line of questioning.
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Affiliation(s)
- Solomon Sloat
- Department of Biology and Center for Genomics and Systems Biology, New York University, New York, NY 10003
| | - Matthew Rockman
- Department of Biology and Center for Genomics and Systems Biology, New York University, New York, NY 10003
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Chinn SM, Smyser T, Beasley JC. Variance in offspring sex ratio and maternal allocation in a highly invasive mammal. Ecol Evol 2023; 13:e10136. [PMID: 37250446 PMCID: PMC10213710 DOI: 10.1002/ece3.10136] [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: 03/07/2023] [Revised: 05/01/2023] [Accepted: 05/09/2023] [Indexed: 05/31/2023] Open
Abstract
Skewed sex ratios at birth are widely reported in wild populations, however, the extent to which parents are able to modulate the sex ratio of offspring to maximize their own fitness remains unclear. This is particularly true for highly polytocous species as maximizing fitness may include trade-offs between sex ratio and the size and number of offspring in litters. In such cases, it may be adaptive for mothers to adjust both the number of offspring per litter and offspring sex to maximize individual fitness. Investigating maternal sex allocation in wild pigs (Sus scrofa) under stochastic environmental conditions, we predicted that under favorable conditions, high-quality mothers (larger and older) would produce male-biased litters and invest more in producing larger litters with more males. We also predicted sex ratio would vary relative to litter size, with a male-bias among smaller litters. We found evidence that increasing wild boar ancestry, maternal age and condition, and resource availability may weakly contribute to male-biased sex ratio, however, unknown factors not measured in this study are assumed to be more influential. High-quality mothers allocated more resources to litter production, but this relationship was driven by adjustment of litter size, not sex ratio. There was no relationship between sex ratio and litter size. Collectively, our results emphasized that adjustment of litter size appeared to be the primary reproductive characteristic manipulated in wild pigs to increase fitness rather than adjustment of offspring sex ratio.
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Affiliation(s)
- Sarah M. Chinn
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAikenSouth CarolinaUSA
| | - Timothy Smyser
- National Wildlife Research Center, United States Department of Agriculture, Wildlife ServicesFort CollinsColoradoUSA
| | - James C. Beasley
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAikenSouth CarolinaUSA
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6
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DeVilbiss EA, Purdue-Smithe AC, Sjaarda LA, Taylor BD, Freeman JR, Perkins NJ, Silver RM, Schisterman EF, Mumford SL. The Role of Maternal Preconception Adiposity in Human Offspring Sex and Sex Ratio. Am J Epidemiol 2023; 192:587-599. [PMID: 36460625 PMCID: PMC10404066 DOI: 10.1093/aje/kwac209] [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: 04/04/2022] [Revised: 11/15/2022] [Accepted: 11/30/2022] [Indexed: 12/04/2022] Open
Abstract
We evaluated relationships between preconception adiposity and human offspring sex and sex ratio. Using data from a prospective preconception cohort nested within a randomized controlled trial based at 4 US clinical sites (2006-2012), we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for male:female sex ratio, and log-identity regression to estimate risk differences (RDs) and 95% CIs for male and female livebirth according to preconception adiposity measures. Inverse-probability weights accounted for potential selection bias. Among 603 women attempting pregnancy, there were meaningful reductions in sex ratio for the highest category of each adiposity measure. The lowest sex ratios were observed for obesity (body mass index of ≥30, calculated as weight (kg)/height (m)2, OR = 0.48, 95% CI: 0.26, 0.88) relative to normal body mass index, and the top tertiles (tertile 3) of serum leptin (OR = 0.50, 95% CI: 0.32, 0.80) and skinfold measurements (OR = 0.50, 95% CI: 0.32, 0.79) relative to the lowest tertiles. Reductions were driven by 11-15 fewer male livebirths per 100 women (for obesity, RD = -15, 95% CI: -23, -6.7; for leptin tertile 3, RD = -11, 95% CI: -20, -3.2; and for skinfolds tertile 3, RD = -11, 95% CI: -19, -3.3). We found that relationships between preconception adiposity measures and reduced sex ratio were driven by a reduction in male births.
