Investigating The Effect Of A Prolonged Gap 1 Phase On Specification Of Progenitors During Zebrafish Embryogenesis

The development of a vertebrate organism requires a single cell to become all of the cells that make up the adult, through the processes of proliferation and differentiation. A relationship has been observed between the cell cycle, specifically the gap phases, and a stem cell’s decision to remain undifferentiated or differentiate into a specific cell type. My research is focused on understanding this relationship by manipulating the cell cycle and observing the effects on vertebrate development. A transgenic line of zebrafish [tg(hsp70l:ccnd1DN)] allowed for prolonging the normally short gap 1 phase observed in stem cells by expressing a mutated form of cyclin D1. I determined the timing of heat induced gene expression from the transgene in order to understand how an altered gap phase affects the critical windows of tissue development during embryogenesis. Using this information, I looked at how expression of a gene involved in differentiation of sensory neurons changed with a manipulated gap 1 phase. The decrease in expression observed in transgenic organisms suggests that there is a relationship between the length of the first gap phase and specification of sensory neurons in zebrafish.