Reptile & Amphibian Forums

Well, I am about to give up figuring this out.

My whole clutch of prairie/cal king crosses hatched. I got 6.4 of the little buggers, and they all have that banded black and silver pattern. While these are pretty, in my opinion, they didn't answer all of my questions.

If you recall, I bred this cross with these particular two animals because last year I cycled the mother of this clutch, and witnessed NO copulation, although I paired her with several males. The only male that I didn't observe with her completely was my blizzard cali male. Because I didn't think she had bred, I put her back in the rack and forgot about her. Later she started exhibiting egg-laying behavior, so I have her a lay box, and she gave me 23 eggs. Of these, one hatched as an albino Prairie-looking snake. One other wierd patterned baby died in the egg. The rest went bad.

I caught a lot of flack for claiming that the one albino was a hybrid because she looks just like an albino calligaster baby. The problem is that her mother was a virgin and I don't own a male calligaster. However, the female HAS to be het for albino. So i repeated the breeding that HAD to have produced her. They gave me these black and silver babies.

That proves to me that A) Calligaster and L.g.Californiae albinism are not allelic, and B) The patterns on ALL of my babies this year are nearly identical, and nothing like that of the albino from last year, so the baby from last year was NOT a california/calligaster hybrid.

But what was it? The only possible answer is parthenogenesis. However, my understanding is that parthenogenesis occurs when a female basically clones herself, and therefore even a het female could not have an albino baby.

Pleeeeaase give me feedback, as I am beyond confused.

nate.

Sorry, minor factual error: I actually got 4.6 of the back and silver babies, not 6.4.

nate

One thought comes to mind. When breeding a het to a homozygote, you should get 50% het 50% normal, but that is statistical. In practice, sometimes "fate" works against you and you dont actually see the 50/50 split. Here is an example from my fowl breeding. I had 2.8 birds that were het for recessive white. I knew this for a fact because all had 1 recessive white homozygote parent. I bred them together, expecting to get 25% recessive white homozygote and 75% normal appearing. In the first hatch, I set 133 eggs the first set. Out of that, 93 were fertile and 88 hatched. Not one birds was white. I continued to hatch from them all summer,and never got one white, until the last hatch of 53 birds when 47 were white. I kinda felt like the gods had decided to play a joke on me. This illustrates that while I "should" have gotten a certain outcome in theory, I didnt in practice. Why? Because there is no rhyme or reason to which chromosome actually gets contributed through the fertilizing sperm. Chance takes over there. It is russian roulette. So, in this instance, just because all ten were non-amel, doesnt mean they are not the siblings of the alb from last year. Chance could have played with you here. I am not saying it did, but that could explain your result.
Keep at it, you will figure it out. Breed that female again to toher males and see the results. In the end, you have some great looking f1 this year. Keep some of those and breed them back to each parent and together and see what happens. They may be the beginnings of a fine domestic strain. Please keep records and leep us all informed. You might want to submit your results to a data collection as well.
Thanks.
BDR
Panoplia Geneticus

I don't know if parthenogenesis is involved or if there is some other explanation but I can explain a few things about parthenogenesis to you.

There are essentially two kinds of parthenogenesis that might apply to snakes. One is where an oogonial cell in the ovary does not undergo meiosis but develops directly into an egg. Babies produced this way are essentially clones of the mother. This is how some whiptail lizards of the American Southwest reproduce. The other way involves meiosis. In meiosis, the diploid (2 sets of chromosomes) oogonial cell first duplicates its chromosomes, then divides twice. One of the products is a haploid (one set of chromosomes) egg nucleus within a cell that will develop into an egg. Another product is called a polar body and is also within the same cell. Normally a haploid sperm nucleus will unite with the haploid egg nucleus to produce a diploid fertilized egg. In some animals, the Beltsville line of turkeys for instance, the polar body behaves as a sperm nucleus and unites with the egg nucleus in some of the eggs of virgin females. In this type of parthenogenesis it is quite possible, indeed probable, for heterozygous females to produce homozygous progeny.

