gooeydog Posted November 17, 2002 Share Posted November 17, 2002 I've been wondering about two things for a while... First, in brindle dogs, which color is considered the "real" base coat color? Like in Goo, the predominate color is black/dark brown, with red being the less "shown" color... but which is [i]really[/i] her true color? Is the red over the "black"? Or is the "black" over the red? Or are they just "sharing" the space, and neither is over the other? Second, what exactly is it that makes the double dappling (or merling?) in dachshunds lethal? Is the gene "connected" to the merle gene? Or is it just a product of the type of breeding that was used in producing them? Quote Link to comment Share on other sites More sharing options...
yellowlabsrule Posted November 18, 2002 Share Posted November 18, 2002 Sorry don't know anything :oops: but I will try to find something and will pm someone more knowledgeable. Quote Link to comment Share on other sites More sharing options...
yellowlabsrule Posted November 18, 2002 Share Posted November 18, 2002 Here's a site on colors, more about genetics and stuff, don't know if it will help, but i'll post it anyway. [url]http://www.borzois.com/coat.color/coat.color.html[/url] Quote Link to comment Share on other sites More sharing options...
ShadyLady Posted November 18, 2002 Share Posted November 18, 2002 Gooey call HOBBIT he's mad about this sort of thing!! And should steer you in the right direction Quote Link to comment Share on other sites More sharing options...
yellowlabsrule Posted November 18, 2002 Share Posted November 18, 2002 pm'd Hobbit about this post, hopefully will be here soon! Quote Link to comment Share on other sites More sharing options...
Smooshie Posted November 18, 2002 Share Posted November 18, 2002 I don't know if the same applies to [i]Pits[/i]...but in [i]Boxers[/i],Brindle dogs are still considered fawn...Brindle is a marking of black stripes over the basecoat rather than a color in itself,so I would assume that (in Goo,for example) the red would be her actual [i]color[/i] . Going back to Boxers again...if the dog has heavy brindle striping(to the point where he appears or ALMOST appears black), the dog is called a [i]reverse brindle[/i], but his basecoat is still considered fawn..... I'm sure Hobbit can better explain [i]why[/i] this is ,because I don't have a clue about genetics and the brindling gene :wink: Quote Link to comment Share on other sites More sharing options...
Hobbit Posted November 18, 2002 Share Posted November 18, 2002 [quote name='gooeydog']I've been wondering about two things for a while... First, in brindle dogs, which color is considered the "real" base coat color? Like in Goo, the predominate color is black/dark brown, with red being the less "shown" color... but which is [i]really[/i] her true color? Is the red over the "black"? Or is the "black" over the red? Or are they just "sharing" the space, and neither is over the other? [b][color=red]Brindle is not well understood genetically speaking. In Labs, it's thought to be various things: a mutation, chromosome nondisfunction, chromosome loss. In breeds that can be brindle, it is thought to be located in the E series. It is now thought that the brindle color is dark pattern on lighter base coat. There is a black brindle, but the brindling can not be seen. Brindle also comes in blue and fawn coloration. So, since Goo has a black nose, black eye rims -- she is technically - genetically, black; BUT she is phenotypically red with black stripes. The fact there are black and tan dogs with brindling in the "tan" areas suggests that brindle involves suppression of agouti or independent stimulation of eumelanin production (i.e., that it is a "dark" pattern which requires a "light" background to be visible). [/color][/b] Second, what exactly is it that makes the double dappling (or merling?) in dachshunds lethal? Is the gene "connected" to the merle gene? Or is it just a product of the type of breeding that was used in producing them?[/quote] [b][color=darkred]Double dappling is not a color, it is a pattern. It is a merle gene. And it is a dilution gene. Breeding merle to merle -- the resulting offspring are known as "Double Dapples" or "Double Merles" and can be lethal (in any breed). Congenital deafness in dogs (or other animals) can be acquired [caused by intrauterine infections, ototoxic drugs like gentamicin, liver disorders, or other toxic exposures before or soon after birth] or inherited. Inherited deafness can be caused by a gene defect that is autosomal dominant, recessive, sex-linked, or may involve multiple genes. It is usually impossible to determine the cause of congenital deafness unless a clear problem has been observed in the breed or carefully planned breedings are performed. The deafness, which usually develops in the first few weeks after birth while the ear canal is still closed, usually results from the degeneration of part of the blood supply to the cochlea (the stria vascularis). The nerve cells of the cochlea subsequently die and permanent deafness results. The cause of the vascular degeneration is not known, but appears to be associated with the absence of pigment producing cells (melanocytes) in the blood vessels, related to the merle and piebald gene. The function of these cells is not known but appears to be critical for survival of the stria. A lethal allele's phenotype, when expressed, causes the death of an organism. Lethal alleles arise when a mutation to a normal allele disrupts the function of an essential gene. Without this essential gene, the organism dies. Lethal alleles can be embryonic or postnatal.[/color][/b] [b][color=blue]Goo -- were Annies parents both merles (dapples)? She could be a phantom or cryptic merle. If she has black hairs in her red, then she is a sable -- sometimes the red merling (dapples) can't been seen in the sable coloration. Sable merles are not desired (for breeding), because you can't tell if they are a sable, merle or a phantom --- until you breed them, and then sometimes there are fatal results. [/color][/b] Quote Link to comment Share on other sites More sharing options...
