Copy number variants in the sheep genome detected using multiple approaches

Area of Science:

• Genomics
• Animal Genetics
• Bioinformatics

Background:

• Copy number variants (CNVs) contribute to phenotypic variation in humans and livestock.
• Previous livestock CNV studies primarily focused on cattle, often using single detection methods.
• A comprehensive characterization of CNVs in sheep using multiple approaches was lacking.

Purpose of the Study:

• To conduct the first comprehensive survey of copy number variant regions (CNVRs) in the sheep genome.
• To identify and characterize the distribution, prevalence, and characteristics of CNVs in sheep.
• To compare the validation rates of different CNV detection methodologies.

Main Methods:

• Utilized multiple platforms including array comparative genomic hybridization (CGH), SNP chips, and whole genome sequencing data.
• Collected comprehensive data from small pedigrees (trios).
• Applied multiple analytical approaches for CNV identification and verification.

Main Results:

• Identified 3,488 autosomal CNV regions (CNVRs), significantly expanding the known CNVRs in sheep.
• CNVRs averaged 19 kb in length, with shorter variants being more frequent.
• Whole genome sequence data demonstrated the highest validation rate (>60%) for CNV detection.

Conclusions:

• This study provides the first comprehensive characterization of CNVRs in sheep.
• A combination of detection methodologies is recommended for large-scale CNVR verification.
• The identified 3,488 CNVRs offer a valuable dataset comparable to findings in other species.