Collaborative Research: Determining the Mechanisms by which Parental Testosterone Biases the Ratio of Male to Female Birds

雌性鸟类决定后代的性别，因为它们是异性恋的，但它们也控制着雄性和雌性后代的比例，性别比，以应对环境变量。最近的工作表明，睾酮(T)处理在多个物种中诱导了偏向男性的性别比例，这可能是通过影响减数分裂I期间哪个性染色体保留在卵母细胞中(即分离扭曲)来实现的。激素可以影响后代遗传的遗传物质的想法，不仅在理解所有脊椎动物系统中的性别比例调整方面具有巨大的潜力，而且在考虑决定后代表型的其他遗传性状的遗传时也具有巨大的潜力。这项工作将促进人们对环境和内分泌系统如何共同决定遗传以及减数分裂的细胞动力学的理解。研究人员还将为高中生和教师制作教育模块，并就这项工作在家禽生产中的潜在应用展开合作。这项研究还将为众多本科生和研究生提供研究培训机会，并继续参与旨在让未被充分代表的群体参与科学研究的项目。先前数据的结果支持这样的假设，即T通过在减数分裂过程中性染色体的分离扭曲来刺激男性偏见的性别比例。为了进一步分析母体睾酮的影响，计划进行以下研究：在减数分裂分离附近测试生发盘和毛囊细胞上雄激素受体的存在；测试从T处理母鸡收集的卵母细胞中参与纺锤体纤维形成和染色体运动的基因表达的变化；以及确定减数分裂分离时T升高是否是性别比偏差所必需的。组织学、内分泌学和转录学分析是与研究相关的计划。这项研究有望揭示导致分离扭曲的细胞内途径，确定调控的关键点，并确定这些途径如何应对环境和社会条件的变化，从而影响后代的性别比例。研究结果将发表在同行评议的期刊上，并在区域和国家科学会议上公布。

Female birds determine the sex of offspring because they are heterogametic, but they also control the ratio of male to female offspring, the sex ratio, in response to environmental variables. Recent work shows that testosterone (T) treatment induces male-biased sex ratios in multiple species, and that it may do so by influencing which sex chromosome is retained in the oocyte during meiosis I (i.e. segregation distortion). The idea that a hormone can influence the genetic material inherited by offspring has enormous potential not only for understanding sex ratio adjustment in all vertebrate systems, but also when considering the inheritance of other genetic traits that determine offspring phenotype. The work will advance understanding of how the environment and endocrine system work together to determine genetic inheritance, as well as the cellular dynamics of meiosis. The researchers will also generate educational modules for both high school students and teachers and collaborate on potential applications of this work to poultry production. The research will also afford research training opportunities to numerous undergraduate and graduate students and continue their participation in programs geared towards involving under-represented groups in science.The results of previous data support the hypothesis that T stimulates male-biased sex ratios through segregation distortion of sex chromosomes during meiosis. To further analyze the effects of maternal testosterone, studies are planned to: test for the presence of androgen receptors on the germinal disc and follicle cells near the time of meiotic segregation; test for changes in the expression of genes involved in spindle fiber formation and chromosome movement in oocytes collected from T-treated hens; and to determine whether T elevations at meiotic segregation are necessary for sex ratio biases. Histologic, endocrine, and transcriptomic analyses are planned in association with the studies. The research is expected to reveal the intracellular pathway responsible for segregation distortion, to identify key points of regulation, and to determine how the pathways respond to changes in environmental and social conditions shown to influence offspring sex ratios. Results from the studies will be published in peer-reviewed journals and presented at regional and national scientific meetings.