Inheritance of thelytoky in the honey bee Apis mellifera capensis.

Asexual reproduction via thelytokous parthenogenesis is widespread in the Hymenoptera, but its genetic underpinnings have been described only twice. In the wasp Lysiphlebus fabarum and the Cape honey bee Apis mellifera capensis the origin of thelytoky have each been traced to a single recessive locus. In the Cape honey bee it has been argued that thelytoky (th) controls the thelytoky phenotype and that a deletion of 9 bp in the flanking intron downstream of exon 5 (tae) of the gemini gene switches parthenogenesis from arrhenotoky to thelytoky. To further explore the mode of inheritance of thelytoky, we generated reciprocal backcrosses between thelytokous A. m. capensis and the arrhenotokous A. m. scutellata. Ten genetic markers were used to identify 108 thelytokously produced offspring and 225 arrhenotokously produced offspring from 14 colonies. Patterns of appearance of thelytokous parthenogenesis were inconsistent with a single locus, either th or tae, controlling thelytoky. We further show that the 9 bp deletion is present in the arrhenotokous A. m. scutellata population in South Africa, in A. m. intermissa in Morocco and in Africanized bees from Brazil and Texas, USA, where thelytoky has not been reported. Thus the 9 p deletion cannot be the cause of thelytoky. Further, we found two novel tae alleles. One contains the previously described 9 bp deletion and an additional deletion of 7 bp nearby. The second carries a single base insertion with respect to the wild type. Our data are consistent with the putative th locus increasing reproductive capacity.

Mitochondrial sequencing reveals five separate origins of 'black' Apis mellifera (Hymenoptera: Apidae) in eastern Australian commercial colonies.

Establishment of a closed population honey bee, Apis mellifera L. (Hymenoptera: Apidae), breeding program based on 'black' strains has been proposed for eastern Australia. Long-term success of such a program requires a high level of genetic variance. To determine the likely extent of genetic variation available, 50 colonies from 11 different commercial apiaries were sequenced in the mitochondrial cytochrome oxidase I and II intergenic region. Five distinct and novel mitotypes were identified. No colonies were found with the A. mellifera mellifera mitotype, which is often associated with undesirable feral strains. One group of mitotypes was consistent with a caucasica origin, two with carnica, and two with ligustica. The results suggest that there is sufficient genetic diversity to support a breeding program provided all these five sources were pooled.