Genetical and molecular characterization of divers in Drosophila melanogaster

潜水员位于X染色体的8D8-9区域。强壮的等位基因的翅膀较短，颜色较深，前翼和后翼弯曲。结合黄色突变，它有卷曲的翅膀。然而，较弱的等位基因如dvr84b无法与野生型区分，因此，通过对其p元素的再动员实验分析了三个p插入的dvr等位基因。证实了这些dvr突变是由P-lacW插入引起的，该试验独立获得了3株致死菌株，并在8D8-9上绘制了它们的致死性。PCR和Southern分析显示，在p插入位点附近有小的缺失。因此，dvr的功能缺失表型是致命的。致死期为第一或第二龄幼虫期。从三个P-lacW插入的dvr等位基因中克隆出了dvr的基因组区域。它们都在相同的位置以相同的方向插入P-lacW。我已经围绕p插入扩展了大约70 kb的基因组图谱。该区域存在许多类似微卫星的重复序列。虽然在p插入点周围的20kb区域进行了Northern blotting和cDNA筛选探针，但我没有检测到任何转录本。dvr的转录水平似乎很低。已知dvr与叉状和鳞状以及黄色相互作用，但它们的相互作用未被观察到。我还表明，黄色的色素沉着水平与dvr翼表型不直接相关。通过这些实验，我发现携带y+ y染色体的菌株诱导了后期致死（刚羽化后）。这种致死性是由dvr和Y染色体引起的，因为所有dvr+复合体都不表现出这种致死性，而提取的Y +Y染色体仍然诱导。遗传数据表明，复制的y+基因对这种致死率没有影响，rDNA基因在这条y染色体上被放大。

divers is located on the 8D8-9 region of the X chromosome. Strong alleles have shorter, darker wings and its anterior and post-scutellars are bowed in. In combination with yellow mutation, it gives curled wings. However, weaker alleles such as dvr84b cannot be distinguished from a wild type without y. three P-inserted dvr alleles were analyzed by the re-mobilization experiment of their P-elements. It was confirmed that these dvr mutations were caused by the P-lacW insertion, three lethal strains were obtained independently by this test and their lethality were mapped on the 8D8-9. PCR and Southern analysis of them showed that there are small deletions near the P-insertion site. Therefore, loss-of -function phenotype of dvr is lethal. The lethal stage is the first or the second instar larval period. The genomic region of the dvr had been cloned from three P-lacW inserted dvr alleles. All of them have P-lacW insertion at the same site with the same orientation. I have expanded the genomic map about 70 kb around P-insertion. Many micro-satellite like repeated sequences exist in this region. Although the 20 kb region around P-insertion was used for the Northern blotting and cDNA screening probe, I could not detect any transcripts. The transcription level of dvr seems to be low. The dvr is known to interact with forked and scute as well as yellow, but their interaction was not observed. I also showed that the pigmentation level of yellow does not directly correlate with dvr wing phenotype. Through these experiments, I have found a strain carrying y+Y chromosome induce the late stage lethality (just after eclosion). This lethality is caused by dvr and Y chromosome because all of dvr+revertants did not show such lethality and the extracted y+Y chromosome still induced it. Genetical data suggest that the duplicated y+gene has no effect for this lethality and rDNA genes are magnified on this Y chromosome.