BACKGROUND:Spermatogonial stem cel s with abilities of differentiation, self renewal and proliferation are a kind of adult stem cel s that can transfer genetic information into offspring, which have great application prospects in medicine, genetics and zoology. OBJECTIVE:To review the source, biological characteristics, and application of spermatogonial stem cel s as wel as self-renewal and molecular regulation underlining these differentiations. METHODS:PubMed and CNKI databases were searched by the first author using key words of“spermatogonial stem cel , biological characteristics, self-renewal, differentiation”in English and in Chinese, respectively, to retrieve relevant articles published from 1990 to 2015. Literatures addressing spermatogonial stem cel s were included, and 46 articles were chosen for further analysis eventual y. RESULTS AND CONCLUSION:Spermatogonial stem cel s can be cultured in vitro, cryopreserved, and genetical y modified as wel as used for al ogeneic or xenogeneic transplantation, al of which contribute to understanding the mechanisms of spermatogenesis, thereby providing new means for treatment of male sterile disease and genetic diseases and providing new hopes for chemotherapy-induced germ cel damage in young cancer patients. Microenvironment and Plzf, GDNF, SCF/c-Kit signaling pathways can play an important role in the regulation of spermatogonial stem cel self-renewal and differentiation. As a cel model, spermatogonial stem cel s become an important tool for the researches on spermatogenesis mechanism, regeneration of spermatogenesis in sterile individuals and reproduction of transgenic animals.

Objective To explore the role of tetramethylpyrazine (TMP) in protection of homocysteine (HCY)-induced apoptosis of hippocampal neurons in mice. Methods One hundred healthy adult Kunming mice of clean grade were randomly divided into 5 groups, 20 for each group. HCY was injected into lateral ventricle using stereotaxic technique. FJB staining was used to detect neural apoptosis and the Morris water maze test was applied to assess memory and cognitive abilities. Results FJB staining showed that apoptosis of hippocampal neurons in the mice treated with TMP at different doses decreased significantly as compared with that in HCY group, especially at a dose of 20 g/L. Conclusions TMP can alleviate HCY-induced damage of the hippocampal neurons in mice and improve memory and cognitive functions, which suggests TMP has a potential clinical value in prevention and treatment of Alzheimer′s disease.

Objective To study the genetic diversity of germplasm resources for Potentilla discolor.Methods Twelve species of germplasm resources for P.discolor were analyzed by ISSR molecular markers.To make up the systematic diagram of genetic relationship by POPGENE 1.32 software,cluster by UPGMA method,and establish the dendrogram.Results A total of 128 ISSR bands were scored for 12 primers,among which 101 were polymorphic bands.The average percentage of polymorphic bands was 78.91%.Genetic similarity coefficient was changed from 0.179 2 to 0.632 5.By cluster analysis,the geographical distribution is mutually related to the relationship of germplasm resources for P.discolor and it was also showed some of P.discolor from the same region were in the same group which presented the rule of geographical distribution in the tested materials.Conclusion The diversity level of the different germplasm resources for P.discolor higher and the relationship of P.discolor correlates with the geographical location in some way.