The Mutation without childrenrglCauses Ecdysteroid Deficiency in Third-Instar Larvae of Drosophila melanogaster

Autor: Wismar, Jasmine, Habtemichael, Negusse, Warren, James T, Dai, Ji-Da, Gilbert, Lawrence I, Gateff, Elisabeth
Zdroj: Developmental Biology; October 2000, Vol. 226 Issue: 1 p1-17, 17p
Abstrakt: Larvae homozygous for the recessive lethal allele without childrenrgl(wocrgl) fail to pupariate. Application of exogenous 20-hydroxyecdysone elicits puparium formation and pupation. Ecdysteroid titer measurements on mutant larvae show an endocrine deficiency in the brain–ring gland complex, which normally synthesizes ecdysone, resulting in a failure of the larvae to achieve a threshold whole body hormone titer necessary for molting. Ultrastructural investigation revealed extensive degeneration of the prothoracic cells of the ring gland in older larvae. Thewocgene, located in polytene chromosomal region 97F, consists of 11 exons. A 6.8-kb transcript is expressed throughout development but is absent in the mutant wocrgllarvae. Thewocgene encodes a protein of 187 kDa. Eight zinc fingers of the C2–C2 type point to a possible function as a transcription factor. The wocprotein shows considerable homology to human proteins which have been implicated in both mental retardation and a leukemia/lymphoma syndrome.
Databáze: Supplemental Index