Re: I really need some information on limited gene pools(particually in animals

As you may probably know, within a particular animal population, you often 
find a set of genetic disorders which (a)have been passed down through the 
generations and (b)are extremely common (prevalent) within the 
population.  As you trace back the ancestry of such a population you will 
often find that the population arose from a limited number of FOUNDER 
members.  It is precisely this small number of Founder members which 
appears to be, according to some studies, the important factor in 
determining the prevalence of genetic disorders in the population in 
question (i.e- a small number of Founder Members leads to a LIMITED GENE 
POOL which increases the incidence of the genetic disorder).

To outline an example of this Carol Adley, a Candian Kennel Club director, 
has written an article on the internet entitled "Breeding for Genetic 
Health".  You will find this on 
 http://www.bogartsdaddy.com/bouvier/BouvZine2/Breeding-LimitedGenePool1.htm


In this article Carol Adley dicusses breeding between dogs.  More 
specifically she looks at a particular breed of dog called the Saluki.  
She recalls that in the last 15 years she has seen the onset of a 
particular disorder called the Saluki Sudden Death Syndrome.  She 
attributes this disorder to the fact that there were, as outlined above, a 
small number of FOUNDER MEMBERS.

In comparison, there have been a number of Saluki imports which, because 
of interbreeding, have lead to a diffferent population of very healthy 
Saluki's.

What we can conclude from this study is that a limited/small gene pool is 
detrimental to the long term survival of a given species.

I am not sure how much Genetics you have studied at school.  The genetic 
reasoning for why a limited gene pool will increase the frequency of a 
genetic disorder in the population is that you increase the probability of 
recessive genes coming together.  Recessive disease genes are genes that 
cause a genetic disorder when two copies of the recessive gene, one from 
the mother and one from the father, are inherited by an individual.


do not hesitate to contact me if you require further information on 
References on limited Gene Pools (email robertdeyes@easicom.com).  Most 
basic Genetics texts should have a section on the subject (eg: Basic 
Genetics by Weaver ).



Thanks

Robert Deyes
Technical Adviser
Life Technologies http://www.lifetech.com