| UNDERSTANDING CROSSOVER GENETICS IN MULTIPLE MUTATIONS Copyright © 2003-2007 Linda S. Rubin All Rights Reserved |
| 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 little 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 |
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| Understanding Crossover Genetics in Multiple Mutations Copyright © 2003 LINDA S. RUBIN CF Genetics Consultant/Panel Judge All Rights Reserved www.CockatielsPlusParrots.com Selected Q&A's "From My Mailbox" Q. I have a Lutino cock paired with a Cinnamon-Pearl Pied hen. By my calculations, all hens will be Lutino/Pied and all cocks will be Normal Grey split to Lutino, Pied, and Cinnamon-Pearl. However, when I double-check my results with the Virtual Breeder computer program, it shows my cocks split to Lutino, Pied, Cinnamon, and Pearl. Now I'm confused; do the Cinnamon-Pearl genes split up when you breed this pair as the computer program shows, or am I right? Also, does this mean I can never have males split to double or multiple mutations i.e., Cinnamon-Pearl, because they will always be split to Cinnamon and Pearl? If I breed a Cinnamon-Pearl male to a Normal Grey hen, will all the female babies - according to the program - be either Cinnamon or Pearl (XC Y or XP Y) and not Cinnamon-Pearl (XCP Y)? Thanks for your help, Sandy A. Hello Sandy, Actually, yours was the correct answer. Congratulations! You know more than you give yourself credit for. You understand the inheritance of multiple sex-linked mutations and the processes of crossover (and recombinant genetics), which I cover under separate chapters in my workbook “Cockatiel Genetics Made Easy!” Beginning with your original pair, a Lutino cock mated to a Cinnamon- Pearl Pied hen = XL XL - nn | XCP Y - pp --------------------------------------- XL XCP - pn XL Y - pn XL XCP - pn XL Y - pn 50% Normal Grey split Lutino, Cinnamon-Pearl, and Pied cocks 50% Lutino split to Pied hens You were quite right to perceive that the Cinnamon-Pearl genes carried by this double split male, will be passed on TOGETHER to his future female offspring, regardless of his mate. Unfortunately, some websites and computer programs cannot integrate more sophisticated information, either because they do not understand it, or because they are unable to demonstrate the inheritance of multiple sex-linked color mutations when they are inherited together on the SAME X Chromosome. The answers you were given were not fully complete. If you breed a Cinnamon-Pearl cock to a Normal Grey hen, you will produce: XCP XCP | X Y -------------------------------------- XCP X XCP Y XCP X XCP Y 50% Normal Grey split Cinnamon-Pearl cocks 50% visual Cinnamon-Pearl hens Of course we hadn't included the Pied mutation here, but if the male were also split Pied, then half the offspring, both cocks and hens, could be split Pied. You appear to have a natural bent towards learning color genetics and it is just as important, in my opinion, to not only figure out the charts, but to have an intrinsic understanding of what to expect. Kudos to you for not taking what you read at face value simply because it appears in print. You were correct to question the site you solicited for feedback. After all, if we never got double split males, we'd NEVER be able to produce any of our lovely, visual cross mutations! Keep up the good work. If you'd like to delve more into charting and learning about genetics, you may wish to refer to the chapter on crossover in my workbook. |