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Affiliation(s)
- Elizabeth A DeVilbiss
- Correspondence to Dr. Elizabeth DeVilbiss, Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6710B Rockledge Drive, MSC 7004, Bethesda, MD 20892-7004 (e-mail: )
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7
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Palacios MG, Bronikowski AM, Amer A, Gangloff EJ. Transgenerational effects of maternal corticosterone across early life in a viviparous snake. Gen Comp Endocrinol 2023; 331:114162. [PMID: 36356645 DOI: 10.1016/j.ygcen.2022.114162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Glucocorticoids (GCs) are central mediators of vertebrate responses to intrinsic and extrinsic stimuli. Among the sources of variation in circulating GCs are transgenerational effects mediated by mothers. Here we studied potential maternal effects mediated by GCs on offspring phenotype in a live-bearing reptile, the western terrestrial garter snake (Thamnophis elegans). We evaluated the association between baseline corticosterone (CORT) levels during gestation (i.e., preparturition) in field-captured mothers and 1) reproductive success and offspring sex ratios, 2) birth phenotypic traits of offspring born under common-garden laboratory conditions, and 3) neonate (age 3 months) and juvenile (age 12 months) traits of offspring raised under two thermal regimes ('warm' and 'cool') during their first year of life. Reproductive success and offspring sex ratios were not associated with preparturition maternal CORT, but pregnant snakes with higher CORT levels gave birth to smaller, lighter offspring, which tended to grow faster to age three months. Neonate baseline CORT varied with preparturition maternal CORT in a sex-specific manner (positive trend for females, negative for males). Maternal CORT effects on offspring phenotype were no longer detectable in juveniles at age one year. Instead, juvenile phenotypes were most influenced by rearing environment, with offspring raised under the cool regime showing higher baseline CORT and slower growth than those raised under warmer conditions. Our findings support the notion that offspring phenotype might be continuously adjusted in response to environmental cues -both pre- and post-natal- and that the strength of maternal CORT effects declines as offspring develop and experience unique environmental challenges. Our results contribute to a growing literature on transgenerational effects of hormones and help to fill a gap in our knowledge of these effects in ectothermic amniotes.
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Affiliation(s)
- Maria G Palacios
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA; Centro Para el Estudio de Sistemas Marinos, CCT CONICET-CENPAT, Blvd. Brown 2915, Puerto Madryn, Chubut, Argentina.
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA; Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
| | - Ali Amer
- Department of Biological Sciences, Ohio Wesleyan University, Delaware, OH, USA
| | - Eric J Gangloff
- Department of Biological Sciences, Ohio Wesleyan University, Delaware, OH, USA
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8
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Sanmartín-Villar I, Yu X, Cordero-Rivera A. Direct and cross-generational effects of reproduction on fitness and behavioral variability in male-biased environments. Curr Zool 2022. [DOI: 10.1093/cz/zoac045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Population structure determines individuals’ interactions and trade-offs with evolutionary consequences. Male-biased populations increase intrasexual competition and intersexual harassment, reducing female resource acquisition, and thus, resources availability for the following generation. We analyzed direct and cross-generational effects of male harassment in two generations of damselflies (Odonata). We exposed adult females to treatments with different sex-ratio and density (balanced and male-biased) to modify the male harassment level. We analyzed female fecundity, fertility, and number of faecal deposits as an indirect measure of resources acquisition. We studied female flight performance after repeated exposures to males. We analyzed survivorship, development, exploration, thigmotaxis, and feeding latency of larvae produced by the experimental females. In both generations, we analyzed four metrics of behavior: mean value, interindividual differences in plasticity, intra-individual unpredictability, and repeatability. Mating duration increased in male-biased treatment, whereas female resources acquisition and fertility decreased. Females that mated longer showed higher fecundity when they were exposed to balanced treatment, but not if they were exposed to male-biased treatment. Females from the male-biased treatment showed interindividual differences in plasticity and no repeatability in flight performance. Offspring showed balanced sex-ratio and similar survivorship, development, and feeding latency independently of the parental treatment; however, females exposed to male-biased treatment produced offspring with higher differences in exploration plasticity and daughters less explorative and with higher unpredictable thigmotaxis. We propose prolonged copulation as courtship at balanced sex-ratio but a cost to females under male-biased sex-ratio. Cross-generational effects in behavioral variability may be a mechanism to cope with predicted future environments.
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Affiliation(s)
- Iago Sanmartín-Villar
- Universidade de Vigo, ECOEVO Lab, Escola de Enxeñaría Forestal, Campus Universitario A Xunqueira , 36005 Pontevedra, Galiza , Spain
| | - Xin Yu
- Universidade de Vigo, ECOEVO Lab, Escola de Enxeñaría Forestal, Campus Universitario A Xunqueira , 36005 Pontevedra, Galiza , Spain
- College of Life Sciences, Chongqing Normal University , Daxuecheng Middle Rd, Shapingba District, Chongqing 401333 , China
| | - Adolfo Cordero-Rivera
- Universidade de Vigo, ECOEVO Lab, Escola de Enxeñaría Forestal, Campus Universitario A Xunqueira , 36005 Pontevedra, Galiza , Spain
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9
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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.
