Alterations in calcium oscillatory activity in vitrified mouse eggs impact on egg quality and subsequent embryonic development.

Cryopreservation of mature eggs is a useful technique that can be applied in assisted reproductive technology. However, the method has some limitations, such as cryodamage induced by biophysical modifications during the cryopreservation process. To assess these biophysical damage, we analyzed the relationship between intracellular calcium ([Ca2+]i) oscillatory activity via type 1 inositol 1,4,5-trisphosphate receptor (IP(3)R1) distribution after vitrification and efficiency of cryopreservation according to cryoprotectant (CPA) composition.

Identification of an intermediate state as spermatogonial stem cells reprogram to multipotent cells.

The aim of this study was to understand the mechanisms that allow mSSC lines to be established from SSCs. Small, multilayer clumps of SSCs formed during two to four weeks of in vitro culture and were then transferred to MEF feeders. Small, round, monolayer colonies containing cells destined to convert to mSSCs, designated as intermediate state SSCs (iSSCs), first appeared after two to three passages.