Morata G
J Embryol Exp Morphol. 1975 Aug;34(1):19-31.
Contrabithorax, a mutant of the bithorax system in Drosophila melanogaster produces a partial homeotic transformation of mesothorax (wing) into methathorax (haltere). The wing of a fly homozygous or heterozygous for the mutant is a mosaic of wing and haltere structures. A genetic analysis of the mutant suggests that its phenotype is due to some form of derepression in the wing of two other genes of the bithorax system (bithorax and postbithorax) which are not normally active there. This repression is not complete. The activity of the two genes is below the normal level resulting in only a partial transformation of wing into haltere. Clones of marked cells were generated by X-rays and were found to include both transformed (haltere) and untrasformed (wing) territory; this was true even for those generated late in development. Thus the final expression of a cell depends not on its immediate ancestry but perhaps on the level of the products of the wild-type alleles of bithorax and postbithorax.
反双胸突变体是黑腹果蝇双胸系统的一种突变体，它会使中胸（翅膀）部分同源异型转化为后胸（平衡棒）。该突变体纯合或杂合的果蝇翅膀是翅膀和平衡棒结构的嵌合体。对该突变体的遗传分析表明，其表型是由于双胸系统的另外两个基因（双胸和后双胸）在翅膀中某种形式的去抑制所致，这两个基因在正常情况下在那里不活跃。这种抑制并不完全。这两个基因的活性低于正常水平，导致翅膀仅部分转化为平衡棒。通过X射线产生了标记细胞的克隆，发现其中既有转化的（平衡棒）区域，也有未转化的（翅膀）区域；即使是在发育后期产生的克隆也是如此。因此，细胞的最终表型并不取决于其直接谱系，而可能取决于双胸和后双胸野生型等位基因产物的水平。
