BACKGROUND & AIM: This study is to explore the dynamic trends of cell proliferation, apoptosis and the expression significance of involved genes as P21 and Ki-ras in developing intestines of mouse. MATERIAL & METHODS: Intestine tissues were taken from different developmental phases of kunming mouse. Immunohistochemistry and TUNEL techniques were adopted to observe the variation of cell proliferation and apoptosis and the expression characteristics of P21 and Ki-ras were detected by in situ hybridization. RE...