DNA, RNA, etc and some theories

[Nesikep]

I'm trying to remember my Biology 101 from darned near 18 years ago, and my memory is a little shaky about it... so perhaps Milkmaid, or one of the vets can confirm what I'm remembering..

We always say that a calf gets half it's DNA from each side of it's family, and yes, that is true, but not exactly half of it's genetic makeup... Here's why, according to what I remember

The mitochondria, a small structure in a cell (an organelle), are the energy producers in a cell, and have genetic material of their own, it is a like DNA of it's own. This genetic material is ONLY inherited from the mother (the egg) and not from the sire or sperm.

The reason I remember this is that apparently there was some murder case where a strand of the suspects hair was found, and the only genetic material on it was from mitochondria, and no cell DNA, so since it could have been anyone on the mothers side of the family, it wasn't enough to convict them.

Now I'm thinking of how this could affect breeding.. After all, the mitochondria is the energy supplier of the cell, and perhaps why some cow families are great producers through generations, even when the percentage of DNA of the original cow is getting pretty darned small, the mitochondrial genes are still unchanged. This would of course be especially evident in feed efficiency and milk production, but not calving ease and physical appearance.

Does this sound right to anyone? Can anyone correct me on errors or forgetfulness?

 

[Nesikep]

One of the implications of this would be keeping a bull from one of these maternal lines would not transfer those traits to the bull's offspring

 

[hillsdown]

Nesi, I think epigentics play the major role rather than just DNA .

 

[Nesikep]

Since I didn't know what epigenetics was... http://en.wikipedia.org/wiki/Epigenetics

From what I gather about that, it could be why some cows "work" with certain bulls so well, while other equally good cows just don't seem to.

It's a vast field, and with limited knowledge of genetics and cell functions, that is well covered in cobwebs I'm certainly no expert in it... just a few things I think about while going around the fields

 

[wbvs58]

Nesi my memory of this stuff is very hazy and goes way back probably before a lot of this more complicated stuff was dreamed up but I know what you mean. It is amazing what the brain churns over when going round and round on a tractor.
Ken

 

[Ozhorse]

From what I remember of genetics at uni, what you remember is right. Add to this the egg also contributes ribosomes which control the production of proteins and telemeres which control formation of the genetic material out of the blob that is the yolk into the distinct bodies that are the chromosomes. Anything that is supplied by the cytoplasm to the offspring, is supplied on the maternal side only.

I think there is a limit to the amount of improvement to be made by bringing in outside males only. There may be plenty of wisdom in following good cow lines, and bringing them into a herd.