gooeydog Posted November 20, 2002 Author Share Posted November 20, 2002 Thanks everyone :lol: That pretty much answered both of them. Hobbit, I don't know what color Annie's parents were, but she is AKC registered, so if it would say on there, I'll try to get the papers from my aunt and see what they say. I remember my aunt saying that she was registered as a red dapple, but she got her from a local petshop known for selling poorly bred or sick dogs, so who knows if her papers are even "real", or if the information on them is valid. She does have some darker hairs, mostly along the spine, ears, and tail. Quote Link to comment Share on other sites More sharing options...
Hobbit Posted November 20, 2002 Share Posted November 20, 2002 [quote name='gooeydog']Thanks everyone :lol: That pretty much answered both of them. Hobbit, I don't know what color Annie's parents were, but she is AKC registered, so if it would say on there, I'll try to get the papers from my aunt and see what they say. I remember my aunt saying that she was registered as a red dapple, but she got her from a local petshop known for selling poorly bred or sick dogs, so who knows if her papers are even "real", or if the information on them is valid. She does have some darker hairs, mostly along the spine, ears, and tail.[/quote] If the darker hairs are black, then she is a sable (could be a merle/dapple -- you just can't see the red merle pattern). Yeah, petshops --- shaking my head trying to figure out how they stay in business! Quote Link to comment Share on other sites More sharing options...
Poofy Posted December 30, 2002 Share Posted December 30, 2002 If you really want to understand color genetics, pick up Malcolm Willis's book, Genetics of the dog. It is a well written book. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 22, 2003 Share Posted January 22, 2003 Hey i know this isn't really related..well it is a bit..but can you actually breed two dog colors to purposely get another? Like if you wanted to breed a black dog would you have to get like a black parent and a fawn or 2 blacks? Also what's the deal with dominat colour genes> Please explain. Quote Link to comment Share on other sites More sharing options...
Poofy Posted January 22, 2003 Share Posted January 22, 2003 Genes are located on chromosome, which in dogs there are 39 pairs, called homologs. Two chromosomes that are homologs mean those chromosomes are alike in size and shape. eukaryotes (animals like dogs) inherit one chromosome from each parent. Chromosomes are made up of chromatin, which you cam think of as a wild tangle of string with beads all up and down in. Those "beads" are the genes. Chromosomes are found in every cell of the body that has a neucleus. Red blood cells do not have a neucleus. The "chromosomes" remain in an ununiformed state, until the cell divides, which is when you can actually see the chromosomes. Any how. On each chromsome there are hundreds if not thousands of genes. And genes can have variations of themselves called alleles. The location of an allele on a gene is called a loci. When two homologs are together they should have many of the same genes which influence expression of traits in the dogs. The only exception to this is the sex chromsomes where in males they are not homologs (x and y) There are exceptions to the rule I am about to state, but we won't worry with that right now. Each chromosome will have a copy of the gene, making a "pair". Some genes are dominant to other genes or their alleles. When a gene is dominant autosonomal (all the chromosome but the sex chrmosomes), it means it only takes one copy to be expressed. Genes that are recessive, take two copies to be expressed. There are only two places available for a gene to occupy, however there can be dozens of variations ( alleles) of the same gene. Some times the dominat gene doesn't completely dominate, which is called incompete dominance and you can get some interesting coat combinations. Some times chrmosomes don't divide correctly and instead of an even division, one side can wind up with an extra and you can have nondysjunction (which is how you get a male calico cat in most cases) You can also have crossing over, one gene exchanges place with another gene or breakage, when an entire section of chromosome breaks off and exchanges with another. All these things that promote genetic diversity withen the species..can change the way genes are "normally" expressed...mutations also can occur...these are usually molecular however they can be great enough to alter protien sequencing and thus affect expression.... Epistasis is another factor...this is when the presence of a gene or its alleles effects the expression of another set of genes or their alleles... and so on... :) If you really want to understand more...the book I suggest above is really easy to read and understand...I would get it...invest the money, especially if you are into dogs...and learn... :) Its really fun once you get over the initial hump. :) Take care :jumpie: Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 23, 2003 Share Posted January 23, 2003 [quote name='DieselChick']Hey i know this isn't really related..well it is a bit..but can you actually breed two dog colors to purposely get another? Like if you wanted to breed a black dog would you have to get like a black parent and a fawn or 2 blacks? Also what's the deal with dominat colour genes> Please explain.[/quote] To put it in terms that you could more understand: The black color is dominant. If you want the entire litter to be black, then the parents must be black and their parents must be black >> this is to ensure that the black dogs that you are breeding are not carrying another color, like red. If the black dogs that you are breeding have parents that are any color other than black >> you stand a chance of getting another color, other than black, in the litter. [b]HOPEFULLY, you are not breeding to begin with because there are lots of other things involved than just putting two dogs together.[/b] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 23, 2003 Share Posted January 23, 2003 To Hobbit and Poofy: Thankyou for replying to my question. It was just something which came into my head, so Hobbit, don't worry, I am not about to start breeding! :D I'm only 13 so that is not really on my to do list RIGHT now. Thanks again! Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 23, 2003 Share Posted January 23, 2003 That's good. Have you posted pictures of your dog, yet?? Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 24, 2003 Share Posted January 24, 2003 [quote name='Kiwi']This genetics stuff is WAY over my head :-? I'm adament that one day I'll get it though :o Hobbit, I have a question regarding the litter Kobi was from. Her Dam was brindle, and her Sire was white carrying brindle, yet all 9 puppies from the litter turned out to be white :-? Is this normal? I know that in the coloured Bull Terriers, the preferred colour is brindle - as it is so easily "lost" in this breed, but surely some of the dogs in that litter should have been coloured?[/quote] Brindle is said to be a dominant gene. Was the dam a carrier of the "Piebald" gene? This is common in Bull Terrier's. Have these particular parents been mated again? If so, was the entire litter white? If mated again, this complete coloration may not occur again. Sire and dam are extreme white factored. No, this isn't normal. It sounds like an extreme case of severe white piebald. Quote Link to comment Share on other sites More sharing options...
