Meeting Abstract
Zebrafish; Danio rerio, skeletal muscle exhibits characteristics of determinate-like growth, similar to that of many mammals, where muscle growth is limited in sexually mature adults. Zebrafish have been shown to exhibit significant age-related senescence, however it is unknown if muscle repair mechanisms are limited in adults. Evidence shows that as myogenic precursor cells (MPCs) progress through the myogenic program during development Pax3, Pax7, and other myogenic regulatory factors (MRFs), MyoD, Myf5, and myogenin are expressed at distinctive times. During the muscle regeneration process, following physical or chemical injury or exercise, quiescent MPCs are activated to proliferate and differentiate to form new muscle fibers or repair damaged fibers. This process is regulated by MRFs, but it is unknown if the Pax genes are activated during repair in adult zebrafish indicating self-renewal of the MPC population. Therefore, the goal of this study was to characterize the expression of Pax7a, Pax7b, Myf5, MyoD1, and myogenin, after physical injury to test the hypothesis that over one-week post injury MRF expression will increase in conjunction with the recruitment of MPCs to the wound site while Pax7 expression will remain stable or decrease. Injuries were inflicted to the left anterior muscle in between the pectoral and dorsal fins using a four-pronged tool. Muscle samples were collected over one-week post injury, snap frozen in liquid nitrogen, and RNA was extracted using RNA-zol for qPCR analysis. Wound healing included an activation of the myogenic process with in the one-week period
