Embryonic expression and characterization of a Ptx1 homolog in Drosophila.
We describe the molecular characterization of the paired-type homeobox gene D-Ptx1 of Drosophila, a close homolog of the mouse pituitary homeobox gene Ptx1 and the unc-30 gene of C. elegans, characterized by a lysine residue at position 9 of the third alpha-helix of the homeodomain. D-Ptx1 is expressed at various restricted locations throughout embryogenesis. Initial expression of D-Ptx1 in the posterior-most region of the blastoderm embryo is controlled by fork head activity in response to the activated Ras/Raf signaling pathway. During later stages of embryonic development. D-Ptx1 transcripts and protein accumulate in the posterior portion of the midgut, in the developing Malpighian tubules, in a subset of ventral somatic muscles, and in neural cells. Phenotypic analysis of gain-of-function and lack-of-function mutant embryos show that the D-Ptx1 gene is not involved in morphologically apparent differentiation processes. We conclude that D-Ptx1 is more likely to control physiological cell functions than pattern formation during Drosophila embryogenesis.
Vorbrüggen
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Max-Planck-Institut für biophysikalische Chemie, Abt. Molekulare Entwicklungsbiologie, Am Fassberg, Göttingen, Germany.
Constien
R
R
Zilian
O
O
Wimmer
E A
EA
Dowe
G
G
Taubert
H
H
Noll
M
M
Jäckle
H
H
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001756:Blastoderm; D019521:Body Patterning / Q000235:genetics; D004330:Drosophila / Q000196:embryology* / Q000235:genetics*; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian; D051858:Forkhead Transcription Factors; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D051761:Paired Box Transcription Factors; D010641:Phenotype; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D029721:Drosophila Proteins; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D051761:Paired Box Transcription Factors; C110587:Ptx1 protein, Drosophila; D014157:Transcription Factors; C101485:homeobox protein PITX1