Three and a half days after division begins (in mouse embryos), the proliferating cells form a structure called a blastocyst. It is 100 to 150 micrometers wide, or roughly the same size as the egg ...

Finally, there are ES cells, derived from the inner cell mass of blastocyst-stage embryos. These pluripotent cells are the most ubiquitous of all. Once removed from the blastocyst they lack the ...

This process, known as blastocyst complementation, involves injecting rat stem cells into mouse blastocysts—early-stage embryos lacking the ability to develop a pancreas due to genetic mutations.

In a study of early embryonic development in primates, an international research team under the leadership of Berthold ...

However, to create ES cell lines, it is necessary to destroy preimplantation embryos at the blastocyst stage of 100–200 cells. Many people believe that life begins at conception and that ...

Researchers knock out a gene that drives the development of a specific organ in the host blastocyst and implant pluripotent stem cells from a donor species. Early studies demonstrated that this ...

Osaka Metropolitan University Professor Shingo Hatoya led a Graduate School of Veterinary Science team in pioneering the generation of feline embryonic stem cells using lab-grown blastocysts.

Early embryonic cell polarity and lineage differentiation, which are vital to implantation, and continued embryonic growth climax with the onset of blastocyst formation. These processes are ...

After 4 days of this development in the fallopian tube, the formed cellular mass of the morula migrates to enter the uterus with formation the blastocyst (polarized cells with accumulating fluid ...