发育重演律与干细胞研究

发育重演律是生物个体发育的一般规律，也是干细胞分化的一般规律，可以为干细胞研究提供指导。本文根据发育重演律提供的个体发育基本模式和干细胞分化的一般过程，提出了干细胞分化周期的概念，不但指出了成体干细胞在体内存在的部位，还对多潜能干细胞和单能干细胞存在的部位进行了区分，并对间充质干细胞的本质及相关现象进行了阐释。

The Ontogenic Law and Stem Cell Research

The ontogenic law is also the law of stem cell differentiation, which may provide the guidance for stem cell research. According to this law, stem cell differentiation usually results in formation of blastocyst like structure (BLS), which is composed of a trophectoderm like structure （TLS）and an inner mass like structure (IMLS) or IMLSs, and this process repeats circularly. TLSs will finally develop into connective tissue or epithelium tissue. Niches, which somatic stem cells reside in, are attachments of tissue derived from TLSs. Mesenchymal stem cells (MSCs) are progenitors of several connective tissue cell lineages, they are distributed widely in the body. Characteristics of MSCs differ among laboratories, species and tissues, and there is no specific marker or combination of markers that identify MSCs either in vivo or in vitro. In view of the ontogenic law, MSCs should be IMLSs except for that of the lowest hierarchy BLSs, this is the reason why MSCs are distributed so widely and their markers are various.