Grossman M, Eisen E J
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Hered. 1989 Mar-Apr;80(2):137-42. doi: 10.1093/oxfordjournals.jhered.a110812.
Knowledge about the relationships between relatives for X-chromosomal loci is necessary to compute genetic variances and covariances for the genetic evaluation of individuals for economically important traits in livestock and poultry. Using a unified approach, we derived explicitly the coefficient of inbreeding for individuals and the coefficient of coancestry between collateral and lineal relatives of the same or different sex, assuming that the male is heterogametic and the female is homogametic. Collateral relatives include full sibs, paternal and maternal half-sibs, paternal and maternal single first cousins, and double first cousins. Lineal relatives include parent-offspring, paternal and maternal grandparent-grandoffspring, and aunt- or uncle-niece or -nephew. We also defined additive and dominance relationships to compute genetic covariance between relatives, assuming random mating equilibrium, and clarified misinterpretations and corrected errors in the literature. Our results are also applicable to organisms that have few autosomal loci, such as Drosophila, in which X-chromosomal loci can account for a large amount of genetic variance, and to haplodiploid organisms, such as the honeybee, in which the entire genome is equivalent to being X-chromosomal.
了解X染色体位点的亲属关系对于计算畜禽经济重要性状个体遗传评估的遗传方差和协方差是必要的。我们采用统一方法，明确推导了个体的近交系数以及同性或异性旁系和直系亲属之间的共祖系数，假设雄性为异配性别，雌性为同配性别。旁系亲属包括全同胞、同父异母和同母异父半同胞、父系和母系单第一代堂表亲以及双第一代堂表亲。直系亲属包括亲子、祖父母与孙子女以及叔伯姑舅与侄甥。我们还定义了加性和显性关系以计算亲属间的遗传协方差，假设处于随机交配平衡，并澄清了文献中的误解和纠正了错误。我们的结果也适用于常染色体位点较少的生物，如X染色体位点可占大量遗传方差的果蝇，以及整个基因组相当于X染色体的单倍体二倍体生物，如蜜蜂。
