Researchers use DNA origami to generate tiny mechanical devices that deliver a drug that cuts off the blood supply to tumors in mice.
A genomic interrogation of homosexuality turns up speculative links between genetic elements and sexual orientation, but researchers say the study is too small to be significant.
December 7, 2017|
ISTOCK, EPICSTOCKMEDIAScanning the genomes of 1,077 homosexual men and 1,231 heterosexual men, researchers identified several genetic regions with multiple single nucleotide polymorphisms (SNPs) that segregate between the two groups. But the findings, published today (December 7) in Scientific Reports, have been met with severe criticism.
Two loci had particularly strong associations, according to the report: a section of chromosome 13 near the gene SLITRK6, which is primarily expressed in a brain region called the diencephalon that has previously been found to vary in structure between gay and straight men; and a section of chromosome 14 near the gene for thyroid stimulating hormone receptor (TSHR), which coincides with reports that have linked homosexuality with atypical thyroid function.
“Understanding the origins of sexual orientation enables us to learn a great deal about sexual motivation, sexual identity, gender identity and sex differences, and this and subsequent work may take us further down that path of discovery,” lead author Alan Sanders, a psychiatrist who studies behavioral genetics at NorthShore University HealthSystem’s Research Institute, says in a press release sent to reporters.
Many researchers expressed skepticism about the results. “This study is way, way, way too small to draw any meaningful conclusion,” Jeffrey Barrett of the Wellcome Trust Sanger Institute says in a statement for Science Media Centre (SMC). “None of their findings meets the accepted thresholds for statistical significance in a genome-wide association study (which is why it is published in Scientific Reports). The comments about SLITRK6 and TSHR are utter speculation, and don’t belong anywhere near a modern genetic study—we had decades of such claims that never held up because they didn’t meet statistical significance.”
“The researchers have found weak evidence for genetic variation that influences self-reported sexual preferences in men. However, the sample size is small, the results have not been replicated in an independent study and the level of evidence presented doesn’t meet the threshold of significance typically required within the field,” agrees Gil McVean of the University of Oxford in a statement for SMC. “The press release is appropriate, but I don’t think the work would have been published if it were on a less controversial topic. It is—at best—preliminary.”
December 8, 2017
It is well known that estrogen levels in utero play a major role in the masculinization of the fetus. In some species, if the estrogen surge is repressed, the animals will all be morphologically female. It can be afected by changing the timing of exposure or by blocking receptors. Estrogen from birth control run-off pollution at extremely low levels can transsexualize certain species of fish. While the effect on the human in utero is not fully understood, and morphologically masculinization is genetically determined apart from the surge, we can be certain that estrogen plays a part in the masculinization of the human brain.
The xenoestrogens in birth control pills are extremely powerful substances that can persist in the organism for a very long time. They are so powerful that a "thanatos syndrome" scenario is even possible (J. Walker Percy, 1987) Along with sociological acceptance, I am convinced that these chemically stable persistent environmental pollutants are playing a large role in the tendency toward sexual orientation in our day. These pollutants could potentially cause a reduction in developmental masculinization in the male brain or a partial masculinization of the female brain with subsequent psychological effects.
It is quite possible that these "putative gay genes" are related to sensitivity to estrogen of the organism in-utero or the estrogen surge in some manner. By our lack of foresight into the effects of our sociological controls we may have caused great human suffering in the form of altered sexual orientation. The presence of the these xenoestrogen pollutants is so pervasive that establishing a scientific cotrol is extremely difficult and expensive if not impossible.
What is our lack of foresight doing to our children?
December 8, 2017
With no statiscal significance, and very little evidence, one can read anything they want into GWAS SNP data, and apparently there's a strong "want" out there. Similar data in a cancer paper would never see the light of day. The public's understanding of science, the scientific method, and peer review is fragile enough as it is without providing weapons to the anti-science movement.
In the interest of support for the research effort, as well as gay rights, could we please have a re-examination of the assumptions for the need to find a genetic cause that would force someone to be gay as though it was a disease? What is the benefit of this campaign, and what are the drawbacks? Is telling people "I have no choice. I'm forced to do it." really that essential?
December 8, 2017
GerryS, your points about endocrine disruption are important. However, I think you might be confusing in utero estrogen during normal development with in utero androgens from fetal testes of the "typical" XY individual. All fetuses bathe in ever-rising concentrations of maternal estrogen and progesterone. The gonads of fetal males pour out a surge of androgens starting around the end of the first trimester and lasting for several weeks. Also, I don't dispute the role of xenoestrogens in endocrine disruption, but homosexuality is pervasive in non-human animals (e.g. Bagemihl's Biological Exuberance) and, in humans, homosexuality predates technology's ability to produce xenoestrogens and dump them widely in the environment.
December 8, 2017
Thanks for the comment Neurona.
I agree with you. Every possible avenue needs to be investigated.
The hormones are generated by the fetus.
When I was in social work studies, one of the points brought up was the increase in the prevalence of homosexuality throughout modern years. This points to a cause beyond nature introduced in modern times, post industrial revolution. For Human beings, as social beings, I know of two modern day varients, one sociological and the other environmental. Both need to be investigated. By the way, there are quite a few phytoestrogens that could be introduced by diet also depending on what we eat.
It also needs to be accepted that it it is possible that nature is introducing a lot of its own accidents into the picture and that complicates the matter. Sex is survival through reproduction. We have inculturated other uses for it. I deal with the accidents in my own person by confronting them with joy and courage. They are serious thorns in my flesh and they sometimes conflict with my gifts. Nature never gives without exacting a price.
I would not put it past certain individuals to purposefully introduce agents into the environment to induce sociological controls with all their hidden side effects. There was no concern for the human person when birth control was introduced. It is an irrefutable historical fact that birth control was developed in the last century for the purpose of "peaceful" genocide. The US government funded two instances of birth control used on the women of Puerto Rico that I am aware of.
December 8, 2017
Geryy S, I am curious as to how in your work you came to determine that the increase in homosexuality prevalence in modern times is actually due to an increase in actual homosexuals, and not entirely due to more induviduals identifiying as such as attitutes towards homosexuality improve.
December 9, 2017
There is a huge, but always repeating, mistake in logic/statistics here. In physics, finding a minute difference (when theory predicts no difference), can lead to a great discovery. But in biology, finding a minute difference by increasing the sample is useless because this result will only tell you that the difference is BIOLOGICALLY insignificant. In the past, four + four rats were enough to show if the drug is effective. Now they hugely increase the sample and "prove" that it is effective, well - it prolongs life by 1 day. Get back to four rats!