title: Drosophila castor is regulated negatively by the Ubx and abdA genes, but positively by the AbdB gene.
abstract: The ventral nerve cord (VNC) of Drosophila exhibits significant segmental-specific characteristics during embryonic development. Homeotic genes are expressed over long periods of time and confer identity to the different segments. castor (cas) is one of the genes which are expressed in neuroblasts along the VNC. However, at late embryonic stages, cas transcripts are found only in head and thoracic segments and terminal abdominal segments, while Cas protein lasts longer in all segments. In this study, we investigated the regulation of temporal and spatial expression of cas by the bithorax complex genes. In the loss-of-function mutants of Ultrabithorax (Ubx) and abdominal-A (abdA), cas transcripts were ectopically expressed in abdominal segments at late embryonic stage. However, unlike in Ubx and abdA mutants, in Abdominal-B (AbdB) loss-of-function mutant embryos, cas disappeared in the terminal region. Ectopic Ubx and abdA suppressed cas expression, but ectopic AbdB activated cas expression in most abdominal segments. Moreover, cas was co-expressed in the cells in which AbdB was normally expressed, and overexpressed in the ectopically expressed AbdB embryos. These results suggest that the expression of cas is segment-specifically regulated negatively by Ubx and abdA genes, but positively by the AbdB gene.
authors.affiliation: Department of Biology Education, Seoul National University, Seoul, Korea.
authors.forename: Ju-Hyun
authors.initials: JH
authors.lastname: Ahn
authors.forename: Siuk
authors.initials: S
authors.lastname: Yoo
authors.forename: Hyun-Joo
authors.initials: HJ
authors.lastname: Park
authors.forename: Keuk-Il
authors.initials: KI
authors.lastname: Jung
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Sang-Hak
authors.initials: SH
authors.lastname: Jeon
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C062393:Abd-B proteins, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; C110593:cas protein, Drosophila; C066591:abd-A protein, Drosophila