G. K. F. Merighe, Biase, F. H., Santos-Biase, W. K. F., Miranda, M. S., de Bem, T. H. C., Watanabe, Y. F., and Meirelles, F. V.,
“Gene silencing during development of in vitro-produced female bovine embryos”, vol. 8, pp. 1116-1127, 2009.
In early development, female embryos (XX) produce twice the transcripts of X-linked genes compared with male embryos (XY). During the course of development, inactivation of the X chromosome equilibrates gene dosage, making the development of female embryos viable. Moreover, the biotechnologies used for producing embryos in vitro seem to work better with male embryos, making it easier for them to reach the blastocyst stage and allow for complete gestation.
