Esterase variation in herring studied by isoelectric focusing
Original version
This report is not to be cited without prior reference to the authorsAbstract
Few suitable genetic characteristics for studying herring population structure are
available, and the main aim of the study reported here has been to reveal traits which
display useful genetic variations for application on more extensive population studies of
herring in Northeast Atlantic waters. Esterase is aften found to be highly variable among
fishes, but often the phenotypes are difficult to discern and thus the genetic background
for the observed variation is difficult to reveal. In the present report isoelectric focusing
of blood esterases has been used as an analytic tool for revealing and describing
variations and their genetic background. Material has been collected from coastal and
offshore Norwegian waters, and more than 1500 specimens of 24 samples have been
analysed at two pH ranges (3.5-9.5 and 4.0-6.5). Four groups of esterase components
were found, each probably representing at least one polymorphic locus. Two of these
groups were clear enough for proper classification of the individuals, and at least one
seemed useful for further studies of herring population structure. Clear variations were
seen in phenotype distributions between samples, and especially the samples of autumn
spawning herring deviated from the bulk of the spring spawners.