On Mochi, the Hamada Familyâs Male Calico Cat
So Iâve heard some stuff going âround at how Mochi is supposed to be a female cat since itâs a calico cat, contrary to supplementary material, where Hiro uses male pronouns to address Mochi. For a long time after seeing the movie, I thought that âheh, the official materialâs a bit wrong there lmaoâ but then after thinking about it for a while I realised that, yes, theyâre actuallyÂ right, or at least possibly right about Mochi being a male calico rather than a female calico. Lots of science under the cut.
I legit spent half an hour on this. Wow. Not sure if someoneâs actually explained this before or that Iâm a total nerdy loser lmao
Thereâs this thing called the Klinefelter Syndrome, itâs a genetic disorder involving the sex chromosomes of an individual. It affects Y chromosome-carrying individual physical and cognitive development, and the symptoms vary among individuals, many of them not even manifesting at all in affected individuals.
The Klinefelter Syndrome results from an addition of an extra X chromosome in the cells of the Y-carrying individual, so instead of the usualÂ XY that males carry, Klinefelter individuals have a genotype ofÂ XXY.
(image source:Â http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Human_chromosomesXXY01.png/768px-Human_chromosomesXXY01.png)
This genetic condition actually occurs pretty frequently, in an estimated 1:500 to 1:1,000 human male live births. The addition of the extra X chromosome comes in the nondisjuction of the sex chromosomes during division of the sex cells of the individualâs parent, resulting in one sex cell possessingÂ two sex chromosomes, and its partner, having none (ifÂ that got fertilised it would bring about another genetic disorder, the Turner Syndrome). The sex cell having the two sex chromosomes would then be fertilised and would bring about the individual having the XXY genotype.
Now, in cats, colour is genetically inherited through the sex chromosomes. Specifically, the X chromosomes. Each X chromosome carries a gene for a certain fur colour, thereâs orange, black, et cetera. For a cat to be a calico cat, it must express both colour gene-linked X chromosomes, so it has to have, for example, an X(orange)X(black) genotype to express the calico pattern. The differing patches of colour happens due to the action of X-chromosome inactivation, or Barr body formation, which is a mechanism of the body to avoid double- or over-expression of any genes on the nearly-identical X-chromosomes. One X-chromosome is inactive per area of colour, so the other still active one will express its colour, giving the catâs coat the calico patterning weâre all familiar with.
(image source:Â http://img1.wikia.nocookie.net/__cb20140925154631/disney/images/4/48/Big-Hero-6-49.png)
That being said, calico cats should generally beÂ female, but male catsÂ can be calico cats,Â if they have genetic abnormalities, like having two X-chromosomes, meaning, they have to be sterile Klinefelter individuals. Theyâre actually kinda common, with approximately 1 male in 3,000 calico individuals.
So, MochiÂ can be male. Whodâve thought.
tl;dr: Mochi may have a genetic disorder that lets him be a calico cat even though heâs male. Thatâs it lmao gomen for the science
Bock, Robert (August 1993). âUnderstanding Klinefelter Syndrome: A Guide for XXY Males and their Familiesâ. NIH Pub. No. 93-3202. Eunice Kennedy Shriver National Institute of Child Health and Human Development. Retrieved December 13 2014.
Centerwall WR, Benirschke K (1975). âAn animal model for the XXY Klinefelterâs syndrome in man: Tortoiseshell and calico male catsâ. American journal of veterinary research 36 (9): 1275â1280.
âKlinefelter Syndromeâ. Health Information. Eunice Kennedy Shriver National Institute of Child Health and Human Development. 2007-02-19. Retrieved December 13 2014.
Spadafori, Gina. âFeline Fallaciesâ. The Pet Connection. VeterinaryPartner.com. Retrieved December 13 2014.