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Affiliation(s)
| | | | - Beth L Dumont
- The Jackson Laboratory, Bar Harbor, ME 04609, USA.,Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
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10
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Abdulateef SM, Majid AA, Al-Bayer MA, Shawkat SS, Tatar A, Mohammed TT, Abdulateef FM, Al-Ani MQ. Effect of aromatase inhibitors on sex differentiation and embryonic development in chicks. Vet Med Sci 2021; 7:2362-2373. [PMID: 34472216 PMCID: PMC8604131 DOI: 10.1002/vms3.623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background Sexual differentiation can occur after exposure to aromatase into the left gonad at 6.5 days of incubation. Aromatase inhibitors work by inhibiting the action of the aromatase, which converts androgens into estrogens by a process called aromatization. Objectives The aim of this study was to investigate the effect of in ovo exposure to the aromatase inhibitor from tomato and garlic extract on sexual differentiation and embryonic development in chicken embryos. Methods Three hundred eggs divided into five groups: Control 1 (CO; no injection); control 2 distilled water, DW; 0.1 ml/egg); garlic extract (GAR; 0.1 mg/egg); tomato extract (TOM; 0.1 mg/egg); and garlic and tomato extract mixed (ATM, 0.1 ml/egg). The solution was prepared and injected into the albumin from the thin end of the eggs on day five by using a 1 ml syringe with a 23‐gauge needle. The embryonic test (embryo/egg weight) conducted at 7, 14 and 17 days of incubation. After hatching, feather sexing conducted to determine the initial male. Chicks sex was later confirmed on day 42 by an optical microscope lens. Results The results revealed that there was a significant increase (p < 0.01) in embryonic growth traits in all experimental treatments as compared to control treatments. There was a significant increase (p < 0.01) in the percentage of hatchability for all experimental treatments compared to control treatments and a significant increase (p < 0.01) in chick quality including one‐day‐old chick length and body weight. All experimental treatments showed a significant increase (p < 0.01) in the male‐to‐female ratio compared to control treatments. Conclusions The effect of in ovo exposure to aromatase inhibitors stimulated female‐to‐male sex reversal and improved embryonic development.
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Affiliation(s)
- Salwan M Abdulateef
- Animal Production, College of Agriculture, University of Anbar, Ramadi, al-Anbar, Iraq
| | - Ahmad A Majid
- Animal Production, College of Agriculture, University of Anbar, Ramadi, al-Anbar, Iraq
| | - Mohammed A Al-Bayer
- Animal Production, College of Agriculture, University of Anbar, Ramadi, al-Anbar, Iraq
| | - Srwd S Shawkat
- Animal Sciences, College of Agricultural Sciences, University of Sulaimani, Sulaimani, Kurdistan, Iraq
| | - Ahmad Tatar
- Animal Science Research Department, Golestan Agricultural and Natural Resources Research and Education Center, AREEO, Gorgan, Iran
| | - Thafer T Mohammed
- Animal Production, College of Agriculture, University of Anbar, Ramadi, al-Anbar, Iraq
| | - Firas M Abdulateef
- Ministry of Agriculture - Directorate of Anbar Agriculture, Ramadi, Iraq
| | - Mohammed Q Al-Ani
- Department of Biology, College of Science, University of Anbar, Ramadi, al-Anbar, Iraq
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11
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James WH, Grech V. Is exposure to high levels of maternal intrauterine testosterone a causal factor common to male sex, autism, gender dysphoria, and non-right-handedness? Early Hum Dev 2020; 141:104872. [PMID: 31492544 DOI: 10.1016/j.earlhumdev.2019.104872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We present evidence that male sex, autism, gender dysphoria and non-right-handedness share a common cause, viz. high levels of maternal first-trimester intrauterine testosterone. This provides an explanation for the (as yet unexplained) co-occurrences and co-morbidities between these conditions and pathologies.
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Affiliation(s)
- William H James
- Galton Laboratory, Department of Genetics, Evolution and Environment, University College London, United Kingdom of Great Britain and Northern Ireland.
| | - Victor Grech
- Department of Paediatrics, Medical School, Mater Dei Hospital, Malta.
