Meeting Abstract
Transport of molecules to and from the nucleus is a critical process controlled, in part, by proteins of the karyopherin-alpha (KAP-α) and karyopherin-beta (KAP-β) families. By regulating entry of transcription factors into the nucleus, karyopherins have the potential to influence cell fate specification and differentiation. To better characterize roles of the karyopherins in these processes, the Byrum lab is developing the sea urchin embryo as a model for investigation of nuclear transport. Traditionally, studies examining these processes utilized yeast or isolated cell lines, but to further explore roles of nuclear transport proteins in developmental events, these processes must be studied in an intact system. The sea urchin embryo offers many advantages for this sort of investigation. In the sea urchin, both transcriptomic and genomic data are available, gene families and molecular networks are simpler than in vertebrates, and cell fate specification/differentiation has been thoroughly investigated. These are just a few of many reasons why the sea urchin would be a strong model. This study is part of an initial effort to better characterize nuclear transport in the sea urchin embryo. Using reverse transcriptase PCR, 16 of the 18 known human KAP-β forms were found to be present in the sea urchin (7 importins, 7 exportins, & 2 transportins). Using wholemount in situ hybridization, spatial distribution of several KAP-β forms is described in the developing sea urchin embryo (Lytechinus variegatus). The distribution of these forms has been mapped at six distinct stages, from fertilization to the pluteus stage. This study is an important step in developing hypotheses about how these proteins could influence early development and in exploring use of the sea urchin embryo as a model for studying nuclear transport.
