#91028 - 08/13/10 05:07 AM
Re: Mottling and Linkages
[Re: Wieslaw]
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Bantam
Registered: 09/18/07
Posts: 57
Loc: France
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I have another reference about this linkage :
Brumbaugh & Hollander, Genetics 48:884, 1963
It's an abstract of a presentation in congress, where they say that pourcentage of recombinants between E and Mo is 26% (+/- 4,5%).
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#92332 - 10/28/10 11:55 AM
Re: Mottling and Linkages
[Re: Wieslaw]
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Classroom Professor
Registered: 08/30/02
Posts: 2881
Loc: Australia
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I'm hoping for some help with French The following from the French book: Les Poules. Diversite Genetique Visible - page 87 J.C.Martin (communication personalle), en croisant des animaux Bantam de Pekin cailloute noir avec des Bantam de Pekin perdrix, obtient une F1 noire; en F2 il denombre 131 noirs cailloutes sur 310 noirs totaux. Cette proportion de 42,26%, proche des 43,84% attendus avec 265 de recombinants, est egalement proche de 7/16c soit 43,75% que donnerait une F2 avec deux alleles recessifs appartenant a deux loci independants. What I've gathered is that Black Mottled Pekin were crossed with Partridge Pekin. All F1 were black. But then it gets confusing, eg - poor translation: in F2 it denombre(?) 131 Black Mottled on 310 black totals. This proportion of 42.26%, close of the 43.84% awaited with 265 of recombinants, is egalement(?) close of 7/16 is 43.75% that would give one F2 with two alleles recessives belonging has two loci independants. "131" is 42.26% of 310. So, are they saying that in the F2: * 131 black mottled * 179 solid black ? = 310 E phenotype total (ie both solid black & black mottled). Then I'm lost in the maths  I "think" they are saying (by the last sentence)" that the two loci (mo & E) segregated independently? P.s. they also mention on another page (p63) the 26% linkage of mo - E (Brumbaugh & Hollander, 1965). --------------- Unfortunately, personally although I had many mottled & non-mottled (mostly mo/Mo+) phenotype birds with E locus alleles e Wh, e+, E (or ER), but they were, eg: e+/e+ mo/Mo+, E/E mo/Mo+, ER/e+ mo/Mo+ etc in foundation birds, so a nightmare to work out if any linkages between mo & E loci.
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#92333 - 10/28/10 12:40 PM
Re: Mottling and Linkages
[Re: KazJaps]
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Classroom Professor
Registered: 08/30/02
Posts: 2881
Loc: Australia
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Just for the fun of it.... J.C.Martin's F1 (E-mo/e b-Mo+) x F1 (E-mo/e b-Mo+)= F2 result:  (* Henk's punnett square image generator) ------------- If the E locus & mo locus had no linkage (segregated independently): Gametic Ratio = 1.1.1.1 (ie 1/4 (25%) Mo+ E, 1/4 (25%) Mo+ e b, 1/4 (25%) mo e b, 1/4 (25%) mo E) Genotypic Ratio = 1:2:1: 2:4:2: 1:2:1 Phenotypic Ratio = 9:3:3:1 9/16 (56.25%) black, 3/16 (18.75%) black mottled, 3/16 (18.75%) partridge (brown -e b), 1/16 (6.25%) partridge mottled (brown –e b/e b mo/mo)) ---------------------- If the E locus & mottled locus had 26% linkage, & parental birds were P1: e b-Mo+ plus P2: E-mo linkage, the F1 X F1 (F2) dihybrid crosses gametic ratios would be: 37% e b Mo+, 13% E Mo+, 37% E mo, 13% e b mo *Phenotypic % = 74% P1 & P2 parental phenotypes (e b-Mo+ or E-mo), 26% crossovers (E-Mo+ or e b-mo). Any errors in the above?
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#92346 - 10/29/10 05:06 AM
Re: Mottling and Linkages
[Re: Wieslaw]
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Moderator
Classroom Professor
Registered: 02/13/06
Posts: 3234
Loc: Netherlands
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Glad to see that the green square is working on this board. Also glad to see you post again, Kaz  (Degree of gladness not in that order)
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#92348 - 10/29/10 05:30 AM
Re: Mottling and Linkages
[Re: Henk69]
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Ruler of the Roost
Registered: 11/23/06
Posts: 1150
Loc: Holland
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Translation: JCMartin (personal communication), crossed black mottled Pekin bantams to partridge Pekins, and got black F1; in F2 he countes 131 black mottled and 310 blacks in total. This proportion of 42,26%, comes near to 43,83% of the expected 265 recombinants, and it equal to almose the 7/16c which is 43,75% which were given in the F2 on two recessive alleles which appear to be on two independent loci.
I've crossed E Mo+/mo po+/po+ Pti1/pti1+(incl. brachydactyly) x eb/eb Mo+/mo Po/Po Pti-2/Pti2. Of 26 chicks, all mottleds (6) had 4 toes and Pti1. The others were self choc, had all 5 toes, all Pti1 pure or Pti2 impure (feathered shanks but clean middle toe), and app. 1/3 brachydactyly.
I wondered about why all mottleds had 4 toes instead of 5. Of the self chocs only one had 4 + 5 toes. It looked as if the mottleds did not want to have 5 toes.
Owh, PS: of those 6 mottleds, 4 died of Mareks, none of the others.
Edited by Sigi (10/29/10 05:37 AM)
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#92349 - 10/29/10 05:45 AM
Re: Mottling and Linkages
[Re: KazJaps]
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Bantam
Registered: 09/18/07
Posts: 57
Loc: France
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Hello,
Maybe I can help for translation :
"J.C. Martin (personal communication), by crossing black mottled Pekin Bantam with partridge Pekin Bantam, obtains a black F1; in F2, he counts 131 black mottled out of 310 black in total. This proportion of 42.6%, close to the expected 43.84% with 26% of recombinants, is also close to 7/16th, so 43.75%, that would give a F2 with two recessive alleles belonging to two independant loci."
I agree with the expected values calculated by KazJaps. Then, I'm not so sure to understand how the values of 43.84% or 43.75% have been obtained.
If I follow the gametic ratios provided by KazJaps if E and Mo are linked (26 cM), I find a proportion of 31% of mottled among blacks.
Best regards.
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