ffrench-Constant R H, Rocheleau T
Entomology Department, University of Wisconsin, Madison 53706.
J Neurochem. 1992 Oct;59(4):1562-5. doi: 10.1111/j.1471-4159.1992.tb08475.x.
Genomic clones from the Rdl locus of Drosophila, whose mutant phenotype is resistant to cyclodiene insecticides and picrotoxin, were characterized by restriction mapping and partial sequencing to determine intron/exon structure. The coding region of the gene comprises nine identified exons and spans greater than 25 kb of genomic DNA. The structure of the Drosophila Rdl receptor subunit was compared with those of vertebrate gamma-aminobutyric acid subtype A (GABAA) receptors and nicotinic acetylcholine receptors (nAChRs). The first six introns in Rdl show positions similar to those in vertebrate GABAA receptors, whereas the last two differ. It is interesting that the last intron appears to be in a position similar to that in nAChRs. These results are examined in relation to the proposal, based on amino acid identities, that Rdl codes for a novel class of GABAA receptor subunit more closely related to glycine receptors, and the possible place of Rdl in the lineage of the receptor superfamily is discussed.
来自果蝇Rdl基因座的基因组克隆，其突变表型对环二烯类杀虫剂和印防己毒素具有抗性，通过限制性图谱分析和部分测序来确定内含子/外显子结构。该基因的编码区包含9个已鉴定的外显子，跨越超过25kb的基因组DNA。将果蝇Rdl受体亚基的结构与脊椎动物γ-氨基丁酸A亚型（GABAA）受体和烟碱型乙酰胆碱受体（nAChRs）的结构进行了比较。Rdl中的前六个内含子显示出与脊椎动物GABAA受体中的内含子相似的位置，而最后两个则不同。有趣的是，最后一个内含子似乎处于与nAChRs中相似的位置。基于氨基酸同源性，有人提出Rdl编码一类与甘氨酸受体更密切相关的新型GABAA受体亚基，本文结合这一观点对这些结果进行了研究，并讨论了Rdl在受体超家族谱系中的可能位置。
