Keles Esin, Malama Eleni, Bozukova Siyka, Siuda Mathias, Wyck Sarah, Witschi Ulrich, Bauersachs Stefan, Bollwein Heinrich
Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, CH-8057, Zurich, Switzerland.
Veterinary Research Institute, Hellenic Agricultural Organization Demeter, 57001, Thermi, Thessaloniki, Greece.
BMC Genomics. 2021 Jan 7;22(1):30. doi: 10.1186/s12864-020-07280-9.
The use of sex-sorted sperm in cattle assisted reproduction is constantly increasing. However, sperm fertility can substantially differ between unsorted (conventional) and sex-sorted semen batches of the same sire. Sperm microRNAs (miRNA) have been suggested as promising biomarkers of bull fertility the last years. In this study, we hypothesized that the miRNA profile of cryopreserved conventional sperm is related to bull fertility after artificial insemination with X-bearing sperm. For this purpose, we analyzed the miRNA profile of 18 conventional sperm samples obtained from nine high- (HF) and nine low-fertility (LF) bulls that were contemporaneously used to produce conventional and sex-sorted semen batches. The annual 56-day non-return rate for each semen type (NRR and NRR, respectively) was recorded for each bull.
In total, 85 miRNAs were detected. MiR-34b-3p and miR-100-5p were the two most highly expressed miRNAs with their relative abundance reaching 30% in total. MiR-10a-5p and miR-9-5p were differentially expressed in LF and HF samples (false discovery rate < 10%). The expression levels of miR-9-5p, miR-34c, miR-423-5p, miR-449a, miR-5193-5p, miR-1246, miR-2483-5p, miR-92a, miR-21-5p were significantly correlated to NRR but not to NRR. Based on robust regression analysis, miR-34c, miR-7859 and miR-342 showed the highest contribution to the prediction of NRR.
A set of miRNAs detected in conventionally produced semen batches were linked to the fertilizing potential of bovine sperm after sex-sorting. These miRNAs should be further evaluated as potential biomarkers of a sire's suitability for the production of sex-sorted sperm.
在牛的辅助生殖中，性别分选精子的使用量在不断增加。然而，同一头公牛的未分选（常规）精液批次和性别分选精液批次之间的精子生育力可能存在显著差异。近年来，精子微小RNA（miRNA）被认为是公牛生育力的有前景的生物标志物。在本研究中，我们假设冷冻保存的常规精子的miRNA谱与用携带X染色体的精子人工授精后的公牛生育力相关。为此，我们分析了从9头高生育力（HF）公牛和9头低生育力（LF）公牛获得的18个常规精子样本的miRNA谱，这些公牛同时用于生产常规精液批次和性别分选精液批次。记录了每头公牛每种精液类型的年度56天不返情率（分别为NRR和NRR）。
总共检测到85种miRNA。MiR-34b-3p和miR-100-5p是表达量最高的两种miRNA，它们的相对丰度总计达到30%。MiR-10a-5p和miR-9-5p在LF和HF样本中差异表达（错误发现率<10%）。MiR-9-5p、miR-34c、miR-423-5p、miR-449a、miR-5193-5p、miR-1246、miR-2483-5p、miR-92a、miR-21-5p的表达水平与NRR显著相关，但与NRR无关。基于稳健回归分析，miR-34c、miR-7859和miR-342对NRR预测的贡献最大。
在常规生产的精液批次中检测到的一组miRNA与性别分选后牛精子的受精潜力有关。这些miRNA应作为公牛生产性别分选精子适宜性的潜在生物标志物进行进一步评估。
