Genetic and environmental variation in transcriptional expression of seminal fluid proteins
Genetic and environmental variation in transcriptional expression of seminal fluid proteins
复制标题
DOI：
10.1038/s41437-018-0160-4
复制
发表时间：
2019-05-01
期刊：
影响因子：
3.8
通讯作者：
Ramm, Steven A.
中科院分区：
文献类型：
--
作者：
Patlar, Bahar;Weber, Michael;Ramm, Steven A.
精液蛋白（SFPs）是性选择和性冲突的重要媒介。最近的研究主要集中在环境诱导的可塑性作为SFP表达变异的一个来源，特别是对不同精子竞争水平的反应。然而，理解异质环境中性状的进化需要对变异的环境和遗传来源以及它们之间的相互作用进行估计。因此，我们研究了环境（特别是交配群体大小，这是精子竞争强度的一个很好的预测因素）、基因型和基因型与环境的相互作用如何影响精液表达。为此，我们培养了12个同时雌雄同体的扁形虫（Macrostomum lignano）自交系，分别为2个或8个，并测量了58个推测的SFP转录本的表达水平。然后，我们分别检查了每个转录本表达的变异来源，并从主成分分析中提取了多变量轴。根据单转录本分析，我们发现交配群体的大小不影响表达水平，也不影响第一主成分（可能代表精液生产的总体投资）。然而，交配群体的大小确实影响了第二主成分捕获的不同转录本的相对表达（可能反映了精液成分的变化）。大多数转录本在表达水平上具有遗传变异，一些转录本表现出基因型与环境的相互作用；相对组成也表现出较高的遗传变异。总的来说，我们的研究结果揭示了精液转录组紧密整合的本质，并为精液投资和组成的定量遗传基础提供了新的见解。
Seminal fluid proteins (SFPs) are crucial mediators of sexual selection and sexual conflict. Recent studies have chiefly focused on environmentally induced plasticity as one source of variation in SFP expression, particularly in response to differing sperm competition levels. However, understanding the evolution of a trait in heterogenous environments requires estimates of both environmental and genetic sources of variation, as well as their interaction. Therefore, we investigated how environment (specifically mating group size, a good predictor of sperm competition intensity), genotype and genotype-by-environment interactions affect seminal fluid expression. To do so, we reared 12 inbred lines of a simultaneously hermaphroditic flatworm Macrostomum lignano in groups of either two or eight worms and measured the expression levels of 58 putative SFP transcripts. We then examined the source of variation in the expression of each transcript individually and for multivariate axes extracted from a principal component analysis. We found that mating group size did not affect expression levels according to the single transcript analyses, nor did it affect the first principal component (presumably representing overall investment in seminal fluid production). However, mating group size did affect the relative expression of different transcripts captured by the second principal component (presumably reflecting variation in seminal fluid composition). Most transcripts were genetically variable in their expression level and several exhibited genotype-by-environment interactions; relative composition also showed high genetic variation. Collectively, our results reveal the tightly integrated nature of the seminal fluid transcriptome and provide new insights into the quantitative genetic basis of seminal fluid investment and composition.