Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB E3B 5A3, Canada.
Genome. 2013 Dec;56(12):753-8. doi: 10.1139/gen-2013-0210. Epub 2013 Dec 9.
Septins are cytoskeletal proteins that form hetero-oligomeric complexes and function in many biological processes, including cytokinesis. Drosophila melanogaster has five septin genes. Sep5, which is the most recently evolved septin gene in Drosophila, is a retrogene copy of Sep2. Sep5 mutants appear wild type, whereas Sep2 mutant females are semisterile. Their ovaries have egg chambers containing abnormal numbers of nurse cells. The egg chamber phenotype is rescued to wild type by expressing a Sep2 cDNA, but it is only partially rescued by expressing a Sep5 cDNA, showing that these paralogs have diverged in function at the protein level. Sep2 Sep5 double mutants have an early pupal lethal phenotype and lack imaginal discs, suggesting that these genes have redundant functions during imaginal cell proliferation.
Septins 是细胞骨架蛋白，它们形成异源寡聚复合物，并在许多生物学过程中发挥作用，包括胞质分裂。果蝇有五个 septin 基因。Sep5 是果蝇中最近进化的 septin 基因，是 Sep2 的返祖基因拷贝。Sep5 突变体表现为野生型，而 Sep2 突变体雌性则为半不育。它们的卵巢中含有异常数量的滋养细胞的卵室。通过表达 Sep2 cDNA，卵室表型可恢复至野生型，但通过表达 Sep5 cDNA 仅部分恢复，表明这些旁系同源物在蛋白质水平上的功能已经分化。Sep2 Sep5 双突变体具有早期蛹致死表型，并且缺乏 imaginal discs，表明这些基因在 imaginal 细胞增殖过程中具有冗余功能。
