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#101850 - 01/31/12 06:36 PM An issue with the use of the RJF as wildtype std
Htul Offline
Coop Keeper

Registered: 03/02/07
Posts: 495
Loc: Australia
Originally Posted By: Wieslaw
Welsummers are said to carry Mahoganny or other red enhancer, making them much more rusty than Brown Leghorns. But watching many pictures of RJF on the Internet you can find many pictures of rusty females. I have seen pictures of Brown Leghorns from Australia, and many of them are much lighter in the hackles than European ones, as if they carry some kind of gold diluter.



Wieslaw's comment has encouraged me to post an issue that has been playing on mind: simply put, if we are to use RJF as the reference wildtype (a long established convention since the time of at least Jaap and Hollander (1954) - and one which I think is entirely reasonable, given that the RJF is generally accepted as the major contributing ancestor of the domestic fowl), the question still arises as to "which one?".

There are 5 recongised subspecies of RJF - all of which are believed to have some sort of phenotypic difference (and no doubt other genotypic differences) of which one (Gallus gallus gallus) is believed to be sufficient as the sole matriachal ancestor of the domestic fowl (as described by Fumihito et al, 1994 ).

OK - so perhaps we should take G. g. gallus as the reference to use as wildtype? Even so, within any given population, there is some level of heterozygosity. So which individual should we select to represent the 'reference wildtype'? Further, even every individual in a population is also likely to have some degree of heterozygosity (as is the case with all diploid organisms): so in those cases, which allele do we designate as 'wildtype'?

I realise that in the vast majority of plumage colour genetics - this probably doesn't have a huge impact; but if there are plumage modifiers that are present in some subpopulations, but not others (especially if they have impacts on 'non-wildtype' genes, then this could have some consequence.

Regards,
htul

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#101864 - 02/01/12 02:25 AM Re: An issue with the use of the RJF as wildtype std [Re: Htul]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2792
Loc: Australia
It depends on the research project.

Yes, for a simple single pigment mutation comparison, RJF lines /examples already sequenced would suffice (ie in gene databases, eg genbank). If there is a known variation in a specific RJF line, not common in other lines, then this needs to be taken into consideration. But it might not matter - depends on whether it will influence the specific research project.

I wouldn't worry about sub-species & variations within, unless researching jungle fowl, not so much domestic fowl (unless maybe an evolutionary biology project).

But, as an example, say you wanted to research the trait of neck hackle striping in domestic fowl (eg neck striping in Brown Leghorns, Dutch Bantams, Phoenix etc in comparison to OEG, Moderns, etc), & you had the deep pockets, then it might be worth the while to look at various RJF sub-species, populations & other JF. Plus, take into consideration wild RJF individuals - proximity to people & domestic fowl, etc. But I don't see such research projects on subtle modifiers happening in the DNA sequencing world, not in the near future.

So instead just use "the average" RJF phenotype as a datum reference (wild-type Standard).

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