The Journal of Heredity 1999:90(5)
© 1999 The American Genetic Association 90:565-568
Brief communication. Evidence for temperature-dependent selection for malate dehydrogenase allele frequencies in honeybee populations
School of Biological Sciences A12, University of Sydney, NSW 2006, Australia *Corresponding author e-mail: Boldroyd@bio.usyd.edu.au
The MDH-1 genotype and a mitochondrial DNA haplotype was determined for feral honeybees (Apis mellifera L.) collected from 10 sites in southern New South Wales, Australia. The frequency of the Mdh65 allele was positively correlated, and the Mdh80 allele negatively correlated with increasing average daily temperature for July and January (P<.01), whereas no cline was found for the mitochondrial marker. Parallel clines in MDH allele frequencies have now been found on four continents, and the Mdh80 allele has been shown to be less heat stable in vitro than the other alleles. We conclude that this is very strong evidence that the MDH-1 clines observed in honeybees are due to temperature-dependent selection.