Molecular Genetics Tools for Breeding and Biotechnology in Companion Animals

Punnett Square

A tool used in genetics to predict the probability of offspring inheriting particular traits from parents' genotypes.

Gene

A segment of DNA that contains instructions for producing a biological product, usually a protein.

Allele

Different versions of a gene that can produce variations in traits.

Genotype

The specific allele combination for a gene in an individual.

Phenotype

The observable traits expressed in an organism, influenced by genotype and environment.

Dominant Allele

An allele that can express its effect in the phenotype with only one copy present.

Recessive Allele

An allele that typically requires two copies to express its effect in the phenotype.

Mendel’s Law of Segregation

States that alleles segregate during gamete formation, so each gamete carries only one allele for a gene.

Mendel’s Law of Independent Assortment

States that alleles of different genes assort independently during gamete formation if the genes are unlinked.

Monohybrid Cross

A genetic cross that examines the inheritance of a single trait.

Dihybrid Cross

A genetic cross that examines the inheritance of two different traits.

Heterozygous

An organism that has two different alleles for a particular gene (e.g., Aa).

Homozygous

An organism that has two identical alleles for a particular gene (e.g., AA or aa).

Codon

A sequence of three RNA bases that specifies an amino acid during protein synthesis.

Transcription

The process of converting a gene's DNA sequence into an RNA sequence.

Translation

The process of synthesizing proteins from mRNA at the ribosome.

Artificial Selection

The human-directed process of breeding individuals with desirable traits to increase those traits in future generations.

Inbreeding

The mating of closely related individuals to increase homozygosity in a population.

Outcrossing

Mating unrelated individuals within the same breed to increase genetic diversity.

Crossbreeding

Mating individuals from different breeds to enhance traits or introduce new genetic variations.

Hybrid Vigor (Heterosis)

The improved or superior quality in traits of hybrids compared to their parents.

Polygenic Traits

Traits that are influenced by multiple genes, often resulting in a continuous range of phenotypes.

Segregation

The separation of alleles during gamete formation as described by Mendel's laws.

Genetic Drift

The change in allele frequencies in a population due to random sampling effects.

Mutation

A change in the DNA sequence that can lead to new traits or variations.

Carrier

An individual that has one copy of a recessive allele and does not show the recessive trait.

Genetic Diversity

The total number of genetic characteristics in the genetic makeup of a species.