Prof. Dr. med.
Division Chief and Research Group Leader
University Hospital Basel
Phone +41 79 510 99 78
Research Group Christian DeGeyter
Endocrinology, Metabolism & Divelopmental Disorders
Area of Research
Gynecological endocrinology, especially reproductive medicine
Approved Resarch Projects
Research Group Leader "Swiss Center of Applied Human Toxicology" (since 2014)
- Friedrich Miescher Institute (FMI), Basel
- Swiss Center of Applied Human Toxicology (SCAHT)
- EIM (ESHRE)
Ongoing Research Projects
The RME has developed the infrastructure (FACS) and the technology needed to sort human ejaculated spermatozoa according to sperm membrane permeability and the density of the chromatin. Whereas differences in membrane permeability are thought to relate to apoptosis, differences in chromatin density relate to chromatin abnormalities, arising from abnormal spermatogenesis. Whereas RME has access to human spermatozoa (both in the semen and in testicular tissue) for research purposes, the Friedrich Miescher Institute (FMI) has the technology to determine genetic conditions of the sorted spermatozoa with RNA-seq and with ChIP-seq to determine and quantify differences in chromatin and epigenetic markers of sorted spermatozoa.
Chromatin condensation occurs during progressive maturation of spermatozoa during transit in the testis and in the epididymis. Testicular and epididymal spermatozoa may be collected during testicular biopsy (TESE) carried out in the RME. If differences are detected, the distribution and location of epigenetic markers may be determined in a targeted fashion. Knowledge about the regulation of epigenetic regulation of sperm maturation may be used to understand diffferences in chromatin density of ejaculated spermatozoa.
If significant differences in the distribution of epigenetic markers in sorted populations of spermatozoa are found and if the location of the markers in the genome are relevant in the process of testicular and epididymal sperm maturation, sorting of spermatozoa may be used to improve the outcome of assisted reproduction. This can be done by performing prospective randomized clinical trials (as already done in RME with spermatozoa stained with YoPro and sorted with FACS).
Xiaoli Shen, MD PhD