Welcome to BengalLegacyCats Genetics page.
I will start off by thanking all the breeders who have educated me on Bengal genetics, it has opened my eyes to so much within this breed.
To any breeders I am advising, I know genetics can be tricky to get your mind around, but with practice and effort you can do this! I hope this page is of some help to you, I will attempt to break it down as simply as I can....
Ok lets start off with the basics.
Every cat when mating gives each kitten 1 copy of there 2 allele's, so one from the Queen and one from the Sire. Breeders will use a punnett square to work out the percentages expected from pairing up a male and female.
We will now work out the expected genetics as if we were to mate these two Bengal cats.
Sire: Seal Silver Mink (cb/cs)
Dam: Brown, but carrier of seal lynx (cs).
25% Brown that carries lynx.
25% Brown that carries sepia.
25% Seal lynx.
25% Seal Mink.
Now notice that the Sire is Silver also, this means we need to work out what percentage of the kittens will be Silver (if not brown) or Silver Snows.Working out Silver is a little different as it can also depend on factors such as, were the grandparents both Silver or not? For this example we will assume the Sire is I/i one copy of the Silver inhibitor gene and not two (I/I).The Silver punnet will be explained.Results: 50% Silver (Heterozygous I/i)50% Non Silver (i/i).
If I/i is Silver, then what is I/I?
It also means Silver but that kitten/cat owns 2 copies of the inhibitor gene, some breeders call this cat/kitten pure of Silver or Homozygous for Silver (I/I).
I/I (pure of Silver) means that when older this cat will only produce Silver, unless he/she carries other genetics such as snow or is a Silver Snow.
Since we cannot test for Silver, we need to breed this (I/I) Silver to a non Silver to know for sure 100%.
I have personally done this with GarraDeKato IMOS BLUES, he is (I/I) Homozygous Silver, I know this as I mated him to different Queens, these were the results:
Queen 1 Brown = All kittens Silver.
Queen 2 Silver (I/i)= All kittens Silver.
Queen 3 Snow Mink = All kittens Silver.
Queen 4 Silver (I/i) = All kittens Silver.
From this we can see he is Homozygous Silver (I/I), now what gave IMOS such a high percentage of being Homozygous Silver?
Let's take a look at his heritage and just how much Silver that has been bred into his beautiful blood line...
From looking at his pedigree, we can see a lot of Silver has been bred into IMOS lines, both parents are Silver, 3 out of 4 Grandparents were Silver.
Looking at his Mother and her parents- Her Sire was Seal Silver Mink, and Dam was Brown Black Spotted Tabby, this meant IMOS mum Pandora was (I/i) Heterozygous Silver, she had one copy, but because Silver is dominant that was enough to continue the Silver line.
Looking at his Father and his parents- His Sire was Silver & mum was Seal Silver Lynx, this meant Pride of Russia Boogy-Woogy stood a chance of being:
50% Heterozygous Silver ( I/i) and 25% Homozygous Silver (I/I).
So how did IMOS end up being (pure of) Homozygous Silver?
We know mum is (I/i) Heterozygous Silver, but we need to work out what Dad was, he could have been
Heterozygous Silver like Pandora or he was Homozygous Silver Like IMOS.
Lets work out the percentages for both scenarios ...
Scenario 1= Only 25% chance of being Homozygous Silver
Scenario 2= 50% chance of being Homozygous Silver.
We can clearly see that IMOS would have only had a 25% chance at being Homozygous Silver, from Scenario 1, not impossible and is actually the case! His breeder Irina GarraDeKato has informed me there was 1 brown kitten in IMOS litter which means IMOS father is also (I/i) as is his Mother Pandora. Obviously scenario 2 would give better odds, but just goes to show its always possible with the correct genetics.
One last thought, when everyone met IMOS at the cat show at the start of 2020 they all commented on just how light he is for a Silver charcoal, they even asked me to test him to see if he was in fact double Apb, we tested and confirmed he was a charcoal (Apb/a).
Thinking about just how dark the majority of Silver Charcoals are today, could it be the (I/I) Homozygous Silver that lighted the Apb and non-Agouti? Silver generally lightens every colour it is put to, IMOS does not really have a strong Zorro mask and non-existent cape so typical of a charcoal Bengal, so if it is not the Silver causing this, then what other factors could be?
Ahhh the wonderful imagination runs wild yet again……