A genome-wide survey of genes encoding transcription factors in Japanese pearl oyster Pinctada fucata: II. Tbx, Fox, Ets, HMG, NFκB, bZIP, and C2H2 zinc fingers.

To gain a better understanding of molluscan development and its relation to the evolution of their unique body plan, we performed a genomic survey of genes encoding transcription factors, such as Tbx, Fox, Ets, HMG, NFκB, bZIP, and C2H2 zinc finger proteins in the Japanese pearl oyster, Pinctada fucata. We annotated 133 transcription factor genes. Together with the orthologs of known deuterostome genes, we found several orphan genes in each class of transcription factor. Some possessed clear orthologs in other species of lophotrochozoans, while no counterpart genes were found in the deuterostomes or ecdysozoans. These observations suggest that a number of transcription factor genes are unique to lophotrochozoans, and thus additional research frontiers remain to be explored with regard to such transcription factors.