What is a gene? The basics of animal genetics explained

Every living creature, from the smallest insect to the largest mammal, carries instructions inside its body that determine how it grows, functions, and reproduces. These instructions are encoded in genes, the basic units of heredity. For hedgehogs and tenrecs, as for all animals, understanding genes is the first step in understanding colour inheritance, health risks, and how traits are passed from one generation to the next.

Genes and DNA

Genes are made up of DNA (deoxyribonucleic acid), a molecule shaped like a twisted ladder, known as the double helix. Each gene is a segment of DNA that contains the “recipe” for a particular protein. Proteins are the building blocks and workers of the body: they build tissues, carry oxygen, fight infections, and regulate countless processes.

In simple terms:

• DNA = the code.
• Genes = the instructions.
• Proteins = the result of those instructions.

Chromosomes

Genes are packaged into structures called chromosomes. Each species has its own set number of chromosomes. Hedgehogs and tenrecs, like all mammals, inherit one set of chromosomes from their mother and one from their father, meaning they carry two copies of each gene.

Alleles: Variations of a Gene

Not all genes are identical. Different versions of the same gene are called alleles. For example:

• A gene might determine coat colour.
• One allele could code for a dark colour, another for a light colour.
• Which combination an animal inherits will determine its visible trait.

Some alleles are dominant (expressed even if only one copy is present), while others are recessive (only expressed if both copies are the same). This explains why two animals that look alike (phenotype) can carry very different hidden genetics (genotype).

Genes and Environment

Genes provide the blueprint, but the environment influences how that blueprint is expressed. A hedgehog may carry genes for lean body type, but if overfed and under-exercised, it will still become overweight. This interaction between nature (genes) and nurture (environment) is what shapes the full animal.

Why This Matters for Hedgehogs and Tenrecs

• Colour and patterns in hedgehogs: Breeders use knowledge of genes and alleles to predict offspring colours, but hidden recessives often make outcomes unpredictable.
• Health conditions: Some diseases, such as Wobbly Hedgehog Syndrome (WHS), are suspected to have a genetic component. Tracking pedigrees helps monitor these risks.
• Tenrec conservation: In captive tenrecs, understanding genetic variation is vital to avoid inbreeding and to keep populations sustainable.

In Summary

A gene is a unit of heredity made of DNA, carrying instructions to build proteins that shape an animal’s traits. Genes are organised in chromosomes, come in different versions called alleles, and interact with the environment to produce the final result: the phenotype. For hedgehogs and tenrecs, understanding the basics of genetics is essential for responsible breeding, health management, and conservation.