Tiong S, Bone L M, Whittle J R
Mol Gen Genet. 1985;200(2):335-42. doi: 10.1007/BF00425445.
Genetic deficiencies of the bithorax-complex (BX-C) in Drosophila, have been used to recover recessive lethal mutations in this chromosome region following mutagenesis. Complementation analysis separates these lethal mutations into five groups within a smaller deficiency, thought to remove the entire BX-C, and into 20 to the left and 4 to the right of the region. Homozygotes for each of only three groups of lethals, Ubx, abdA and AbdB, produce homoeotic segmental transformations in embryos. The functional domains of abdA and AbdB have been defined by changes in the appearance of larval hypodermal structures and of clones in imaginal tissue. The function abdA is required in all the compartments caudal to the anteroposterior border of abdominal segment 1 up to and including the anterior region of abdominal segment 8, whilst AbdB is required in abdominal segments 5 to 9. One allele of AbdB produces a ninth abdominal setal band and structures characteristic of head segments posterior to A8. Rare adult survivors hemizygous for an AbdB allele have eight abdominal segments in both sexes, and lack genitalia in females. Our findings are discussed in the context of the organisation of genetic functions within the BX-C.
果蝇中双胸复合体（BX-C）的遗传缺陷已被用于在诱变后恢复该染色体区域的隐性致死突变。互补分析将这些致死突变分为五组，其中一组在一个较小的缺失内，该缺失被认为去除了整个BX-C，另外20组在该区域左侧，4组在右侧。只有三组致死突变（Ubx、abdA和AbdB）的纯合子在胚胎中产生同源异型节段转化。abdA和AbdB的功能域已通过幼虫皮下结构和成虫组织中克隆的外观变化来定义。abdA的功能在腹部第1节前后边界尾侧的所有体节中都是必需的，直至并包括腹部第8节的前部区域，而AbdB在腹部第5至9节中是必需的。AbdB的一个等位基因产生第九腹节刚毛带和A8后方头部节段的特征结构。罕见的成年幸存者，其AbdB等位基因半合子，两性均有八个腹节，雌性缺乏生殖器。我们的研究结果将在BX-C内遗传功能组织的背景下进行讨论。
