11. He then observed how the remaining blastomere developed, and found that it became a half embryo. 12. Most of the blastomeres in this stage become polarized and develop tight junctions with the other blastomeres. 13. Most of the blastomeres in this stage become polarized and develop tight junctions with the other blastomeres . 14. In stage 3, during the second cleavage, an unequal division occurs in the CD blastomere . 15. Mintz went on to create viable chimeric embryos containing blastomeres from up to fifteen different laboratory mice. 16. After four divisions, the conceptus consists of 16 blastomeres , and it is known as the morula. 17. Each blastomere produced by early embryonic cleavage does not have the capacity to develop into a complete embryo. 18. In twinning assays, molecules are injected into the ventral blastomere of a four-cell stage embryo. 19. Further segregation of blastomeres into the trophoblast and inner cell mass are regulated by the homeodomain protein, Cdx2. 20. This polar lobe forms at the vegetal pole during cleavage, and then gets shunted to the D blastomere .
