title: Zinc-finger paralogues tsh and tio are functionally equivalent during imaginal development in Drosophila and maintain their expression levels through auto- and cross-negative feedback loops.
abstract: teashirt (tsh) and tiptop (tio) are two Drosophila gene paralogues encoding zinc-finger transcription factors. While tsh is an important developmental regulator, tio null individuals are viable and fertile. Here, we show that tio and tsh have coincident expression domains in the imaginal discs, the precursors of the adult body, and that both genes show similar functional properties when expressed ectopically. Furthermore, tio is able to rescue the development of tsh mutants, indicating that both genes are functionally equivalent during imaginal development. Of interest, the transcriptional regulation of tio and tsh is linked by a negative feedback loop. This mechanism might be required to maintain a tight control on the total levels of tio/tsh and could help explaining why Drosophila keeps an apparently dispensable gene.
authors.affiliation: Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide, Campus UPO, Seville, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Bessa
authors.forename: Laura
authors.initials: L
authors.lastname: Carmona
authors.forename: Fernando
authors.initials: F
authors.lastname: Casares
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology* / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D025461:Feedback, Physiological; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D009024:Morphogenesis; D034622:RNA Interference; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: D029721:Drosophila Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C496672:tio protein, Drosophila; C066830:tsh protein, Drosophila