# Genetics 101



## arkreptiles (Sep 26, 2007)

As an aid to the inevitable question "what do i get if I cross x with y" we've put up a page on our website showing pictorially how Recessive, Co-Dom and Dominant traits work together with a brief glossary of terms put into 'laymans' language.

We hope this assists to a small degree anyone who (like we were) is scratching their heads over possible outcomes of their pairings. If anyone believes any of it is either misleading or incorrect, please let us know!! None of us are perfect and we all learn new stuff everyday!!

Cheers
Nick & Carrie


----------



## Ssthisto (Aug 31, 2006)

I would personally remove the information about recessive traits from the definition of "heterozygous".

Describe what a heterozygous-recessive looks like under *recessive* - otherwise, it looks like only recessives can be heterozygous for a trait, when in actual fact all three types of genes can and do have heterozygous and homozygous presentations.

I would also remove "normal" from the list of "dominant" traits, because "normal" isn't a single trait in itself.


----------



## arkreptiles (Sep 26, 2007)

Ssthisto said:


> I would personally remove the information about recessive traits from the definition of "heterozygous".
> 
> Describe what a heterozygous-recessive looks like under *recessive* - otherwise, it looks like only recessives can be heterozygous for a trait, when in actual fact all three types of genes can and do have heterozygous and homozygous presentations.
> 
> I would also remove "normal" from the list of "dominant" traits, because "normal" isn't a single trait in itself.


Many thanks - sage advice!! we will make the alterations.


----------



## bladeblaster (Sep 30, 2008)

the explanations very good, I would have perhaps picked more strikingly different pictures to illustrate the het form in the co-dom section maye a dif colour background. Thats purely a visual thing though.


----------



## arkreptiles (Sep 26, 2007)

bladeblaster said:


> the explanations very good, I would have perhaps picked more strikingly different pictures to illustrate the het form in the co-dom section maye a dif colour background. Thats purely a visual thing though.


thanks - we were thinking that too - will have to get the camera out again!!!


----------



## Blackecho (Jun 30, 2008)

Just semantics really, but in the heterozygous x normal outcome:

Instead of having 4 x '50% heterozygous' I would put 2 'heterozygous' and 2 'normal'.


----------



## gazz (Dec 9, 2006)

Patternless as you've put it.I assume you mean patternless striped-aka-patternless reverse striped.And reverse striped are both polygenetic trait not simple recessive. 


For Murphy patternless a (recesseive) trait you put (Murphy patternless) or (patternless).For the patternless reverse striped a (polygenetic) trait that come from the RAPTOR/APTOR line.You put (patternless striped) or (patternless reverse striped).

And hypo is DOMINANT not co-dominant.And you've forgoten Rainwater albino ofcourse (recessive).


----------



## gazz (Dec 9, 2006)

Blackecho said:


> Just semantics really, but in the heterozygous x normal outcome:
> 
> Instead of having 4 x '50% heterozygous' I would put 2 'heterozygous' and 2 'normal'.


Agree.

Normal X HET Albino= . 

50%Normal.
50%HET Albino.

so two pic's as normal and two as HET.

Also in the HET X HET the 66% HET Albino.

HET Albino X HET Albino = .

25%Normal.
50%HET Albino.
25%Albino.

So one pic should be normal.Two pic's should be HET Albinne pic should be albino.


----------



## Blackecho (Jun 30, 2008)

Yep, Gazz has explained what I meant much better than I did, cheers.


----------



## paulh (Sep 19, 2007)

Under the definitions for dominant, recessive, and codominant, you might like to put the freely distributable chart at the bottom of the page linked below. It is mine, and I mean it when I say it is freely distributable.

Genetics Primer - BOADDICTION


----------



## paulh (Sep 19, 2007)

You might want to run the page through a spell checker. I noted at least two misspellings of "heterozygous". 

"*Co-Dominant x Normal = 50% Normal, 50% Co-Dominant*". "Heterozygous" should be used instead of "co-dominant".


----------



## bladeblaster (Sep 30, 2008)

Blackecho said:


> Yep, Gazz has explained what I meant much better than I did, cheers.


I would say that they have got it right, they will all look normal but the percenatges will apply to all, so nothing wrong with the way they have done it.

het x normal will produce all normals (as shown) which will all be classed 50% hets (as shown).

I know what you are saying, but I think its easier to understand for someone starting to learn about it.

One thought though (I didn't read it all so I apologise if this is already there) it would be worth explaining that the percentages are per egg, some people don't realise this.


----------



## arkreptiles (Sep 26, 2007)

bladeblaster said:


> I would say that they have got it right, they will all look normal but the percenatges will apply to all, so nothing wrong with the way they have done it.
> 
> het x normal will produce all normals (as shown) which will all be classed 50% hets (as shown).
> 
> ...


Thanks everybody for your input - much appreciated.

As Bladeblaster has pointed out, we are just showing what the chances of being Het each animal has to keep things simple. Clearly to determine whether a normal looking animal is het or not requires further breeding to test it out.

On balance therefore we intend to leave the pictures as they are a fair representation of the phenotypical outcome - we think however a note making it clear that it only shows what chance each outcome has of being Het should be included.

Many thanks again for everyones input.


----------

