Frizzle Modifier Gene and phenotypes

[tellynpeep]

I have hatched so far 7 chicks from my frizzle roo and non-frizzle hen (Cochins.) So far only one chick is showing frizzling. I know it may just be the odds, and I still have more to hatch, but I am wondering if anyone can talk about the modifier gene and how to tell if my hen is a carrier of it. Does anyone have pics of a heterozygote modified frizzle, or of the individual feathers of one?

Several of the chicks have what I would consider poor quality feathers (a bit "shaggy" but not curled) and I am wondering if they are modified frizzles. If so, will they be able to produce frizzled offspring, or will all future generations carry the modifying gene?

Or can someone point me to a good reference on this. Beyond the basic "there is a modifying gene that can make heterozygotes appear nearly normal."

Many thanks!!

 

[tellynpeep]

Anyone know anything about frizzle genetics??

 

[Dipsy Doodle Doo]

Hi! I wish I could help. I've hatched a boat-load of Frizzles here (all Frizz x smooth) and have never seen what *I think* would be 'heterozygote modified' frizzle.
I read about that and it left me scratching my head.

All mine either have been obviously frizzled or not frizzled (smooth).

Good luck figuring out what you have.

Lisa

 

[nzpouter]

mf is the modifier, it reduce the effect of F,F on a bird to look like a normal F,f.

 

[Henk69]

frizzle modifyer mf
Recessive.
Reduces/modifies the effect or expression of the frizzle gene. This gene can modify frizzle heterozygote expression to the point that they are almost indistinguishable from the wild type. Modifies the extreme expression of the frizzle homozygote.

Would not worry about it. It is (rare? and) recessive.

 

[tellynpeep]

Hi. The only on-line reference I can find is from a 1936 book, that says the mf gene is in "most" non-frizzled birds tested. What I'm trying to find is how to figure out of my non-frizzle hen is carrying the mf gene. OR if my frizzle roo is actually a modified FF. The roo has lots of breakage of his primaries (mostly loss of barbs and broken raches) but not actual feather loss you would expect in a homozygous frizzle.
Here is a pic:

So how do you tell the difference? (Between a Ff and a modified FF, or between a ff and a modified Ff?)

 

[Henk69]

No one breeds frizzles as purebreeds.
Why would the mf mutation be in most non frizzled breeds?

If the frizzled breeding lines, where else would it become apparent, ever had mf then they seem to have lost it.

Very doubtful status...

 

[tellynpeep]

Quote:
"The modifying gene is widely distributed among domestic fowls because of its selective advantages in its ancestors."
Full text of reference here: http://www.ias.ac.in/jarch/jgenet/32/277.pdf

Beyond feather changes, the frizzled birds have altered metabolisms that presumeably have negative selective value especially in colder climates.

The article is interesting and pretty complete by mendelian standards of the day; I was hoping someone had a more recent reference with better photos.

 

[Henk69]

Thanks for the article.

The easiest way for evolution to avoid frizzle problems is to simply let the first frizzles die. The dominant mutation would be gone, problem solved.
When mf becomes established in the population it would keep producing frizzled = unfit individuals!
Therefor Mf+ would be favorable in the end. And it was, since that is or has become the wildtype gene.

So maybe it is the other way around: frizzle gene was "recessive" due to the old wildtype gene mf, frizzles were produced.
Then the Mf+ mutation (the new wildtype) was favorible in eliminating the frizzled mutation and became established.
Fascinating stuff.

I understand that by great coincedence one frizzled animal in the experiment was carrier for mf, else the entire gene mutation would have never been detected!

If I were you I would just ignore it.

 

[Bresseman]

There has been some work done w/ the frizzle modifier gene to increase egg production in tropical breeds. There is apparently a co-relation in some African breeds, Frizzle = increased egg production. Also introducing naked neck modifier genes also increase egg production in tropical chicken breeds. I assume that it's the ability to keep cool and not the gene that causes the increase in egg production.