Reptile & Amphibian Forums

There is a barrage of ideas expressed here but I think we need to stop and gather ourselves with some sense or order. these are the rules of scientific method that has worked for centuries to divulge scientific information and that is what we are after here. there is not some mystery with no answer but rather a mystery that we do not yet have the answer to.
1) Observe some aspect of the universe
2) Invent a tentative description, called a hypothesis, that is consistent with what you have observed.
3) Use the hypothesis to make a prediction
4) Test those predictions by experiment or further observations and modify the hypothesis in light of your results.
5) Repeat steps 3 and 4 until there are NO discrepancies between theory and experiment and/or observation

I say at best we are at step 3 with many thoughts here not making it past step 2. This issue is in fact a scientific phenomenon that can be figured out with the right approach. My input is to say if all involved can rally together it can be determined but we have to be careful not to cloud the water with to much conjecture. Don't get me wrong I love this stuff and lie awake many nights with much of this rattling around in my head. The fact remains we DO NOT have enough info at this point to really know what is happening here. We do have some info regarding whats NOT happening in that it cannot be a simple double recessive characteristic since the breeding of two "extremes" did not yield 100 % "extremes"
My hypothesis at this point (step 2) is that the "extremes" are in fact phenotypic variances based upon on an alignment of multiple genes (caused by crossovers during meiosis) that produces these very light hypo animals. My prediction (step 3) is that the extremes will continue to be produced within other hypo lines and within the already existing "extreme" line. Until further tests are done to prove or dis-prove this hypothesis that is it for me for now. Anyway, again thanks to all and this is going to be fun.

Matt Woodhall

Matt,
I have to say that I agree with you on many of these points?
With that being said,I am going to tell you something that will seem impossible but has happened three times in five years to me?This is not hear say or it happened to my friend or whatever,
You keep bringing up the fact that the extreme x extreme didn't yeild 100% extreme's?

I have a pair of applegate albino gophers.They were both produced by Bob himself.In 98 I bred them for the first time and had seven eggs hatch out and had seven albinos?Great,
Now in 99 I had nine eggs hatch and there was one normal in there????????????????????How could this be?No idea?
so,in 00 I had 10 eggs and all of them hatched out albino?I must have mixed a egg from another clutch in there or one my friends played a joke or ??????????whatever.I wrote it off like it didn't happen.
So,in 00 I had 11 eggs and I hatched two normals?in 01 I hatched one normal out of 11 ,in 02 I didn't get any good eggs and in 03 one more hatched out of 12 eggs.This year she laid 15 eggs but only six hatched and all were albino?
o.k. so I have hatched 4 normal san diego gophers out of 68 eggs thats about 4 percent or so?

So tell me how did this happen and I will tell you why he only got 5 out of six extreme,s

shannon

First of all Shannon my only point to be made on this post was to simply slow down on our information gathering process and the results from Mike's clutch are no where near enough for any of us to determine whats going on. we can only get to the hypothesis and prediction stage. Future tests will allow us to expand on that and we can go from there. That is to say I would never believe my hypothesis correct until more info is gathered. As far as your 'normal' gopher popping out of albino breeding..I don't know on that one either. I would do some further breedings to other albino and normal snakes, keep good records and modify my thoughts (hypothesis) as I go. I just don't think it is smart to jump out ahead of ourselves. As we all know we get one shot a year to pair these animals and incoming data is slow. But it is that fact that keeps this hobby alive and kickin' and a heck of alot of fun! Thanks Shannon...Take Care

Matt Woodhall

In your case of the albino gophers the only rational explaination is that the applegate albino trait is a dual gene trait where the two genes are clustered close together at the end of the same chromesome. These could be true "linked" genes. Your "normal" appearing offspring had the ends of their teleomeres exchanged in mitosis, the break happened between loci for the genes involved. The teleomers broke between the two traits in the normal appearing offspring and the albino offspring have the break before or after the pair of genes. A four percent occurance (high) of normals points to the traits being near the end of the chromesomes and located a slight distance apart.

An similar linked trait in humans is blonde hair and blue eyes. One doesn't always have both, but most blondes are blue-eyed because of the proximity of both genes on the same chromesome. Gene linkage is pretty common and it is why many geneticists question Mendle's near perfect numbers with his famous pea experiments.

Bob Bull

Thanks bob,

It sounds good to me?LOL.I have no idea but it is weird.

shannon

In meiosis, the parent cell containing two sets of chromosomes divides into two new cells each containing one set of chromosomes. This is the process whereby sperm and eggs are produced. In order to separate the two sets of chromosomes line up on each side of the nucleus of the cell. As the chromosomes segregate to each side they often "exchange" their tips or ends(teleomers). Most of the time this process goes off without a hitch. Sometimes pairs of genes that are located close together are sometimes split.

How does this relate to your situation?

IF in the case of your Applegate albinos it is possible that there are two genes at play and they are normaly paired close together at the end of a single chromosome. Most of the time your pair produces Albinos, but some times a normal is produced because the ends of that chromosome separated between the two genes.

Just an idea for an interesting puzzle,
Bob Bull

Well so much for my thread but oh well this is also a facinating questions. Bob, first of all as not to confuse people your first post said during mitosis and your second correctly stated meiosis. Meiosis is the process by which gametes (eggs and sperm) are formed, the ONLY haploid cell in the body. You also said two sets of chromosomes which implies 4 chromosomes. It is ONE set (2 chromosomes, diploid)that divide into 2 single (haploid) chromosomes to form the single chromosome gamete. Your proposal of gene linkage is a good one along with what I have been throwing out there with crossovers during meiosis lending to phenotypic diversity in all animals. Crossovers for example are the reason we get 16 differant genotypes in a DH breeding. Anyway thanks for the thoughts and it is worth thinking more about.

Matt Woodhall

As I understand it, San Diego gophers have two independent albino mutants, each of which is recessive to its normal allele. One snake is homozygous for the first albino mutant and heterozygous for the second albino mutant. The second snake is heterozygous for the first albino mutant and homozygous for the second albino mutant. Whether the two loci are on different chromosomes or linked, the possible genotypes in the gametes are identical.

To pick up evidence of crossing over, a double heterozygous individual would have to be bred to a double homozygous individual. And those gopher snakes do not qualify for either.

BTW, linkage is not necessary to produce 16 different genotypes from a DH xDH mating. Three or four alleles at each locus are necessary, though. OTOH, I'm open to being convinced. Show me how you can get more than nine unique genotypes from mating two individuals that are

---A-----B---
---a-----b---

Paul Hollander

This is exactly how the confusion begins. We are in a thread about 'exteme hypo' hondos talking about albino gophers. I think maybe a seperate thread would appropriate. And just for the record my stance was that crossovers NOT linkage account for the 16 possible variations in genotype between DH X DH. To continue the discussion start a new thread.