Genetic Diversity Of Honey Bees Research Articles

Urban ecosystem drives genetic diversity in feral honey bee

Urbanization can change biodiversity in both directions, positive and negative, and despite the rising global trend of urban beekeeping, little is known about the impact of urbanization on the genetic diversity of honey bees. We investigate how urbanization affects the genetic variability of feral and managed honey bee colonies that are spread throughout the entire city, even in highly urban areas, through genetic analysis of 82 worker bees. We found convincing evidence of high genetic differentiation between these two groups. Additionally, by comparing city samples with 241 samples from 46 apiaries in rural parts of the country, variations in mitochondrial tRNAleu-cox2 intergenic region and microsatellite loci indicated that feral colonies have distinct patterns of genetic diversity. These results, with evidence that feral honey bees find niches within highly modified and human-dominated urban landscapes, lead us to conclude that urbanization is a driver of the genetic diversity of feral honey bees in the city.

GENETIC CHARACTERIZATION OF HONEY BEES (Apis mellifera) IN THE DRY COASTAL ZONE OF THE O’HIGGINS REGION, CHILE

The natural diversity of the honey bee (Apis mellifera) includes five evolutionary lineages and 26 subspecies, currently described that come from Africa, Europe, and the Middle East. They were introduced by humans to almost every continent and each of them has adapted favorably to the environmental and climatic conditions of their geographical areas of origin, which has led to greater genetic diversity and hybridization processes between subspecies. The genetic diversity of honey bees in Chile was characterized by the presence of European subspecies, such as Apis mellifera mellifera and Apis mellifera ligustica, but no updated information is available. The objective of this study was to assess the current genetic characterization of honey bees in the coastal zone of the O’Higgins Region, due to its national importance in beekeeping, using geometric morphometrics. Samples were taken from five counties taking samples of five apiaries from each one, including 3 colonies per apiary with a total of 30 bees per colony. The results indicate that there is evidence of hybridization between the subspecies Apis mellifera carnica and Apis mellifera ligustica, which reveals that the genetic pattern of the region has changed. This raises the questions as to whether this hybridization with predominantly Apis mellifera carnica is the most suitable for the ecological conditions of the region and how this could affect colony productivity and local beekeeping.

Разнообразие медоносной пчелы Apis mellifera L. в Томской области по морфометрическим и молекулярно-генетическим маркерам

Разнообразие медоносной пчелы Apis mellifera L. в Томской области по морфометрическим и молекулярно-генетическим маркерам

Genetic diversity of honeybees in different geographical regions of Siberia

An assessment of the genetic diversity of nine microsatellite loci in honeybees of different origin (evolutionary lineages M, C, and hybrids) from different geographical regions of Siberia was conducted in order to find the genetic markers of the Siberian ecotype of dark-coloured forest bee (Apis mellifera mellifera). The greatest genetic diversity (both in the number of alleles and the calculated expected heterozygosity) was shown for loci A008, A113, Ap049, and A043 in honeybees from the Tomsk region, as bees from the southern districts had higher genetic diversity than bees from the northern districts. Honeybees from the Eastern region of Siberia (Yenisei population) had the lowest level of genetic diversity on these loci compared to Tomsk bee populations. Allele 162 pb of the locus A008, allele 126 bp of the locus A043, and allele 218 bp of the locus A113 can be considered as genetic markers of the A. m. mellifera Siberian ecotype.

