本帖最后由 细胞海洋 于 2011-10-27 09:12 编辑 6 y/ Z9 X- t! ` 6 r! _+ k' Y" F% B H# P, J印度科学家近日在stem cells dev 2011 年10月发表一篇有关睾丸干细胞的文章。认为睾丸干细胞是唯一一个成体存在，可以去分化后不经任何基因改造就可重编程成为全能干细胞的干细胞品种。这种干细胞体积非常小，表达Oct-4等胚胎干细胞特性，所以也可归类为VSELs（very small embryonic like stem cells）,而且这种睾丸干细胞总是伴随着间充质干细胞出现，所以研究者认为，有的研究认为MSCs的跨谱系分化（transdifferentiation）是由于其中掺杂了VSELs的缘故。( N3 A- ~6 \5 T. [4 P+ N7 ^
It has been suggested that testicular germ stem cells represent the only adult body stem cells that dedifferentiate and reprogram into pluripotent state without any genetic modification. Emerging debate about the authenticity of ES-like cells derived from adult testicular tissue has prompted us to put forth this letter. We wish to reinforce our findings that pluripotent very small embryonic-like stem cells (VSELs) exist as a small population in adult mammalian testis and may result in ES-like colonies. Because of their small size, it is felt that VSELs could be contaminating the initial cells used for seeding, although efforts were made to place single germ cell per well in 96 well plate for clonal expansion or MACS sorted α6 integrin positive cells were used. On similar note, it is felt that the presence of VSELs in various tissues along with MSCs may provide an alternative explanation to the transdifferentiation potential of MSCs. We conclude that like Oct-4 biology, presence of VSELs in adult body tissues has somewhat surprised stem cell biologists.6 j( c- R, A y5 `% {8 S