Excited to share our new preprint in which we address:.(1) Accurate sequencing of sperm at scale.(2) Positive selection of spermatogenesis driver mutations across the exome.(3) Offspring disease risks from male reproductive aging.[1/15].

RT @giladevrony: Happy to see our new paper out! A great collaboration with @jeshoag. We collected sequential sperm samples separated by de….

RT @seplyarskiy: Excited to share our preprint: Cohort-level analysis of human de novo mutations points to drivers of clonal expansion in s….

RT @R_Rahbari: II'm excited to finally share our study on the mutational landscape and selection dynamics in sperm, now live on medRxiv: ht….

RT @imartincorena: Excited to share our latest work. We introduce an improved version of NanoSeq, a duplex sequencing protocol with <5 erro….

Huge thanks to @TwinsUKres volunteers & researchers, @R_Rahbari who led this work, @mehurles who co-supervised this project, @imartincorena and team for their insights and support with NanoSeq, @RasheshSanghvi, @MimyPham, @ATJCagan, and many others. Feedback welcome! [15/15].

These findings show the power of sperm sequencing for understanding positive selection and offspring disease risk. They also raise many new questions that we’re excited to follow up on… [14/15].

What about the genes which aren’t currently associated with disease? We find that 4 of them have excess loss-of-function variants in healthy populations, suggesting that they are over transmitted to offspring but are at least partially tolerated [13/15]

This suggests that positive selection in spermatogenesis is driving a much broader disease risk in ageing fathers than previously appreciated. We caution however that not all disease mutations in sperm will necessarily appear in live births at the same rate [12/15].

Assessing the % of sperm per individual that have a likely disease mutation in their exome, we find a striking ~3-fold enrichment over expectation. Currently, we can attribute ~55% of this enrichment to known driver mutations under positive selection [11/15]

The novel genes are mostly known cancer and developmental disorder genes, but unlike previously known genes, most are enriched for loss-of-function (LOF) mutations rather than missense hotspots and they are linked to diverse pathways [10/15]

We detected >35k coding mutations in sperm, equivalent to yields from sequencing >20k trios (!). Using dN/dS tests, we replicate 9 of 13 previously known genes and identify 31 novel genes under positive selection in sperm [9/15]

Can we investigate this at scale in sperm? An updated NanoSeq protocol unlocks our ability to deeply sequence coding regions in sperm. See the method and incredible insights into somatic evolution from @imartincorena and team here [8/15].

To date 13 genes have been linked to this effect. Critically, all 13 are causal for severe developmental disorders, leading to increases (up to 1,000-fold) in the sporadic birth prevalence of these disorders, with a strong correlation to elevated age of the father [7/15].

Next, we investigated positive selection of driver mutations during spermatogenesis. This effect was uncovered and has been extensively characterised by the Wilkie and @GorielyLab groups. A summary figure of theirs here [6/15]

Applying NanoSeq to 81 sperm samples from men of the @TwinsUKres cohort aged 24-75 we find mutation accumulation in sperm consistent with testis sequencing (Moore et al, 2021) and gold-standard rates from trio sequencing (Sasani et al, 2019) [5/15]

Error-corrected duplex sequencing approaches such as NanoSeq have overcome challenges of polyclonality by achieving single-molecule accuracy and error rates compatible with the low mutation rate of sperm [4/15].

Trio sequencing studies have revealed much about the rates of mutation accumulation in germ cells. However, like other polyclonal tissues, assessing mutations directly in germ cells like sperm has been challenging… [3/15]

Mutations accumulate in all cells over time, but those that occur in reproductive cell lineages like sperm and eggs are transmitted to offspring as germline de novo mutations [2/15]

RT @R_Rahbari: My old account has disappeared, and I'm not sure why. I’m hoping to recover it somehow or link it to my new one! Thank you t….