| COMUTER PROGRAMS & THE REALITY OF CROSSOVER IN REAL LIFE COMPLEX PAIRINGS Copyright © 2003 LINDA S. RUBIN CF Genetics Consultant & Panel Judge www.CockatielsPlusParrots.com First published and adapted from "My Mailbox" All Rights Reserved. QUESTION I thought I had the genetics figured out, but I’ve become confused. I used a program that others have sent me and thought I knew exactly what one of my pairs could produce. It has broken the male splits down and changed the possible outcome of my pair. I'm looking for Linda's help on this. I will be getting her workbook soon, as now I am extremely interested in how this all works. The cock is a Whiteface split to Pied, Lutino and Pearl - I thought it was Lutino-Pearl, but because of the babies he's thrown, it must be Lutino and Pearl. (This cock’s mother is a Whiteface Lutino and his father is a Whiteface. There must be Pearl in there somewhere). The hen is a Normal Grey split to Whiteface, and I am unsure of her background. The pair produced the following offspring: Normal Grey, Whiteface Lutino, Whiteface, and a Whiteface Pearl in the first clutch. The second clutch had 2 Normal Greys, a Whiteface and a Whiteface Pearl. Here's where the confusion comes in. According to my new chart all the males are either Normal Grey or Whiteface and none of the females are. This is different than before and I am wondering if I did this right? I also played around with the Lutino and Pearl and in order to throw a Whiteface Pearl, my male has to carry each of these genes ... is this correct? Is it normal to get the same mutations in females (i.e., Whiteface Pearl and Whiteface Lutino, but not the standard Pearl or Lutino)? The program showed the same probability for both and I'm wondering if this is correct? And if so, will the Normal and Whiteface offspring be male? If this is correct, it will be easier than I thought to tell whether chicks from this pair are male or females. Thanks, Diana ANSWER Hi Diana, I am glad you are getting my workbook because I wrote it to end this kind of confusion by teaching breeders a simple method they can learn and exercise on their own. Unfortunately, computer programs do not always teach these types of skills or chart more complex crosses in depth. You are on the right track. Your cock's sire was a Whiteface, but he was also split to Pearl in order to throw a Whiteface/Lutino, Pearl and Pied male offspring when paired to a Whiteface Lutino hen. In addition, either one, or both of the grandparents had to be visual Pied, or split to Pied, in order for the Pied gene to be inherited in split form in your adult breeding cock. Therefore: Breeding a Whiteface/Lutino, Pearl and Pied cock to a Normal Grey/Whiteface hen = cocks: 6.25% Whiteface/Lutino Pied 6.25% Whiteface/Lutino 6.25% Normal Grey/Whiteface Lutino and Pied 6.25% Normal Grey/Whiteface Lutino 6.25% Whiteface/Pearl Pied 6.25% Whiteface/Pearl 6.25% Normal Grey/Whiteface Pearl Pied 6.25% Normal Grey/Whiteface Pearl hens: 6.25% Whiteface Lutino/Pied 6.25% Whiteface Lutino 6.25% Lutino/Whiteface Pied 6.25% Lutino/Whiteface 6.25% Whiteface Pearl/Pied 6.25% Whiteface Pearl 6.25% Pearl/Whiteface Pied 6.25% Pearl/Whiteface As you can see by the above colors, you will be able to sex the young once they are fully feathered. Cocks will appear as Whiteface or Normal Grey; hens will appear as Whiteface Lutino, Whiteface Pearl, Lutino, or Pearl. However, ALL the young have extra color mutations that they carry and can pass onto their future offspring. What a great pairing! Remember, too, that all percentages are based upon every 100 chicks produced per pair. Therefore, while you may have a preponderance of several phenotypes (visual mutations) in the first nest or two, future nests will eventually throw the remaining predicted colors. This remaining balance will eventually even out the numbers predicted for each genotype (i.e., the complete genetic makeup of an individual organism) as listed above. However, should you produce any of the following visual mutations: Whiteface Lutino-Pearl cocks, Lutino-Pearl cocks, Whiteface Lutino-Pearl hens, or Lutino-Pearl hens, then you have encountered the rare phenomenon of genetic crossover. In this case, the Pearl gene has crossed over to combine with the Lutino gene on the same X sex chromosome in the male. As a result, many of the genotypes above will differ accordingly. If you do experience the event of crossover, it can be compensated for in a new chart that will reflect such changes and you are encouraged to submit it as another question. |
Copyright 2007 Linda S. Rubin
| RELATED ARTICLES Crossover in a Yellowcheek Pearl Pied hen |
| COMPUTER PROGRAMS & THE REALITY OF CROSSOVER IN REAL LIFE COMPLEX PAIRINGS Copyright © 2003Linda S. Rubin All Rights Reserved |
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| 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! |
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