各种生物都具有其独特的遗传信息,深入了解生物体的形成过程以及各种生命活动都离不开基因组的研究成果。由于在世界范围内马具有良好的健康情况记录和详细的系谱记录,使得马成为生命科学研究中极具价值的模式动物。尽管起步较晚,但在过去的几年中,马基因组图谱经历了前所未有的发展。文章主要对近年来马基因组遗传图谱、物理图谱、基因组比较作图以及功能基因组学等研究进展进行了综述,这些图谱也正是世界各地研究人员用以探寻与马的各种性状(包括全部的健康状况、抗病性能、生殖生育能力、运动性能以及诸如毛色这样的表型特征等)相关基因的重要工具。相信这些研究成果将为马匹疾病预防、诊断和治疗提供新的思路与方法,并将为马遗传育种提供更好的选配依据。
Mammalian skin epidermis contains different epidermal stem cell pools which contribute to the homeostasis and repair of skin epithelium.Epidermal stem cells possess two essential features common to all stem cells: self-renewal and differentiation.Disturbing the balance between self-renewal and differentiation of epidermal stem cell often causes tumors or other skin diseases.Epidermal stem cell niches provide a special microenvironment that maintains a balance of stem cell quiescence and activity.This review primarily concentrates on the following points of the epidermal stem cells: the existing evidences,the self-renewal and differentiation,the division pattern,the signal pathways regulating self-renewal and differentiation,and the microenvironment (niche) and macroenvironment maintaining the homeostasis of stem cells.