Origin of α-glycerophosphate dehydrogenase isozymes inDrosophila melanogasterand their functional relationship in the α-glycerophosphate cycle
✍ Scribed by Glenn C. Bewley; John C. Lucchesi
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 934 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0006-2928
No coin nor oath required. For personal study only.
✦ Synopsis
The basis for the differentiation of L-glycerol-3-phosphate dehydrogenase (alpha-GPDH) into larval and adult isozymes in Drosophila melanogaster was investigated by the correlation of a lack of appearance of each isozyme during development within Drosophila bearing alpha-GPDH "null" alleles and by the study of a putative conversion factor. Conversion studies indicate the presence of a heat-labile RNase-resistant conversion factor present in crude larval extracts with the ability to convert GPDH-1 to GPDH-2 and GPDH-3 but not vice versa. In addition, "null" mutations at the Gpdh locus obliterate all isozymatic species of alpha-GPDH in all developmental stages. These observations suggest that all alpha-GPDH isozymes are the product of a single structural gene and that the multiple forms of this enzyme arise during successive developmental stages through an epigenetic modification of the primary Gpdh+ polypeptide. Finally, observations are reported which bear on the functional divergence of the alpha-glycerophosphate cycle in the adult and larval stage of development.