2012年1月17日星期二

Same sex reproduction, possible?

At present, there are a number of research labs that are focused on the creation of cells that are genetically male but have been produced from eggs. Alternately, they are also trying to create sperm from female eggs. If the research proves to work, the consequences are particularly important for gay and lesbian couples that wish to have children. The idea is an extremely controversial one that mixes in with politics, religion and ethics. The experiment was widely reported in the news but has not yet been published or successfully replicated, the work does still show that potential for same-sex reproduction exists, and it will likely spur further research in this area. The reproductive revolution is really already in progress.

    Is same-sex reproduction really possible? I think we should figure out the nature of reproduction first. Theoretically, the human reproduction just requires the fusion of two haploid gametes, and then cell development into a baby under certain conditions. I will elaborate the possibility of same-sex reproduction from two different thinking.

1, the thinking of Surrogacy


There are 2 types of surrogate mother: complete surrogacy and partial surrogacy. Partial surrogacy is not true surrogacy, and what I mention here is complete surrogacy.

Complete surrogacy: to use consignor couple’s sperm and eggs, implanting into surrogate mother’s womb then through artificial insemination till the birth of baby. In the whole process, surrogate mother only rents out uterus, no any gene relationship between baby and her.

    When we talked about reproduction before meiosis was discovered and described for the first time in sea urchin eggs in 1876 by the German biologist Oscar Hertwig, people always linked a man, a woman and sex together. On July 25, 1978, Louise Joy Brown, after the world's first successful "test-tube" baby was born in Great Britain, people realized reproduction doesn’t require a man, a woman and sexual behavior between them , but only need sperm, egg and uterus. In this process, sperm replaced a man, and a woman divided into an egg and uterus (as carrier), and sex can be abandoned. We can follow this line of thought and continue to dig deep. The nature of sperm is human haploid nucleus, and an egg can be divided into a haploid nucleus and a shell with enough nutrients and energy but without any nucleus. In my view, the egg without nucleus is another form of surrogate mother, one is considered from a macro perspective, and the other is from a micro perspective, and both of them share the same nature and just provide a place and nutrients and energy required for the cell development. I think, maybe one day, the shell and uterus both can be replaced by some complete set of reproduction mechanisms, and this reproductive system can total replace all certain conditions for a child. In that time, parents just only need to provide two gamete nuclei of them, and female polar body also can be used as same as egg.



2, the thinking of Cloning Techniques


Cloning Techniques: Nuclear transfer involves transferring the nucleus from a diploid cell to an unfertilised egg cell from which the maternal nucleus has been removed. The egg and donor cell are normally fused and the 'reconstructed embryo' activated by a short electrical pulse, and allowed to develop into an embryo, and the embryo is then implanted into a surrogate.

    We can also use this thinking of cloning techniques on the same-sex reproduction. In this method, two haploid nuclei from two different people are injected into an egg that has had its nucleus removed, and then make them fused three together using some specific method or stimulus in order to develop into an embryo, and the embryo is then implanted into a surrogate. This method is really possible in theory, but so far, we just don’t find a suitable reproductive system to replace an egg and uterus, we still should use a woman as a surrogate. In this whole process, we use the two gametes from two people after meiosis themselves, it means recombination occurs freely and allele exchange freely, the offspring is also have diversity. We just control the fusion of two nucleuses, but not the production of gametes, in order to avoid the trouble with some kinds of trigger stem cell into spermatogonia or oogonia and then force them meiosis.

    I know same sex reproduction is a complicated one in terms of political, religious and ethical controversy, but to have descendants keeping parents genes continue to exist in the world should be the common consensus for the human being, whatever straight or gay couples, they do also enjoy the same human rights. Except these artificial resistances, same sex reproduction also has a fatal gender problem. Two female gametes fusion, of course, only can have a baby girl. But what about two male gametes fusion? There are 3 kinds of situations after that. Baby girl is 25 percents, baby boy is 50 percents, and another baby (I don’t know how to call) is 25 percents. What if the YY can survive? Is YY super manly? I don’t know. I think this would be a really interesting subject.

    As technology advances, i think it is not difficult for human being to do same sex reproduction. In my opinion, everyone has the right to choose their own way of life, without affecting the others.

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