Gene Expression Response to Naturally Fluctuating Temperature in Turtles with Alternative Sex Determining Mechanisms

具有替代性别决定机制的海龟对自然波动温度的基因表达反应

• 批准号: 0743284
• 负责人: Nicole Valenzuela
• 金额: $ 40万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0743284&HistoricalAwards=false
• 关键词: Gene; Expression; Response; Naturally; Fluctuating

Sex is determined by genetic constitution (GSD) in most animals (as by sex chromosomes in humans), and by environmental temperature (TSD) in others, including reptiles. The proportion of males to females (sex ratio) greatly influences populations. Male-biased populations reproduce slowly because females are limited, while female-biased populations may have lower genetic variability because few males father all offspring. Yet we know little about how naturally-fluctuating temperatures of nests affect sex ratios of TSD reptiles. This gap obscures the effect of TSD on sex ratio evolution, the growth potential of populations, the rate of change of genetic variability, and how species adapt to the environment. This project will help elucidate the effect that naturally-fluctuating temperature has on the expression of genes involved in gonadal formation in TSD turtles, and how males and females are produced in nature. Explicit hypotheses derived from previous gene expression and ecological research will be tested to help reveal how TSD species may respond to short- and long-term climate change. Intellectual Merit: This project will advance our understanding of the effects of environmental change on the regulation of sexual development and sex ratio production at the gene-expression level in TSD species. The application of molecular techniques under ecologically-relevant conditions will shed light on how and why sex is determined by nest temperature in so many reptiles, thus facilitating the study of sex ratio evolution under TSD and its implications for the conservation of endangered TSD species facing global warming. Broader Impacts: This project will (a) integrate undergraduate discovery-based learning through a novel service-learning activity to recruit biology undergraduates into the field and lab modules of this project; and (b) broaden the participation of underrepresented groups in biology by providing direct training opportunities for students and their mentors; and by engaging women and minorities through outreach activities.

性别由大多数动物（如人类的性染色体）以及包括爬行动物在内的其他动物（例如人类的性染色体）以及环境温度（TSD）确定。男性与女性（性别比）的比例极大地影响了人群。男性偏见的种群由于女性受到限制而缓慢繁殖，而女性偏见的人群可能具有较低的遗传变异性，因为很少有男性父亲是所有后代。然而，我们对巢的自然裂开温度如何影响TSD爬行动物的性别比有何了解。这一差距掩盖了TSD对性别比进化的影响，人群的生长潜力，遗传变异性的变化率以及物种如何适应环境。该项目将有助于阐明天然裂开的温度对TSD海龟中性腺形成的基因表达以及在自然界中如何产生男性和女性的作用。将测试从先前基因表达和生态研究中得出的明确假设，以帮助揭示TSD物种如何应对短期和长期气候变化。知识分子的优点：该项目将提高我们对环境变化对TSD物种基因表达水平的性发展和性别比例产生的影响的影响。分子技术在与生态相关的条件下的应用将阐明在如此多的爬行动物中通过巢温度确定性别的方式和原因，从而促进了TSD下的性别比演化的研究及其对濒危TSD面临的濒危TSD的影响。更广泛的影响：该项目将（a）通过新的服务学习活动整合基于本科的研究，以招募生物学本科生进入该项目的现场和实验室模块； （b）通过为学生及其导师提供直接培训机会来扩大代表性不足的群体的生物学参与；并通过宣传活动与妇女和少数民族吸引。