2/7
We wanted to evaluate the effects of #ageing on the #germline/ #sperm while excluding the confounding factors of age-related morbidities. Basically, our only inclusion criterion was good health. We assembled a cohort of 197 health men, aged 18-84 years!
3/7
We found no sig changes in sperm parameters such as sperm count, concentration, motility, etc. Moreover, hormonal parameters remained within the normal ranges! Likewise for quality of life and sexual wellbeing.
->General health is associated with good reproductive health!
4/7
However, sperm DNA underwent clear changes with age. We found a strong increase in sperm DNA fragmentation, more pronounced after the 6th decade. Remember, these were healthy men and showed no decline in sperm or hormonal parameters!
->Sperm quantity ≠ sperm quality.
5/7
Also, using whole genome bisulfite sequencing, we identified >200 differentially methylated regions (>30% #DNAmethylation difference) between young and old sperm. Changes appear to be germline-specific; we could not find them in blood DNA from same men.
6/7
Sperm DNA methylation changes were mostly nearby genes encoding for transcription factors. We found an enrichment in neurodevelopmental pathways, which fits well with results from other groups using different techniques.
7/7
Difficult to argue for a direct link between these changes and advanced paternal age effects at large. Further studies will need to focus on this but we argue for counselling of older prospective fathers.
->Remember: reproductive ageing is not just a female problem!
Finally, a shout-out to my co-authors including @FTuttelmann @ClaudiaKrallma1 and others who are not on Twitter. This has been a wild ride, but it was worth it.
You can follow @SandLaurentino.
Tip: mention @twtextapp on a Twitter thread with the keyword “unroll” to get a link to it.

Latest Threads Unrolled: