While in vitro cell culture has been applied broadly in studies of mammals, it has been of limited use in comparative biology on a wider scale, primarily because of the scarcity of cell cultures from non-mammalian sources. This limitation is now being overcome, and among the most recent additions to continuously proliferating cultured cell lines are those derived from cartilaginous fishes. In particular, cell lines have been developed from embryos of Squalus acanthias, the dogfish shark, and Leucoraja erinacea, the little skate. These lines were derived by means different from the standard approaches for the development of mammalian cell cultures. The lines particularly have been useful in studies of membrane transport protein structure and regulation of expression. Furthermore, genomic studies with shark cultures have identified evolutionarily conserved untranslated regions in certain mRNAs that may be of significance in controlling gene expression. In other experiments, over three thousand unique mRNA transcripts have been identified from the shark and skate cultures, presumably derived from genes that were formerly unrecognized in any organism. Computational gene ontology analysis of both shark and skate cultures identified considerable similarity between the two, suggesting a common cell type of origin. This work and continued exploration into both the cell biology of the existing cultures and the development of new ones will provide a basis for comparative biology at a deeper level than previously possible.
Buy this Article