Biémont C
Mech Ageing Dev. 1978 Jul;8(1):21-42. doi: 10.1016/0047-6374(78)90004-0.
Mating studies on individual couples of Drosophila melanogaster allowed the structure of inbred populations in terms of egg hatchability and egg-to-adult survival to be elucidated. The comparison between inbred (from brother-sister matings) and control (randomly crossed) populations distinguished between couples sensitive and insensitive to inbreeding. Mendelian ratios were observed for this "phenotypic trait" in the progeny of single couples. These ratios and a double mating experiment indicated that a gene or gene complex implicated in morphogenetic events blocked development during embryonic and larvo-pupal stages. The expression of this lethal gene in homozygous embryos depended on the genetic makeup of both parental flies, i.e., on male and female factors which act as regulatory components. Homozygous embryos which survived the first critical phase (from fertilization to hatching) continued to develop normally until the larvo-pupal period, when they died. Lethality was also modulated by the cytoplasmic composition of the parental eggs, as shown by taxonomic analysis and the double mating experiment. The results account for lethality throughout development due to inbreeding. They lead to an estimated genetic load from laying to adult stage of one "lethal equivalent".
对黑腹果蝇个体交配的研究，使得根据卵孵化率和卵到成虫的存活率来阐明近交群体的结构成为可能。近交群体（来自亲兄妹交配）和对照群体（随机杂交）之间的比较，区分了对近交敏感和不敏感的交配组合。在单个交配组合的后代中观察到了这种“表型性状”的孟德尔比率。这些比率以及一个双重交配实验表明，一个与形态发生事件相关的基因或基因复合体在胚胎期和幼虫-蛹期阻断了发育。这个致死基因在纯合胚胎中的表达取决于双亲果蝇的基因组成，即取决于作为调控成分的雄性和雌性因子。在第一个关键阶段（从受精到孵化）存活下来的纯合胚胎会继续正常发育，直到幼虫-蛹期死亡。分类分析和双重交配实验表明，致死性也受到亲代卵细胞质组成的调节。这些结果解释了近交导致的整个发育过程中的致死性。它们导致从产卵到成虫阶段估计有一个“致死当量”的遗传负荷。
