Evolution of distinct developmental functions of three Drosophila genes by acquisition of different cis-regulatory regions.
It is generally accepted that the specific function of a gene depends on its coding sequence. The three paired-box and homeobox genes paired (prd), gooseberry (gsb) and gooseberry neuro (gsbn) have distinct developmental functions in Drosophila embryogenesis. During the syncytial blastoderm stage, the pair-rule gene prd activates segment-polarity genes, such as gsb, wingless (wg), and engrailed (en), in segmentally repeated stripes. After germ-band extension, gsb maintains the expression of wg, which in turn specifies the denticle pattern by repressing a default state of ubiquitous denticle formation in the ventral epidermis. In addition, gsb activates gsbn, which is expressed mainly in the central nervous system, suggesting that gsbn is involved in neural development. Here we show that, despite the functional difference and the considerably diverged coding sequence of these genes, their proteins have conserved the same function. The finding that the essential difference between genes may reside in their cis-regulatory regions exemplifies an important evolutionary mechanism of how function diversifies after gene duplication.
Li
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Institute for Molecular Biology II, University of Zürich, Switzerland.
Noll
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D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D006358:Hot Temperature; D007814:Larva; D008969:Molecular Sequence Data; D005810:Multigene Family; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D014157:Transcription Factors; D004247:DNA