DROSOPHILA BRACHYENTERON REGULATES GENE ACTIVITY AND MORPHOGENESIS INTHE GUT

Citation
Jb. Singer et al., DROSOPHILA BRACHYENTERON REGULATES GENE ACTIVITY AND MORPHOGENESIS INTHE GUT, Development, 122(12), 1996, pp. 3707-3718
Citations number
58
Categorie Soggetti
Developmental Biology
Journal title
ISSN journal
09501991
Volume
122
Issue
12
Year of publication
1996
Pages
3707 - 3718
Database
ISI
SICI code
0950-1991(1996)122:12<3707:DBRGAA>2.0.ZU;2-F
Abstract
Chromosomal region 68D/E is required for various aspects of Drosophila gut development; within this region maps the Brachyury homolog T-rela ted gene (Trg), DNA of which rescues the hindgut defects of deficiency 68D/E, From a screen of 13,000 mutagenized chromosomes we identified six non-complementing alleles that are lethal over deficiencies of 68D /E and show a hindgut phenotype. These mutations constitute an allelic series and are all rescued to viability by a Trg transgene. We have n amed the mutant alleles and the genetic locus they define brachyentero n (byn); phenotypic characterization of the strongest alleles allows d etermination of the role of byn in embryogenesis. byn expression is ac tivated by tailless, but byn does not regulate itself, byn expression in the hindgut and anal pad primordia is required for the regulation o f genes encoding transcription factors (evert-skipped, engrailed, caud al, AbdominalB and orthopedia) and cell signaling molecules (wingless and decapentaplegic). In byn mutant embryos, the defective program of gene activity in these primordia is followed by apoptosis (initiated b y reaper expression and completed by macrophage engulfment), resulting in severely reduced hindgut and anal pads. Although byn is not expres sed in the midgut or the Malpighian tubules, it is required for the fo rmation of midgut constrictions and for the elongation of the Malpighi an tubules.