Background: In vitro cultivation of cells allows novel investigation of in vivo-mechanisms and is a helpful tool in developmental biology, biochemistry and functional genomics. Numerous cell lines of insect species, e.g., silkworm and mosquito, have been reported. However, this is not the case for successful long-term cultivation of cells in honeybees.

The production of chimeras, by use of cell transplantation, has proved to be highly valuable in studies of development by providing insights into cell fate, differentiation, and developmental potential. So far, chimeric honeybees have been created by nuclear transfer technologies. We have developed protocols to produce chimeric honeybees by use of cell transplantation. Embryonic cells were transplanted between pre-gastrula stage embryos (32-34 hr after oviposition) and hatched larvae were reared in vitro for 4 days. Chimeric individuals were detected by use of microsatellite analysis and a conservative estimation approach. 4.8% of embryos, posteriorly injected with embryonic cells, developed into chimeric honeybee larvae. By injection of cells pre-stained with fluorescent cell tracer dye, we studied the integration of transplanted cells in the developing embryos. Number of injected cells varied from 0 to 50 and cells remained and multiplied mainly in the area of injection.

-The production of chimeras by nuclear transfer or cell transplantation requires functional tools for the detection of individuals that have successfully incorporated donor material. Quantitative Fluorescent PCR (QF-PCR) on microsatellites was employed on artificial chimeric honeybee DNA samples, to develop protocols for detection and quantification of donor genotypes after nuclear transfer and cell transplantations into honeybee embryos. Standard curves were produced for three microsatellite markers and demonstrate that there is a close to linear correlation between the amounts of donor genotypes estimated with QF-PCR and actual amounst of genotypes. The method was sensitive down to a 1% level and could detect and quantify small amounts of donor DNA in artificially mixed samples. QF-PCR offers fast and sensitive detection and quantification of genotypes and, thus, provides a useful tool for studies of chimeric honeybees and other species.Quantitative Fluorescent PCR (QF-PCR) / microsatellites / nuclear transfer / honeybee / Apis mellifera