Study On Cloning And Expression Of Myomodulin-related Gene During The Process Of Regeneration And Embryo Development Of Notoplana Humilis

Planarians belong to the Turbellaria, Platyhelminthes, and planarians are among thesimplest animals which possess a centralized nervous system (CNS). The CNS consists ofpair cephalic ganglia (CG) and a pair of ventral nerve cord (VNC) running along with thelength of the body. The cephalic ganglia is surrounded by an outer layer of epithelium ofguard and send nine main pairs of nerve trunks, with transverse nerves connected to the nervalnetwork, spreading all over the body. Because of its strong ability of regeneration, planarian isconsidered as the ideal material for study the mechanism of regeneration. Moreover, thesexual reproduction of planarian is common and easily observed, so the animal is alsoperceived as important material for study on developmental biology.In this paper, we study on the cloning of cDNA library from Notoplana humilis. We findthat a clone is myomodulin-related gene by sequence alignment. The evolutionary treeindicates that Notoplana humilis possesses the high homology of Macrostomum lignano,followed by Schmidtea mediterranea, and mollusca come last.Study on expression of myomodulin-related gene in Notoplana humilis by in situhybridization histochemistry(ISHH) shows that myomodulins are mainly located in thecephalic ganglia, nerve trunk, female genital pore and pharynx.This relates to the function ofmyomodulin in other species, such as feeding, reproduction, muscle contraction.Study on the expression of myomodulin-related gene during regeneration of Notoplanahumilis by ISHH shows that myomodulins are mainly located in anterior ventral cell groupsof CG, and the number of positive cells decreased first and then increased. Posterior ventralcell groups don’t show the positive signal until regenerate for11days. Positive cells are alsolocated in tissue and the number gradually increases.Study on the expression of myomodulin-related gene during embryo development ofNotoplana humilis suggests that there are no any positive signals. From this; myomodulinmay not play a role in the process of embryonic development of Notoplana humilis.