Abstract
Summary. On Day 10 of implantational delay, mouse blastocysts contain relatively more mural trophectoderm cells, but relatively fewer inner cell mass cells, than do 'non-delayed' blastocysts immediately before implantation. These differences are probably due to prolonged polar trophectodermal cell division plus polar to mural cell movement, and to reduced inner cell mass mitotic activity in 'delayed' blastocysts. Implantation began 18 h after a single injection of oestradiol and there was no increase in cell numbers or mitotic activity in the intervening period. It is concluded that 'delayed' blastocysts, whether before or after activation by oestradiol, are not true counterparts of 'non-delayed' blastocysts immediately before implantation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
