Genetics gets a little tricky when it comes to things like hair and eye color in humans, so I'm assuming it's that way with dogs as well. You would also have to consider what genes Aniu's parents might have had, as well as the genes Balto's father's parents might have had. I think that Aniu's white coloring is a recessive trait in wolves, and there are a lot of fur color variations in huskies that could be dominant over that. This seems like an interesting topic to research. *goes to research* ...
Okay, here is all of the relevant info I could find. There is really not that much scientific knowledge in the area of canine/lupine genetics, but this is what I found:
From:
http://www.fiu.edu/~milesk/Genetics.htm :
Animals have two types of DNA, nuclear (nDNA) and mitochondrial (mtDNA). Nuclear DNA is found in the nucleus of a cell. The genes coded for by nDNA are responsible for external characteristics and for behavior, but they also have important regulatory functions inside the cells. Mitochondrial DNA is separate and distinct from nDNA and is found in the mitochondria of the cell. The gene coding here is strictly regulatory and has little effect on external characteristics or behavior in comparison to nDNA.
Nuclear DNA occurs in the cell as tightly packed units called chromosomes and each cell has two copies of each chromosome. One pair of chromosomes are involved in sex-determination and are, therefore, called sex chromosomes; females have two X chromosomes and males have an X and a Y. The other chromosomes are called autosomes. All mammals have only one pair of sex chromosomes, but the number of autosomes varies according to species.
Genes are discrete pieces of DNA on the chromosomes that code for particular gene products, which are proteins. Slightly different forms of the same gene are referred to as alleles and each chromosome pair has two alleles; some alleles are dominant and are always expressed, while others are recessive and are only expressed when both alleles of a gene are recessive.
It is a myth that female (or male) genetics are stronger. Certain forms of genes (alleles) are dominant and these are expressed over recessive alleles, but dominant alleles do not occur in a higher frequency in males or females. However, there are sex-linked genes (e.g., male pattern baldness in humans) and these recessive alleles--slightly different forms of the same gene--occur in nDNA, specifically on the X chromosome. Though we know much about sex-linked genes in humans, I personally know of no such studies that have been done on canids.
Mitochondrial DNA comes solely from the female parent; the egg carries mitochondria as there is no room in the part of the sperm that fuses with the egg at fertilization. Here are a couple of examples to clarify how DNA is passed from parent to offspring:
• A female pure wolf breeds with a pure male dog--the pups will all have the wolf mtDNA of the mother. There will be a half-and-half mixing of dog and wolf nuclear DNA. The male pups will have a pure dog Y chromosome and a pure wolf X chromosome, with all genes of the latter being expressed. The female pups would have an X chromosome from the mother (wolf) and an X chromosome from the father (dog) and the genes on these two X chromosomes will "compete" with each other, with dominant alleles being expressed and recessive being suppressed.
From:
http://www.nal.usda.gov/awic/newsletters/v5n4/5n4wille.htm :
Wolf hybrids have been known to exhibit physical characteristics of both the wolf and dog in differing combinations and to varying degrees. Though closely related, there are a number of anatomical and physiological differences between the two species.
Wolves generally weigh between 80 and 100 pounds, with females weighing less than males. An unusual wolf may reach 150 pounds or more. They have slim torsos with narrow chests, long legs with large feet, and large heads with larger teeth and more powerful jaws than those of the dog. Their coat varies with the seasons; it is very thick with a dense undercoat in the winter and sheds to a thinner, shorter haired coat in the summer. Coat color varies from all black to a grizzled gray to all white. The eyes are usually a yellowish golden color.
Dogs come in a variety of sizes, shapes, and colors that vary greatly with the breed. The malamute and husky closely resemble the wolf in appearance, making them the dog breeds most preferred for hybridization.
Wolves are seasonal breeders and generally have two to four pups per litter. Dogs are nonseasonal breeders and generally have larger litters than wolves.
Because of the range of possible variations, there is no general description that can be made of the wolf hybrid. They are often larger in size than either the wolf or dog from which they were bred, a phenomenon termed "hybrid vigor." Though most high- percentage hybrids often retain much of the physical appearance of the wolf, many hybrids are indistinguishable from dogs in appearance.
The initial mating most commonly occurs between a male dog and a female wolf, though the opposite mating can also occur. The offspring produced from such a mating are first generation, or F1, hybrids. F1 and subsequent hybrids can then be bred with other hybrids, with pure wolves, or with the same or different breeds of dog, resulting in a group of hybrids with a wide range of genetic makeup.
Wolves and dogs each have 78 chromosomes arranged into 39 pairs. Wolves are physically different from dogs because they have a number of genes located on these chromosomes, coding for wolf characteristics, that dogs do not have. But which genes differentiate a wolf from a dog? How many are they and on which chromosomes are they located?
Unfortunately, the answers to these questions are not currently known.
Using the pedigree method, each pup in a given litter would be assigned the same percentage of wolf blood. Yet no two pups in that litter have the identical genotype, unless they are identical twins. This is easily demonstrated by noting the differences in physical appearance, or phenotype, amongst the pups. Some will be more wolf-like than others. These phenotypic differences reflect the differences in their genotypes.
One complicating factor in determining accurate percentages results from the close biological relationship of wolves to dogs. As previously stated, wolves are recent ancestors of the domestic dog. Though not identical, the genotypes of wolves and dogs are very similar. It is probable, in fact, that 99 percent or more of the genotypes of these two species are indistinguishable. (Consider that 98 percent of the genotypes of humans and chimpanzees are indistinguishable.) The large majority of wolf genes that enter into pedigree percentage calculations are, therefore, identical to the corresponding dog genes.
There may be as few as several hundred genes in a genotype containing more than a 100,000 genes that differentiate the wolf from the dog. But the locations of these genes on the various chromosomes are unknown. They may be located on all or only a few of the 39 chromosome pairs, making it unlikely for them to be evenly distributed between daughter cells following the random separation of chromosomes that occurs during meiosis.
With current knowledge and technology, it is not possible to accurately determine the percentage of wolf genes in a wolf hybrid. Therefore, although they do not accurately represent the "wolf content" of an individual hybrid, the percentages assigned to wolf hybrids by the pedigree method may still have some value. Pedigrees are a traditional way of determining ancestry in human lineages as well as animal breeding. These percentages, if honestly assigned and accurately calculated, can be used to depict the breeding history and ancestry--the pedigree--of the individual animal. Since there is no way of accurately calculating the percentage of wolf genes in a hybrid, it may still be the best method currently in use to describe an individual hybrid.
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This doesn't give us an answer to how Balto inherited his fur color, but it does explain the genetic variation in wolves and dogs, and explains how Aleu can look so different from the rest of her siblings. I hope someone finds this interesting, though.
