S. Holmes. The Northumbrian Water Ecology Centre, Sunderland University, Sunderland, SRI 3SD, UK. The genus Calliostoma is world-wide in distribution,.
J. Moll Stud (1997), 63, 469-471
© The Malacological Society of London 1997
RESEARCH NOTES Inheritance of the calmodulin gene-1 intron 3 in Mytilus edulis juveniles M.A. Del Rio-Portillat and A.R. Beaumont School of Ocean Sciences. University of Wales, Bangor, Menai Bridge, Gwynedd, LL595EF, U.K.
t Praent Addreu: CICESE Acuicultura. Apdo. Postal 2732. Ensenada, Baja California, 22800. Mexico
Corte-Real et al.Ai reported two alleles, A and B, with approximate sizes of 525 and 460 bp respectively and these agree with the sizes of the amplified DNA found in the present study. We have named the alleles according to their approximate size (525 and 460 bp) rather than using letters because we have detected an additional longer variant (600 bp) in a local wild M. edulis population6. All offspring from crosses AM and BM produced only a single band from the amplified segment. In both groups from cross CM, heterozygote offspring exhibited two bands of the expected sizes (Table 1). However, when first scored, a few of these individuals exhibited an extra third band but this extra band never occurred again following repeat PCRs and was therefore a secondary PCR product rather than a real product from the mussel genome. Agreements with Mendelian expectations were found in both groups (a) and (b), and overall, from family CM (Table 1). Therefore, Mendelian inheritance of the 460 and 525 alleles at the CaM-1 intron 3 locus is confirmed using relatively small numbers of juveniles produced from crosses under laboratory conditions. Confirmation that there was no contamination between families and that there were no other unexpected irregularities has been obtained by allozyme analysis. From the six allozyme loci tested (Table 2), five were polymorphic for cross AM (ldh-1, Idh-2, IMP, Csr, and Pgm) and CM {ldh-1, Idh-2, Lap, Dia, and Pgm), whilst three loci were polymorphic for cross BM (Lap, Dia, and Pgm, Table 2). No significant deviations from Mendelian inheritance at any loci were found when allele and genotype frequencies were tested in offspring from families AM and BM. Offspring from cross CM which had been selected for fast larval growth (a) differed significantly (p
