Yanicostas C, Ferrer P, Vincent A, Lepesant J A
Institut Jacques Monod, CNRS et Université Paris 7, France.
Mol Gen Genet. 1995 Mar 10;246(5):549-60. doi: 10.1007/BF00298961.
The genes janus (jan) A and B, and serendipity (sry) beta and delta are two pairs of duplicated genes that are adjacent to each other on the third chromosome of Drosophila melanogaster. The jan A and sry beta genes are expressed throughout development in both males and females. They are transcribed in opposite orientations from start sites separated by only 173 bp of DNA. We report here the complete sequence of the jan A and B genes in Drosophila pseudoobscura, a species distantly related to D. melanogaster in which the overall organization of the sry beta, jan A and jan B genes is identical to that in D. melanogaster. Sequence comparison of the jan A-sry beta intergenic region and 5'-transcribed domain of each gene between D. melanogaster and D. pseudoobscura reveals short stretches of conserved sequences that may correspond to cis-acting regulator elements. In order to test the possibility that some cis-acting regulatory sequences are shared by the two genes, we carried out a deletion analysis of the jan A/sry beta intergenic region in D. melanogaster using transgenic lacZ fusion genes. Our results show that sry beta cis-acting sequences are located in the (-117; +137) 5'-region of the gene and that jan A cis-regulatory sequences are included in the (-56; +151) 5'-domain of this gene. Together these data indicate that in spite of the physical proximity of the jan A and sry beta genes, their transcription is regulated by separate cis-acting sequences.
“两面神”（jan）A和B基因，以及“意外发现”（sry）β和δ基因是两对重复基因，在黑腹果蝇的第三条染色体上彼此相邻。jan A和sryβ基因在雄性和雌性个体的整个发育过程中均有表达。它们从仅相隔173个碱基对的起始位点以相反的方向转录。我们在此报告拟暗果蝇中jan A和B基因的完整序列，拟暗果蝇是一种与黑腹果蝇亲缘关系较远的物种，其中sryβ、jan A和jan B基因的整体组织与黑腹果蝇中的相同。对黑腹果蝇和拟暗果蝇中jan A - sryβ基因间区域以及每个基因的5'转录结构域进行序列比较，发现了可能对应于顺式作用调节元件的短保守序列片段。为了测试这两个基因是否共享一些顺式作用调节序列，我们利用转基因lacZ融合基因对黑腹果蝇中的jan A / sryβ基因间区域进行了缺失分析。我们的结果表明，sryβ顺式作用序列位于该基因的（-117；+137）5'区域，而jan A顺式调节序列包含在该基因的（-56；+151）5'结构域中。这些数据共同表明，尽管jan A和sryβ基因在物理位置上相邻，但它们的转录由不同的顺式作用序列调控。
