Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico

Abstract

BackgroundThe Africanized honey bee is one of the most spectacular invasions in the Americas. African bees escaped from apiaries in Brazil in 1956, spread over Americas and by 1994 they were reported in Puerto Rico. In contrast to other places, the oceanic island conditions in Puerto Rico may mean a single introduction and different dynamics of the resident European and new-coming Africanized bees.To examine the genetic variation of honey bee feral populations and colonies from different locations in Puerto Rico, we used eight known polymorphic microsatellite loci.ResultsIn Puerto Rico, gAHB population does not show any genetic structure (Fst = 0.0783), and is best described as one honey bee population, product of hybridization of AHB and EHB. The genetic variability in this Africanized population was similar to that reported in studies from Texas. We observed that European private allele frequencies are high in all but one locus. This contrasts with mainland Africanized populations, where European allele frequencies are diminished. Two loci with European private alleles, one on Linkage Group 7, known to carry two known defensiveness Quantitative Trait Loci (QTLs), and the other on Linkage Group 1, known to carry three functionally studied genes and 11 candidate genes associated with Varroa resistance mechanisms were respectively, significantly greater or lower in European allele frequency than the other loci with European private alleles.ConclusionsGenetic structure of Puerto Rico gAHB differs from mainland AHB populations, probably representing evolutionary processes on the island.

Colonization history and population differentiation of the Honey Bees (Apis mellifera L.) in Puerto Rico

“…Previously, even with only a few markers it was observed that two of eight microsatellite loci tested deviated from the expected allele frequencies based on an admixture model (Galindo-Cardona et al, 2013). We tested this hybrid mosaic hypothesis now with 917 markers across the genome and found 6.5% of the markers to deviate from the admixture model, demonstrating the "mosaic" characteristic.…”

“…This admixed population is part of the broader history of the accidental introduction of Africanized honey bees (AHB) to continental Brazil and later spread across the Neotropics and southern Nearctic. However, AHB's continental origin remains unknown and only one introduction event is thought to have occurred (see Rivera-Marchand et al, 2008;Galindo-Cardona et al, 2013). As part of this expansion and assisted by human transit, AHB arrived to Puerto Rico in 1994 (Cox, 1994).…”

“…suggested by the presence of a single mtDNA haplotype in Puerto Rico of five available within AHB populations(Rivera-Marchand et al, 2008). The Texas AHB origin hypothesis was also suggested based on similarity of microsatellite genetic profiles across Texas AHB and PR gAHB populations(Galindo-Cardona et al, 2013). The Texas AHB origin hypothesis was also suggested based on similarity of microsatellite genetic profiles across Texas AHB and PR gAHB populations(Galindo-Cardona et al, 2013).…”

Stock composition of northern neotropical honey bees: mitotype and morphotype diversity in Mexico (Hymenoptera: Apidae)

“…For instance, the expansion of Africanized honey bees in the temperate region of the southern United States seems to have been greatly enhanced by the decimation of resident feral European honey bee colonies following the arrival of the Varroa mite (Pinto et al 2005). Similarly, in Puerto Rico, a genetically stable honey bee population has formed, with European-and Africanlike traits associated with Varroa resistance (Galindo-Cardona et al 2013). The reported spread of Africanized colonies in neotropical highlands (Quezada-Euán et al 2003;Kraus et al 2007) may have been helped by similar parasite-related events.…”

Individual responsiveness to shock and colony-level aggression in honey bees: evidence for a genetic component

“…In at least one study, the aggressive response of Africanized honey bees was reduced by as much as 50 % via artificial selection (Guzman-Novoa and Page 1999). More recently, a colony-level study by Rivera-Marchand et al (2012) showed that aggressive response was reduced in colonies of Africanized honey bees in Puerto Rico (coined gAHB, gentle Africanized honey bee, Galindo-Cardona et al 2013). …”