Beyond spermatogenesis: Additional roles of seminal fluid fatty acids in male fertility and age-related reproductive success

项目概要/摘要 在许多动物中，精液在雄性生殖成功中起着重要作用。精液中的蛋白质 对雄性和雌性生殖生理的多个特征具有显著影响。然而，相对较少 除了作为精子膜外，还知道精液的第二个主要成分是脂质 选民。本提案的总体目标是i）确定脂质组学和转录组学的差异， 年轻和老年男性的精液轮廓;和ii）直接测试如何操纵精液的脂质轮廓， 液体影响男性生殖成功。这项建议将解决这一假设，即精液脂质体 影响男性生育能力，并随年龄变化，从而导致与年龄相关的生殖能力下降。 成功该假设得到了申请人已发表的研究的支持，该研究表明，脂肪酸和相关的脂肪酸可以被转化为脂肪酸。 果蝇雄性精液中的脂质对于雄性生育力是必需的。转座子介导的基因敲除 和RNAi敲低男性射精球（EB）中的一种关键脂肪酸生物合成酶， 不参与精子发生，导致男性生育力显著下降，强烈支持 精液脂肪酸对男性生殖成功的贡献。与哺乳动物模型相比， 果蝇允许EB中产生的精液脂质被操纵而不干扰 睾丸中的精子发生。强大的遗传操作与脂质组学和转录组学相结合 分析将用于追求以下目标：提案的目标1将检验假设的预测 精液脂肪酸和其他脂质成分的变化伴随着与衰老相关的脂肪酸的损失。 生育使用多种质谱方法，将在年轻和年轻的人中表征精液脂质组。 老年男性，以确定与高生育力和低生育力相关的血脂特征。目标2将测试一个 第二个预测的假说，即脂肪酸合成基因的表达在EB中随衰老而变化 男性，导致精液中脂肪酸和相关脂质成分的变化。转录组学分析 来自年轻和老年男性的EB，随后通过基因敲除进行功能验证， 这是与年龄相关的精液脂质含量变化的基础。在目标3中，假设的直接检验将是 通过评估男性生育能力是否在精液基因操作后提高或下降来进行。 液体脂肪酸含量预期成果是重要的，因为它们可能会发现新的 调节雄性和雌性生殖生理学的机制，并可能指向以前未被认识到的 特发性男性不育症的病因拟议的研究是创新的，因为它预计将确定一个新的 这类分子和新的生化途径可用于改善不孕症的诊断， 加强辅助生殖技术，治疗与年龄相关的生育能力下降。

Project Summary/Abstract In many animals, the seminal fluid plays a major role in male reproductive success. Proteins in the seminal fluid have significant effects on multiple features of male and female reproductive physiology. However, relatively little is known about a second major component of seminal fluid, lipids, beyond their roles as sperm membrane constituents. The overall objectives in this proposal are to i) identify differences in the lipidomic and transcriptomic profiles of seminal fluid in young and aged males; and ii) directly test how manipulating the lipid profile of seminal fluid impacts male reproductive success. This proposal will address the hypothesis that the seminal fluid lipidome influences male fertility and changes with age, thus contributing to the decline of aging-related reproductive success. This hypothesis is supported by the applicants’ published studies showing that fatty acids and related lipids in the seminal fluid of Drosophila males are essential for male fertility. Both transposon-mediated knockout and RNAi knockdown of a key fatty acid biosynthesis enzyme in the male ejaculatory bulb (EB), an organ that is not involved in spermatogenesis, causes a significant decrease in male fertility, strongly supporting the contribution of seminal fluid fatty acids to male reproductive success. In contrast to mammalian models, use of Drosophila allows seminal fluid lipids produced in the EB to be manipulated without interfering with spermatogenesis in the testes. Powerful genetic manipulation in combination with lipidomic and transcriptomic analysis will be used to pursue the following aims: Aim 1 of the proposal will test a prediction of the hypothesis that changes in the composition of seminal fluid fatty acids and other lipids accompany aging-related loss of fertility. Using multiple mass spectrometry methods, the seminal fluid lipidome will be characterized in young and old males in order to identify features of the lipid profile that correlate with high and low fertility. Aim 2 will test a second prediction of the hypothesis, that the expression of fatty acid synthesis genes in the EB changes in aging males, leading to a shift in fatty acid and related lipid composition in the seminal fluid. Transcriptomic analysis of the EB from young and old males followed by functional validation with genetic knockdown will identify genes that underlie age-related changes in seminal fluid lipid content. In Aim 3, a direct test of the hypothesis will be performed by assessing whether male fertility improves or declines upon genetic manipulation of the seminal fluid fatty acid content. The expected outcomes are significant because they are likely to identify new mechanisms that modulate male and female reproductive physiology and may point to previously unrecognized causes of idiopathic male infertility. The proposed study is innovative because it is expected to identify a new class of molecules and novel biochemical pathways that could be used to improve the diagnosis of infertility, enhance assisted reproductive technology, and treat aging-related decline in fertility.