Mitochondrial DNA genetic diversity of honey bees, Apis mellifera, in Hawaii

Honey bees, Apis mellifera, in the Hawaiian Islands are geographically isolated from honey bees in mainland United States. We conducted a study on the mitochondrial DNA genetic diversity of honey bees from seven of the Hawaiian Islands by sequencing the intergenic region between the Cytochrome Oxidase I and Cytochrome Oxidase II genes (COI-COII). We observed a total of 10 haplotypes from 235 samples collected from 2009 to 2014. Haplotypes belonged to the A. mellifera C lineage (64 %), M lineage (35 %), and O lineage (1 %). Four of the five C lineage haplotypes found were common among queen breeders in continental United States (C1, C2, C11, C19) and accounted for 99 % of the C lineage bees. Haplotype C33 (1 %) has been observed in feral honey bee populations in continental United States. For the M lineage, which includes the dark honey bee, A. m. mellifera, four haplotypes were observed (M3, M4c”’, M7 and M70), with a novel haplotype unique to Hawaii, M70, being the second most common. Five islands had M lineage haplotypes, with their frequency ranging from 70 % on Maui to 22 % on Molokai. Two individuals of the O lineage, haplotype O1, were found on Oahu. Among the islands, Oahu and Maui, had the greatest amount of haplotypic diversity (haplotypic diversity (H d ) = 0.76 and 0.75). Lanai and Kahoolawe had only one haplotype, C1, present.

Genetic diversity of the locus COI-COII of mitochondrial DNA in honeybee populations (Apis mellifera L.) from the Tomsk region

An assessment of the genetic diversity of the COI-COII mtDNA locus in honeybee populations from the Tomsk region was conducted. Three variants of the COI-COII mtDNA locus were registered: PQQ, PQQQ (typical for Middle Russian race), and Q (typical for southern breeds). It was established that 64% of bee colonies of the maternal line originate from the Middle Russian honeybee race, 28% of bee colonies originate from southern species, and 8% are mixed bee colonies. The southern parts of the region show a higher genetic diversity of honey bees as compared to northern regions, which are dominated by bee colonies (96%) and apiaries (73%) that are homogeneous for the genetic variant of locus COI-COII. The Tomsk region has no large areas with bee colonies maternally originating from the Middle Russian breed; only a few apiaries (both in the northern and southern areas) were revealed in which all bees originated from the Middle Russian breed.

Mitochondrial DNA Diversity of Honey Bees (Apis mellifera) from Unmanaged Colonies and Swarms in the United States

To study the genetic diversity of honey bees (Apis mellifera L.) from unmanaged colonies in the United States, we sequenced a portion of the mitochondrial DNA COI-COII region. From the 530 to 1,230 bp amplicon, we observed 23 haplotypes from 247 samples collected from 12 states, representing three of the four A. mellifera lineages known to have been imported into the United States (C, M, and O). Six of the 13 C lineage haplotypes were not found in previous queen breeder studies in the United States. The O lineage accounted for 9% of unmanaged colonies which have not yet been reported in queen breeder studies. The M lineage accounted for a larger portion of unmanaged samples (7%) than queen breeder samples (3%). Based on our mitochondrial DNA data, the genetic diversity of unmanaged honey bees in the United States differs significantly from that of queen breeder populations (p < 0.00001). The detection of genetically distinct maternal lineages of unmanaged honey bees suggests that these haplotypes may have existed outside the managed honey bee population for a long period.

Conserving genetic diversity in the honeybee: Comments on Harpur et al. (2012)

The article by Harpur etal. (2012) 'Management increases genetic diversity of honey bees via admixture' concludes that '…honey bees do not suffer from reduced genetic diversity caused by management and, consequently, that reduced genetic diversity is probably not contributing to declines of managed Apis mellifera populations'. In the light of current honeybee and beekeeping declines and their consequences for honeybee conservation and the pollination services they provide, we would like to express our concern about the conclusions drawn from the results of Harpur etal. (2012). While many honeybee management practices do not imply admixture, we are convinced that the large-scale genetic homogenization of admixed populations could drive the loss of valuable local adaptations. We also point out that the authors did not account for the extensive gene flow that occurs between managed and wild/feral honeybee populations and raise concerns about the data set used. Finally, we caution against underestimating the importance of genetic diversity for honeybee colonies and highlight the importance of promoting the use of endemic honeybee subspecies in apiculture.

Admixture increases diversity in managed honey bees: Reply to De la Rúa et al. (2013)

De la Rúa etal. (2013) express some concerns about the conclusions of our recent study showing that management increases genetic diversity of honey bees (Apis mellifera) by promoting admixture (Harpur etal. 2012). We provide a brief review of the literature on the population genetics of A.mellifera and show that we utilized appropriate sampling methods to estimate genetic diversity in the focal populations. Our finding of higher genetic diversity in two managed A.mellifera populations on two different continents is expected to be the norm given the large number of studies documenting admixture in honey bees. Our study focused on elucidating how management affects genetic diversity in honey bees, not on how to best manage bee colonies. We do not endorse the intentional admixture of honey bee populations, and we agree with De la Rúa etal. (2013) that native honey bee subspecies should be conserved.

