A gradient of sexual selection and sexual conflict: parental investment and sex-role reversal and their genomic footprints

选择对雄性和雌性的作用不同，导致了它们的表型差异。大多数研究都集中在男性身上，以及在获得女性伴侣的背景下，性选择如何塑造他们的装饰品和武器。这不仅仅是因为人类和大多数其他脊椎动物一样，表现出“传统的”、“达尔文式的”性别角色，把我们的观念集中在有竞争力的雄性和有爱心的母亲身上。然而，在一些海马、海龙和管鱼物种中，雌性会竞争获得配偶的机会，而雄性则是挑剔的性别，在雄性怀孕期间提供亲代照顾。我们的项目将研究这些物种是如何在雌性性选择加剧的情况下进化的，以及性别之间共享的基因组中性别特异性特征的进化是如何受到父权照顾增加的影响的。为此，我们将在性别冲突程度不同的物种中，识别性别特异性序列（性染色体）以及性别偏倚基因表达，这些基因在组织中具有强烈或轻微的性别差异。我们将分析调节性别角色的基因是否来源于性别决定基因。得益于性别角色逆转的重复进化，我们将在合颌纲动物中测试新的和趋同的序列进化模式，也将在其他也进化出怀孕的脊椎动物群体中测试。雄性怀孕不仅是合鱼的一种独特的繁殖策略，而且维持胚胎依附于父亲身体的结构——育儿袋——在合鱼体内也进化得更加复杂了好几倍。我们将使用这种重复的进化模式来比较基因组和转录组的进化，以及它们在上升父本投入的重复梯度上的生理影响。前面提到的“性别角色转换”伴随着两性二态性的进化，表现为女性身上美丽的，有时是壮观的装饰，这在合颌纲的几个系统发育亚群中独立地进化了。我们将研究性别特异性表型是如何建立在性别偏倚的基因表达上的，以及这可能如何导致它们共同基因组中的性别拮抗冲突。此外，我们将仔细研究激素在调节基因表达和性表型（包括行为）中的作用。该项目将描述女性和男性的遗传和内分泌网络，并将其与基于生成高质量参考基因组、男性和女性基因组重测序数据、多组织转录组学以及内分泌操作的性别角色网络区分开来。

Selection acts differently on males and females and drives their phenotypic dissimilarities. Most research has focused on males and how sexual selection shapes their ornaments and weaponry in the context of gaining access to female mates. This is not least due to the fact that humans, as most other vertebrates, show "conventional", "Darwinian" sex roles concentrating our perception on competitive males and caring mothers. In several seahorse, seadragon and pipefish species (family Syngnathidae), however, females compete for access to mates, while males are the choosy sex and provide the parental care during male pregnancy. Our project will investigate how these species evolved under intensified sexual selection on females and how the evolution of sex-specific traits from a genome shared between the sexes and hence with sexual conflict is impacted by increasing paternal care. To this aim we will identify sex-specific sequences (sex chromosomes) as well as sex-biased gene expression in tissues with strong or little sex differences in species with varying degrees of sexual conflict. We will analyze if genes mediating sex roles are derived from sex-determining genes. Benefitting from the repetitive evolution of sex-role reversal, we will test for patterns of novel and convergent sequence evolution within syngnathids but also to other vertebrate groups that also evolved pregnancy. Not only is male pregnancy a unique reproduction strategy of syngnathids but the structure sustaining embryonic attachment to the father´s body, the brood pouch, also evolved increased complexity several times within syngnathids. We will use this repetitive evolutionary pattern for comparative studies of genome and transcriptome evolution as well as their physiological impacts along repeated gradients of ascending paternal investment. The afore mentioned "sex-role reversal" accompanied by the evolution of sexual dimorphism manifested with beautiful and sometimes spectacular ornaments in the female sex has independently evolved in several phylogenetic subgroups of syngnathids. We will investigate how sex-specific phenotypes are built upon sex-biased gene expression and how this might lead to sexual antagonistic conflict in their common genome. In addition, we will scrutinise the role of hormones in regulating gene expression and sexual phenotypes including behaviour. This project will characterise the genetic and endocrinological network of female- and maleness and distinguish it from the sex-role network building upon generating of high-quality reference genomes, genome resequencing data of males and females, multi tissue transcriptomics as well as endocrinological manipulations.