Molecular structure of rare but geographically widespreadsn-glycerol-3-phosphate dehydrogenase ‘ultra-fast’ electrophoretic alleles inDrosophila melanogaster
✍ Scribed by Tomasz M. Wilanowski; Phillip T. Barnes; John B. Gibson
- Publisher
- Springer Netherlands
- Year
- 1996
- Tongue
- English
- Weight
- 686 KB
- Volume
- 97
- Category
- Article
- ISSN
- 0016-6707
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✦ Synopsis
Six naturally occurring but rare alleles of sn-glycerol-3-phosphate dehydrogenase (Gpdh) in Drosophila melanogaster have been investigated in this study. They all belong to a class of Gpdh tJF (ultra-fast) alleles, because their electrophoretic mobilities are faster than that of the Gpdh F (fast) allele. The Gpdh UF variants are widespread, and have been reported from five continents. DNA sequence analysis has shown that the change in electrophoretic mobility was in each allele caused by a single amino acid residue substitution in the encoded protein. In the Xiamen UF allele it is a substitution of lysine (AAA) to asparagine (AAT) in exon 1 (residue 3). An asparagine (AAT) to aspartate (GAT) change was found in exon 6 (residue 336) in the Iowa UF and Netherlands uF alleles. The mobility of the Raleigh UF allele was altered by a valine (GTG) to glutamate (GAG) substitution in exon 3 (residue 76). Two mutations were detected in the Brazzaville UF allele: a lysine (AAG) to methionine (ATG) substitution in exon 2 (residue 68) is responsible for the ultra-fast phenotype of this variant, while a tyrosine (TAT) to phenylalanine (TI'T) substitution in exon 4 (residue 244) is not expected to alter the electrophoretic mobility of the encoded protein. These results indicate that the Gpdh UF alleles originate from different mutational events, and only two of them -Iowa UF and Netherlands UF -might share a common ancestry. The GPDH activity of the Iowa uF allele is intermediate between those of the Gpdh s and Gpdh F control stocks. The other Gpdh uF variants have lower activities than the controls: Xiamen uF -83%, Raleigh UF -80% and Brazzaville UF -73% of the Gpdh F control.