Infomaniac. I have been reading "Genetics of the fowl" Hutt. I have it on loan from the university library. It has helped me to understand some of what you and Rokimoto are able to speak of. They are searching for others for me. My question to you is this: can you explain what autosomal means. I have an idea, but it is not clear to me/ Thankyou.
Thank you for your post, Robb. A gene that is "autosomal" is NOT on the sex chromosome. That's what "autosomal" means.
Infomaniac, Thankyou, and yes, I would like that URL>The book is as out of date as me, 1947.
LOL! Robb, I'm only about 10 years behind you! The link to the genetics pages is:
By Infomaniac on Wednesday, January 16, 2002 - 10:38 pm:
As you surely know, male birds (not just chickens) have two Z sex chromosomes. Females have one Z and one W sex chromosome. So, males can have two copies of genes that are on the Z sex chromosome, like sex-linked (cuckoo) barring, while females can have only one. This is actually the basis for the autosexing breeds. Sex-linked barring has a 'dose' effect... male birds having two copies of the gene (one on each Z chromosome) have a barring that has a different appearance than do birds having only one copy of the gene. So, Barred Rock males can be distinguished from Barred Rock females as day-old chicks. Sex-linked barring is also a potent inhibitor of eumelanin (black pigment in feathers and skin) so the female Barred Rocks tend to have darker shanks than the males ... again, due to the "dose effect" of the sex-linked barring gene.
There are two types of barring... one is sex-linked and has the gene symbol, B. The other is "autosomal barring" which is actually due to several genes none of which are on the sex chromosome, so one always puts the "autosomal" in front to distinguish it from the sex-linked barring.
There are some genes on the W chromosome, which is shorter than the Z chromosome, but not many that fanciers would recognize.
If the book by Hutt you have is more than 10-15 years old, it will surely have a lot of out-of-date information. If you would like, I can send you the URL for a set of online genetics pages. (Hutt may still be alive, but, if he is, he is really old now. A lot of his work was done before the middle of last century.
By Robbpa on Thursday, January 17, 2002 - 09:43 am:
By Infomaniac on Thursday, January 17, 2002 - 10:52 am:
Online Genetics Pages