Comparison of microsatellite DNA diversity among commercial queen breeder stocks of Italian honey bees in the United States and Italy
Lelania Bourgeois, Allen Sylvester, Robert Danka, Thomas Rinderer.
Declines in the numbers of breeder honey bee queens and the concomitant loss of genetic diversity could potentially result in inbreeding, and increased susceptibility to pests and diseases. Genetic diversity of commercial Italian bee colonies in the United States and Italy was assessed using six variable microsatellite DNA loci. Worker bees were sampled from colonies of queen breeders in both countries (USA, n = 18; Italy, n = 24). Overall, allelic richness (mean alleles/locus), gene diversity (heterozygosity), and FIS (inbreeding coefficient) did not differ between the two groups. A total of 48 alleles were present among all colonies. Sampled colonies from each country had a total of 38 alleles, although alleles were present that were unique to each group. There were a total of 10 unique alleles among USA bees and 10 among Italian bees. Estimates of the level of genetic differentiation based on different allele frequency patterns among the USA and Italian bees were measured with the population genetic parameter FST. These estimates showed that bees from the USA and Italy were measurably distinct relative to the frequencies of the microsatellite alleles present in samples from each country. Overall allelic diversity levels were sufficiently high indicating that inbreeding does not appear to be an immediate threat to existing honey bee populations.
honey bee, Varroa destructor,microsatellite, genetic diversity, Italy, Italian bees