Genetic testing for phenotype-causing variants in sheep and goats.

Area of Science:

• Animal Genetics
• Genomics
• Molecular Biology

Background:

• Genetic disorders, production traits, and coat colors in sheep (ovine) and goats (caprine) are influenced by known causal gene variants.
• Most of these phenotypes are inherited in an autosomal-recessive or dominant manner, often due to single nucleotide substitutions or deletions.

Purpose of the Study:

• To provide a comprehensive overview of identified causal gene variants in ovine and caprine species.
• To summarize the inheritance patterns and molecular basis of these genetic variations.
• To discuss the methodologies used for variant discovery and genotyping.

Main Methods:

• Candidate gene sequencing was historically used for variant identification.
• Recent advancements include whole-genome analysis utilizing ovine 50k SNP chips.
• Genotyping methods range from PCR-fragment length polymorphism analysis to high-throughput techniques like MALDI-ToF MS and real-time PCR.

Main Results:

• A significant number of causative sequence variants for various ovine and caprine phenotypes have been identified.
• Autosomal inheritance patterns (recessive and dominant) are predominant.
• A variety of PCR-based and high-throughput genotyping methods have been established for these variants.

Conclusions:

• Continued development of ovine and caprine genome sequences and SNP chips will accelerate the discovery of additional causative variants.
• Understanding these genetic variants is vital for improving animal health, breeding, and production traits in sheep and goats.