Genetic terminology - Proper use of the word "heterozygous"

[miiike]

i think it will do the opposite. Tony. I see what your trying to do and understand, but a new person trying to learn everyday call names of gecko genetics ..this thread is gonna throw them for a loop!!!!

I do not agree at all. This thread has helped me out a TON.

 

[yellermelon]

Except the entire rest of the reptile community does it one way and you do it a different way.
Edit: i stand corrected I will quit now. Sorry to have hindered this thread.

 

[Northstar Herp]

I think this thread, though initially off-topic, has been a good thing overall. I think we were going nowhere for a while, but some of you guys came back and wrapped it up pretty well. I have learned from it.

 

[Tony C]

Except the entire rest of the reptile community does it one way and you do it a different way.

It's not me, it is the entire scientific community. A clear understanding of the fundamental concepts is absolutely necessary to the study of genetics. The reptile community as a whole may apply terms in a different way from how they are defined, but that doesn't make it correct. The field of genetics is one of those rare areas where there is a clear-cut right and wrong, and to be perfectly frank most of the reptile community is wrong in their understanding.

 

[robin]

*watches everyone get their pannies in a wad*

 

[Tony C]

*watches everyone get their pannies in a wad*

Want to help pick my wedgie? :uhoh2:

 

[cassadaga]

I agree with Thad and Travis, as far as marketing. There is no need to market a mack snow as het SS, but with Enigmas it can matter. With the few Enigmas I have bought, I always want to know whether the Enigma is a heterozygous, or a homozygous. Why? Because when I breed Enigmas, I like getting non-Enigma offspring. How can I be positive my Enigma is a het and not a homo? Well, I buy Enigmas that only have one Enigma parent, because if both parents are Enigmas, 66% of the Enigmas produced will be homozygous.

Here's some info from Wikipedia on heterozygous for anyone who may still be confused:

If two alleles are identical, the organism is called a homozygote and is said to be homozygous; if instead the two alleles are different, the organism is a heterozygote and is heterozygous. The genetic makeup of an organism, either at a single locus or over all its genes collectively, is called the genotype. The genotype of an organism directly or indirectly affects its molecular, physical, behavioral, and other traits, which individually or collectively are called the phenotype. At heterozygous gene loci, the two alleles interact to produce the phenotype. The simplest form of allele interaction is the one described by Mendel, now called Mendelian, in which the appearance/phenotype caused by one allele is apparent, called dominant, and the appearance/phenotype caused by the other allele is not apparent, called recessive.
In the simplest case, the phenotypic effect of one allele completely masks the other in heterozygous combination; that is, the phenotype produced by the two alleles in heterozygous combination is identical to that produced by one of the two homozygous genotypes. The allele that masks the other is said to be dominant to the latter, and the alternative allele is said to be recessive to the former.[1]

http://en.wikipedia.org/wiki/Dominance_(genetics)

 

[OhioGecko]

Good info Tony, thanks!

Here are a few definitions from my genetics textbook that may help:

Gene - Genetic factor that helps determine a trait.

Allele - One of two or more alternate forms of a gene.

Locus - Position on a chromosome where a specific gene is located.

Phenotype - Appearance or manifestation of a characteristic.

Heterozygous - Refers to an individual organism that possesses two different alleles at a locus.

Homozygous - Refers to an individual organism that possesses two Identical alleles at a locus.

Dominant - Refers to an allele or a phenotype that is expressed in Homozygotes and Heterozygotes; only the dominant allele is expressed in a homozygote phenotype.

Codominance - Type of allelic interaction in which the heterozygote simultaneously expresses traits of both homozygotes.

Incomplete Dominance - Refers to the phenotype of a heterozygote that is intermediate between the phenotypes of the two homozygotes.

Recessive - Refers to an allele or phenotype that is expressed only when homozygous; the recessive allele is not expressed in the heterozygote phenotype.

 

[robin]

Want to help pick my wedgie? :uhoh2:

i got a crowbar around here somewhere...

 

[Enigmatic_Reptiles]

For real though my son just gave his friend the worst wedgie I have seen in years...sorry to be off topic but i mean I could see the bottom of his friends underwear over his waste line (they are 5 years old). So robin bring that crowbar when you can

 

[paulh]

I'm late to this discussion. However, put me squarely at Tony C's side. Herpers use a ghetto dialect of genetics terminology. For what it's worth, I've had a university genetics course and worked for several years in the university genetics lab.

The misunderstanding of the definition of heterozygous is so bad that I have taken to listing both genes in a gene pair. A gene pair containing an enigma mutant gene and a normal gene is enigma//normal (AKA heterozygous enigma).

By the way, another misused word is "trait". Trait is what you see (phenotype). "Enigma//normal" give the identity of the two genes in a gene pair (genotype).

A trait and a gene may have the same name or may have different names. "Mack snow" is the name of a gene and the name of the trait produced by a Mack snow//normal gene pair. Super Mack snow is not the name of a gene, so there is no het super Mack snow. Super Mack snow is the name of the trait produced by a Mack snow//Mack snow gene pair.

"Heterozygous" refers only to genotype, not to phenotype.