Clark A G
Department of Biology, Pennsylvania State University, University Park 16802.
Genetics. 1990 Jul;125(3):527-34. doi: 10.1093/genetics/125.3.527.
Deficiency mapping with Y autosome translocations has shown that the Y chromosome of Drosophila melanogaster carries genes that are essential to male fertility. While the qualitative behavior of these lesions provides important insight into the physiological importance of the Y chromosome, quantitative variation in effects on male fertility among extant Y chromosomes in natural populations may have a significant effect on the evolution of the Y chromosome. Here a series of 36 Y chromosome replacement lines were tested in two ways designed to detect subtle variation in effects on male fertility and total male fitness. The first test involved crossing males from the 36 lines to an excess of females in an attempt to measure differences in male mating success (virility) and male fecundity. The second test challenged males bearing each of the 36 Y chromosomes to competition in populations with males bearing a standard, phenotypically marked (BsY) chromosome. These tests indicated that the Y chromosome lines did not differ significantly in either male fertility or total fitness, but that interactions with autosomes approached significance. A deterministic population genetic model was developed allowing Y autosome interaction in fertility, and it is shown that, consistent with the experimental observations, this model cannot protect Y-linked polymorphism.
利用Y染色体与常染色体易位进行的缺失作图表明，黑腹果蝇的Y染色体携带对雄性育性至关重要的基因。虽然这些损伤的定性行为为Y染色体的生理重要性提供了重要见解，但自然种群中现存Y染色体对雄性育性影响的定量变异可能对Y染色体的进化产生重大影响。在此，以两种旨在检测对雄性育性和雄性总适合度影响的细微变异的方式，对一系列36个Y染色体替代系进行了测试。第一个测试包括将来自这36个品系的雄性与过量雌性杂交，试图测量雄性交配成功率（生殖力）和雄性繁殖力的差异。第二个测试让携带36条Y染色体中每条的雄性与携带标准的、表型标记（BsY）染色体的雄性在种群中竞争。这些测试表明，Y染色体品系在雄性育性或总适合度方面没有显著差异，但与常染色体的相互作用接近显著水平。开发了一个确定性种群遗传模型，该模型允许Y染色体与常染色体在育性方面相互作用，结果表明，与实验观察结果一致，该模型无法保护Y连锁多态性。
