Extent With Modification: Leg Patterning in the Beetle Tribolium castaneum and the Evolution of Serial Homologs

G3: Genes, Genomes, Genetics

Elizabeth L. Jockusch¹  David R. Angelini²  Frank W. Smith¹ 

[1] Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043;Department of Biology, American University, Washington, DC 20016-8007Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043Department of Biology, American University, Washington, DC 20016-8007Department of Biology, American University, Washington, DC 20016-8007Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043Department of Biology, American University, Washington, DC 20016-8007Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043

关键词: appendage patterning;    adult development;    metamorphosis;    developmental constraint;    serial homology;   

DOI  :  10.1534/g3.111.001537

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

Serial homologs are similar structures that develop at different positions within a body plan. These structures share some, but not all, aspects of developmental patterning, and their evolution is thought to be constrained by shared, pleiotropic gene functions. Here we describe the functions of 17 developmental genes during metamorphic development of the legs in the red flour beetle, Tribolium castaneum. This study provides informative comparisons between appendage development in Drosophila melanogaster and T. castaneum, between embryonic and adult development in T. castaneum, and between the development of serially homologous appendages. The leg gap genes Distal-less and dachshund are conserved in function. Notch signaling, the zinc-finger transcription factors related to odd-skipped, and bric-à-brac have conserved functions in promoting joint development. homothorax knockdown alters the identity of proximal leg segments but does not reduce growth. Lim1 is required for intermediate leg development but not distal tarsus and pretarsus development as in D. melanogaster. Development of the tarsus requires decapentaplegic, rotund, spineless, abrupt, and bric-à-brac and the EGF ligand encoded by Keren. Metathoracic legs of T. castaneum have four tarsomeres, whereas other legs have five. Patterns of gene activity in the tarsus suggest that patterning in the middle of the tarsal region, not the proximal- or distal-most areas, is responsible for this difference in segment number. Through comparisons with other recent studies of T. castaneum appendage development, we test hypotheses for the modularity or interdependence of development during evolution of serial homologs.

【 授权许可】

Unknown