Abstract
Beekeeping activities, especially queen trading, have shaped the distribution of honey bee (Apis mellifera) subspecies in Europe, and have resulted in extensive introductions of two eastern European C-lineage subspecies (A. m. ligustica and A. m. carnica) into the native range of the M-lineage A. m. mellifera subspecies in Western Europe. As a consequence, replacement and gene flow between native and commercial populations have occurred at varying levels across western European populations. Genetic identification and introgression analysis using molecular markers is an important tool for management and conservation of honey bee subspecies. Previous studies have monitored introgression by using microsatellite, PCR-RFLP markers and most recently, high density assays using single nucleotide polymorphism (SNP) markers. While the latter are almost prohibitively expensive, the information gained to date can be exploited to create a reduced panel containing the most ancestry-informative markers (AIMs) for those purposes with very little loss of information. The objective of this study was to design reduced panels of AIMs to verify the origin of A. m. mellifera individuals and to provide accurate estimates of the level of C-lineage introgression into their genome. The discriminant power of the SNPs using a variety of metrics and approaches including the Weir & Cockerham’s FST, an FST-based outlier test, Delta, informativeness (In), and PCA was evaluated. This study shows that reduced AIMs panels assign individuals to the correct origin and calculates the admixture level with a high degree of accuracy. These panels provide an essential tool in Europe for genetic stock identification and estimation of admixture levels which can assist management strategies and monitor honey bee conservation programs.
Highlights
The role of introgression and admixture in conservation is a dilemma: While natural admixture may be an important evolutionary force in speciation and maintenance of genetic diversity [1,2], admixture induced by human activities may contribute, either directly or indirectly, to the extinction of many taxa [3]
The majority of the 1183 single nucleotide polymorphism (SNP) assessed in this study using five selection methods contain high levels of information content
The 50th percentile ranges of the four training datasets were 0.6974–0.7712, 0.5459–0.6362, 0.5532–0.7601, 0.3345–0.3583 and 0.0038–0.0040 for the Weir & Cockerham’s FST, FST-based outlier test, Delta, In and principal component analysis (PCA), respectively, indicating a high level of information content for most SNPs and a similar pattern among the four training datasets (Fig 1)
Summary
The role of introgression and admixture in conservation is a dilemma: While natural admixture may be an important evolutionary force in speciation and maintenance of genetic diversity [1,2], admixture induced by human activities may contribute, either directly or indirectly, to the extinction of many taxa [3]. The genetic diversity harbored in native honey bee subspecies is amongst the most important legacies that we can leave to future generations of beekeepers and farmers [9,10]. Native honey bee subspecies are important reservoirs of local adaptations; their extinction means the loss of unique combinations of traits shaped by natural selection over extended periods of time. These combinations can be important for a more sustainable beekeeping, as shown by a recent pan-European experiment [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
