ISSN:
1573-4927
Keywords:
Drosophila melanogaster
;
NADP+-dependent isocitrate dehydrogenase (NADP-IDH)
;
cis-acting regulation
;
population null alleles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract We have characterized biochemical effects of Idh GB1 in Drosophila melanogaster. This is a “null”-activity allele for NADP+-dependent isocitrate dehydrogenase (NADP-IDH) isolated from a natural population. The homozygous mutant strain has 5% of the NADP-IDH specific activity found in controls and less than 24% of the immunologically cross-reacting material (CRM). This mutation maps to 27.2 on the third chromosome, to the right of h. The biochemical phenotype of this mutant strain includes a coordinate reduction in malic enzyme (ME) specific activity and CRM and an increase in specific activity for the pentose-phosphate shunt enzymes, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase. The K m values for purified NADP-IDH are not different from those found for the purified control enzyme for NADP+ or isocitrate. It is suggested that this allele may represent a cis-acting control mutation for one of at least two loci involved in the production of NADP-IDH in D. melanogaster.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00498919
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