Pssm results are in

and I cannot believe them! I recently stumbled across a discussion on PSSM in horses. Background on this disease can be found here. The reason why I became really interested is given here. In this blogpost, the author reports on a horses that showed some symptoms that reminded me quite a lot of my Gus. Since the mutation that causes PSSM is known, and I am a molecular geneticist I decided to sequence the exon 6 of the Gys1 gene in both my horses myself. So one morning I went out and plucked some hair from my horses manes, in order to extract their DNA from the hair follicles. It is quite amazing how massive those follicles are. I got plenty of DNA out of those small tissue samples.

Next I set up my PCR and run it in the PCR machine.

A few days later the University's core sequencing facility has sent the results of the sequencing back! The frequency of the mutation is about 8% in the QH population. It is dominantly inherited, meaning that just a single copy of the disease allele will cause some symptoms. However, symptoms can be very subtle and are easily misdiagnosed, especially when Vets, owners, etc., have not had any prior experience with this disease.

I must say that I was blown away to see that Molly carried the disease allele, but Gus did not. As I never really saw any symptoms on her. But as I know now, after researching a lot on the disease, Molly has always shown clear signs of the disease, I just never knew it and they were very mild, partly because she has always been kept in an ideal way for PSSM1 horses. I also was skeptical enough that I could have made an error, so I repeated the sequencing. Same result.

Molly through the years...

I looked through my summer pictures, as I cannot stand the snow anymore. It is still so cold, every night close to -20C. I have not been able to ride in 3 months now, and I must say the snow is getting old!

Just for fun, I made this slide, Molly in 2007 (at her breeders in Michigan) and last August. Molly and I have been together for 6.5 years now. And I loved her every single day during this time. I can't believe she is already going to turn 10 in March! For me, she is still my baby, and she always will be :-)!

It is quite interesting how different her coat looks like. The pictures have been taken at the same time of year, so the difference is not between winter and summer coat. I have never again seen Molly as bleached as in 2007. Partly, my feeding regime could make a difference, but mostly, I think it is a reflection of life style. In my place, Molly lives in the shady woods in the summer, whereas she used to live out in the open pasture 24/7 in Michigan. So she simply got bleached out by the sun in Michigan. Even in my place I can clearly see that her coat is not pure black. After all, she is only heterozygous for the black allele, her mom was chestnut and her dad was black.

snow, snow, and then some more snow...

It seems as if this year we just don't get a break from the snow. I have not seen earth in over 2 months now, only snow. It is an interesting cycle. Either it is "warm", around 0 to -5 degree C, and then it snows, or it is freezing cold (lower than -19 C) and the sun is bright up and the skies are blue. All creatures on my little farm have by now gotten used to it, even I have become very proficient in snow shuffling. I have to add an extra 30 minutes each day, to heat up my water pump in the barn, and mostly to dig my path to the manure pile and also from the barn to the house.

The only thing I am missing is studying hoof pictures. And hooves for that matter. I cannot see my horses hooves in the snow. When I try to pick them up, the snow is stuck in them and is all around them. Cleaning them out is a task too, as I am very clumsy with my big winter gloves, and by the time I have taken off the glove I have dropped the hoof pick and have to search for it in the snow. It is not fun, and so I have pretty much just given up doing anything with the feet. 3 days ago, I did a thorough check and everything looked great. Hardly anything to do. Horses grow thick soles in the snow and that is a good thing. Also, they get quite a lot of exercise. It is really exhausting to walk all day in the deep snow.

The horses love the cold days with the bright sun out. Molly, in her black fur, positions herself in parallel to the sun. Within seconds, the black fur gets hot and I see steam coming off from the skin underneath it. She just loves "baking" in the sun on days like this, especially after the cold night. Gus, with his lighter hair does not get nearly as hot. But he too must feel the warmth of the sun. At least he is at an advantage in the summer, where he does not get as hot and attracts way less horse flies than Molly's black coat does. But I do think in the cold winter, the black coat must be an advantage. Also, since yesterday, Molly starts dropping some hair! It always amazes me, how much in advance they anticipate the change in season. On the hottest days in August, they start growing in their winter fur and at the coldest days at the end of January, they start dropping them.