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12
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James WH, Grech V. The significance of the low sex ratios of offspring and of sibs of probands with systemic lupus erythematosus or rheumatoid arthritis. Early Hum Dev 2020; 141:104871. [PMID: 31492546 DOI: 10.1016/j.earlhumdev.2019.104871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
There is good evidence that there are significantly low sex ratios (proportions male) in the offspring of patients with some immune diseases e.g. systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). There is also strong evidence that there are significantly low sex ratios in the sibs of patients with SLE and RA and it has been suggested that the low SLE sib sex ratio may be explained by male fetal loss. However, no explanations for these low sex ratios has been established. Bearing in mind the posited hormonal involvement in immune processes, this paper suggesst an additional potential solution. It is that both the pathology and the sex ratio share a hormonal cause - testosterone. The argument depends on the hormonal hypothesis of sex ratio. This paper will describe the hypothesis and describe its relevance to SLE and RA.
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Affiliation(s)
- William H James
- Galton Laboratory, Department of Genetics, Evolution and Environment, University College London.
| | - Victor Grech
- Department of Paediatrics, Medical School, Mater Dei Hospital, Malta.
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13
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Mulley JF. Greater Loss of Female Embryos During Human Pregnancy: A Novel Mechanism. Bioessays 2019; 41:e1900063. [DOI: 10.1002/bies.201900063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/29/2019] [Indexed: 12/14/2022]
Affiliation(s)
- John F. Mulley
- School of Natural SciencesBangor University Deiniol Road Bangor LL57 2UW UK
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14
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Vanthournout B, Busck MM, Bechsgaard J, Hendrickx F, Schramm A, Bilde T. Male spiders control offspring sex ratio through greater production of female-determining sperm. Proc Biol Sci 2019; 285:rspb.2017.2887. [PMID: 29563266 DOI: 10.1098/rspb.2017.2887] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 02/26/2018] [Indexed: 01/07/2023] Open
Abstract
Sex allocation theory predicts that when sons and daughters have different reproductive values, parents should adjust offspring sex ratio towards the sex with the higher fitness return. Haplo-diploid species directly control offspring sex ratio, but species with chromosomal sex determination (CSD) were presumed to be constrained by Mendelian segregation. There is now increasing evidence that CSD species can adjust sex ratio strategically, but the underlying mechanism is not well understood. One hypothesis states that adaptive control is more likely to evolve in the heterogametic sex through a bias in gamete production. We investigated this hypothesis in males as the heterogametic sex in two social spider species that consistently show adaptive female-biased sex ratio and in one subsocial species that is characterized by equal sex ratio. We quantified the production of male (0) and female (X) determining sperm cells using flow cytometry, and show that males of social species produce significantly more X-carrying sperm than 0-sperm, on average 70%. This is consistent with the production of more daughters. Males of the subsocial species produced a significantly lower bias of 54% X-carrying sperm. We also investigated whether inter-genomic conflict between hosts and their endosymbionts may explain female bias. Next generation sequencing showed that five common genera of bacterial endosymbionts known to affect sex ratio are largely absent, ruling out that endosymbiont bacteria bias sex ratio in social spiders. Our study provides evidence for paternal control over sex allocation through biased gamete production as a mechanism by which the heterogametic sex in CSD species adaptively adjust offspring sex ratio.
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Affiliation(s)
- Bram Vanthournout
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Aarhus C, Denmark.,Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
| | - Mette Marie Busck
- Department of Bioscience, Section for Microbiology, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Aarhus C, Denmark
| | - Jesper Bechsgaard
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Aarhus C, Denmark
| | - Frederik Hendrickx
- Biology Department, Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium.,Entomology Department, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium
| | - Andreas Schramm
- Department of Bioscience, Section for Microbiology, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Aarhus C, Denmark
| | - Trine Bilde
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Aarhus C, Denmark
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15
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Page AE, Myers S, Dyble M, Migliano AB. Why so many Agta boys? Explaining 'extreme' sex ratios in Philippine foragers. EVOLUTIONARY HUMAN SCIENCES 2019; 1:e5. [PMID: 37588404 PMCID: PMC10427305 DOI: 10.1017/ehs.2019.4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Male-biased sex ratios have been observed in multiple small-scale societies. Although intentional and systematic female-biased mortality has been posited as an explanation, there is often a lack of ethnographic evidence of systematic female neglect and/or infanticide. The Agta, a foraging population from the Philippines, have a skewed sex ratio of 1.29 (129 males per 100 females) aged 15 years or under. We hypothesised that this skew was not caused by greater female deaths, but due to an adaptive response, where more males were produced at birth in reaction to high male-biased extrinsic mortality. To test this hypothesis we utilise census, childcare and mortality data from 915 Agta. The Agta's sex ratio is significantly male-biased in the <1 (n = 48, 2:1) and 1-5 year (n = 170, 1.39:1) age cohorts; however, we find no evidence of systematic female neglect in patterns of childcare. Furthermore, the sex ratio decreases over cohorts, becoming balanced by the end of the juvenile period, owing to significantly higher male mortality. Taken together, these results are not supportive of female infanticide or neglect, and instead suggest an adaptive mechanism, acting in utero as a response to male-biased juvenile mortality, following Fisherian principles of equalising parental investment.
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Affiliation(s)
- Abigail E. Page
- Department of Anthropology, University College London, London, UK
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Sarah Myers
- Department of Anthropology, University College London, London, UK
| | - Mark Dyble
- Jesus College, University of Cambridge, Cambridge, UK
| | - Andrea Bamberg Migliano
- Department of Anthropology, University College London, London, UK
- Department of Anthropology, University of Zurich, Zurich, Switzerland
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16
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Rapaport T, Villaseñor FA, Altman RM, Nepomnaschy PA. Sex ratio and maternal age in a natural fertility, subsistence population: Daughters, sons, daughters. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:368-376. [DOI: 10.1002/ajpa.23838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Tomas Rapaport
- Maternal and Child Health Laboratory, Faculty of Health SciencesSimon Fraser University Burnaby British Columbia Canada
| | - Fernando A. Villaseñor
- Maternal and Child Health Laboratory, Faculty of Health SciencesSimon Fraser University Burnaby British Columbia Canada
- Department of Statistics and Actuarial ScienceSimon Fraser University Burnaby British Columbia Canada
| | - Rachel M. Altman
- Department of Statistics and Actuarial ScienceSimon Fraser University Burnaby British Columbia Canada
| | - Pablo A. Nepomnaschy
- Maternal and Child Health Laboratory, Faculty of Health SciencesSimon Fraser University Burnaby British Columbia Canada
- Crawford Laboratory of Evolutionary StudiesSimon Fraser University Burnaby British Columbia Canada
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17
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Health status of the lizard Podarcis siculus (Rafinesque-Schmaltz, 1810) subject to different anthropogenic pressures. C R Biol 2019; 342:81-89. [DOI: 10.1016/j.crvi.2019.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 12/24/2022]
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18
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Wada H, Kriengwatana BP, Steury TD, MacDougall-Shackleton SA. Incubation temperature influences sex ratio and offspring’s body composition in Zebra Finches (Taeniopygia guttata). CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0099] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Incubation temperature has the potential to influence offspring sex, phenotype, and survival, particularly in species with temperature-dependent sex determination. However, relatively little is known about how incubation temperature affects sex ratio and offspring condition in other animals. Incubating birds allocate varying time for egg incubation depending on the parents’ condition and ambient temperature, likely altering nest microclimate. To understand how incubation temperature impacts offspring phenotype in birds, we artificially incubated Zebra Finch (Taeniopygia guttata (Vieillot, 1817)) eggs at 36.2, 37.4, or 38.4 °C during the entire incubation period and examined sex ratio and offspring quality. We found that incubation temperature of 36.2 °C resulted in a greater likelihood of a young being male compared with 37.4 °C, indicating that it is more likely for males to survive until the juvenile stage compared with females in the 36.2 °C group. We also found sex-specific effects of incubation temperature on body composition. Although incubation temperature did not affect fat or lean mass of female young, male offspring from the 38.4 °C group had significantly less lean mass throughout their lives compared with males from 37.4 or 36.2 °C. This study shows that there are sex differences in the effects of incubation temperature, and variable incubation temperature has a capacity to influence offspring secondary sex ratio and body condition in songbirds.
