Schulz R A, Shlomchik W, Cherbas L, Cherbas P
Department of Cellular and Development Biology, Harvard University, Cambridge, Massachusetts 02138.
Dev Biol. 1989 Feb;131(2):515-23. doi: 10.1016/s0012-1606(89)80022-3.
The Eip28/29 gene of Drosophila is known to be regulated by the steroid hormone ecdysone in Kc cells and other cell lines. An investigation of Eip28/29 gene expression in intact animals has led to the discovery of two new genes on its 5' flank. Together these three genes generate at least seven distinct transcripts with diverse patterns of developmental expression. gonadal (gdl) is transcribed on the same strand as Eip28/29 and is expressed in two modes. gdlM transcripts, observed exclusively in the testes, are 1200 and 1500 N long, differing by their polyadenylation site but probably otherwise identical; gdlF transcripts are 900 and 1200 N long and share their terminal exons with the two gdlM transcripts. In adults they are exclusively ovarian, but they are also present in early embryos and, at a lower abundance, in Kc cells. In each mode, the longer transcript results from use of a polyadenylation site within the 5' exon of Eip28/29. The shared region includes 3' noncoding sequences of gdl transcripts and 5' flanking DNA and 5' noncoding sequences of Eip28/29. gdl expression in Kc cells is, however, unaffected by ecdysone. z600 is more distal to Eip28/29 but still contained at least in part within the 2 kb upstream of that gene. Its 600 N transcript is expressed predominantly during the first few hours of embryogenesis. Finally, the Eip28/29 transcripts are present at low levels during most developmental stages.
已知果蝇的Eip28/29基因在Kc细胞和其他细胞系中受类固醇激素蜕皮激素的调控。对完整动物中Eip28/29基因表达的研究导致在其5'侧翼发现了两个新基因。这三个基因共同产生至少七种不同的转录本，具有不同的发育表达模式。性腺基因（gdl）与Eip28/29在同一条链上转录，并以两种模式表达。gdlM转录本仅在睾丸中观察到，长度分别为1200和1500个核苷酸，它们的区别在于多聚腺苷酸化位点，但其他方面可能相同；gdlF转录本长度为900和1200个核苷酸，并与两个gdlM转录本共享其末端外显子。在成虫中，它们仅存在于卵巢中，但也存在于早期胚胎中，并且在Kc细胞中的丰度较低。在每种模式下，较长的转录本是由于使用了Eip28/29的5'外显子内的一个多聚腺苷酸化位点产生的。共享区域包括gdl转录本的3'非编码序列、Eip28/29的5'侧翼DNA和5'非编码序列。然而，Kc细胞中gdl的表达不受蜕皮激素的影响。z600基因距离Eip28/29更远，但至少部分仍包含在该基因上游2 kb范围内。其600个核苷酸的转录本主要在胚胎发生的最初几个小时内表达。最后，Eip28/29转录本在大多数发育阶段的水平都很低。
