All about IG's
Understanding Coat Colour Inheritance
Do you want to know why Italian Greyhounds are blue, some fawn and some black or red, but you freak out as soon as genetics alleles, A ay d D recessives etc. are mentioned.
Well here it is made easy - well, made easier I hope.
For these purposes I am going to be strictly scientifid as I should be useing the term allele to denote an alternative from of the gene and using the correct letters for the genetic code. These can be found at the end of the article if you make it that far.
You know that you are half your mother and half father. This is because you inherit one gene from each parent. All genes come in pairs just like Levis.
What you see on the outside is called your phenotype.
What you inherit nut may not be visible is called your genotype.
There are basically two genes for coat colour in IG's.
And there is one gene which modifies the coat colour called the dilute gene.
The gene which gives the black coat colour we shall signify by the letters BL.
The gene which gives the red coat colour we shall sighify be the letters rd.
The gene which dilutes BLACK to BLUE and red to fawn we shall signify be the letters dil.
The gene which does not affest coat colour is the NON DILUTE gene which we shall signify be the letters ND.
You will notice that BL and ND are in capital letters.
And rd and dil are in lower case letters.
The reason that BL is in capitals is to show that it is a dominant gene. ND is also a dominant gene.
rd and dil are both recessive genes.
What does Dominant and Recessive mean?
Well doesn't mean that one is more likely to be inherited than the other - a common mistaken belief.
It simply means that if your IG inherits one dominant gene from one parent and one recessive gene from the other it is the dominant gene that will give the visible coat colour.
One gene from each parent will be for coat colour the other will determine whether the coat will be diluted ot NOT DILUTED.
Dog BL BL dil dil is a Clear Blue.
Bith BL rd ND dil is a seal/black Possible gene combinations their puppies mau inherit:
1. BL (from dad) BL (from mum) dil (from dad) ND (from mum), - Black,
2. BL (from dad) rd (from mum) dil (from dad) dil (from mum), - Blue,
3. BL (from dad) BL (from mum) dil (from dad) dil (from mum), - Blue,
4. BL (from dad) rd (from mum) dil (from dad) ND (from mum), - Seal.
You will see how we got to the colour when you read on.
Examples of colour genetics:
1. Jack is a BL BL ND ND. He has inherted dominant genes from both his parents. He will be BLACK. Because he has all dominant genes all his offspring will be black too as he can give them BL for colouor and ND for non dilute irrespective of the colouor of the mother. This is called a Clear Black. What you see in this coat colour is what he will pass to his offspring.
2. James is a BL rd ND dil. He has inherted a mixture of both dominant and recessive genes. He will also be BLACK or possibly Seal, - but he could pass on his redessive genes to his offspring and depending on the genotype of his mate could producte BLACKS, BLUES reds or fawns. Unlike Jack his phenotype and genotype are different. That is what you see is not necessarily what you will get.
3. Jeremy is a BL BL dil dil. He has inherted the dominant BLACK gene but no dominant ND gene so the dil genes have a chance to work their magic. He will be BLUE. He can only pass on his dominant colour gene and his dil gene so all his offspring will be either BLUE or possibly BLACK if his mate passes on a ND gene to prevent colour dilution or seal if his mate passes on a rd as well as an ND. He is knows as a CLEAR BLUE. He cannot produce reds or fawns as his dominant BL genes will always overcome the rd gene that gives the red ot fawn coat.
NB. Clear Black and Blues are relatively uncommon.
4. Justin is BL rd dil dil. He will have dilutedcoat colour and althought he has the rd gene his BL gene will be dominant. He will also be BLUE but unlike Jack and Jeremy but just like James his phenotype and his genotype are different.
5. Jazz is a rd rd ND ND. He has inherted only the recessive red gene and only the dominant non dilute gene. He will be red. His offsprinig can only inherit recessive genes from him and depending in the genotupe of his mate he can producte any colour as a mate with dominant genes will always overcome his.
Fawns mated to fawns will producte fawns.
