A gene question for all the breeding experts here...

darlene0614 wrote:

NONE of the babies had black mask!!!

Both girls are black and brindle with a white chest, some white on their paws and a blaze on their face.

My vet said it made sense that I got brindles but I am still confused. So much for that theory!!! I had a buyer who wanted one with a black mask and we were hoping for one but no luck.

I will be breeding her again in late spring so we will have to wait and see next time what we get. I am praying for the black and white pied!! It is possible just not probable!!

Now, I have only read two papers on dog color genes, so I am no expert and could be wrong, but this is what I think I have figured out for you:

Ok, well now you know both dog's phenotypes! Dad has to have a E(M) because he has a mask, and his other E has to be E because his babies were black. So dad is E(M)/E or e. Because his babies are brindle and brindle is dominant over fawn (you only need one brindle k(br) to express it). We know he has at the K locus a k(br) and his other K must be a K(B) because he is not brindle.
Dad is E(M)/E and K(B)/k(br) because he is not brindle, K(B) is dominant to brindle and is either black, brown, or blue/gray. Is dad brown or red?
Mom is e/e and k(y)/k(y) because she is fawn with no mask and no black, brown or blue/gray.

So, if you do a Punnet square:
You have a 25% chance of getting a black mask, E(M).
You have a 50% chance of getting a brindle with these parents. k(br)
You have no chance of having a fawn (k(y) is recessive to k(br) and K(B)).
You have a 50% chance of having a brown, like dad. K(B)

That is just my quick look at a Punnet square, I could have it wrong. I just like puzzles!
The E locus is not adding up because of the red or brown dad, but I'll look at this later and confirm. I can't see how the dad can be red because red is recessive. It would make sense if dad is brown. I'm pretty sure I got the K locus correct though.

I don't know what piebald is, but I will look it up and let you know your odds, if I can figure it out from the parents, this weekend. Please describe it a little more for me and I will research.

Do you mean Irish spotting? Well, maybe Wind can answer that one then.
Do you think the Mom and sister are piebald because of their white chest and feet? The paper I read said white tips on the feet and a white chest is not genetic, but simply missing the color. It is not irish spotting. The color starts at the neural tube (spine), the feet and chest are the furthest away and last to get colored. The color was halted before it finished, and this is because mom had a cold or was sick or something when she was pregnant.
Weird, huh?

Wind said it was something else, so I don't know what to think on this one, if that is the white coloring you were refering to, let me know if you meant something else.

The website paper also says on the brindle page that brindles can have a white chest and legs. Check it out, Darlene, there are pics of Frenchies on the brindle page!!

Happy Thanksgiving!!!

Now your getting into things that do have a start in genetic research but not always completely understood. Sometimes something like the spotting issue can probably be caused by genetics or incomplete fusion of the conceptus but,,,,,the big question is but,,,,,,,,there is absolutley no way to tell either of them apart. I beg to differ that it is always from incomplete fusion but probably one or the other on any given dog.

I know what your speaking of with neural tube defects, open fonts and cleft palates are also a more advanced evidence of this, which we know the Bulldog breeds do tend to have on occasion, more so than some other breeds. But, neural tube defects can have a very wide range of causes, included genetic predisposition but more often than not it is enviromental. Stress caused by either a fight, being moved to another place like as in being sold, sickness, a sudden fright or it can be caused by a lack of folic acid in the expecting mothers diet. I supplement my dams with brewers dried yeast which is very potent with folic acid and can help even compensate if the dam does meet another enviromental stress during her pregnancy. I start this as soon as they come in heat. Show dogs also sometimes on it year round because it really makes their coat glow nicley and improves overall health.

It is caused by the hormones in the system such as adrenaline or and norepinephrins that affect the growth stages of the embryo. Embryo's start out as flat disks and fold upward to create a fusion along the top, that top seal is the neural tube. The whole thing is made up a large part by folic acid and needs a certain amount in order to fuse correctly. High stress or or high strung dams can highly likely to create alot of these hormones jsut because the flightiness causes them to which can equate to easily stress dams producing alot of birth defects.

