Role and function of telomere in reproduction

Telomeres as noncoding hetrochromatic and protective structures contain hexa-nucleutid repeats with rich in guanine at the end of each chromosomes. These structures are conserved during evolution, and their function depends on their length. In somatic cells, telomeres length decreases by each cell division. Shortening of telomere length lead to cell cycle arrest, chromosomes anomalies and cell death. While, telomere length does not short in germ cells and cancer cell due to high activity of telomerase enzyme. Other factors that influenced the telomere length are: 1) parental age at child's birth, 2) gender, 3) family history of cancer, 4) syndromes, 5) smoking, 6) X-radiation, 7) psychological stress, 8) alcohol consumption and 9) improper eating habits. Therefore, we aimed in this review, to discuss the role of telomere length in male germ cells.

For this review, all relevant information were collected via databases including PubMed and Google Scholar during the period 1965-2016.

Normal size of the sperm telomere can be considered as an indicator of semen quality, ability to fertilize and result in formation of good quality embryo and pregnancy.

Examination of telomeric structure especially telomere length could provide a new insight for our understanding of the etiology of human infertility.