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Critique?

The last few months in computer class we've been making websites, and mine is on horse color genetics (what a shocker, right?). It's due Thursday, and I'd love to get second opinions on it. Also, for you genetics geniuses, is all this info correct? And are the pictures under the correct terms? It's not done yet...I still have more pages and pictures to add, and the navbar across the top isn't finished, but I just want to see if there's anything I need to change. Here's an album to screenshots of the pages. http://s1106.photobucket.com/albums/h372/TMWGraphics/Horse%20Genetics/&…; Thanks!

Monsterpony Tue, 03/08/2011 - 22:54

Picture 1: Eumelanin is the black pigment and pheomelanin is red. You have these reversed. Also, agouti is what causes bay coloration. Bay horses are black horses (EE/Ee) that have at least one dominant agouti allele which restricts the black to the points. Extension allows to black pigment to be present; agouti restricts it to the points.

Picture 5: Black horses that fade can have brown appearing hairs on their muzzle, but it looks different from a brown/bay. I am not sure how to word it better though. Also, this is completely unrelated, but I think you might want to replace 'told apart' with 'differentiated'; in my opinion, it is a more appropriate word choice.

Picture 7: The usually appear on chestnuts, bays and blacks is a bit misleading. All colors appear on chestnut, bay or black as those are the three base colors that exist in horses.
In the palomino (and again in the cremello) section, there is no such thing as a 'chestnut gene.' If you mean, it is red (ee) + cream (CcrC), then saying one chestnut gene is incorrect because you require two copies of the e mutation to be chestnut. Also, the whole perlino mention is rather confusing. First, there is no such thing as an 'aa perlino' as a perlino is, by definition AA or Aa. I think you mean smokey cream, which is E? aa CcrCcr. Also, perlino X chestnut can produce buckskins and smokey blacks. If I were you, I would not mention perlino until you have defined it in a later page.

Picture 8: First, you start a whole second section on cremello. Perlino X cremello definitely doesn't always have a 50:50 shot at each. If the perlino is EE, then you have no chance at a cremello. If neither the perlino or cremello are not AA, then you can get a smokey cream.
Buckskins can have one bay (dominant agouti) mutation or two. Your math for creating a buckskin gets a little hard to follow; it is correct, but it might be to much for a genetics newbie in my opinion.

Picture 9: Breeding two perlinos can give you a perlino, cremello or smokey cream. I already explained the cremelloXperlino not being 50/50 earlier.
Smokey blacks are pretty easy to distinguish from bays and usually browns too. Smokey blacks look black, though some come have a more faded black appearance.

Picture 10: I like your use of complete dominant and the zygosities. You might want to add that to your cream section. Bay dun is the oldest color, everything else is caused by mutation.

Picture 12: Silver is only rare depending on the breed. Shetlands and minis are rife with the silver mutation.

Picture 13: Homozygous champagnes are lighter and have pinker skin than heterozygotes.

Picture 14: Pearl (Cprl) has been mapped and is an allele of the cream gene (MATP) so it is understood. I have never heard the term incomplete recessive. What do you mean by that?

Picture 15/17: Blue eyes can occur on horses with no white markings. They just need to carry the splash mutation.

Picture 18: I don't quite understand your definition of a modifier, but that could just be me.

Picture 19: Agouti is a separate gene. The dominant agouti allele (the wild type) of the ASIP locus is what causes the bay coloration. A+ is still mostly hypothesized.

Picture 20: Some of the bay images are probably browns.

Picture 22: Horses, very rarely, can be born partially greyed.

Picture 25: Flaxen inheritance is not known so you can't say for sure it is recessive. The whole section about yellow versus red and homozygous making them yellow is not something I have ever heard of.

Picture 31: More than 11 DW mutations have been found.

Picture 32: Overo Lethal White Syndrome is the name given to the foals affected by being homozygous for the Overo Lethal White mutation. Horses that are heterozygous wouldn't be referred to as OLWS. They would be called Overo Lethal White carriers.

Picture 33: Lp allows the horse to have appy pattern. PATN determines the size of the pattern. Also, you mention that homozygous Lp have solid white, but not that heterozygous have spots in their white.

Picture 34: You describe tobiano under blanket? Also, if one parent is tobiano, then [i]at least[/i] 50% will be tobiano.

Picture 36: Appys have mottled skin, not grey skin.

Picture 38: Not sure what you mean by sooty versus roan.

Picture 41: I personally have not seen rabicano and sabino travel together.

Picture 42: In my opinion, calling roan and sooty similar is rather confusing.

Picture 43: The definition of sabino is rather fluid at the moment. The only known sabino is Sb-1. I honestly have no idea how help with this page because my own personal definition of Sabino and sabino (aka scape goat) are not well defined. The horse in the blanket and the middle one are splash (with something else fighting for the eyes).

loco4poco Tue, 03/08/2011 - 23:28

In reply to by Daylene Alford

Thank you so much! It really helps a lot.

Sorry if some of the pages are confusing--I had to cut a few of them in half in order to fit it in the screen shot (all the cream genes are together).

For the blanket tobiano thing...thanks for catching that! I copied and pasted the tobiano info to keep the same text format, but totally forgot to change it!

Thanks again, and I'll post the finished product on Friday.

accphotography Wed, 03/09/2011 - 00:18

Incomplete recessive in this case means that it is recessive on it's own but because it does show at some point (in the presence of another gene) it can't truly be considered fully recessive.

NZ Appaloosas Thu, 03/10/2011 - 21:20

Picture 33: Lp allows the horse to have appy pattern. PATN determines the size of the pattern. Also, you mention that homozygous Lp have solid white, but not that heterozygous have spots in their white.

Or have just roaning... if they are LpLp without any Patn gene(s).

Diane