This isn't that extraordinary, scientists have been making lesbian and gay flies since 2007 (at least that's when the study was published) by altering their DNA. Scientifically, it's always been pretty certain that homosexuality is genetic. No study on homosexuality ever conducted has ever shown any environment that is more likely to produce homosexual adults than any other.
And I just have an odd question... One that I cannot bare to hold in any longer. I am interested in science and technology in general. So, using pure human logic, how in the hell could a homosexual gene be passed down throughout humanity if homosexual people have sex with another man (or woman if lesbian)? Would it halt the "spread" of the gene? I mean, one gets genes via combination of a MOTHER and a FATHER. So, just saying... it sounds a little unesplained. (yes I meant that typo)
You learned about recessive genes in school, I hope. If a woman has a gay son and a straight daughter, then the family's homosexuality gene is still passed through the sister's children even if the son never reproduces. It's the same way with genetic diseases that always result in the death of the child. A gene doesn't have to be expressed in a person for that person to carry the gene.