Long coat GSD - Page 2

@Hundmutter, regarding Genetic research on Coat length, I also couldn't find anything other than LL causing StockHaar, ll causing LangHaar/LangStockHaar & Ll causing anything in between, but also INCLUDING ALL.

So, logically speaking, shouldn't both the alleles rather be co-dominant ?? 😯😇
Searching for genetical research on undercoat was frustrating 😞😞

From "Genetic Principles as they Apply to the GSD", Chapter 8 of The German Shepherd Dog: A Genetic History Of The Breed.

By Malcolm B Willis.

 

"Dominants and Recessives"

Some alleles of a gene will express themselves even when present only singly (ie on only one chromosome), others will only express themselves when they are present in duplicate (ie on both of the chromosomes). Any allele which expresses itself phenotypically when present only singly is said to be a dominant allele, while one that is masked by a dominant allele and can only express itself when present in duplicate is termed recessive.

... Note the use of the word 'autosomal' which refers to genes carried on the autosomes as opposed to the sex  chromosomes where things operate differently.

The various matings that can occur with dominant/recessive traits are shown in this Table, using the normal/long coat characteristic:

Table 8.1

Mating results expected for normal/long coat genes

                                                % progeny each type

Mating               Parents            LL           Ll           ll

number          [sex unimportant] (normal)(normal)(long)

 

1                        LL x LL                100           0         0

2                        LL x Ll                    50         50         0

3                        LL x ll                        0       100         0

4                        Ll  x Ll                     25         50        25

5                         Ll x ll                         0         50        50

6                          ll x ll                          0          0       100

 

Note that percentage figures are exact for matings 1,3 and 6 but others will only be exact over large numbers of matings/progeny.  Note also that long coats can only occur when BOTH parents carry the 'l' allele (matings 4 to 6). When only one parent carries the 'l' allele (matings 2 and 3) then long coats cannot be produced.  Thus the fact that a bitch does not give long coats may not mean that she is LL.  She may be Ll but always mated to LL dogs, or alternatively when mated to an Ll dog the 25% did not turn up, through small litter size or sheer chance. ...Any dog who gives a high percentage of long coated progeny is probably getting a higher than expected percentage of Ll mates.  There are of course some dogs which 'pass' for normal coated animals, when they are genetically long coated..." 

 

@Hundmutter, if you haven't already studied these articles, here's a link 

http://homepage.usask.ca/~schmutz/coatType.html#length  

which is  the summary of a genetic research on dog coat types & furnishings and essentially supports the findings of Malcolm B Willis, but I was more interested about the following:- 

"They indicate that the mutation causing long is recessive also, but the length of the "long" is variable within individuals and across the breeds. They classified some dog breeds as having meidum length hair and either or both genotypes were present in some of these." 

You'll find the details of the research here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897713/

 

Thanks, swarnendu. I'll give those a read, but initially my reaction on the face of your quotes ^^^ is "So what's new ?", and doesn't say to me "co-dominant"...

Nothing new, only they seemed to have suggested that any of the combinations of LL, Ll or ll could produce "medium length".

Granted; but that seems to be across all the breeds they were using and for all 3 studies. I think the one in which the Saint Bernards were used is most relevant, since Malcolm said the pattern with Saints & GSDs was the same; there are other breeds where a MEDIUM length coat is the expected 'normal' for those breeds (something like Border Collies, for instance) where there may be differences ?
Who knows ? - the Saints they are talking about may be the SAME lot that Malcolm was referencing, unless this was a more recent study !
[And where did the "three grey wolves" creep in from ???]

I - not being a geneticist, merely an interested observer - do not even
properly know what you mean by "co dominant", so can you explain that more fully ? Thanks.

Co-dominance would roughly mean that influences of both the alleles are visible in the phenotype. So, Ll can be small or medium or long.

It's different from incomplete dominance (penetrance?) where Ll would ALWAYS produce medium.

I'm also not a geneticist, so I'd better ask the geneticist of our group.

Ok so let me ask a few questions regarding this thread , because this is a bit over my head. #1 does it take 2 long coats to produce long coat puppies?
#2 If you have a larger litter do you have more of a chance to get a long coat?
#3 am I reading this right to determine that basically you can never really predict when your gonna get a long coat pup out of a litter because it's so random? YIKES SCIENCE! Not my specialty. Thanks

Lady, see the table given by Hundmutter.

Even two dogs whose phenotypes (looks) are smallcoat, can produce longcoats, provided both parents have the recessive (hidden) longcoat allele small "l". So, the parents will have to be Ll or ll, and supply one "l" each to the pup, so that the pup can be "ll" = Longcoat. To make it more easier, both the parents need to supply one "l" to produce a "ll".

Q.2. Theoretically, yes. But, those all are what is called probability, so you may never, seldom, always get a longcoat. It depends on what got paired with what, just like whether the baby will be boy or girl?

Q.3. If both the parents are true shortcoats (LL), they will always produce LL. If both the parents are true longcoats (ll), they will always produce ll.

If at least one parent is LL, then the puppies will always have one L and show small (and medium?) coat.

If both are Ll, you cannot predict. If one is Ll and another ll, again you cannot predict.