title: Regulation, function and potential origin of the Drosophila gene spalt adjacent, which encodes a secreted protein expressed in the early embryo.
abstract: During early embryogenesis of Drosophila the spatial and temporal expression patterns of the region-specific homeotic gene spalt (sal) and the neighbouring gene spalt adjacent (sala) extensively overlap. We show that the initial expression patterns of the two genes in the blastoderm also have identical genetic controls. However, while sal encodes a transcription factor, sala encodes a precursor protein from which a functional signal peptide is cleaved off to generate the secreted sala protein. Ectopic expression or absence of sala protein does not affect embryonic development, adult viability or fertility. In addition to sal and sala, we identified a third gene nearby, termed spalt related (salr), which shares coding sequence similarity and a late embryonic expression pattern with sal, but lacks the early expression domains that are shared by sal and sala. These results suggest that the three genes and their present cis-regulatory regions arose through a chromosomal rearrangement involving local duplication and transposition events in the 32F/33A region on the left arm of the second chromosome.
authors.affiliation: Max-Planck-Institut für biophysikalische Chemie, Abteilung Molekulare Entwicklungsbiologie, Am Fassberg, D-37077 Göttingen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Reuter
authors.forename: R P
authors.initials: RP
authors.lastname: Kühnlein
authors.forename: G
authors.initials: G
authors.lastname: Frommer
authors.forename: R
authors.initials: R
authors.lastname: Barrio
authors.forename: F C
authors.initials: FC
authors.lastname: Kafatos
authors.forename: H
authors.initials: H
authors.lastname: Jäckle
authors.forename: R
authors.initials: R
authors.lastname: Schuh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004330:Drosophila / Q000196:embryology* / Q000235:genetics*; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000502:physiology; D017344:Genes, Insect; D005807:Genes, Overlapping; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D007301:Insect Hormones; D014157:Transcription Factors; C085793:salm protein, Drosophila