Nutritional regulation of antennal/leg homoeotic mutants inDrosophila melanogaster

Abstract

The expression of the antennal homoeotic mutant, Nasobemia, is shown to be strongly dependent on nutrition. Dietary deficiencies in any of the following: thiamine, calcium pantothenate, nicotinic acid or RNA, cause a curing of the homoeotic defect. It is demonstrated that the effects of thiamine and pantothenate are through limiting acetyl-CoA synthesis and that fatty acids are required for high penetrance of the Ns gene. Similar nutritional effects are described for other Antennapedia and aristapedia alleles. The period of sensitivity to nutritional changes is denned for Ns and compared with the period of temperature sensitivity. These results suggest the hypothesis that the homoeotic mutations Antennapedia and aristapedia share some common metabolic requirements which involve synthesis of acetyl-CoA.

Are entrenched characters developmentally constrained? Creating biramous limbs in an insect

“…Eclosed and pharate adults that died in the pupal case are included in these results. For Antp [ 73b ] frequencies were higher at room temperature than at 25°C, whereas temperature had little effect on the frequency of transformations in Antp [ Ns ] despite the fact that this allele is temperature‐sensitive (Jowett and Sang 1979). Males showed no transformation in obk; Antp [ Ns ] ,hth [ 1422‐4 ], and this stock also showed a higher frequency of antenna duplicates and/or antennal leg duplicates compared to obk; Antp [ 73b ] , hth [ 1422‐4 ].…”

“…These mutations also have global coordinating properties in that they integrate several aspects of changes in organ determination: morphogenesis (antenna to leg transformation), cell differentiation (antenna-or leg-specific bristles), and cell patterning (location and arrangement of bristle arrays). Although our purpose has been to explore the constraints on morphology, it is well to point out that the phenotypes of the mutations used here can be achieved by mutations at a number of different loci and are influenced by modifiers elsewhere in the genome (Jowett and Sang 1979). Therefore, it is possible to imagine scenarios in which genetic variations for a polyramous fly appendage could arise in natural populations (Waddington 1961).…”