Fawns mated to BLUE can only producte dilutes i.e. fawns or BLUE.
There are two other variations:
BL BL ND dil - is a BLACK dog who could pass on his dilute gene.
rd rd ND dil - is a red dog who also has a dilute gene which could be passed on tohis offspring.
OK. so far but how can you tell a red rawn if you don't know it's parentage from a red? If you know it's parentage you will know that the parents are either fown or BLUE i.e. dilutes.
Genetically true reds will have black noses and eye rims. You may think your red fawn hawe black nose but closer inspection will reveal it isn't truly black.
Although it might ne a little tricky to see, the nose on the red fawn in photograph is not black, - and that's not due to the result of the camera flash.
Paler fawns often have lilac/lithr brown noses to match their coat colour.
It would apper that BL can ne affected by rd in some dogs. Many of us have had litters that contain deep blues and mucly blues, come verging on the pale chocolate. Hence dogs which have the dominant BL gene and the recessive rd gene can be wither a deep blue or a blue fawn in the presence ot two dil genes or a bleck or a seal in the presence of an ND gene.
BL rd ND dil (which is the same genetic code as James) or BL re ND ND
BL rd dil dil (which is the same genetic code as Justin)
1. Let's mate James who is BL rd ND dill to a beautiful fawn lady who must be rd rd dil dil. What possible basic colours might the puppies be?
2. Now Justin whois BL rd dil dil meets the same lady next year.
What possible colour will this mating produce?
3. The following years it's Jazz's turn. He is rd rd ND ND.
What possible colours will their puppies be?
Now we have a mating that has productes these puppies. All we know is tyhat the dog is blue abd the bitvh is pied red/white.
From the colour of these puppies can you work out the genetic codes of sir and dam? There is on BLue, two fawns, one red and one seal.
If you would like to know the correct letters for the genetic codes here they are:
BL: A- this stands for the Agouti black gene.
rd: ay-this stands for the sable gene.
ND: D- this letter for the non dilute gene.
dil: d- is the letter for the dilution gene.
Italian Greyhounds do not have the true red coat of say red setter which is the e gene. Instead they have black tips to the red hair hence it is called the "sable gene".
By Jo Amsel, Artmeis and Rilloby IG's
Publicated by SRIV, Levretten 4-2007
FCI-Standard N° 200 / 17. 06. 1998 / GB
(Piccolo Levriero Italiano)
TRANSLATION : Mrs. Peggy Davis.
ORIGIN : Italy.
DATE OF PUBLICATION OF THE ORIGINAL VALID STANDARD : 30.03.1992.
UTILIZATION : Racing dog.
CLASSIFICATION F.C.I. : Group 10 Sighthounds.
Section 3 Short-haired Sighthounds.
Without working trial.
BRIEF HISTORICAL SUMMARY : The little Italian Greyhound descends from small-sized greyhounds which already existed in ancient Egypt at the court of the Pharaohs. Passing through Laconie (Greece), where numerous representations on vases and bowls confirm this, the breed arrived in Italy at the outset of the 5th century BC. Its greatest development occured during the era of the Renaissance at the court of the nobles. It is not rare to find the Italian Greyhound represented in the paintings of the greatest Italian and foreign masters.
GENERAL APPEARANCE : Of an elongated shape, its body fits into a square and its forms recall, in miniature, those of the Greyhound and the Sloughi. May be considered as a model of grace and distinction.
IMPORTANT PROPORTIONS : Its length is equal or only just inferior to the height at the withers. Length of skull is equal to half the length of the head. Length of head can reach the 40% of the height at the withers.
BEHAVIOUR / TEMPERAMENT : Reserved, affectionate, docile.
HEAD : Of elongated shape and narrow; its length can attain 40% of the height at the withers.
CRANIAL REGION :
Skull : Flat with the superior axes of the skull and muzzle parallel. Length of the skull is equal to half the length of the head. Lower orbital region well chiselled.
Stop : Frontal nasal depression only very slightly marked.
FACIAL REGION :
Nose : Of a dark colour, preferably black, with well opened nostrils.
