Berteli TS, Wang F, Navarro PA, Kohlrausch FB, Keefe DL. A pilot study of LINE-1 copy number and telomere length with aging in human sperm.
J Assist Reprod Genet 2023;
40:1845-1854. [PMID:
37382785 PMCID:
PMC10371944 DOI:
10.1007/s10815-023-02857-1]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/03/2023] [Indexed: 06/30/2023] Open
Abstract
PURPOSE
Unlike other cells in the body, in sperm, telomere length (TL) increases with age. TL can regulate nearby genes, and the subtelomeric region is rich in retrotransposons. We hypothesized that age-related telomere lengthening in sperm might suppress Long Interspersed Element 1 (LINE-1/L1), the only competent retrotransposon in humans.
METHODS
We measured L1 copy number (L1-CN) and sperm telomere length (STL) from young and older men to evaluate the relationship between age, TL and L1-CN. We also evaluated L1-CN and TL in individual sperm to determine whether these variables influence sperm morphology. STL was assayed by Multiplex quantitative polymerase chain reaction method (mmqPCR) and L1-CN by Quantitative polymerase chain reaction (qPCR).
RESULTS
We found that STL increased, and L1-CN decreased significantly with paternal age. STL in normal single sperm was significantly higher than in abnormal sperm. L1-CN did not differ between normal and abnormal sperm. Furthermore, morphologically normal sperm have longer telomeres than abnormal sperm.
CONCLUSIONS
Elongation of telomeres in the male germline could repress retrotransposition, which tends to increase with cellular aging. More studies in larger cohorts across a wide age span are needed to confirm our conclusions and explore their biological and clinical significance.
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