Management increases genetic diversity of honey bees via admixture

The process of domestication often brings about profound changes in levels of genetic variation in animals and plants. The honey bee, Apis mellifera, has been managed by humans for centuries for both honey and wax production and crop pollination. Human management and selective breeding are believed to have caused reductions in genetic diversity in honey bee populations, thereby contributing to the global declines threatening this ecologically and economically important insect. However, previous studies supporting this claim mostly relied on population genetic comparisons of European and African (or Africanized) honey bee races; such conclusions require reassessment given recent evidence demonstrating that the honey bee originated in Africa and colonized Europe via two independent expansions. We sampled honey bee workers from two managed populations in North America and Europe as well as several old-world progenitor populations in Africa, East and West Europe. Managed bees had highly introgressed genomes representing admixture between East and West European progenitor populations. We found that managed honey bees actually have higher levels of genetic diversity compared with their progenitors in East and West Europe, providing an unusual example whereby human management increases genetic diversity by promoting admixture. The relationship between genetic diversity and honey bee declines is tenuous given that managed bees have more genetic diversity than their progenitors and many viable domesticated animals.

Genetic Diversity of Honeybees from Moldova (Romania) Based on mtDNA Analysis

Honeybees from 21 locations from Moldova (Romania) were analyzed in order to study phylo-geographic distribution of Apis melllifera subspecies. The fragment of interest was tRNAleu-cox2 intergenic region. More than a half of the samples belongs to C12 haplotype, identical with C2d from Apis mellifera macedonica and Apis melllifera carnica. The second group has the same similarity on 94% of the fragment with Apis mellifera carnica C2c haplotype. There are two haplotypes, which can be associated with different subspecies of Apis melllifera included in C lineage. We discovered also two new haplotypes, C25 and C26 (GenBank acccession numbers: HQ215207, respectivelly HQ215208). One more conclusion has that Carpathian Mountains has not a natural obstacle in honeybees spreading during its natural adaptation process.

Influencia de los cambios climáticos en las poblaciones de abejas y sus enfermedades

The European honey bee, Apis mellifera, is the most economically valuable pollinator of agricultural crops worldwide. Bees are also crucial in maintaining biodiversity by pollinating numerous plant species whose fertilisation requires an obligatory pollinator. Apis mellifera is a species that has shown great adaptive potential, as it is found almost everywhere in the world and in highly diverse climates. In a context of climate change, the variability of the honey bee's life-history traits as regards temperature and the environment shows that the species possesses such plasticity and genetic variability that this could give rise to the selection of development cycles suited to new environmental conditions. Although we do not know the precise impact of potential environmental changes on honey bees as a result of climate change, there is a large body of data at our disposal indicating that environmental changes have a direct influence on honey bee development. In this article, the authors examine the potential impact of climate change on honey bee behaviour, physiology and distribution, as well as on the evolution of the honey bee's interaction with diseases. Conservation measures will be needed to prevent the loss of this rich genetic diversity of honey bees and to preserve ecotypes that are so valuable for world biodiversity.

A study on the genetic diversity of the Apis mellifera meda population in the south coast of the Caspian Sea using microsatellite markers

SummaryThe genetic diversity of honey bees from the south strip area of the Caspian Sea (Guilan, Mazandaran and Golestan provinces in the north of Iran) was estimated using four microsatellite loci. For this purpose, DNA was extracted from the thoracic part of 100 worker honey bees from each province, according to the salting out method. Following amplification, products electrophoresed on 6% denaturing polyacrylamide gel. The results indicated that, the honey bees in the north of Iran had a low variability in terms of number of alleles per locus and heterozygosity. The results of this research confirm the previous morphological and biochemical indications of uniformity in the honey bee population of the south strip of the Caspian Sea despite a geographical spread of 1,000 km.