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Affiliation(s)
- Haruka Wada
- Advanced Facility for Avian Research, University of Western Ontario, 32 Wellington Drive, London, ON N6G 4W4, Canada
- Department of Psychology, University of Western Ontario, London, ON N6A 5C2, Canada
- Department of Biological Sciences, Auburn University, 101 Rouse Life Science Building, Auburn, AL 36849, USA
| | - Buddhamas P. Kriengwatana
- Advanced Facility for Avian Research, University of Western Ontario, 32 Wellington Drive, London, ON N6G 4W4, Canada
- Department of Psychology, University of Western Ontario, London, ON N6A 5C2, Canada
| | - Todd D. Steury
- School of Forestry and Wildlife Sciences, Auburn University, 602 Duncan Drive, Auburn, AL 36849, USA
| | - Scott A. MacDougall-Shackleton
- Advanced Facility for Avian Research, University of Western Ontario, 32 Wellington Drive, London, ON N6G 4W4, Canada
- Department of Psychology, University of Western Ontario, London, ON N6A 5C2, Canada
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19
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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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20
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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]
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21
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Sheriff MJ, Bell A, Boonstra R, Dantzer B, Lavergne SG, McGhee KE, MacLeod KJ, Winandy L, Zimmer C, Love OP. Integrating Ecological and Evolutionary Context in the Study of Maternal Stress. Integr Comp Biol 2018; 57:437-449. [PMID: 28957523 DOI: 10.1093/icb/icx105] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Maternal stress can prenatally influence offspring phenotypes and there are an increasing number of ecological studies that are bringing to bear biomedical findings to natural systems. This is resulting in a shift from the perspective that maternal stress is unanimously costly, to one in which maternal stress may be beneficial to offspring. However, this adaptive perspective is in its infancy with much progress to still be made in understanding the role of maternal stress in natural systems. Our aim is to emphasize the importance of the ecological and evolutionary context within which adaptive hypotheses of maternal stress can be evaluated. We present five primary research areas where we think future research can make substantial progress: (1) understanding maternal and offspring control mechanisms that modulate exposure between maternal stress and subsequent offspring phenotype response; (2) understanding the dynamic nature of the interaction between mothers and their environment; (3) integrating offspring phenotypic responses and measuring both maternal and offspring fitness outcomes under real-life (either free-living or semi-natural) conditions; (4) empirically testing these fitness outcomes across relevant spatial and temporal environmental contexts (both pre- and post-natal environments); (5) examining the role of maternal stress effects in human-altered environments-i.e., do they limit or enhance fitness. To make progress, it is critical to understand the role of maternal stress in an ecological context and to do that, we must integrate across physiology, behavior, genetics, and evolution.
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Affiliation(s)
- Michael J Sheriff
- Department of Ecosystem Science and Management, Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Alison Bell
- School of Integrative Biology, Program in Neuroscience, and Program in Ecology, Evolution and Conservation Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana Champaign, IL 61821, USA
| | - Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Ben Dantzer
- Department of Psychology, and Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sophia G Lavergne
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Katie E McGhee
- Department of Biology, the University of the South, Sewanee, TN 37383, USA
| | - Kirsty J MacLeod
- Department of Ecosystem Science and Management, Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, PA 16802, USA
| | - Laurane Winandy
- CNRS, Université Toulouse 3 Paul Sabatier, ENFA, UMR5174 (Laboratoire Évolution and Diversité Biologique), 31077 Toulouse, France.,CNRS, UMR5321, Station d'Ecologie Théorique et Expérimentale, 09200 Moulis, France
| | - Cedric Zimmer
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Oliver P Love
- Department of Biological Sciences, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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22
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van Hooft P, Dougherty ER, Getz WM, Greyling BJ, Zwaan BJ, Bastos ADS. Genetic responsiveness of African buffalo to environmental stressors: A role for epigenetics in balancing autosomal and sex chromosome interactions? PLoS One 2018; 13:e0191481. [PMID: 29415077 PMCID: PMC5802885 DOI: 10.1371/journal.pone.0191481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 01/05/2018] [Indexed: 02/04/2023] Open
Abstract
In the African buffalo (Syncerus caffer) population of the Kruger National Park (South Africa) a primary sex-ratio distorter and a primary sex-ratio suppressor have been shown to occur on the Y chromosome. A subsequent autosomal microsatellite study indicated that two types of deleterious alleles with a negative effect on male body condition, but a positive effect on relative fitness when averaged across sexes and generations, occur genome-wide and at high frequencies in the same population. One type negatively affects body condition of both sexes, while the other acts antagonistically: it negatively affects male but positively affects female body condition. Here we show that high frequencies of male-deleterious alleles are attributable to Y-chromosomal distorter-suppressor pair activity and that these alleles are suppressed in individuals born after three dry pre-birth years, likely through epigenetic modification. Epigenetic suppression was indicated by statistical interactions between pre-birth rainfall, a proxy for parental body condition, and the phenotypic effect of homozygosity/heterozygosity status of microsatellites linked to male-deleterious alleles, while a role for the Y-chromosomal distorter-suppressor pair was indicated by between-sex genetic differences among pre-dispersal calves. We argue that suppression of male-deleterious alleles results in negative frequency-dependent selection of the Y distorter and suppressor; a prerequisite for a stable polymorphism of the Y distorter-suppressor pair. The Y distorter seems to be responsible for positive selection of male-deleterious alleles during resource-rich periods and the Y suppressor for positive selection of these alleles during resource-poor periods. Male-deleterious alleles were also associated with susceptibility to bovine tuberculosis, indicating that Kruger buffalo are sensitive to stressors such as diseases and droughts. We anticipate that future genetic studies on African buffalo will provide important new insights into gene fitness and epigenetic modification in the context of sex-ratio distortion and infectious disease dynamics.
