The genome of the dog is estimated to be approximately 2.5 billion bases in size. This genetic information is divided into 78 chromosome - 38 pairs of acrocentric (single-armed) autosomes and a pair of sex chromosomes. In females both sex chromosomes are X chromosomes and in males there is one X chromosome and one Y chromosome. A typical chromosome preparation (at the metaphase stage of mitosis) from a male dog is shown below. In this preparation, the chromosomes have been banded to allow identification of chroimosome pairs.
Using multicolor FISH we are able to conclusively identify each chromosome pair and generate a karyotype of the above cell, as shown below.