When I have a dam produce a puppy with cleft palates or other neural tube related defects, I usually have her spayed directly since I do as much as I can to eliminate or reduce the chances of it coming from her enviroment. Any other reason I have to assume is genetic and no longer wish to continue breeding that female. Perhaps it isn't genetic and maybe just a dam who produces too much natural adrenaline that the folic acid supplement can't compete with but still, is that something I want to continue my program with, regardless if it is genetic or hormone related? I don't want to breed a female with either issue so even though I don't know exaclty why, I just spay her anyway. I do not have very many neural tube defects. I think I have only ever had 2 defects the whole time. 1 was a female who I think had a hormonal problem. Took many heat cycles to finally get her pregnant, her hormones failed to initiate second stage labor nor did she ever dialate and she had a severe cleft palate puppy and a severe open font puppy. I just think her hormones were whacked.

You are so good, Wind! I love that you take good care of your mom's diets to ensure healthy litters.
I don't think the paper was saying the lack of color was a neural tube defect though. It is saying that pigment, melanin, comes from the neural tube and migrates along the body. If the migration is halted for some reason, such as dam catching a cold, then the process is halts before there is enough melanin and there is an absence of color at the furthest areas. On a mouse embryo pictured, you can see heavy concentrations of melanin at the ears and rump. Hence the theory that too much white means deafness in some breeds.

Well, it is essentially caused the same way and in the same fashion. A cold or stress causes a halt or reduction in the growth. Even the migration of melanin is a part of the embryo development process. Lack of pigment isn't as big of deal as an open font but it is just more evidence why to keep our pregtnant bitches healthy and very happy during their pregnancy. I am careful with my girls as soon as they are bred. I will let them out to play but never with one of their buddies as they sometimes will argue over bones or toys in the yard. As soon as they come in heat, I clip their nails and don't do it again until after pups are born. Most of my girls are pretty much OK with getting their nails clipped but sometimes they get a wild hair up their rear and throw a fit which I just avoid entirley while pregnant. I pet pet pet and pet and love on them some more. Keep em happy and satisfied. I also avoid things that could make them mildly ill for a few days. This is one of the reasons you NEVER vaccinate a pregnant dog. Because that modified live virus vaccine essentially affects the lymphnodes for a short period of time causing yet again hormones and other chemical reactions in the body that "could" have an affect on their growth and development.

Yes, it sounds like she is describing a neural tube defect, migration halting and all, but it didn't seem that way when I read it. Just that the melanin migrates from the neural tube out to the body. I agree with you that it is not incomplete fusion of the neural tube.
I spoil my Shammy rotten when she is pregnant too. Because she demands it. It's funny how you can read a dog, and know when they need extra attentions!
My Cassie has a little white on her chest, but her feet are solid colored.

OK Darlene, I think I got the dad's E locus figured out.
He is expressing his E(M) because he has a mask. The black, brown, blue/gray is expressed in the mask (not the body, this is where I got confused), and the body is yellow, red, fawn or cream when the mask is expressed.
So now I know his 2nd E is a dominant E, because the babies had no mask (didn't inherit the E(M)) but they are black, so they had to get a big E from the dad. Mom is fawn with no mask, so she has to be little e/e.

This is fun! Let me know about your piebald discriptions if you want to look into it.

Oh geesh, now the mom just got confusing. Apparently, fawn Frenchies and Afghans can be hidden carriers of brindle because they don't have a big E. I guess I would need to know more about the mom's past litters or her parents and litter-mates to figure out her K locus. Throw out the first Punnet square percentages!

OK kinda crazy around here with the holidays and all so I appologize for not responding sooner.

Mia's parents were fawn and white and Pied. Mia has the parti gene.

So based on what you told me I will never get a pied with Mia and Tucker. I may have to use a different stud on my 3rd breeding then!!!

Hi Darlene, it seems that the spotting gene is separate from the ones I listed on your mom and dad. The spotting gene is really confusing though. But what I can figure out, the spotting (all including piebald) is recessive and solid colored is dominant in Frenchies. In order to have a piebald puppy, both parents must carry the piebald gene. So I think you still have a chance if Tucker carries for the piebald. Good luck and Merry Christmas!