Selection of appropriate isolation method based on morphology of blastocyst for efficient derivation of buffalo embryonic stem cells.

The efficiency of embryonic stem cell (ESC) derivation from all species except for rodents and primates is very low. There are however, multiple interests in obtaining pluripotent cells from these animals with main expectations in the fields of transgenesis, cloning, regenerative medicine and tissue engineering. Researches are being carried out in laboratories throughout the world to increase the efficiency of ESC isolation for their downstream applications. Thus, the present study was undertaken to study the effect of different isolation methods based on the morphology of blastocyst for efficient derivation of buffalo ESCs. Embryos were produced in vitro through the procedures of maturation, fertilization and culture. Hatched blastocysts or isolated inner cell masses (ICMs) were seeded on mitomycin-C inactivated buffalo fetal fibroblast monolayer for the development of ESC colonies. The ESCs were analyzed for alkaline phosphatase activity, expression of pluripotency markers and karyotypic stability. Primary ESC colonies were obtained after 2-5 days of seeding hatched blastocysts or isolated ICMs on mitomycin-C inactivated feeder layer. Mechanically isolated ICMs attached and formed primary cell colonies more efficiently than ICMs isolated enzymatically. For derivation of ESCs from poorly defined ICMs intact hatched blastocyst culture was the most successful method. Results of this study implied that although ESCs can be obtained using all three methods used in this study, efficiency varies depending upon the morphology of blastocyst and isolation method used. So, appropriate isolation method must be selected depending on the quality of blastocyst for efficient derivation of ESCs.