Reptile & Amphibian Forums

What can I do with a ParaHet?
So, we have a ParaHet, which we know is het. for either Sharp-albino or Caramel hypo but we don’t know which. Clearly, the questions we are interested in answering are, “What are the breeding trials that could be performed to determine whether it is a het. Sharp albino or a het. Caramel hypo, and what offspring do we have the potential to produce from these breeding trials?”

The first option we will consider is breeding the ParaHet to another ParaHet. In selecting any two ParaHets at random, we can have either two het. Sharp albinos (probability ¼), two het. Caramel hypos (probability ¼), or one of each (probability ½). The Punnett squares for each of these three test crosses and the associated expected offspring summaries are shown below.

So, if we breed two ParaHets we would expect approximately ¼ of the litter to be either Sharp-albino, Caramel-hypo, or Paradigm. If there are Sharp-albinos in the litter then both parents are now known to be het. Sharp albinos. If there are Caramel hypos in the litter then both parents are now known to be het. Caramel hypos. Finally, if there are Paradigms in the litter, then we know that one parent is het. Sharp albino and the other parent is het. Caramel hypo – though we know we have one of each, we cannot tell which parent is which, but who cares….we made Paradigms from just a couple of ParaHets!

The even better news is that producing Paradigms is the most likely outcome as indicated by the probabilities above. To repeat, in choosing any two ParaHets at random, the odds are ¼ that both are het. Sharp albino and thus will produce Sharp albinos, and ¼ that both are het. Caramel hypo and thus will produce Caramel hypos. But the odds are ½ that we have one of each, and that they will produce Paradigms.

These examples also point out a further advantage of using the name ParaHet. In the cross above that produces Paradigms, the remaining ¾ of the litter consists of 1/3 normal, 1/3 het. Sharp albino and 1/3 het. Caramel hypo. It is equivalent to say that 2/3 of these are ParaHets. As such, we can simply call all of the normal appearing offspring in this litter 66% possible ParaHets (or just 66% ParaHets) analogous to the way we would arrive at the more familiar 66% het. Sharp albinos.

What Else Can I do with a ParaHet?
The other possible ParaHet breeding trials include crossing a ParaHet with a Sharp albino, a Caramel hypo, or a Paradigm (a ParaHet could also be crossed to a 100% het. Sharp albino or a 100% het. Caramel hypo; those outcomes are already described above in the analysis of the ParaHet to ParaHet cross). Each of these crosses and the possible outcomes are shown below. The Punnett squares on the left show the case in which the ParaHet is a het. Sharp albino, and those on the right show the case in which the ParaHet is a het. Caramel hypo. Note that in each case, the phenotypes of the offspring allow us to determine whether the parent ParaHet is a het. Sharp albino or a het. Caramel hypo.

We have now shown all of the possible crosses that can be performed to determine if a ParaHet is a het. Sharp albino or a het. Caramel hypo, and the expected offspring from all of those crosses. Obviously, crosses that also include another trait, such as a Motley het. Sharp albino to a ParaHet, can also be done, but the other trait (Motley in this case) will be controlled by a different gene and will have no effect on the genetics of the Paradigm locus - at least as far as we know today!

Such multi-trait crosses can also be evaluated using a Punnett square (4x4 for two traits, 6x6 for three traits, etc.), but it gets very tricky to correctly distribute the alleles in the parent’s boxes of the square as the square gets larger and it is easy to make mistakes. In some future posts we will present examples of some multi-trait crosses that include the Paradigm trait, along with a simpler statistical approach to evaluating these crosses – and you don’t even have to know anything about statistics to do it!

Thanks for looking,

Steve Reiners

www.BoaMorph.com

Job well done, and thank you for putting the time into doing such a masterful job of clearing up any confusion that people might have when it comes to the genetics of the Paradigm and ParaHet!
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Kevin Blumenthal
www.blumenboas.com

seen something this scholarly on this forum in a while. Where's Paul Hollander? I am interested to hear how our resident Geneticist responds to your post. How did you do those tables/charts? They look like they were taken from the pages of some biology textbook! I love that we have a morph that does not follow the rules of dominance, simple recessive, or co- or incomplete dominance. I will be lecturing on multiple alleles in my AP Biology class in a couple of weeks and it will be fun to use the Paradigm as an example. The charts you came up with will be GREAT references to those individuals who purchase and work with the Parahets, or Paradigms for that matter.

Thank you for all you hard work. The genetics may be easy, but it takes time to write it up clearly and concisely.

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Ron Michelotti

Class Reptilia
www.classreptilia.com

Excel to do all of the graphics. Most people would probably find it easier to use a simple graphics program such as Vizio, but I do so much work in Excel that I can now make it do just about anything I ever need.
Steve
www.BoaMorph.com

I am thoroughly impressed. Fortunately I had a basic understanding but your posts really cleared it up for me. Way to hit home man. Good job. Thank you for taking the time to share such valualbe and need explanations.
Brendan Saffron

time and energy to get all of that layed out like you did. I only got threw about half so far but I wanted to make sure you got your well deserved props for that.

Ruben Michel

Mostly a good write up. My major quibbles are with the symbols. In modern genetics, the plus character is the recognized symbol for the normal allele in genetics. And all alleles of a multiple allele series have the same base character(s) but different superscripts except the first mutant of the series, which has no superscript:

s = sharp albino (and s is the name of the locus)
s^c = caramel hypo
s^(plus character) = normal

Everything to the left of the ^ character is the base, and everything to the right of the ^ character is the superscript. I'm using the ^ to separate the base from the superscript because this editor will not do superscripts. It will not do the plus symbol, either.

Paul Hollander

used for multiple alleles- it can be easlily fixed. It is good having you around.
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Ron Michelotti

Class Reptilia
www.classreptilia.com

is interesting, but certainly is not light reading - LOL! Definitely beyond my knowledge level. I was not aware of specific rules for nomenclature of loci as you described in your other response. Were the naming protocols described on the JL site developed specifically for rats/mice and vary between species, or are they universal? Some of both?

I decided to go with a simplified nomenclature (rather than the locus name with allele as superscript) for a number of reasons. One as you noted, is that any further discussion within this editor would not support that style. Another is that I didn't want to create unnecessary confusion for folks with the more complicated nomenclature style (i.e., I wanted the notation to look the same as the two-allele notation that most folks are much more familiar with so that it would be easier for all to see that the alleles combine in the same familiar way; there are just three options rather than two). I also wasn't sure about selecting a locus symbol for the superscript notation - where does one go to find the "official" name/symbol for a particular Boa genome locus?! Though I suppose I could have gone with the "we'll use the letter S" approach without calling it "the name" of the locus. I'll put some more thought into how I could introduce this notation without introducing confusion as I refine the write-up for my website.

All very interesting stuff and I very much appreciate your input!
Steve
www.BoaMorph.com