Genetic difference between Tan/Otter?

[rotdogz]

So the title is a little misleading, I know the at gene is responsible for tan/otter, and it's usually a matter of just terminology difference. However, I wanted to know if there was a difference between coloration of it such as in the tan breed, like this:


And the "normal" tan/otter pattern, like this:


Is it wideband, or some form of polygenetic rofusing? (or something else?)

 

[Alaska Satin]

So the title is a little misleading, I know the at gene is responsible for tan/otter, and it's usually a matter of just terminology difference. However, I wanted to know if there was a difference between coloration of it such as in the tan breed, like this:
View attachment 41989

And the "normal" tan/otter pattern, like this:
View attachment 41990

Is it wideband, or some form of polygenetic rofusing? (or something else?)

Yes, tan and otter are almost genetically the same, except for differences in wideband alleles and the number of rufus modifiers. "Tan" can refer to the Tan breed, to the allele <a(t)>, or to the pattern of agouti trim on a self rabbit, i.e. the "tan pattern." "Otter" refers to a tan-patterned variety without the wideband influence, here in the U.S. anyway. (Many things are different in Europe and the UK - maybe the folks from over there can comment further.)

Tans, the tan variety of Belgian Hares, and Thriantas, for instance, call for bellies and even undertails as close to the same reddish color as on the chest and trim as as possible. They generally have +5 rufus modifiers (on a scale of 0-5) and are homozygous for the wideband allele. All of these varieties/breeds disqualify (Tans and Thriantas) or fault (Belgian Hares) for belly undercolor anything other than red, orange or creamy white.

Wideband <ww> changes the dark undercolor that's usually found on an agouti or tan-patterned variety - it's supposed to match the undercolor appropriate to the surface color - to white undercolor on the belly and undertail. It also helps with deeper color and undercolor on the belly and chest markings on breeds like the Tan and Thrianta; and it makes an orange rabbit red, with deeper overall color, and a red or dark cream belly and undertail. The difference in shade desired on a red Rex or NZ, vs Thrianta, then, is really the rufus modifiers, and probably some additional modifiers that impact the expression of wideband as well.

 

[MsTemeraire]

Yes, tan and otter are almost genetically the same, except for differences in wideband alleles and the number of rufus modifiers. "Tan" can refer to the Tan breed, to the allele <a(t)>, or to the pattern of agouti trim on a self rabbit. "Otter" refers to a tan-patterned variety without the wideband influence, here in the U.S. anyway. (Many things are different in Europe and the UK - maybe the folks from over there can comment further.)

Absolutely the same here in the UK, although I've not heard the paler parts of an agouti referred to as Tan. We might talk about 'tanning' on an Otter though, since they should have nice reddish chests (but pure white/cream bellies apart from the groin spots). If they are orangey or reddish on the belly we'd call that a 'hot' belly colour, and it's a fault.

 

[Alaska Satin]

Absolutely the same here in the UK, although I've not heard the paler parts of an agouti referred to as Tan. We might talk about 'tanning' on an Otter though, since they should have nice reddish chests (but pure white/cream bellies apart from the groin spots). If they are orangey or reddish on the belly we'd call that a 'hot' belly colour, and it's a fault.

Thanks for your reply. I am really enjoying learning about how rabbits are "done" in the UK and Europe.

I have never heard the term "tan" used in relation to agouti varieties, either. When I say "the pattern of agouti trim on a self rabbit" it's just my own description of an otter, since it seems that people better understand what an otter (which is a less familiar term to non-rabbit people) looks like when I describe it as a self rabbit with agouti trim.

Regarding the tan pattern, the ARBA recognizes not only discrete varieties, but in some breeds those varieties are also judged in "Groups" which often include "Tan Pattern." Groups are midway in hierarchy between variety and breed in placement. So, for example, the animals will be judged in their regular sex, age and variety classes; and then the Best and Best Opposite in the varieties within a particular Group will be judged again to award "Best and Best Opposite in Group." The Group winners are then judged to award Best and Best Opposite of Breed. I think this system is growing in popularity because it makes judging the huge classes of some breeds a bit more manageable.

For instance:

In American Fuzzy Lops the "Tan Pattern Group" includes the four base colors of Otter (black, blue, chocolate and lilac).

Holland Lops are shown as Self and Broken Pattern, but within those classes, recognized varieties include "Tan Pattern Group" which likewise consists of Otter in the four base colors.

Mini Rex "Group 4 - Tan Varieties" includes all four Otter colors, as well as Silver Marten in the four base colors.

In the Jersey Wooly the "Tan Pattern Group" includes Otters (in blue and black only) and Silver Martens (in all four base colors, plus sable and smoke pearl)

And in the Netherland Dwarf, the "Tan Pattern Group" includes Otter (in all four base colors), Silver Marten (in all four base colors, plus sable and smoke pearl), and Tan (all four base colors).

 

[Sagebrush]

This entire thread is interesting to me but your last comment @Alaska Satin is rather mind boggling to me. So many varieties with so many breeds, I just can't keep them straight. So of course taking notes and trying to learn lol.

 

[Alaska Satin]

This entire thread is interesting to me but your last comment @Alaska Satin is rather mind boggling to me. So many varieties with so many breeds, I just can't keep them straight. So of course taking notes and trying to learn lol.

I rarely attempt to answer color questions without the ARBA SOP (Standard of Perfection) open on my lap... I never feel 100% certain I have it straight either.

 

[rotdogz]

LOL yeah very interesting!! And thank you for ur responses, useful to know!