昆虫中的3类Hox基因与zen的起源

Falciani F, Hausdorf B, Schröder R, Akam M, Tautz D, Denell R, Brown S

Department of Genetics, Wellcome/Cancer Research Campaign Institute, Cambridge, England.

Proc Natl Acad Sci U S A. 1996 Aug 6;93(16):8479-84. doi: 10.1073/pnas.93.16.8479.

We have cloned, from a beetle and a locust, genes that are homologous to the class 3 Hox genes of vertebrates. Outside the homeobox they share sequence motifs with the Drosophila zerknüllt (zen) and z2 genes, and like zen, are expressed only in extraembryonic membranes. We conclude that the zen genes of Drosophila derive from a Hox class 3 sequence that formed part of the common ancestral Hox cluster, but that in insects this (Hox) gene has lost its role in patterning the anterio-posterior axis of the embryo, and acquired a new function. In the lineage leading to Drosophila, the zen genes have diverged particularly rapidly.

我们从一种甲虫和一种蝗虫中克隆出了与脊椎动物3类同源异型基因同源的基因。在同源异型框之外，它们与果蝇的零细胞（zen）基因和z2基因共享序列基序，并且像zen基因一样，仅在胚外膜中表达。我们得出结论，果蝇的zen基因源自构成共同祖先同源异型基因簇一部分的3类同源异型序列，但在昆虫中，这个（同源异型）基因已失去其在胚胎前后轴模式形成中的作用，并获得了新功能。在导致果蝇的谱系中，zen基因分化得特别快。