Investigation of the relationship between allozyme variation and some fitness components in stellate sturgeon Acipenser stellatus
Ryabova, G.D.; Ofitserov, M.V.; Shishanova, E.I.
Genetika 31(12): 1679-1692
1995
ISSN/ISBN: 0016-6758 Accession: 032033748
The relationship between biochemical gene markers and polygenic traits in adult and juvenile stellate sturgeon from the Volga and Ural rivers was analyzed. The polygenic traits included maturity and growth rates, body length in males and females, and female longevity. Allozymes of lactate dehydrogenase (LDH, two loci), phosphoglucomutase (PGM), and esterase (EST) in adult fish and LDH in juveniles were used as markers. The effect of heterozygosity on juvenile growth rate was different for different Ldh loci and depended on environmental conditions (natural or hatchery populations). Heterozygosity level showed an inverse association with the age of the fish. Individuals with highest heterozygosity (males and females from the Ural and females from the Volga) had a smaller size, indicating earlier maturity of heterozygotes for the Ldh3, Pgm1, and Est2 loci. The lower heterozygosity in older fish might indicate that heterozygous individuals have a shorter life span. Higher heterozygosity for Ldh3, Pgm1, and Est2 in females from the Ural population was associated with lower fecundity; in contrast, higher heterozygosity for Ldh4 was related to higher fecundity. In both populations examined, some cases of association between high heterozygosity and reduction in size in both sexes were recorded. Variation in growth rate was higher in the suboptimal (hatchery) environment than in the optimal (natural) one, while differences in fecundity were more pronounced in relatively optimal ecological conditions (Ural). Heterozygosity for the Ldh3 locus promoted high juveniles survival and growth rates in suboptimal conditions; it was associated with lower fecundity of stellate sturgeon females in ecologically optimal conditions.