Butler B, Pirrotta V, Irminger-Finger I, Nöthiger R
EMBO J. 1986 Dec 20;5(13):3607-13. doi: 10.1002/j.1460-2075.1986.tb04689.x.
In Drosophila, the primary signal for sex determination is given by the ratio of X chromosomes to sets of autosomes (X:A). The primary signal is read by a key gene (Sxl) and transmitted down to the differentiation genes by the subordinate control genes tra, tra-2, ix and dsx. Mutations in tra transform chromosomal females (X/X; tra/tra) into sterile males (pseudomales). We have cloned the tra region by microdissection and chromosomal walking. We identified the gene using deficiency breakpoints, DNA aberrations in three different alleles of tra and by P-mediated transformation. A 3.8-kb fragment perfectly rescued the mutant phenotype of X/X; tra/tra flies, showing that it contained all the necessary information to restore female-specific functions in the mutant flies. We present evidence that most of the function of tra can be provided by a subsegment of 2 kb that is differentially transcribed or processed in males and females.
在果蝇中，性别决定的主要信号由X染色体与常染色体组的比例（X:A）给出。主要信号由一个关键基因（Sxl）读取，并通过从属控制基因tra、tra-2、ix和dsx传递给分化基因。tra基因的突变会将染色体雌性（X/X；tra/tra）转变为不育雄性（假雄性）。我们通过显微切割和染色体步移克隆了tra区域。我们利用缺失断点、tra的三个不同等位基因中的DNA畸变以及P介导的转化来鉴定该基因。一个3.8 kb的片段完美地拯救了X/X；tra/tra果蝇的突变表型，表明它包含了恢复突变果蝇雌性特异性功能所需的所有信息。我们提供的证据表明，tra的大部分功能可由一个2 kb的亚片段提供，该亚片段在雄性和雌性中差异转录或加工。
