Dun in PSL and PRE



  • I thought Dun was an accepted colour for both PRE/Andalusian and PSL/Lusitano but it doesn't seem to be on the list already.

    Examples:

    Quiosque (Lusitano)
    Grulla Lusitano

    Foal of Quiosque (Lusitano)

    Mill Gravitar and Mejicano XXIX (Andalusian)

    Lavrador (Lusitano)
    He's listed as sooty buckskin but he has a dorsal stripe and shoulder barring

    Also, although I can't find them online now, I think the two listings of possible colours for each breed from Equine Tapestry listed dun as recorded in Lusitanos and Andalusians.

    Thanks :)



  • Unfortunately I do not think this is not evidence that this is true dun. Mill Gravitar and Mejicano XXIX are listed as tested as EE AA nd1/nd1 and Ee aa nd1/nd1 respectively. This is the genotype of "false dun" -- primitive markings without a dilution of the coat as seen in true dun. You can read more about this here. BC director has final say, but dorsal stripes and sometimes other primitive markings are not always indicative of true dun (D) and these breeds have been confirmed as having this false dun. There are not restrictions against having a dorsal stripe (sometimes called "countershading") in these breeds because of the existence of this false dun phenotype.



  • So what would Quiosque be then? I've always wanted to make one based on him.

    This one might be a better picture.


  • Administrators

    This horse is likely either showing nd1 (false dun) or sooty/countershading aligning with primitive patterns.



  • @Elsie-Spectre said in Dun in PSL and PRE:

    This horse is likely either showing nd1 (false dun) or sooty/countershading aligning with primitive patterns.

    As I understand it, that might be an explanation for the dark markings, but I don't think it accounts for the coat dilution that is apparent in the pictures of this horse. If he's not a black based dun, what else would be a viable explanation of the dilution in both this horse and his foal?

    @Alastair-Schrödinger said in Dun in PSL and PRE:

    ...
    This is the genotype of "false dun" -- primitive markings without a dilution of the coat as seen in true dun. You can read more about this here. ...

    I had a look at that page previously and found some different text, however the page now clearly states "Dun is present in many breeds of horses including (but not limited to) Appaloosa, Bashkir Curly, Iberian horse breeds (rare, except in Sorraias),

    I'm aware that there may be a different variation of dun in Iberian horses and testing wasn't previously made available for them apart from a research project which was discontinued. However at least some horses were tested and there seems to be at least one positive:

    ...
    Macetero is heterozygous for grey and is one of the few PRE's confirmed by UCDavis to have a dominant dun gene (PRE variant).

    Also, the PRE registry up until recently excluded all colours other than grey and bay. Horses that would have been dun or grulla were listed as bay or were covered by grey.

    Even if it is a variant of the regular gene I think it should be listed as allowed, even if it is rare.

    Some other references:

    ...
    Portuguese-bred: There are some undisputed duns in the Lusitano breed. Others are being studied.
    Spanish-bred: This list/website recognizes at least one Andalusian dun, Afortunado.

    http://www.hippo-logistics.com/newdilutions/other_dun/index.htm

    The British Association for the Purebred Spanish Horse



  • There is now a test for dun that is not simply a marker test (that site is outdated) but a test for the specific alleles. It distinguishes between D (dun). nd1 (non-dun 1) and nd2 (non-dun 2). Prior to this test (which is only about a year old), no one knew that nd1 and dun were different so it is possible a lot of horses labelled as 'dun' by breeders are in fact nd1. This seems to be true of Lusitanos and Andalusians.

    So far all Andalusians and Lusitanos that have been tested as far as I know come back as nd1 or nd2. This has been a long-standing quest of mine actually - to find a true dun PRE/PSL. But sadly every time I think I've found one, it turns out not to be!

    nd1 does cause some dilution and it causes primitive markings. Two copies (homozygous) causes more dilution than one copy. You can represent all the shades of 'dun' PRE/PSL that exist with nd1 on Equus. Or if you're after a horse like that buckskin with a dorsal, that's also allowed and would be genetically buckskin (with sooty perhaps).

    Saying that, if you ever come across a tested dun of either breed, we'll add it and I'll be overjoyed!



  • @Morgan-Cameron said in Dun in PSL and PRE:

    So far all Andalusians and Lusitanos that have been tested as far as I know come back as nd1 or nd2. This has been a long-standing quest of mine actually - to find a true dun PRE/PSL. But sadly every time I think I've found one, it turns out not to be!

    Same here :)

    That's a shame though. It's strange how they're the ancestors of the quarter horses and other breeds that have it and must have inherited it from them in the first place.

    One of my registered horses may need to be changed then, as she was registered as dun when it was still allowed. It's a foal of hers that I'm trying to make.

    So what would be Quiosque's genotype then if I was trying to recreate his coat? E- A- Cr- Sty- nd1- ?

    Thanks Morgan :)


  • Administrators

    Hello, following a recent study which found several PRE to be positive for dun (D), dun has been added as an allowed color for PRE on the Master Breed List. :smile:



  • Awesome!

    Do you happen to have links to the information at all? Just for my own self education :)



  • Hey Samantha,

    Just to clarify, it was one horse that tested positive for dun in France. His name is Preferido de la Reina. Here are his test results: https://www.facebook.com/1578870695667635/photos/pcb.1917038508517517/1917038401850861/?type=3&theater The lab that tested him is not, obviously, UC Davis (who were the first to create and publish the direct dun/nd1/nd2 test). There was therefore quite a lot of controversy over whether this test should be taken seriously but UC Davis has since confirmed in an email that a PRE in France tested by this lab did indeed test positively for dun, which is clearly this horse... So no published research or anything like that as of yet but this is finally a confirmed grulla purebred PRE so dun must exist in the breed! Here's a photo of him as well: https://www.facebook.com/1578870695667635/photos/pcb.1917038508517517/1917038368517531/?type=3&theater I am SO over the moon about this :D


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