Double and triple mutant combinations of bithorax complex of Drosophila.
We have constructed double and triple mutant combinations for the Ubx, abd-A and Abd-B genes of the bithorax complex and have examined the homeotic transformations they produce in the larval and adult patterns. Embryos hemizygous for the triple combination exhibit a metameric pattern consisting of parasegments 5-12 being transformed into parasegment 4. In addition, parasegment 13 develops like a mixture of parasegment 3 and 4, and parasegment 14 is abnormal. The same phenotype is displayed by embryos homozygous for DfP9, lacking all the BX-C DNA, >300 kb. This result strongly supports the notion that the BX-C contains only three genes which account for all the developmental functions of the complex. The phenotypes of the different double combinations also support the same view; the Ubx abd-a comthoracic and several abdominal functions. The abd-A Abd-B combination exhibits the same phenotype of DpP10 DfP9, lacking all the abdominal functions except those specific for A1. Our results also indicate that each BX-C gene becomes active autonomously regardless of the presence or functional state of the other BX-C genes.
Casanova
J
J
Centro de Biología Molecular C.S.I.C., Universidad Autónoma de Madrid, Canto Blanco, Madrid 28049, Spain.
Sánchez-Herrero
E
E
Busturia
A
A
Morata
G
G
D000818:Animals; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
C062393:Abd-B proteins, Drosophila; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; C066591:abd-A protein, Drosophila