Genetics Q&A – Part 1

When we talk about genetics in the context of dogs and animals, it refers to the science of animal heredity, and involves study of how different animal characteristics and traits get transmitted from one generation to the next. Although it’s a fairly complex subject, dog breeders must understand it well and appreciate its importance. This is because learning about genetics can help them in preventing breeding of unsuitable dogs and production of unhealthy offspring. Let’s now go over the top 18 genetics related questions and answers that every responsible dog breeder should be aware of. As the questions are many, we have divided this article into two parts. Here’s part 1 for you!

1. What’s meant by DNA?
DNA stands for deoxyribonucleic acid. It governs the cytoplasm activities and is a molecular substance which controls the hereditary factors from parents to their offspring. It’s a double-stranded molecule whose every strand comprises of two long complementary chains bound together by the base pairs. Such kind of structure is called double helix. The genes that we often talk about are created from DNA.

2. What’s meant by inbreeding?
Inbreeding is the term used for referring to the selective breeding of closely related family members of a dog/animal breed, for increasing the homozygosity and fixing the desired characteristics of that breed. You can learn more about inbreeding by referring to our detailed article on this subject.

3. What’s meant by line breeding?
It’s the act of mating in a family wherein the act happens with a particular ancestor for preservation of the desired characteristics of that breed.

4. What’s meant by chromosomes? How many are possessed by domestic dogs?
Chromosomes are the special structures inside the nucleus of a cell. They consist of chromatin fibers which have the genetic information of a specific breed. Domestic dogs have 78 chromosomes, of which there are 2 sex chromosomes and 38 pairs of autosomal chromosomes.

5. Why is it important for breeders to correctly identify an animal with a recessive gene?
Genes whose effects get masked by the effects of their allelomorphic partner are referred to as a recessive genes. These are basically unwanted genes and breeding with any animal with such genes should be completely avoided. A carrier of recessive gene can be identified by test mating with unknown heterozygous recessive carrier or with a homozygous recessive carrier. Homozygous is the term used for an animal’s genes when both the allelomorphic partners belong to the same breed and have the same characteristics, while heterozygous is used for describing an animal’s genes when the two allelomorphic partners are different from each other.

6. What is ‘first filial generation’?
First filial generation or F1 generation is the term used for describing the process of test mating, and the offspring produced by that process. The parent generation is the F1 generation and the offspring produced is referred to as the F2 generation.

7. What’s meant by ‘backcross to recessive’?
Mating with unknown heterozygous animal or a homozygous recessive animal is referred to as backcross to recessive. It’s used for discovering the presence of recessive gene in an animal that has the same phenotype as a homozygous animal with a dominant gene.

8. Who was Mendel? What were his first and second laws of genetics?
Mendel’s full name was Gregor Mendel. He was a biologist and a monk of Austrian origin, who lived from 1822 to 1884 and was the discoverer of genes. Mendel’s first law of genetics states that an individual’s characteristics are heavily influenced by his/her genes. These genes exist in pairs (referred to as alleles), and have the same identity from one generation to the other. Mendel’s second law states that every pair of genes exists independently and separately from every other pair.