Man Created Artificial Life?
BY DERYA SONER (MBG/IV)
a_soner@ug.bilkent.edu.tr
News headlines we see on TV or in newspapers can have a way of making overstatements about what scientists do in the lab, or perhaps in some cases, the scientists themselves make the overstatements about their work.
According to headlines in the last few years, scientists have created artificial life, eggs, and sperm, and have found cures for AIDS, cancer, and aging by now. Well, if this were all true, there would not be much left for a biologist to do. Such headlines can be quite misleading, so I would like to try and clarify what the scientists are actually doing in the lab.
First of all, perhaps you have seen headlines such as "No men or women needed" or "Scientists make artificial eggs and sperm." Well, although the research these headlines refer to is quite revolutionary, we have not reached the point of making babies from scratch just yet. What scientist Ji Wu from China and his team have done is taken egg stem cells from the ovaries of mice, cultured them in the lab for more than 6 months, and transplanted them into the ovaries of infertile mice, and interestingly, these eggs developed as normal, and upon fertilization, they were able produce healthy offspring. This is revolutionary in the sense that it may provide a way for infertile women to have babies. Women were thought to be born with a limited number of preliminary egg cells, and go through menopause when their eggs are finished. But with this finding, in the future, women may be able to use eggs derived from their stem cells to have babies.
Next comes the news of artificial sperm production. Scientist Takehiko Ogawa and his team from Japan have managed to produce sperm from mouse testes that contain precursors of sperm cells, and even testis tissue that was frozen was able to generate sperm. They then tested the functionality of the sperm and showed that they were able to fertilize eggs to produce healthy offspring. This is also a revolutionary piece of research because in order to generate functional cells from stem cells, a scientist has to provide the right factors and conditions for correct development. But what I wish to express is, these eggs and sperm are developed from stem cells, and a womb is still needed to grow a baby.
There may also be complications with the offspring of lab-grown eggs and sperm, as there were with the clone sheep Dolly. Our DNA may contain the code for all the proteins we need, but how they are expressed is controlled by other molecules surrounding the DNA; this is called epigenetics. So, a baby may inherit the correct DNA from the lab-grown eggs and sperm, but if the epigenetic regulators are altered, this may give rise to disease.
You might also remember the "Scientist Craig Venter creates life in the laboratory" headlines from last year; well, what this refers to is that Venter and his team synthesized a whole genomic DNA of a bacteria, put this DNA into a bacteria, and saw that the bacteria was able to use this DNA and survive. DNA is basically a chain of molecules called nucleotides, and what is revolutionary about this work is that it is very hard to synthesize a DNA sequence that is longer than a few hundred nucleotides in the laboratory, but Venter and his team were able to synthesize the whole genome of a bacteria, which is about 1,080,000 nucleotides long, and this DNA was functional.
As for the news on other health issues such as cancer, obesity, diabetes, and aging; these have complex underlying mechanisms that work differently in each individual, so one single cure that works for all is not a realistic expectation. What scientists can do is to develop advanced methods of diagnosis and enhanced treatments, so that these findings can be joined to design a treatment that is unique to a person and his/her disease specifically.