We have already touched one of the greatest problems of nowadays society in our ONCOCHECK blog: infertility. Taking into account the current increase in population aging this problem is related not only to the healthcare system, but to economic and social issues as well.
The 30% of infertility cases are due to the male factor, 86% of that cases relate to oligospermia condition (low account of sperm cells in the ejaculate). The molecular origin of oligospermia is still unknown, meaning a high percentage of idiopathic infertility cases, condition which englobes all infertility cases whose cause has not been explained already. (Balmon and Varela, 2018).
Telomeres and male fertility
There are plenty of molecular mechanisms that participates in the regular function of germ cells, and those mechanisms are related indeed with telomere stability.
Telomeres are essential to the male fertility factor, since they are the first region of the genome of the sperm cells to respond to the egg’s signal for the formation of the pronucleus during fecundation. Besides, they play an extremely important role in meiosis, where the correlation in telomere length between homologous chromosomes is essential for synapsis, homologous recombination and segregation. (Thilagavathi, 2013).
A short telomere length in chromosomes of sperm cells is associated with a lower fertilization rate and with problems in embryo’s development, so their shortening implies an increase of infertility. Moreover, a greater percentage of aneuploidies and DNA fragmentation have been found in sperm cells with shorter telomeres.
All this information is related with a decrease in the capacity of fecundation by the sperm cells (Santa Rocca et al., 2018). This is of high interest for the development of artificial reproduction technologies (ART), where the selection of the sperm cells with higher telomere length would result in the maximization of the success of these techniques. (Balmon and Varela, 2018).
Infertility and oxidative stress (OS)
There is a disease called Male Oxidative Stress Infertility (MOSI) that affects to 37 million of men with idiopathic infertility. Oxidative stress (OS) results in a disequilibrium in the formation of reactive oxygen species (ROS) and the capacity of antioxidants to neutralize their production within the cells (Agarwal et al., 2017).
OS has a deleterious effect over the quality parameters of sperm, such as concentration and sperm cells motility. Besides, OS produces DNA fragmentation and telomeres attrition, contributing to increase the chromosome’s instability. (Agarwal et al., 2019)
For these reasons telomeres are excellent biomarkers, telomere length increases knowledge about the causes of idiopathic infertility, and so it is a new tool that allows to evaluate sperm quality and improve results in assisted reproduction (Zhao et al., 2016).
Our high precision technologies measure telomere’s length in the chromosomic DNA of sperm cells. Our TAT test, based on the HT Q-FISH technology, carries the measurements out directly from a sperm sample or isolated sperm cells, obtaining the telomere length of each cell individually. Other techniques that allow us to measure telomere length in out laboratory are TRF and Q-PCR.