Whole genome analysis reveals aneuploidies in early pregnancy loss in the horse

Shilton, Charlotte A.; Kahler, Anne; Davis, Brian W.; Crabtree, James R.; Crowhurst, James; McGladdery, Andrew J.; Wathes, D. Claire; Raudsepp, Terje; de Mestre, Amanda M.

Abstract

The first 8 weeks of pregnancy is a critical time, with the majority of pregnancy losses occurring during this period. Abnormal chromosome number (aneuploidy) is a common finding in human miscarriage, yet is rarely reported in domestic animals. Equine early pregnancy loss (EPL) has no diagnosis in over 80% of cases. The aim of this study was to characterise aneuploidies associated with equine EPL. Genomic DNA from clinical cases of spontaneous miscarriage (EPLs; 14–65 days of gestation) and healthy control placentae (various gestational ages) were assessed using a high density genotyping array. Aneuploidy was detected in 12/55 EPLs (21.8%), and 0/15 healthy control placentae. Whole genome sequencing (30X) and digital droplet PCR (ddPCR) validated results. The majority of these aneuploidies have never been reported in live born equines, supporting their embryonic/fetal lethality. Aneuploidies were detected in both placental and fetal compartments. Rodents are currently used to study how maternal ageing impacts aneuploidy risk, however the differences in reproductive biology is a limitation of this model. We present the first evidence of aneuploidy in naturally occurring equine EPLs at a similar rate to human miscarriage. We therefore suggest the horse as an alternative to rodent models to study mechanisms resulting in aneuploid pregnancies.

Citation

Shilton, C. A., Kahler, A., Davis, B. W., Crabtree, J. R., Crowhurst, J., McGladdery, A. J., …de Mestre, A. M. (2020). Whole genome analysis reveals aneuploidies in early pregnancy loss in the horse. Scientific Reports, 10(1), https://doi.org/10.1038/s41598-020-69967-z

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2020
• Publication Date: Aug 7, 2020
• Deposit Date: Aug 12, 2020
• Publicly Available Date: Aug 12, 2020
• Journal: Scientific Reports
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 1
• DOI: https://doi.org/10.1038/s41598-020-69967-z
• Public URL: https://rvc-repository.worktribe.com/output/1376333
• Publisher URL: https://doi.org/10.1038/s41598-020-69967-z
• Related Public URLs: https://researchonline.rvc.ac.uk/id/eprint/12748/