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Affiliation(s)
- Pim van Hooft
- Resource Ecology Group, Wageningen University, Wageningen, The Netherlands
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Hatfield, South Africa
- * E-mail:
| | - Eric R. Dougherty
- Department of Environmental Science Policy & Management, University of California, Berkeley, California, United States of America
| | - Wayne M. Getz
- Department of Environmental Science Policy & Management, University of California, Berkeley, California, United States of America
- School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Barend J. Greyling
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Hatfield, South Africa
- Agricultural Research Council, Irene, South Africa
| | - Bas J. Zwaan
- Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands
| | - Armanda D. S. Bastos
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Hatfield, South Africa
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23
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24
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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.
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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
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25
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Ahmed AA, Musa HH, Sifaldin AZ. Prenatal corticosterone exposure programs growth, behavior, reproductive function and genes in the chicken. ASIAN PACIFIC JOURNAL OF REPRODUCTION 2016. [DOI: 10.1016/j.apjr.2016.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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26
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Sex allocation and secondary sex ratio in Cuban boa (Chilabothrus angulifer): mother's body size affects the ratio between sons and daughters. Naturwissenschaften 2016; 103:48. [PMID: 27216175 DOI: 10.1007/s00114-016-1369-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/23/2016] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
Abstract
Secondary sex ratios of animals with genetically determined sex may considerably deviate from equality. These deviations may be attributed to several proximate and ultimate factors. Sex ratio theory explains some of them as strategic decisions of mothers improving their fitness by selective investment in sons or daughters, e.g. local resource competition hypothesis (LRC) suggests that philopatric females tend to produce litters with male-biased sex ratios to avoid future competition with their daughters. Until now, only little attention has been paid to examine predictions of sex ratio theory in snakes possessing genetic sex determination and exhibiting large variance in allocation of maternal investment. Cuban boa is an endemic viviparous snake producing large-bodied newborns (∼200 g). Extremely high maternal investment in each offspring increases importance of sex allocation. In a captive colony, we collected breeding records of 42 mothers, 62 litters and 306 newborns and examined secondary sex ratios (SR) and sexual size dimorphism (SSD) of newborns. None of the examined morphometric traits of neonates appeared sexually dimorphic. The sex ratio was slightly male biased (174 males versus 132 females) and litter sex ratio significantly decreased with female snout-vent length. We interpret this relationship as an additional support for LRC as competition between mothers and daughters increases with similarity of body sizes between competing snakes.
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27
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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.
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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.
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28
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Verderame M, Limatola E, Scudiero R. Estrogenic contamination by manure fertilizer in organic farming: a case study with the lizard Podarcis sicula. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:105-14. [PMID: 26475047 DOI: 10.1007/s10646-015-1571-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/09/2015] [Indexed: 05/20/2023]
Abstract
In the last years, worldwide organic farming has grown exponentially; as a consequence, the use of animal manure as a soil fertility source has become the principal agricultural choice. However, the use of manure as fertilizer can increase the amount of steroid hormone metabolites in the soil. In southern Italy, lacertidae lizards are the most abundant vertebrate group in agroecosystems and have been identified as potential model species for ecotoxicological studies. The aim of this study was to understand if the manure applied in organic farming has estrogen-like effects in the lizard Podarcis sicula. Adult male lizards were captured in two organic agricultural fields (manure-treated sites) and in an uncultivated field (control site). Lizards from the two organic farms displayed hepatic biosynthetic alterations typical of an estrogenic contamination; hepatocytes contained both vitellogenin and estrogen receptor alpha transcripts and proteins, detected by in situ hybridization and immunocytochemistry. The same cells did not show cadmium, lead and metallothionein accumulation, indicative of the lack of inorganic contamination. These findings suggest that exogenous estrogens, arising from the use of manure, could affect the welfare of wild animals and animal breeding, leading to bioaccumulation of estrogens in food chain, with possible risk for human consumers. For this reason, organic farming should implement the use of sustainable practices such as crop rotation to preserve the soil biological activity, rather than organic manure as fertilizer.
