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The objectives of this seed proposal are to 1) screen single nucleotide polymorphism (SNP) markers in the Africanized bee population in Puerto Rico, 2) examine the association of SNP markers with defense and mite biting behaviors, and 3) identify SNP markers shared by European, Puerto Rico, and Africanized bees, based on observation of low levels of Varroa mite infestation in the Puerto Rico Africanized bees. <P>
Varroa mites cause extensive losses of honey bees and are a serious threat to the beekeeping industry worldwide. Development of genetic markers that are associated with mite resistance would enable more efficient selection and breeding of bee genotypes that are tolerant to the mite infestation. SNPs are the most common form of genomic variations that are inherited with low mutation rates and can be employed as genetic markers. <P>
The identification of SNPs for mapping the genes or regions that confer mite-resistant in Puerto Rico Africanized bees will lead to improved control strategies for Varroa mites and associated viral diseases. The proposed activities will enhance the infrastructure of the PI's institution for research and education.
NON-TECHNICAL SUMMARY: We found bees in Puerto Rico to be Africanized maternally and morphologically (they are smaller in size). Yet, genomic loci showed high levels of European genes. Surprisingly, and of apicultural significance, these bees also had gentle temperament, more similar to European bees. However, unlike European bees these colonies exhibited heightened grooming and biting behavior against the parasitic mites. These Varroa mites are considered one of the biggest problems that honey bees face today. Since 2001, based on low mite levels in the Puerto Rican Africanized bee stock, we were able to forego miticide treatments but due to high mite levels had to continue treatments in colonies of Italian bees. Proposed project on the genetics and mite resistance of Puerto Rican bees, utilizing large number of SNP molecular markers, will add to our understanding of survival and success of the honey bee at large. This information could lead to development of Varroa resistant bees desirable for beekeeping. This would mean reduced mite load, virus load (due to infection by mites), and elimination of pesticides (used to control mites)from the colony, comb and the honey. Addressing three important factors implicated in bee losses at once may get us closer to solve the colony collapse disorder, and help us respond to any new emergent problems. In addition, eliminating Varroa control chemical as a potential contaminant would improve food safety. The economic implication of such a development would be billions of dollars for the US economy when impacts on food safety, bee health, and securing pollination services are considered.
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APPROACH: Objectives 1 and 2. Association of existing SNP markers with defensiveness, Varroa resistance, and mite biting: The working hypothesis for these objectives is that a subset of markers will show informative variation in the Puerto Rico Africanized bee population and some of the variation will be associated with individual and colony phenotypes. There is variability in mite load and mite biting behavior, and colony defensiveness of Africanized bees in Puerto Rico. For each colony to be genotyped (100 in total) we will determine colony defensiveness, Varroa infestation level, mite biting frequency, and the mite biting behavior of the individual (1/colony) that is sampled. If mite biting and Varroa resistance are linked and independent of colony defense, we predict that similar markers will be associated with mite biting behavior and Varroa infestation levels but different markers will be associated with defensiveness. We expect 30% of over 3K SNP markers to be informative in this population, available for this and for future research. Objective 3. SNP marker alleles shared between the Puerto Rico Africanized bee population and other European and Africanized bee populations: The working hypothesis for this objective is that similar genetic structure will be observed in the source populations and the current Puerto Rico Africanized bee population. Affinity of Puerto Rican bees to other populations may be uniform over the many markers, which would support the working hypothesis. Alternately, different history and conditions on the island may be the cause of observed mosaic of traits. In this case, Puerto Rico Africanized bees may show different affinities based on markers analyzed. Currently a set of 1536 SNPs has been utilized in comparison of different bee populations and approximately 1100 are shown to be informative. We will use this SNP panel for genotyping Puerto Rican bees to compare with other genotyped populations. Support for either the general affinity versus a mosaic of affinities will have important and distinct implications for future research.