Preliminary evidence of PGM-2* allele frequency changes in mass reared whitefish (Coregonus lavaretus L.) larvae

Abstract

Enzyme gene variability was studied at 6 and 12 week in whitefish (Coregonus lavaretus) juveniles fed with Artemia nauplii and with three dry diets. Six of the 12 loci screened were monomorphic: GPI-B1^*, LDH-A1^*, LDH-A2^*, LDH-B1*, LDH-B2^* and sMDH-A1^*, and the remaining 6 loci: GPI-B2^* , sMDH- A2^*, sMDH-B1,2^* , PGDH^*, and PGM-2^*, were variable. Most of the variability was at PGM-2^*, and the variation was reduced from 6 to 12 weeks on all diets. Pooled 12-week sample showed significantly (P<0.05) low'er variability at this locus than pooled 6-week sample. After six weeks of rearing the heterozygosity values ranged from 0.037 to 0.048, and after 12 weeks from 0.025 to 0.037. The loss of genetic variation from 6 to 12 weeks may indicate selection operating during the rearing process. There was no correlation between genetic variation and growth of whitefish juveniles reared in a hatchery.