Zebra genetics question

[Ameza]

I have been reading a little about the zebra finch genetics and I have a few questions since it's a long time since I learned about genetics and some of the english is confusing me.

Dominant colours - they rule out other colours and seem to be double or single factor. What if you have a pair that is both double factor with dominant colour, what happens then?

Sex linked - Does that mean that if the mother is let's say fawn and the father normal, is it then just possible for the female chicks to get the fawn colour?

Recessive Colours - I am not familiar with this term so if someone would be so kind to explain how these colours work I would be most grateful.

And split is when someone carries a gene but doesn't show it, right?


I hope you will tolerate my silly questions

[Chris103]

I will try and answer some questions but if any of it is still not understandable please let me know! There are no silly questions, it's only silly when you have a question and don't ask! Usually the more you learn, the more questions you come up with.

This is all to just to my knowledge so If any info is incorrect PLEASE let me/us know!

Dominant Colors: You have the general description correct. I will try and explain the Double Factor (df) and Single Factor (sf) breeding in a chart. Also, remember that a bird can NEVER be split for a Dominant Color. It either is that color or not.

This could all just confuse you more but I hope not!

I just used AOC to stand for any other color that is not sex linked.

The sex of the parents is makes no difference.


(df) x (df) = 100% (df)
(df) x (sf) = 50% (df) 50% (sf)
(df) x AOC = 100% (sf)
(sf) x (sf) = 25% (df) 50% (sf) 25% AOC
(sf) x AOC = 50% (sf) 50% AOC


Some Dominant traits have a lethal gene....like crested. It can only be a Single factor because the Double factor would cause the chick to never hatch.

Crested(sf) x Non-Crested = 50% crested and 50% Non-Crested

Crested x Crested =
25% (df) Crested (dead, will never hatch)
50% (sf) Crested
25% Non-crested.

Sex Linked: No, The pairing you talked about would be Example 2.

Now If you had a Fawn male and a Normal grey female then you would get only Fawn female chicks and Normal split to Fawn males..... Sooo another chart And a rule:

Female Birds can NEVER be Split for a Sex Linked mutation! They are either that color or not! I can't tell you how many times someone has tried to sell me a female that was "split" for a sex link mutation....it is genetically impossible, so they are lying (or don't know any better).

I will use / to show for splits. Example: Normal gray/Fawn...This would be a normal gray bird that carries the genes for fawn.

Since the sex of the parents makes a difference, the male will always come first in the chart. I will use Fawn just because it is the one you mentioned.

Example 1
Fawn x Grey=
100% Fawn females
and
100% Grey/fawn males

Example2
Grey x Fawn=
100% Grey females
100% Grey/fawn males

Example 3
Grey/Fawn x Grey=
Male Chicks:
50% Grey/fawn
50% Grey
Female Chicks:
50% Grey
50% Fawn

And of course Fawn x Fawn will give you 100% fawn Chicks.

Recessive Colors: I will explain in another reply later today unless someone else gets there before I do.

Again, if anyone feels they can explain this better please do!

[Ameza]

Oh wow thank you, this is making so much more sense now. I look forward for the next post ;)

So about the sex linked mutations, they never show in males unless both parents have it? And it only shows in females if the father has the gene, and if the mother only has it it shows in no chicks at all? Am I getting this right? heh

I am looking forward for more explanation, especially since my pair is pied (f) and split black cheek (m) and that is both recessive colors as far as I know.

Thank you again!