Seminar Honours Programme
Whole genome sequencing of spermatocytic tumours, a rare testicular tumour at the crossroads between somatic and germline mutational processes.
Speaker: Anne Goriely
Department: Molecular Medicine
Subject: Whole genome sequencing of spermatocytic tumours, a rare testicular tumour at the crossroads between somatic and germline mutational processes.
Location: Erasmus MC
The speaker started of the seminar by explaining the fact that there are not just two types of mutations. Beside germline mutations in an embryo and somatic mutations in an adult, there are also somatic mutations during development (postzygotic mutations) and mutations in the germline of an adult. Dr.Goriely by explaining a little bit about spermatocytic tumors. The classical type is type II, but the one that was discussed in the seminar was type III, a slow-growing large tumour in the testes.
The next part of the seminar was about the maternal and the paternal age effect. As men and women age, the chances that their offspring is affected by some kind of disease becomes larger. For women this is well known, however there are also quite a lot of diseases linked to having an older father. In the testes of men, spermatogenesis have to be maintained. In order to do this many cells have to be divided. As the father ages, mutations become more common, leading to defects in the offspring. However, not all mutations show enrichment in sperm as the father ages.
The final part of the seminar was about selfish mutations in the testes. Selfish selection is an oncogenic process, which can lead to the formation of tumours. In regions with strong mutations, there is impaired spermatogenesis. The research group of Dr.Goriely also sequenced the DNA of spermatocytic tumours and they found out that these tumours have quite strange patterns and a low mutation rate (compared to other tumours). The take home message was that spermatocytic tumours provide a unique insight into regulative properties of the male germline.
The image shows a child with apert syndrome, which is a disease associated with the parental age effect.
I found it very interesting to hear that the parental age effect is such a major effect in biology. I was aware of the maternal age effect, but I never knew that the age of the father could have such a big impact. I also did not know that selfish mutations affect spermatogenesis. I think that this discovery will definitely have major effects in the future because this research has contributed to a better understanding of the male germline. Hopefully, many syndromes will be treatable in the future because of this. I also believe that this gives major insight into tumour formation. If selfish mutations impair spermatogenesis, they might have similar effects elsewhere in the body. I found the seminar very educational and nice to attend.