Poofy Posted January 24, 2003 Share Posted January 24, 2003 Genetically, the puppies will probably breed like brindles...unless they are bred to another carrying the white spotting gene. Remember..while some colors are dominant...white spotting conceals what ever color is being expressed (its not really a color rather it inhibits pigment). A dog also not need to carry the white gene to produce white spotted puppies. plus and minus modifiers can put white spots on a solid dog that is homozygous for color CC. Also a dog that is homozygous for irish pattern could carry enough plus modifiers to make it *appear* to be solid in color. Modifier genes can effect the white spotting in great ways...making it look like extreme pie bald when its just pie bald. Its the roll of the genetic dice! I would like to see the breeding done again...man those odds (all white) are like winning the lottery. :) Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 25, 2003 Share Posted January 25, 2003 Kiwi -- it's more than likely a severe piebald gene (since this gene is common in Bull Terriers). Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 25, 2003 Share Posted January 25, 2003 Modifier - A gene that exerts an effect on another gene. It does not act on it's own. Example: it affects how much copper is present in a tan highlighted dog. If a dog does not have tan highlights, then the effects of any modifiers will not be seen (even though they are present). Minus Modifier - A modifying gene or collection of modifying genes that acts to reduce pigment from whatever color or pattern the dog already has. A dog with no spotting pattern (solid color) may have a few white hairs on his chest, or a white toe has minus modifiers pulling pigment from him. Dogs with a spotting pattern, like a collar, minus modifiers can further extend the collar beyond the withers. Plus Modifier - A modifying gene (or collection of modifying genes) that adds pigment to whatever spotting pattern is present. A full Irish spotting pattern --- like a full collar, white legs, blaze face --- can be reduced to a partial collar, to white feet, and little or no blaze, depending on their number and action. Quote Link to comment Share on other sites More sharing options...
Poofy Posted January 25, 2003 Share Posted January 25, 2003 Hobbit... The modifiers that effect white, according to malcolm willis, can "make white" even when the white spottig gene is not there. I had this conversation with him a couple of years ago reguarding white spotting in labs and other breeds...where the "white gene" is not supposed to exsist. Quote Link to comment Share on other sites More sharing options...
Poofy Posted January 25, 2003 Share Posted January 25, 2003 Also he talks about it briefly in his book as well. " Most breeds which do not allow white markings ar SS but from time to time white markings appear...... Frequently these marks are present at birth and are lost during early infancy but somtimes they persist, particularly in black dogs. Little (1957) in a study of 2353 dogs from seven breeds in which white was not desiredfound that 11.3% were mismarked in some sense of having white. Such effects are not due to the other s allelea but to the minus modifiers of the S allele." The piebald gene would have to be present in order to make a dog all white, pie bald with lots of minus modifiers or extreme piebald...but a dog can and does have white markings, on the nose, tail tip, toes and most commonly the chest, with only the minus modifiers present.... These puppies could not be all white due to the modifers..thats not what I am saying...When I said solid color I was meaning color..not white spotting...a dog who is irish spotted could carry enough plus modifiers to make it look solid or almost solid....(was just thinking out loud there giving an example)... Quote Link to comment Share on other sites More sharing options...
Hobbit Posted January 28, 2003 Share Posted January 28, 2003 Kiwi, I contacted a PhD in genetics, she said the color was due to the severe Piebald gene. The all white litter was very rare and she would question the actual sire of the litter. I can't answer back, as I can't access Dog-o from home. I'm pirating a computer. Quote Link to comment Share on other sites More sharing options...
Poofy Posted January 28, 2003 Share Posted January 28, 2003 I don't think there was any question that it would have to be extreme pie bald for all whites...I still say the odds of them being all white out of a solid parent (even if he was carrying the gene) would be lottery odds. Quote Link to comment Share on other sites More sharing options...
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