In vitro production of naked mole-rats' blastocysts from non-breeding females using in vitro maturation and intracytoplasmic sperm injection.

The African naked mole-rat (Heterocephalus glaber) is an attractive model for cancer and aging research due to its peculiar biological traits, such as unusual long life span and resistance to cancer. The establishment of induced pluripotent stem cells (iPSCs) would be a useful tool for in vitro studies but, in this species, the reprogramming of somatic cells is problematic because of their stable epigenome. Therefore, an alternative approach is the derivation of embryonic stem cells from in vitro-produced embryos. In this study, immature oocytes, opportunistically retrieved from sexually inactive females, underwent first in vitro maturation (IVM) and then in vitro fertilization via piezo-intracytoplasmic sperm injection (ICSI). Injected oocytes were then cultivated with two different approaches: (i) in an in vitro culture and (ii) in an isolated mouse oviduct organ culture system. The second approach led to the development of blastocysts, which were fixed and stained for further analysis.