ISSN:
1573-4927
Keywords:
null allele polymorphism
;
duplicate genes
;
loss of duplicate gene expression
;
aspartate aminotransferase
;
brook trout
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Unusual phenotypic distributions at the muscle-specific, duplicate aspartate aminotransferase (AAT) loci were found in wild populations of brook trout (Salvelinus fontinalis), a species of the tetraploid-derivative Salmonidae. Analysis of these phenotypic distributions ruled out disparate gene frequencies, nonrandom association between the two loci, and inbreeding as possible explanations; however, models incorporating a null allele fit the data. Inheritance data from hatchery populations of brook trout also indicated a null allele polymorphism. This proposed AAT null allele, along with other null allele polymorphisms in salmonids, is evidence that loss of duplicate gene expression is still occurring. In contrast, there is no such evidence of ongoing loss of duplicate gene expression in the Catostomidae, another tetraploid-derivative lineage. We interpret this and other differences between salmonids and catostomids as reflecting an autotetraploid origin for salmonids and an allotetraploid origin for catostomids. The significance of these findings is also considered with respect to current models of the rate of loss of duplicate gene expression in tetraploid-derivative organisms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00484565
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