Genetic Switch Makes Female Mice Try to Mate With Other Females

By Joseph Calamia | July 9, 2010 12:17 pm

PCWmice1Geneticists have found a way to alter the sexual preference of lab mice. When they bred mice that had one gene deleted, the females declined male companions and preferred instead to court other females, according to a study published yesterday in BMC Genetics. But whether these results have any implications for humans is still far from clear.

Chankyu Park and his team at the Korea Advanced Institute of Science and Technology deleted the female’s fucose mutarotase gene and, as a result, changed the brain’s exposure to enzymes that control brain development.

The gene, fucose mutarotase (FucM), is responsible for the release of an enzyme by the same name, and seems to cause developmental changes in brain regions that control reproductive behaviors. The mice without the enzyme would refuse to let males mount them, and instead tried to copulate with other females. [AOL News]

The enzyme typically works with a protein to prevent a build-up of the hormone oestrogen in the mouse brain; extra oestrogen causes parts of female mice brains to develop like typical male mice brains. Explains Park:

“The mutant female mouse underwent a slightly altered developmental programme in the brain to resemble the male brain in terms of sexual preference.” [The Telegraph]

Park has not found a “gay gene”–it’s impossible to tell at this stage what relationship, if any, this study has with human sexual preferences. For one, the hormone that “masculinizes” human brains is testosterone rather than oestrogen, and the protein block isn’t the same either. Still, Park hopes to investigate further to see if the study will shed any light on human sexuality.

Now, Park and his colleagues are hoping to use gene screening studies to find out whether fucose mutarotase has any association with sexual orientation in humans. He admits this research may be “very difficult”, partly because it will not be easy to find a suitable number of volunteers. [New Scientist]

Related content:
80beats: A Gay Man’s Brain Looks a Lot Like a Straight Woman’s Brain
80beats: Gay Penguin Couple Adopts Chick in German Zoo
80beats: Familial Rejection of Gay Teens Can Lead to Mental Health Problems Later

Image: Wikimedia

CATEGORIZED UNDER: Living World, Mind & Brain
  • steve

    ” (FucM)”, you just HAD to use that acronym?

  • Stolen Dormouse

    The same kind of phenomenon has been known in fruit flies since the mid-1960s, when Seymour Benzer’s group at Caltech described the fruity mutant, where males followed around and attempted to mate with other males. The mutation name was later changed to fruitless, to avoid using a slur as the mutation’s name.

  • Vectra

    I’m… Iffy about this line of research.

    I don’t really see a useful, humanitarian outcome from messing about with genes that might control sexuality.

    Nor do I see any ethical right to mess with procreation as it has evolved… It’s (To me at least) frightening to consider the problems that might arise from any theoretical human modifications that might be researched and put into production down the track.

    …Sexuality should be a fluke, not some gimmick controlled by science, much like eating and sleeping.

  • Julia

    Vectra: They’re not actually doing anything that would ever lead to “messing about with genes”. Research with mice often involves turning particular genes off, on, up, or down. Just because you can delete a gene in mice, to hopefully determine what the gene is normally responsible for, doesn’t mean that anyone would ever delete the gene in people. The steps taken to produce mice null for a particular gene are not steps you could take with people. Don’t worry, people aren’t going to be deliberately messing about with sexuality genes. 😉

  • rabidmob

    I guess it’s such a touchy issue with sexuality involved that some people may in fact find out they have a mutated gene that screws with their decisions for mates.

  • scribbler

    Quote: “Just because you can delete a gene in mice, to hopefully determine what the gene is normally responsible for, doesn’t mean that anyone would ever delete the gene in people.”

    Unquote: Doesn’t mean they won’t, either…

    rabidmob: Let’s do a thought experiment here and say that we find a gene that when turned off, makes mice eat their children. Does it then make that practice moral and right and should we then champion it as normal behavior?

    To that end this has nothing to do with human sexuality, does it?


    Oh wow, isn’t that kinda dangerous?

  • JP

    If they are able to prove that sexuality is something determined in people’s genes, EVERYTHING would change. Gays and lesbians would have scientific material to argue against bigots and bible crazies. Shoot, even the Bible would be proven WRONG!
    So Vectra, finding the gay gene would be extremely useful, specially for homosexuals like me.

  • Jumblepudding

    A novel method of population control. Induced homosexuality. It’s sapiens to be homo!

  • scribbler

    Your conclusions are unfounded, jp.

    Common mistake, though…

    Everone knows that sexuality is determined by genes, don’t they?

    What does that have to do with morality?

    I mean, I have urges to kill every time I drive and I’m certain they are generated by one gene or other and can be turned off by deleting a gene or two. Is murder now moral and right?