Muzzle : Pointed.
Lips : Thin and tight, with edges of lips very darkly pigmented.
Jaws/Teeth : Jaws elongated with well aligned incisors crown shape, strong in relation to size of dog. Teeth sound and complete, set square to the jaws; scissor bite.
Cheeks : Lean.
Eyes : Large and expressive, neither deep-set nor protruding. Iris of dark colour, eyelid rims pigmented.
Ears : Set very high, small, with fine cartilage, folded in itself and carried well back on the nape and upper part of the neck. When the dog is attentive, the base of the ear is erected and the lobe tends to stand out laterally on the horizontal, position commonly known as « flying ears » or « propeller ears ».
Profile : Upper line slightly arched and broken at its base towards the withers.
Length : Equal to that of the head.
Shape : Truncated cone, well muscled.
Skin : Lean and without dewlap.
BODY : Its length is equal or barely inferior to the height at the withers.
Topline : Straight profile with arched dorsal-lumbar region. The lumbar curve merging harmoniously in the line of the rump.
Withers : Quite well defined.
Back : Straight, well muscled.
Croup : Very sloping, wide and muscled.
Chest : Narrow, deep, let down to the elbows.
TAIL : Low set, fine even at base, tapering progressively to its tip. It is carried low and straight in its first half, the 2nd half curved. Pulled up between the thighs towards the topline, it should surpass the level of the hip-bone slightly. Covered with short hair.
FOREQUARTERS : On the whole straight and vertical with lean muscles.
Shoulder : Very slightly sloping with well developed, lean and salient muscles.
Upper arm : With a very open scapular-humeral angle, and of a parallel direction to the median plane of the body.
Elbows : Neither out nor tied-in at elbows.
Forearm : Length of the limb measured from ground to elbow just slightly longer than the distance from elbow to the withers; very lightly boned; forearm in perfect vertical position as much from the front as in profile.
Pastern : In the prolonged vertical line of the forearm; seen in profile it is a little slanting.
Forefoot : Of almost oval shape, small, with arched and closely-knit toes. Pads pigmented. Nails black or dark according to coat colour or that of the foot, where white is tolerated.
HINDQUARTERS : Seen from behind on the whole straight and parallel.
Upper thigh : Long, lean, not voluminous, with very distinct muscles.
Second thigh : Very sloping, with fine bone structure and well apparent groove in leg muscle.
Hock and metatarsal : In prolongation of a vertical line drawn from the ischial tuber.
Hindfoot : Less oval than the forefoot, with arched and closely-knit toes; pads and nails pigmented like the forefoot.
GAIT / MOVEMENT : Springy, harmonious, no hackney gaiting (high-stepping). Gallop fast with sharp spring.
SKIN : Fine and tight on all parts of the body except for the elbows where it is slightly less tight.
HAIR : The hair is short and fine all over the body without the slightest trace of fringes.
COLOUR : Self-coloured in black, grey, slate grey and yellow (in Italian = Isabella) in all possible shades. White is tolerated only on the chest and feet.
SIZE AND WEIGHT :
Height at the withers : males and females from 32 to 38 cm.
Weight : Males and females : maximum 5 kg.
FAULTS : Any departure from the foregoing points should be considered a fault and the seriousness with which the fault should be regarded should be in exact proportion to its degree.
Hackney or highstepping movement.
ELIMINATING FAULTS :
Aggresive or overly shy.
Accentuated convergence or divergence of the facial-cranial axes.
Nose totally or half depigmented.
Nasal bridge concave or convex.
Overshot or undershot mouth.
Wall eye; total depigmentation of eyelid rims.
Tail carried over the back; anury or short tail, whether congenital or artificial.
Multicoloured coat; white except in chest and feet as mentioned above.
Size below 32 cm or over 38 cm, as well in males as in females.
Any dog clearly showing physical or behavioural abnormalities shall be disqualified.
N.B. : Male animals should have two apparently normal testicles fully descended into the scrotum.
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