Minghua Liu1, Peiru Liu2, Yunjian Chang3, Beiying Xu3, Nengzhuang Wang1, Lina Qin1, Jufen Zheng4, Yun Liu5, Ligang Wu6, Hongli Yan7. 1. Reproductive Medical Center, Changhai Hospital, Naval Medical University, Shanghai, China. 2. MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Zhongshan Hospital, Fudan University, Shanghai, China. 3. State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China. 4. Reproductive Medical Center, Changhai Hospital, Naval Medical University, Shanghai, China. jf_zheng@sina.cn. 5. MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Zhongshan Hospital, Fudan University, Shanghai, China. yliu39@fudan.edu.cn. 6. State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China. lgwu@sibcb.ac.cn. 7. Reproductive Medical Center, Changhai Hospital, Naval Medical University, Shanghai, China. hongliyan@smmu.edu.cn.
Abstract
BACKGROUND: A growing number of studies have reported that sperm DNA fragmentation (SDF) is associated with male infertility. However, no studies have compared genome-wide DNA methylation profiles and sncRNA signatures between sperm with high and low sperm DNA fragmentation indices (DFIs). METHODS: Whole-genome bisulfite sequencing (WGBS) was performed on sperm samples from a weak group (DFI ≥ 30%, n = 6) and normal group (DFI ≤ 15%, n = 7). Small noncoding RNA (sncRNA) deep sequencing was conducted for sperm samples from the weak (DFI ≥ 30%, n = 13) and normal (DFI ≤ 15%, n = 17) groups. RESULTS: A total of 4939 differentially methylated regions (DMRs) were identified in the weak group sperm samples relative to normal group sperm samples, with 2072 (41.95%) of them located in promoter regions. The percentages of hypermethylated DMRs were higher than those of hypomethylated DMRs in all seven examined gene annotation groups. Hypermethylated DMRs were significantly enriched in terms associated with neurons and microtubules. Compared with the normal group, the global DNA methylation level of the weak group sperm showed a downward trend, with lower correlation for methylation in the weak group sperm; therefore, the chromosomes of high-DFI sperm may be loose. On average, 40.5% of sncRNAs were annotated as rsRNAs, 19.3% as tsRNAs, 10.4% as yRNAs, and 7.1% as miRNAs. A total of 27 miRNAs, 151 tsRNAs, and 70 rsRNAs were differentially expressed between the two groups of sperm samples. Finally, 7 sncRNAs were identified as candidate sperm quality biomarkers, and the target genes of the differentially expressed miRNAs are involved in nervous system development. CONCLUSION: Our findings suggest that genome-wide DNA methylation profiles and sncRNA signatures are significantly altered in high-DFI sperm. Our study provides potential biomarkers for sperm quality.
BACKGROUND: A growing number of studies have reported that sperm DNA fragmentation (SDF) is associated with male infertility. However, no studies have compared genome-wide DNA methylation profiles and sncRNA signatures between sperm with high and low sperm DNA fragmentation indices (DFIs). METHODS: Whole-genome bisulfite sequencing (WGBS) was performed on sperm samples from a weak group (DFI ≥ 30%, n = 6) and normal group (DFI ≤ 15%, n = 7). Small noncoding RNA (sncRNA) deep sequencing was conducted for sperm samples from the weak (DFI ≥ 30%, n = 13) and normal (DFI ≤ 15%, n = 17) groups. RESULTS: A total of 4939 differentially methylated regions (DMRs) were identified in the weak group sperm samples relative to normal group sperm samples, with 2072 (41.95%) of them located in promoter regions. The percentages of hypermethylated DMRs were higher than those of hypomethylated DMRs in all seven examined gene annotation groups. Hypermethylated DMRs were significantly enriched in terms associated with neurons and microtubules. Compared with the normal group, the global DNA methylation level of the weak group sperm showed a downward trend, with lower correlation for methylation in the weak group sperm; therefore, the chromosomes of high-DFI sperm may be loose. On average, 40.5% of sncRNAs were annotated as rsRNAs, 19.3% as tsRNAs, 10.4% as yRNAs, and 7.1% as miRNAs. A total of 27 miRNAs, 151 tsRNAs, and 70 rsRNAs were differentially expressed between the two groups of sperm samples. Finally, 7 sncRNAs were identified as candidate sperm quality biomarkers, and the target genes of the differentially expressed miRNAs are involved in nervous system development. CONCLUSION: Our findings suggest that genome-wide DNA methylation profiles and sncRNA signatures are significantly altered in high-DFI sperm. Our study provides potential biomarkers for sperm quality.
Authors: D S Guzick; J W Overstreet; P Factor-Litvak; C K Brazil; S T Nakajima; C Coutifaris; S A Carson; P Cisneros; M P Steinkampf; J A Hill; D Xu; D L Vogel Journal: N Engl J Med Date: 2001-11-08 Impact factor: 91.245