  • rabidmob

    @Jumplepudding : that would certainly be unethical

    @Scribbler: It’s not so much that genetic change makes what a homosexual does right, I think it’s dysfunctional. But it would have 2 major impacts:

    1. It’s not the homosexual’s fault, they were born that way, stop blaming the victim.

    2. Treatment may be possible or may be possible if caught early enough. Or then again people may decide to abort a fetus because it has the mutation (scary).

    You should probably also seek treatment for your homicidal impulses that you get while driving.

  • scribbler

    Why should I get treatment for impulses I do not act upon because of my moral convictions?

    Isn’t that what defines being a human being?

    If homosexuality is a disease as you imply, wouldn’t the logical course of action be treatment as well?

    People choose to stop homosexual behavior all the time. That choice and subsequent behavioral change has nothing to do with genetics, does it?

    Strange genetic condition indeed that is cured by a choice…

  • rabidmob

    I see so you will continue to blame the victim, that is not a very moral course of action.

  • Jennifer Angela

    Well, being gay and female MIGHT have a lot to do with an overload of estrogenes, I am not THAT surprised, as I can think of a friend of the family who is gay and female and has a strong love for the colour pink and pink rooms and anything that is extremely female including cats and all sorts of pink rooms and fluffy items… and anyway… if you knew her you would agree that she does have a very female personality (slighty cryish, sensetive, avoids not only fights but even argumentations, despises any kind of competition, stress…sometimes even things others might consider simpely a challenge…)- the kind of personality that leads to my assumption that she possesses HUGE amounts of estrogenes (probably more than I will ever have – and I am straight, like funny competitions, enjoy watching and doing sports… the only very female thing about me, if that is female, is that I value cats…) I would assume that generally women with lots of estrogen feel better within female environments and somehow emotionally require to be with women as much and as close as possible, while women, who are into sports and love to watch sports on TV and are generally very buddy-like… get along with guys awfully well and love being straight (heterosexual). I also think that extremely female women (like the one described above) who do have relationships with men might have those due to social pressure, but are in fact unconsciously gay. I guess most people never expose their gayness or dare to display their gayness as a life-style, because it is still considered uncool in lots of environments.

    I think nature needs balance. A certain amount of estrogenes are required to be female and straight. I would NOT be suprised to find out that an overload of estrogenes however, leads to being female AND gay. A certain amount of testerones are required to be a man. An overload of testerones however, creates men who are evidently overly aggressive and generally a safety hazard.

    Last but not least, I need to add, that I am not against people being gay. Let them be gay. I am just trying to find out what the roots of gayness are – just like those authors who wrote this fascinating article and people who comment in here (I haven´t noticed any hostile comment against gay folks so far – if I am mistaken, please let me know).

    Certainly, I am not sure about this THEORY myself and would just like others to take this “thinking model” into account – merely as a possibility.

    I would like to add that FucM sounds a little bit like … do something (f…) to males or men…. amusing but inappropriate I guess…. It would certainly hurt my feelings, if I was a guy.

  • bear

    @jennifer angela. liking pink and cats fluffy items has nothing to do with being a female. That is simply a cultural gender binary that you are placing on her. a color cannot be defined as male or female because it has no gender. therefore a person cannot be categorized into a gender based on their preference to that color. the same goes for fluffy things and cats or liking sports.

    the cultural binary of maleness vs. femaleness is not only the cause for the perpetuation of homosexual stereotypes but also an affront to feminism and masculism.

  • Ess

    Isn’t variation, by genetic mutations, the key to all life, through speciation? Everyone has traits that differentiate them from both their parents and other people due to genetic mutations and unique conditions in the womb. These are the factors that make you “you”; The term mutation seems to imply a differ from the norm, but in fact there is no norm, which is pretty evident by the myriads of physical and innate social differences in people.

    Looking for a “gay” gene is detrimental to the acceptance of the spectrum of sexuality because its completely logical that a gene or a condition in the womb causes gayness, there’s also a gene that causes you to have blue eyes, like cheese, laugh, watch that stupid show you’re boyfriend doesn’t like, etc etc. Why is there a focus on the determining factor of ones sexuality, specifically along the lines of the gay-straight binary? We can just as easily lump people into groups based on whether they like blondes or brunettes… It would be just as arbitrary and neglectful of the subsets within.

    Why aren’t we then looking for what makes one heterosexual, or like leather, or straight males who wear lingerie, or straight females who anally penetrate men, or bisexual, or asexual, or only date a certain race, or like to be smothered by a heavy set person, or like hair, or like multiple partners, or prefer monogamy, or like butches, or femmes, or be dominant, or submissive… This focus on homosexuality is as detrimental as its useful and only exists because heterosexuality is falsely construed as a norm.

    So here’s the real issue here: sexuality as is differing and inconsequential as tastes in food.

    Of course changes in developmental hormone levels affect sexuality.

    This is less fascinating than the discovery of the gene that makes some people think cilantro taste like soap.


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