Computational Identification of Genetic Background of Infertility and Calculating Inbreeding Coefficient in Dromedary Camel Herds

TL;DR

This study shows that inbreeding in dromedary camels is strongly linked to infertility, and suggests breeding strategies to avoid related matings.

Contribution

The study links high inbreeding coefficients to infertility in dromedary camels and recommends breeding strategies to reduce inbreeding.

Findings

All five infertile camels had significantly higher inbreeding coefficients than fertile individuals.

Genome-wide association analysis failed to identify specific infertility-linked regions due to limited sample size.

Population structure analysis found genetic differentiation related to coat color near the SLC30A5 gene.

Abstract

Background: Inbreeding is a major genetic problem that reduces fertility and causes genetic disorders. Some breeders of dromedary camels use the same bull for many years due to its excellent characteristics, leading to mating with offspring and subsequent generations, resulting in increased homozygosity and genetic disorders. We hypothesize that inbreeding is associated with infertility in dromedary camels with normal and uninfected reproductive tracts. Methods: We genotyped 96 samples from seven camel breeds using the Illumina 55K SNP BeadChip, including five confirmed infertile individuals. Inbreeding coefficients (F) were calculated using PLINK based on heterozygosity and runs of homozygosity. Genome-wide association analysis using logistic regression was performed to identify potential genomic regions associated with infertility. Results: All five infertile camels showed significantly higher F values (>0.15) compared to 91 fertile individuals (<0.10, p < 0.001). The genome-wide association analysis failed to identify specific genomic regions linked to infertility, likely due to limited statistical power (n = 5 cases) and the polygenic nature of fertility traits. Population structure analysis revealed genetic differentiation related to coat color, with two significant SNPs on chromosome 3 near SLC30A5 (p < 10−7). Conclusions: Our results demonstrate that elevated inbreeding is strongly associated with infertility in dromedary camels. Future studies should employ larger sample sizes (≥50 infertile individuals) or whole-genome sequencing (35× coverage) to identify specific genomic regions. Implementation of breeding strategies avoiding related matings (F < 0.10) is recommended to maintain reproductive performance in camel herds.

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