Moderate heritability and low evolvability of sperm morphology in a species with high risk of sperm competition, the collared flycatcher Ficedula albicollis

Spermatozoa represent the morphologically most diverse type of animal cells and show remarkable variation in size across and also within species. To understand the evolution of this diversity, it is important to reveal to what degree this variation is genetic or environmental in origin and whether this depends on species’ life‐histories. Here we applied quantitative genetic methods to a pedigreed multigenerational data set of the collared flycatcher Ficedula albicollis, a passerine bird with high levels of extra‐pair paternity, to partition genetic and environmental sources of phenotypic variation in sperm dimensions for the first time in a natural population. Narrow‐sense heritability (h2) of total sperm length amounted to 0.44±0.14 SE while the corresponding figure for evolvability (estimated as coefficient of additive genetic variation, CVa) was 0.02±0.003 SE. We also found an increase in total sperm length within individual males between the arrival and nestling period. This seasona...

精子（spermatozoa）是形态多样性最高的动物细胞类型，且在物种间乃至物种内部均表现出显著的体型差异。为解析该多样性的演化机制，明确该变异在多大程度上源于遗传或环境因素，以及其是否与物种的生活史特征相关，至关重要。本研究针对具有高配偶外父权比例的雀形目鸟类——斑姬鹟（Ficedula albicollis）的谱系记录多代数据集，应用数量遗传学方法，首次在自然种群中划分了精子形态参数表型变异的遗传与环境来源。精子总长度的狭义遗传力（h²）为0.44±0.14（标准误，SE），而对应进化潜力（以加性遗传变异系数CVa估算）的数值为0.02±0.003（标准误，SE）。我们还发现，雄性个体在抵达繁殖地至育雏期之间，精子总长度有所增加。这种季节...