In a recent article, Monika A. Ward, an associate professor at the Institute for Biogenesis Research at the John A. Burns School of Medicine explains “Does this mean that the Y chromosome (or most of it) is no longer needed? Yes, given our current technological advances in assisted reproductive technologies.” Ward and her colleagues identified the minimum Y chromosome contribution that is required to create a healthy first generation mouse, that is able to reproduce a second generation on its own without more technological intervention. The Y chromosome contribution is limited to only two genes, the testis determinant factor Sry and the spermatogonial proliferation factor Eif2s3y. The team used transgenic male mice with only the two Y genes and harvested their immature spermatids and then fertilized the oocytes of female mice through a technique called round spermatid injection (ROSI). The developed embryos were then transferred into female mice and live offspring resulted. Even though assisted reproduction can successfully occur without the Y chromosome, it is incredibly vital for normal fertilization and other aspects of male reproduction.
Above is a female mouse that was produced from a male that lacked the Y chromosome, but had the two necessary Y genes; the female is pictured with her own litter
Even though the results of this study are incredibly significant, they cannot be directly applied to male infertility cases in humans. The ROSI technique is still considered experimental because there are issues regarding the safety of injecting immature germ cells. However, in this era where reproductive technologies are becoming more and more common, the ROSI technique may offer hope to overcoming male infertility once it is perfected in the future. There is no way that the Y chromosome will become obsolete as a result of this research, the study simply proves that the Y chromosome is not the only way for viable offspring to be produced.
This was very interesting that the entire y chromosome could be modeled two genes, but it is upsetting that it cannnot be added to human males. It could be possible that the reason for this is due to people being more complex. Maybe the solution could be adding other genes which are active in males to take place of the chromosome.
ReplyDeleteThis idea of not needing the Y chromosome makes me feel emasculated. The Y chromosome is what defines males. Also, I think this idea can be relevant if there was ever an epidemic that would cause the need for reproduction of the human population.
ReplyDelete