S
Saskia K.M. van Daalen
Researcher at University of Amsterdam
Publications - 26
Citations - 2400
Saskia K.M. van Daalen is an academic researcher from University of Amsterdam. The author has contributed to research in topics: Y chromosome & Transplantation. The author has an hindex of 17, co-authored 25 publications receiving 2202 citations. Previous affiliations of Saskia K.M. van Daalen include Academic Medical Center.
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Journal ArticleDOI
Polymorphism for a 1.6-Mb deletion of the human Y chromosome persists through balance between recurrent mutation and haploid selection.
Sjoerd Repping,Helen Skaletsky,Laura G. Brown,Saskia K.M. van Daalen,Cindy M. Korver,Tatyana Pyntikova,Tomoko Kuroda-Kawaguchi,Tomoko Kuroda-Kawaguchi,Jan W.A de Vries,Robert D. Oates,Sherman J. Silber,Fulco van der Veen,David C. Page,Steve Rozen +13 more
TL;DR: It is suggested that the existence of this deletion as a polymorphism reflects a balance between haploid selection, which culls gr/gr-deleted Y chromosomes from the population, and homologous recombination, which continues to generate newgr/gr deletions.
Journal ArticleDOI
Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content
Jennifer F. Hughes,Helen Skaletsky,Tatyana Pyntikova,Tina Graves,Saskia K.M. van Daalen,Patrick Minx,Robert S. Fulton,Sean McGrath,Devin P. Locke,Cynthia Friedman,Barbara J. Trask,Elaine R. Mardis,Wesley C. Warren,Sjoerd Repping,Steve Rozen,Richard K. Wilson,David C. Page +16 more
TL;DR: It is suggested that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within theMSY, and species differences in mating behaviour.
Journal ArticleDOI
Propagation of human spermatogonial stem cells in vitro.
Hooman Sadri-Ardekani,S.C. Mizrak,Saskia K.M. van Daalen,Cindy M. Korver,Hermien L. Roepers-Gajadien,Morteza Koruji,Suzanne Hovingh,Theo M. de Reijke,Jean J.M.C.H. de la Rosette,Fulco van der Veen,Dirk G. de Rooij,Sjoerd Repping,Ans M.M. van Pelt +12 more
Abstract: Context Young boys treated with high-dose chemotherapy are often confronted with infertility once they reach adulthood. Cryopreserving testicular tissue before chemotherapy and autotransplantation of spermatogonial stem cells at a later stage could theoretically allow for restoration of fertility. Objective To establish in vitro propagation of human spermatogonial stem cells from small testicular biopsies to obtain an adequate number of cells for successful transplantation. Design, Setting, and Participants Study performed from April 2007 to July 2009 using testis material donated by 6 adult men who underwent orchidectomy as part of prostate cancer treatment. Testicular cells were isolated and cultured in supplemented StemPro medium; germline stem cell clusters that arose were subcultured on human placental laminin–coated dishes in the same medium. Presence of spermatogonia was determined by reverse transcriptase polymerase chain reaction and immunofluorescence for spermatogonial markers. To test for the presence of functional spermatogonial stem cells in culture, xenotransplantation to testes of immunodeficient mice was performed, and migrated human spermatogonial stem cells after transplantation were detected by COT-1 fluorescence in situ hybridization. The number of colonized spermatogonial stem cells transplanted at early and later points during culture were counted to determine propagation. Main Outcome Measures Propagation of spermatogonial stem cells over time. Results Testicular cells could be cultured and propagated up to 15 weeks. Germline stem cell clusters arose in the testicular cell cultures from all 6 men and could be subcultured and propagated up to 28 weeks. Expression of spermatogonial markers on both the RNA and protein level was maintained throughout the entire culture period. In 4 of 6 men, xenotransplantation to mice demonstrated the presence of functional spermatogonial stem cells, even after prolonged in vitro culture. Spermatogonial stem cell numbers increased 53-fold within 19 days in the testicular cell culture and increased 18 450-fold within 64 days in the germline stem cell subculture. Conclusion Long-term culture and propagation of human spermatogonial stem cells in vitro is achievable.
Journal ArticleDOI
High mutation rates have driven extensive structural polymorphism among human Y chromosomes.
Sjoerd Repping,Sjoerd Repping,Sjoerd Repping,Saskia K.M. van Daalen,Laura G. Brown,Laura G. Brown,Cindy M. Korver,Julian Lange,Julian Lange,Janet D. Marszalek,Janet D. Marszalek,Tatyana Pyntikova,Tatyana Pyntikova,Fulco van der Veen,Helen Skaletsky,Helen Skaletsky,David C. Page,David C. Page,Steve Rozen,Steve Rozen +19 more
TL;DR: High mutation rates have driven extensive structural polymorphism among human Y chromosomes and limited variation in the copy number of Y-linked genes is found, which raises the possibility of selective constraints.
Journal ArticleDOI
A family of human Y chromosomes has dispersed throughout northern Eurasia despite a 1.8-Mb deletion in the azoospermia factor c region
Sjoerd Repping,Sjoerd Repping,Saskia K.M. van Daalen,Cindy M. Korver,Laura G. Brown,Janet D. Marszalek,Judith Gianotten,Robert D. Oates,Sherman J. Silber,Fulco van der Veen,David C. Page,Steve Rozen +11 more
TL;DR: The present findings suggest either that the b2/b3 deletion has at most a modest effect on fitness or that, within branch N, its effect has been counterbalanced by another genetic, possibly Y-linked, factor.