Tumorous-head (tuh-1; tuh-3) modulates Abd-B bithorax-complex functions in Drosophila melanogaster.
Abdominal-B (Abd-B) mutants of the bithorax-complex (BX-C) were studied in trans with tuh-3 to evaluate their interactions with this homeotic mutant and the maternal effect locus (tuh-1) controlling tuh-3 expression. Head defects occur in tuh-3 offspring from tuh-1h homozygous mothers, while genital defects occur in homozygous tuh-3 offspring from mothers carrying the tuh-1g allele. The influence exerted by the tuh-1 maternal effects on tuh-3 Abd-B transcript distribution was evaluated by whole mount in situ hybridization. Results demonstrated that: (1) of the 21 Abd-B mutants tested, head defects were produced by SGA62, I127B, I127O and tuh-3, with I127B and tuh-3 as the only mutants to require the head defect maternal effect for expression; (2) one specific cluster of regulatory (r) mutants, Uab1, 65 and I127B, enhanced penetrance and expressivity of tuh-3 head defects; (3) the most profound suppression of head defect penetrance occurred when Abd-B mutants eliminated the morphogenetic (m) and r functions; (4) genital defects increased in frequency in tuh-3/Abd-B mutant trans-heterozygotes with loss of r function; (5) Abd-B transcription (class A, class B, class C) appears normal in tuh-3 embryos when their mothers pass on the tuh-1h head defect maternal effect, whereas the regulatory transcripts (class B and class C) are reduced when tuh-3 mothers pass on the tuh-1g genital disc maternal effect; (5) tuh eye-antennal imaginal discs express ABD-B protein; and (6) tuh-3 misregulates both m and r function of Abd-B.
Kuhn
D T
DT
Department of Biology, University of Central Florida, Orlando 32816.
Mack
J A
JA
Duan
C
C
Packert
G
G
D000818:Animals; D002874:Chromosome Mapping; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology; D005260:Female; D005801:Genes, Homeobox; D006257:Head / Q000002:abnormalities; D006579:Heterozygote; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D014158:Transcription, Genetic
C062393:Abd-B proteins, Drosophila; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D007301:Insect Hormones