[derefr]

So, in what other species can "bilateral gynandromorphism" occur? I'm not having much success googling this.

Also, is this just a specific type of genetic mosaicism? I've heard of humans with mosaic DNA (sometimes showing up as patches of alternative skin/hair coloration, etc.); but for some reason I've never heard of humans with mosaic DNA of two different chromosomal sexes.

[buildbot]

I believe humans actually, I just stumbled upon this infographic today : https://static.scientificamerican.com/sciam/cache/file/164FE...

[Karawebnetwork]

I don't have any sources for that but I have an anecdotal story.

While I was volunteering in a support group for transgender people, I once spoke to a woman who had a lot of complex issues with her hormone replacement therapy.

She was on a mix of medication that I had never seen before and I got worried that her health provider was prescribing an incorrect treatment.

This got me to ask questions I would never ask usually out of worry.

She told me that the reason that her medication was not the usual treatment is that she had a condition in which different parts of her bodies had different chromosomes. She told the exact name of the condition at the time but I did not write it down. I do remember the word "chimerism" being said during this conversation.

From experience, stories about weird conditions said by trans people are almost always true. She seemed very sincere about her struggles.

[auganov]

AFAIK gynandromorphism doesn't happen in mammals because sexual development is more centralized. Half of your body could have cells of a different sex but it wouldn't matter because organs responsible for sexual development will still effectively turn out one way. In other species each side of the body will develop quite differently because different cells is all it takes.

Tons of different human mosaics have been observed but it usually doesn't cause anything interesting.

Having different hair would imply chimerism - having two different sets of DNA. With mosaicism you start from one set of DNA but it may not duplicate the usual way.

[eyelidlessness]

Most if not all species with biological sex presentation. Binary sex characteristics are an abstraction and extend beyond a specific set of chromosomes (which also present more non-binary configurations). Most humans and other sexed animals bunch up on one side or the other but it’s still a convenience rather than an either/or fact.

[aspaceman]

You might find more luck with the term “intersex” or in more historical sources, hermaphroditism.

From the wiki for mosaic DNA:

> In rare cases, intersex conditions can be caused by mosaicism where some cells in the body have XX and others XY chromosomes (46, XX/XY).[12][13] In the fruit fly Drosophila melanogaster, where a fly possessing two X chromosomes is a female and a fly possessing a single X chromosome is a sterile male, a loss of an X chromosome early in embryonic development can result in sexual mosaics, or gynandromorphs.

> An example of this is one of the milder forms of Klinefelter syndrome, called 46,XY/47,XXY mosaic wherein some of the patient's cells contain XY chromosomes, and some contain XXY chromosomes.

So yes. Looks like it occurs in humans enough to be a big area of study for intersex understanding. There’s a lot of research on sex in this area, but it’s hard to dig through. (And a recommendation for the game “House of Fata Morgana” if you’d like a fictional telling of this history).

[swebs]

>You might find more luck with the term “intersex” or in more historical sources, hermaphroditism.

Not exactly. Intersex only refers to hermaphroditism in humans, mainly for political reasons. In all other species, its still called hermaphroditism.

[pseudalopex]

Intersex includes conditions hermaphroditism doesn't.

[swebs]

Do you have more info?

[pseudalopex]

Usually hermaphroditism means an organism can produce male or female gametes. For humans it meant they had ovarian and testicular tissue.

[mod]

> Not much is known about the unusual phenomenon, but this sexual split has been reported among birds, reptiles, butterflies and crustaceans.

From an article linked in another comment: https://www.nytimes.com/2019/02/09/science/cardinal-sex-gend...

[rriepe]

Try lobsters.