| ORIGINAL BOOK REVIEW by Dr. Rainer R. Erhardt "Well, there is help on the horizon and anyone seriously interested in color genetics should take a look at Linda Rubin's book: COCKATIEL GENETICS MADE EASY! Though this book is primarily directed to breeders of cockatiel mutations, there is enough information in this volume to teach anyone the secrets of dealing with recessive, sex-linked, and dominant mutations..." ACBM, Vol. 65, No.12 CLICK TO READ THE REST OF THE REVIEW! 112 pages, 15 chapters, glossary & more! |
Copyright 2007 Linda S. Rubin
| Multiple Bird Households by Linda S. Rubin |
| Series by Linda S. Rubin |
| Breeding Dominant Yellowcheek to Whiteface Copyright © 2003 LINDA S. RUBIN CF Genetics Consultant/Panel Judge All Rights Reserved www.CockatielsPlusParrots.com Adapted from "My Mailbox" QUESTION I know a breeder who has a clutch of young from a Whiteface Cinnamon Pied hen and a Dominant Yellowcheek Cinnamon Pearl cock. All 6 babies are orange-faced Cinnamon. Is it true that Dominant Yellowcheek and Whiteface will throw only orange-faced even when the baby has the Yellowcheek gene? Thanks, Mc ANSWER Hi Mc, First, I’ve replaced your use of the term “orangedfaced” with the standard nomenclature of Yellowcheek in order to make reading easier. A Dominant Yellowcheek Cinnamon-Pearl cock X a Whiteface Cinnamon Pied hen = 50% Dominant Yellowcheek Cinnamon/Whiteface Pearl Pied cocks 50% Dominant Yellowcheek Cinnamon-Pearl/Whiteface Pied hens Therefore, yes, it is true that all the offspring with be Dominant Yellowcheek. The male chicks will be visual Dominant Yellowcheek Cinnamons split to Whiteface Pied, and the female offspring will be Dominant Yellowcheek Cinnamon-Pearl/Whiteface Pied. Either some of the offspring are so sparsely pearled that the Pearl mutation goes unnoticed, or the ratio of cocks to hens will even out to the correct percentages in future nests. As an example, the next clutch could be comprised of 5 Dominant Yellowcheek Cinnamon- Pearl/Whiteface Pied hens and no male offspring. Your question is not quite clear to me; I will assume you are asking why a Dominant Yellowcheek and a recessive Whiteface will throw all Dominant Yellowcheek young? If you work out the graph and learn to diagram these types of crosses, then you will understand that a dominant gene is always visual over a recessive gene. The recessive genes in this example were the sex-linked recessive mutations Cinnamon and Pearl, and the autosomal recessives mutations Whiteface and Pied. These are all recessive to the Dominant Yellowcheek, which is why the Dominant Yellowcheek is visual. My belief is that the Dominant Yellowcheek mutation in cockatiels is expressed as a phenotypical (visual) Yellowcheek, regardless of whether or not the Dominant Yellowcheek is in its homozygous or heterozygous state. As in the above example, if other color mutations (such as the Cinnamon, Pearl, Whiteface, or Pied, etc.) are present, these mutations are also inherited in the usual manner, but cannot suppress the appearance of the Dominant Yellowcheek mutation. Cockatiel breeders are going to have to learn more than just the sex-linked recessive and autosomal recessive patterns of inheritance as new color mutations develop with other modes of inheritance. Hope that helps, Linda S. Rubin |
| BREEDING DOMINANT YELLOWCHEEK TO WHITEFACE Copyright © 2003 Linda S. Rubin All Rights Reserved |
| c.2007 Sandra Trottrier (click thumbnail for larger image). |
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