Code and datasets associated with: A sex-linked supergene with large effects on sperm traits has little impact on reproductive traits in female zebra finches

Despite constituting an essential component of fitness, reproductive success can vary remarkably between individuals and the causes of such variation are not well understood across taxa. In the zebra finch – a model songbird, almost all the variation in sperm morphology and swimming speed is maintained by a large polymorphic inversion (commonly known as a supergene) on the Z chromosome. The relationship between this polymorphism and reproductive success is not fully understood, particularly for females. Here, we explore the effects of female haplotype, and the combination of male and female genotype, on several primary reproductive traits in a captive population of zebra finches. Despite the inversion polymorphism’s known effects on sperm traits, we find no evidence that inversion haplotype influences egg production by females or survival of embryos through to hatching. However, our findings do reinforce existing evidence that the inversion polymorphism is maintained by a heterozygote advantage for male fitness. This work provides an important step in understanding the causes of variation in reproductive success in this model species.

尽管繁殖成功率是个体适合度（fitness）的核心构成要素，但不同个体间的繁殖成功率差异悬殊，且此类差异的成因在各类生物类群中尚未得到充分阐释。斑胸草雀（zebra finch）作为模式鸣禽，其精子形态与游动速度的几乎全部变异，均由Z染色体（Z chromosome）上的大型多态性倒位（常被称为超基因（supergene））所维持。该多态性与繁殖成功率之间的关联尚未完全明晰，针对雌性的相关研究尤为不足。本研究以圈养斑胸草雀种群为研究对象，探究雌性单倍型（haplotype）以及雌雄基因型组合对多项核心繁殖性状的影响。尽管已知该倒位多态性会对精子性状产生影响，但我们并未发现证据表明倒位单倍型会影响雌性产卵量或胚胎孵化存活率。不过，本研究结果进一步验证了现有结论：该倒位多态性通过雄性适合度的杂合子优势（heterozygote advantage）得以维持。此项研究为阐明该模式物种繁殖成功率差异的成因迈出了重要一步。