Agrobacterium-mediated transformation of sea urchin embryos

Agrobacterium-mediated transformation of higher plants is a well-known and powerful tool for transgene delivery to plant cells. In the present work, we studied whether Agrobacterium can transfer genetic information to animal (sea urchin) embryos. Sea urchin embryos were co-cultivated with A. tumefaciens strains carrying binary vectors containing the nptII marker gene and agrobacterial rolC and rolB oncogenes. Bacterial plasmid T-DNA-sea urchin DNA junction sites were identified in the genome of these embryos, thus indicating successful transformation. The nptII and both rol genes were expressed in the transformed embryos. The processes of transgene integration and transgene expression were suppressed when Agrobacteria contained mutated virA, virB or virG genes, suggesting that Agrobacterium transforms sea urchin cells by a mechanism similar to that which mediates T-DNA transfer to plants. Some of the embryos co-cultivated with Agrobacterium developed teratoma-like structures. The ability of Agrobacterium strains to trigger formation of teratoma-like structures was diminished when they contained the mutated vir genes. In summary, our results demonstrate that Agrobacterium is able to transform animal (sea urchin) embryonic cells, thus indicating a potential of this natural system for gene delivery to animal hosts. We also discuss the possibility of horizontal gene transfer from Agrobacterium to marine invertebrates.