Xq28
Encyclopedia
Xq28 is a genetic marker
on the X chromosome
found by Dean Hamer
and others in 1993
. Hamer's study led to his belief that they found a link between the Xq28 marker and male homosexuality
, but the original study's results have been disputed.
examined 114 families of gay men in Italy
and found increased rates of homosexuality among maternal uncles and cousins, but not among paternal relatives. Genetic linkage
was studied in 40 of the families, in which there were two gay brothers. A correlation to Xq28 and other microsatellite markers was found in approximately 64% of the cases. A similar study by the same team conducted in 1995, again based on Italian material corroborated these results, but failed to find a link to the Xq28 gene among homosexual females.
Although disputed animal trial have discovered removing of a certain gene appears to reverse homosexual behaviors.
A group of Korean geneticists has altered the sexual preferences of female mice by removing a single gene linked to reproductive behavior. Without the gene, the mice gravitated toward mice of the same sex. Those mice who retained the gene, called FucM, were attracted to male mice. (FucM is short for fucose mutarotase.)
disputed the results. Studying Canadian
material consisting of 52 pairs of gay brothers, George Rice and others found no statistically significant linkage in allele
s and haplotype
s and concluded against an X-linked
male homosexuality gene.
When the refuting study was published in Science
, Hamer disputed it, standing by his original results.
Genetic marker
A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify cells, individuals or species. It can be described as a variation that can be observed...
on the X chromosome
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
found by Dean Hamer
Dean Hamer
Dr. Dean Hamer is an American geneticist, author, and filmmaker. He is known for his contributions to biotechnology and AIDS prevention, his research on the genetics of human behavior including sexual orientation and spirituality, and his popular books and documentaries on a wide range of...
and others in 1993
1993 in science
The year 1993 in science and technology involved many significant events, listed below.-Astronomy and space exploration:* December 2 - STS-61 is launched. This Space Shuttle mission to the Hubble Space Telescope installs corrective optics, plus upgrades, that not only allow the telescope to focus...
. Hamer's study led to his belief that they found a link between the Xq28 marker and male homosexuality
Homosexuality
Homosexuality is romantic or sexual attraction or behavior between members of the same sex or gender. As a sexual orientation, homosexuality refers to "an enduring pattern of or disposition to experience sexual, affectional, or romantic attractions" primarily or exclusively to people of the same...
, but the original study's results have been disputed.
1993 study
The 1993 study by HamerDean Hamer
Dr. Dean Hamer is an American geneticist, author, and filmmaker. He is known for his contributions to biotechnology and AIDS prevention, his research on the genetics of human behavior including sexual orientation and spirituality, and his popular books and documentaries on a wide range of...
examined 114 families of gay men in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
and found increased rates of homosexuality among maternal uncles and cousins, but not among paternal relatives. Genetic linkage
Genetic linkage
Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...
was studied in 40 of the families, in which there were two gay brothers. A correlation to Xq28 and other microsatellite markers was found in approximately 64% of the cases. A similar study by the same team conducted in 1995, again based on Italian material corroborated these results, but failed to find a link to the Xq28 gene among homosexual females.
Although disputed animal trial have discovered removing of a certain gene appears to reverse homosexual behaviors.
A group of Korean geneticists has altered the sexual preferences of female mice by removing a single gene linked to reproductive behavior. Without the gene, the mice gravitated toward mice of the same sex. Those mice who retained the gene, called FucM, were attracted to male mice. (FucM is short for fucose mutarotase.)
1999 study
A further study of these results in 19991999 in science
The year 1999 in science and technology involved some significant events.-Aeronautics:* February 27 – While trying to circumnavigate the world in a hot air balloon, Colin Prescot and Andy Elson set a new endurance record after being in a hot air balloon for 233 hours and 55 minutes.* March 3 –...
disputed the results. Studying Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
material consisting of 52 pairs of gay brothers, George Rice and others found no statistically significant linkage in allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
s and haplotype
Haplotype
A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...
s and concluded against an X-linked
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
male homosexuality gene.
When the refuting study was published in Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
, Hamer disputed it, standing by his original results.
External links
- Molecular Genetic Study of Sexual Orientation A genetic study of gay brothers at Northwestern University.