Sequence analysis of 27 alleles of each of the three Ras-related genes in Drosophila melanogaster indicates that they all have low levels of polymorphism but may experience slightly different evolutionary pressures. No amino acid replacement substitutions were indicated in any of the sequences, or in the sibling species D. simulans and D. mauritiana. The Dras1 gene, which is the major ras homologue in Drosophila, has less within-species variation in D. melanogaster relative to the amount of divergence from the sibling species than does Dras2, although the contrast was not significant by the HKA test. Dras2 appears to be maintaining two classes of haplotype in D. melanogaster, one of which is closer to the alleles observed in the sibling species, suggesting that this is not likely to be a pseudogene despite the absence of a mutant phenotype. Although differences in level of expression may affect the function of the genes, it is concluded that genetic variation in the Ras signal transduction pathways cannot be attributed to catalytic variation in the Ras proteins.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Genetics
Research Field:	Quantitative Genetics (incl. Disease and Trait Mapping Genetics)
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Biological Sciences
Author:	Gasperini, RJ (Dr Rob Gasperini)
ID Code:	57738
Year Published:	1999
Web of Science® Times Cited:	17
Deposited By:	Anatomy and Physiology
Deposited On:	2009-08-12
Last Modified:	2011-08-05
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