While snakes are generally thought to be more closely related to lizards than turkeys, their mode of sex inheritance is more similar to that of turkeys than to lizards. Due to the mode of sex inheritance, parthenogenically produced turkeys are always male. If the mother is heterozygous and you get female snake babies that show the recessive trait, it is highly unlikely it was produced by parthenogenesis.

Bigfoot

Thank you both. That was the best that I have ever heard parthenogenesis described. Because she is obviously an albino, indicating the second form of parthenogenesis, I probed her again to make sure that she is in fact female because I had not done that since she was much smaller. At about 24 inches long, she just probed about 2.5 scales deep, and so I believe she is a female. This is getting more interesting at each turn.

You seem to have misread the word "unlikely" in my post. Babies produced by the first form of parthenogenesis will be clones of their mother. The babies will be female but if the mother is het, the babies will be too. Some of the babies produced by the second form of parthenogenesis can be albino if the mother is het but they will ALL be MALE. It is NOT likely any progeny produced parthenogenically from a het female will be albino females. I do not know of a mechanism that would allow that.

Let me explain a bit more about snake sex chromosomes. In humans the sex chromosomes are called X-chromosomes and Y-chromosomes. Women have 2 X-chromosomes (XX). Men have an X-chromosome and a Y-chromosome (XY). The sex chromosomes in snakes and birds are different. They are called Z-chromosomes and W-chromosomes. Males have 2 Z-chromosomes (ZZ). Females have a Z-chromosome and a W-chromosome (ZW). Non-sex chromosomes are called autosomes and snakes have many pairs of them. It is the genes on the autosomes that determine whether the snake is normal or albino (amelanistic).

Since a female snake is ZW with respect to her sex chromosomes, if she produces offspring from cells that do not undergo meiosis, those offspring will have exactly the genotype she has and will be ZW females. If the cells do undergo meiosis, the unfertilized eggs she produces will have a egg nucleus that contains one set of chromosmes. The sex chromosome in that set will be either Z or W. If the sex chromosome is Z, the set of chromosomes in the polar body will also contain a Z-chromosome. If the egg nucleus has a W-chromosome, the polar body will also. Thus, union of polar body with egg will produce ZZ (male) embryos and WW (dead)embryos but not ZW (female) embryos. In this kind of parthenogenesis, the egg and polar body of a het female can both carry the autosomal gene for albinism which means some of the male progeny that are produced can be albino.

Bigfoot

I agree Bigfoot. There is no way this snae came from parthenogenesis, unless it is male and even then it is a long shot, to say the least. I suspect it is something similar to the offspring that have been produced this year and just by chance, none of them are albino and that one last year just by chance was albino. Nate, when did you get this female? Was she an adult when you got her, or did you raise her? How long had you had her when she became gravid with this clutch that produced the alb? Thanks.
BDR

I actually didn't misunderstand, but thank you for the further clarification on the parthenogenesis issue. I was simply attempting to further rule out parthenogenesis by resexing the snake. So, if we agree that parthenogenesis was not the cause, and she wasn't (probably) resultant from the california/prairie mix, what is she?

As stated before, I got her about six months before I cycled her and she laid her eggs. However, I got her from a good friend who bought her as a baby from petco about eight years ago. He NEVER introduced her to another snake, and wouldn't have know what to do if he did. She was the only snake he has ever owned, and I am the only person that he knows who owns or breeds snakes. Even if I believed that he might be lying, I find it unlikely that he even has the resources to find an albino or het for albino calligaster male to mate with this female. That being said, he did tell me that she once clutched for him on her own, having not been cycled purposefully. Those eggs all died as he did not know how to incubate them.

I guess I might be at a dead end as far as what I can deduce online. I have a few more things planned to try to figure her out and I will keep you all posted. Thank you for all of the help. Any further suggestions would be very appreciated.

nate.