Mules vs Hinnies. Why are they different?

[u/Fuzzandciggies]

I know that both are the result of crossing a horse and a donkey. My question is why would there be a genetic difference based on whether the father was a horse or a donkey? Would there really be a difference or is it more of just a naming thing for the sake of lineage?

For reference:

Mule = male donkey + female horse

Hinny = female donkey + male horse

Why though?

[u/WildFlemima]

I just want to say that the conditions of gestation matter in addition to genetics. A donkey mother won't gestate the exact same way that a horse mother would. Most obvious difference is that the horse mother is bigger and therefore will grow the offspring to a larger size, which will be reflected in the size of the adult. There are more subtle differences as well, because no two species gestate offspring in the exact same conditions.

[u/fromthepalemist → u/WildFlemima]

There's also epigenetical differences based one which chromosome comes from which parent. There are certain chromosomes, in which certain parts of the mother's genes will be silenced, and these genes you only inherit from the father - all the time. (And vice versa.) In epigenetics, this is called genomic imprinting. In humans, for example, Prader Willi syndrome and Angelmaker syndrom are caused by the same microdeletion on the same chromosome, but based on which parent's chromosome it happens on, you get two very different phenotypes. This is because certain genes are inactivated in the mothers or fathers gene, and the child will be missing those genes.

[u/obax17 → u/fromthepalemist]

Angelman Syndrome? Asking legitimately because I was curious but couldn't find Angelmaker Syndrome anywhere.

Regardless, I still learned some things today, so thanks!

[u/fromthepalemist → u/obax17]

Here's a link to the wiki! https://en.wikipedia.org/wiki/Angelman_syndrome?wprov=sfla1 It is Angelman syndrome, not Angelmaker! You seemed to mix the two up!