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29
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Iungman JL, Somoza GM, Piña CI. Are Stress-Related Hormones Involved in the Temperature-Dependent Sex Determination of the Broad-Snouted Caiman? SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2015. [DOI: 10.2994/sajh-d-14-00027.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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30
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Marcó MVP, Piña CI, Somoza GM, Jahn GA, Pietrobon EO, Iungman JL. Corticosterone Plasma Levels of Embryo and Hatchling Broad-Snouted Caimans (Caiman latirostris) Incubated at Different Temperatures. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2015. [DOI: 10.2994/sajh-d-14-00026.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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31
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Abstract
Sex chromosome drivers are selfish elements that subvert Mendel's first law of segregation and therefore are overrepresented among the products of meiosis. The sex-biased progeny produced then fuels an extended genetic conflict between the driver and the rest of the genome. Many examples of sex chromosome drive are known, but the occurrence of this phenomenon is probably largely underestimated because of the difficulty to detect it. Remarkably, nearly all sex chromosome drivers are found in two clades, Rodentia and Diptera. Although very little is known about the molecular and cellular mechanisms of drive, epigenetic processes such as chromatin regulation could be involved in many instances. Yet, its evolutionary consequences are far-reaching, from the evolution of mating systems and sex determination to the emergence of new species.
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Affiliation(s)
- Quentin Helleu
- Laboratoire Évolution Génomes et Spéciation, CNRS UPR9034, Gif-sur-Yvette, France and Université Paris-Sud, Orsay, France
| | - Pierre R Gérard
- Laboratoire Évolution Génomes et Spéciation, CNRS UPR9034, Gif-sur-Yvette, France and Université Paris-Sud, Orsay, France
| | - Catherine Montchamp-Moreau
- Laboratoire Évolution Génomes et Spéciation, CNRS UPR9034, Gif-sur-Yvette, France and Université Paris-Sud, Orsay, France
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Navara KJ. Low Gestational Weight Gain Skews Human Sex Ratios towards Females. PLoS One 2014; 9:e114304. [PMID: 25493647 PMCID: PMC4262407 DOI: 10.1371/journal.pone.0114304] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 11/08/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Human males are more vulnerable to adverse conditions than females starting early in gestation and continuing throughout life, and previous studies show that severe food restriction can influence the sex ratios of human births. It remains unclear, however, whether subtle differences in caloric intake during gestation alter survival of fetuses in a sex-specific way. I hypothesized that the ratio of male to female babies born should vary with the amount of weight gained during gestation. I predicted that women who gain low amounts of weight during gestation should produce significantly more females, and that, if gestational weight gain directly influences sex ratios, fetal losses would be more likely to be male when women gain inadequate amounts of weight during pregnancy. METHODS I analyzed data collected from over 68 million births over 23 years to test for a relationship between gestational weight gain and natal sex ratios, as well as between gestational weight gain and sex ratios of fetal deaths at five gestational ages. RESULTS Gestational weight gain and the proportion of male births were positively correlated; a lower proportion of males was produced by women who gained less weight and this strong pattern was exhibited in four human races. Further, sex ratios of fetal losses at 6 months of gestation were significantly male-biased when mothers had gained low amounts of weight during pregnancy, suggesting that low caloric intake during early fetal development can stimulate the loss of male fetuses. CONCLUSION My data indicate that human sex ratios change in response to resource availability via sex-specific fetal loss, and that a pivotal time for influences on male survival is early in fetal development, at 6 months of gestation.
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Affiliation(s)
- Kristen J. Navara
- Department of Poultry Science, The University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Shen ZG, Wang HP. Molecular players involved in temperature-dependent sex determination and sex differentiation in Teleost fish. Genet Sel Evol 2014; 46:26. [PMID: 24735220 PMCID: PMC4108122 DOI: 10.1186/1297-9686-46-26] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 03/24/2014] [Indexed: 12/11/2022] Open
Abstract
The molecular mechanisms that underlie sex determination and differentiation are conserved and diversified. In fish species, temperature-dependent sex determination and differentiation seem to be ubiquitous and molecular players involved in these mechanisms may be conserved. Although how the ambient temperature transduces signals to the undifferentiated gonads remains to be elucidated, the genes downstream in the sex differentiation pathway are shared between sex-determining mechanisms. In this paper, we review recent advances on the molecular players that participate in the sex determination and differentiation in fish species, by putting emphasis on temperature-dependent sex determination and differentiation, which include temperature-dependent sex determination and genetic sex determination plus temperature effects. Application of temperature-dependent sex differentiation in farmed fish and the consequences of temperature-induced sex reversal are discussed.
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Affiliation(s)
| | - Han-Ping Wang
- Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, Piketon, Ohio 45661, USA.
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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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