Characterization of Specter, a Cell Cycle Mutant of Zebrafish cyclin B 1

Abstract

The cell cycle is a very important system for the maintenance and development of an organism. Thus, this system is highly regulated to ensure DNA is replicated successfully. There are many regulatory proteins involved in this system one of which is Cyclin B 1, a protein that complexes with cyclin dependent kinase 1 and controls entry into mitosis from the G2 phase. Studies have shown that down regulation of Cyclin B 1 can possibly treat cancer. The present study looked at specter mutant in zebrafish that is hypothesized to have a mutation in eye/in B 1. Specter displays a similar phenotype to a previous! y identified zebrafish cyclin B 1 mutant. This study aimed to characterize and sequence specter to show that it in fact does harbor a mutation in eye/in Bl, and also learn more about this protein and how its absence may affect the whole organism. Specter mutants showed a lower number of mitotic cells, that were also abnormally shaped and did not migrate to the neural tube, compared to their wild-type siblings after the 15-somite stage. Other in situ experiments showed fewer neural precursors in specter mutants compared to their wild-type siblings. Caspase-3 antibody, a marker of apoptosis, showed higher levels of apoptosis in the brain. A nonsense mutation was detected when the specter eye/in Bl gene was sequenced. Although, the data support the hypothesis that specter is a mutation of cyclin B 1, further research would help to learn more about the effect of manipulating levels of this protein on the whole body and its efficiency as a possible cancer·treatment.