The genetics of Cepaea esterases. I. Cepaea nemoralis.

Abstract

Using Polyacrylamide disk electrophoresis, at least 23 zones of general esterase activity can be distinguished in extracts of Cepaea nemoralis hepatopancreas. Breeding experiments have thrown light on the inheritance of three esterase systems. It has been suggested that the four most cathodally migrating esterase zones may be controlled by four linked loci, forming an esterase supergene. Zone Est. 5 also seems to be part of the same system and might be coded for by another linked locus. At each of these loci three alleles have been postulated, one producing no detectable enzyme, another producing a weak enzyme and the third coding for an active enzyme. Each locus seems to control enzyme activity at one level in the gel. Another esterase system is controlled by three alleles at one locus. The enzyme produced is a dimer, heterozygotes having three zones of activity. Attemps to hybridise “parental” enzymes so as to give a hybrid zone on electrophoresis failed. The third esterase system examined is one of presence and absence of the enzyme. It is controlled by two alleles at one locus with the presence of enzyme being dominant to its absence. There is no linkage detectable between any of the (effective) esterase loci or between the esterase loci and three loci determining the shell colour and banding morphs.