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#92560 - 11/10/10 02:43 PM Re: whence came lavender [Re: Redcap]
Henk69 Offline
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Originally Posted By: Redcap
Originally Posted By: Redcap
But maybe a mutation/polymorphism? Of what? Of melanophilin on Chromosome 7?


Yes, i know, but blue is also called simultanously with melanophilin. So what says us that?? Is blue also on chromosome 7??


By who? smile

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#92561 - 11/10/10 02:58 PM Re: whence came lavender [Re: Henk69]
Redcap Offline
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#92565 - 11/11/10 01:20 AM Re: whence came lavender [Re: Redcap]
Henk69 Offline
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Which one to pick?

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#92568 - 11/11/10 03:04 AM Re: whence came lavender [Re: Henk69]
Redcap Offline
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According blue dog coat ...

In mice melanophilin is found on Chromosome 1
http://www.hiiret.fi/eng/breeding/varieties/blue.html
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#92571 - 11/11/10 05:36 AM Re: whence came lavender [Re: Redcap]
KazJaps Offline
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You know that lav & Bl are not alleles, otherwise the following would not be possible:

lav/lav, Bl/Bl

I haven't come across any linkages for the Bl locus (to give an indication of what chromosome). lav is 32.5 map units to rosecomb, & rosecomb is 0.4 cM to creeper -Cp (so lav similar distance -approx 33cM to Cp).


Yes, in various species, the homolog genes can be found on different chromosomes. Eg, the sex chromosomes in avian species have a different evolution to sex chromosomes in mammals. The brown (b) mutation (TYRP1 locus) in dogs is on an autosomal chromosome, but the brown (br^b) mutation (TYRP1 locus) in quails is on the Z chromosome (ie sex linked). The choc gene in chickens - sex-linked also. Bleu (lavender) quails were crossed with lav chickens and produced lavender phenotype (ie probably MLPH homologs). So, probably wiser to look to more closely related species (especially avian). Similar chicken blue phenotype mutation & incomplete dominant inheritance are in ducks. Two blue mutations in Turkeys, one recessive (sl - Recessive Slate), one incomplete dominant (D - Dominant Slate). But I don't know if any of these have been DNA sequenced.

Blue/grey phenotype mutations are sometimes found on the PMEL17 (or SILV) locus (I - Dominant White locus), eg Is - Smoky in chickens, Z silver (silver dapple) in horses, M (Merle) in dogs, etc. Dc (Dilute - Charolais) in cattle is another one on PMEL17, & is the odd one out in that it dilutes both eumelanin (to grey) & phaeomelanin (to orange) with one dose (incompletely dominant gene). But, we know Bl is not on the PMEL17 (I) locus also (can have Bl/Bl I/I in a single bird).

I suppose you can't rule out translocations, but usually there are similarities with homologs, eg similar inheritance mode, similar bio-chemistry, etc. The lav mutation is very different to Bl on both accounts. MLPH mutations in other species have more similarities to lav in chickens, than lav has to Bl.

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#92576 - 11/11/10 09:48 AM Re: whence came lavender [Re: KazJaps]
Henk69 Offline
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Gene symbols (ABCDE system) are not analogous/homologous between species.
Why would chromosome numbers be? wink


Edited by Henk69 (11/11/10 01:38 PM)
Edit Reason: because I can

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#92577 - 11/11/10 11:16 AM Re: whence came lavender [Re: Henk69]
Redcap Offline
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Err ... there is a difference between analogy (phenotyp) and homology (genotyp) ... and there are many analogies between species ... and ooh wonder there are analogies in the abbreviations for the alleles of the colours ... but what do I know in comparison with You ...?!

In fact I and obviously noone else here don't know on which chromosome blue can be found and which carrier protein (melanophilin has been excluded in the last postings) does play a role, finally.
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#92578 - 11/11/10 11:36 AM Re: whence came lavender [Re: Redcap]
Henk69 Offline
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I think you know a lot, judging by your recent posts, but there are some stubborn personal truths out there smile. I thought I saw one there... wink

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#92579 - 11/11/10 11:52 AM Re: whence came lavender [Re: Henk69]
Redcap Offline
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I just want to understand the origin of the mutation of lavender ... and so far I don't ...


I just know that there are many neurophysiological homologies between species ... so I expect that there will be others ... inside the DNA ...
http://www.abc.net.au/science/news/stories/2007/1954058.htm
http://avianbrain.org/nomen/Chicken_Atlas.html
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#92580 - 11/11/10 01:39 PM Re: whence came lavender [Re: Redcap]
Henk69 Offline
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If you want you can elaborate. Doesn't need to be about chickens...

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