Induced pluripotent stem cell generation from a man carrying a complex chromosomal rearrangement as a genetic model for infertility studies

Aurélie Mouka,Lucie Tosca,Frank Yates,Gérard Tachdjian,Sophie Brisset,Vincent Izard,Leila Maouche-Chrétien,Anne Mayeur,Loïc Drévillon,Rafika Jarray,Philippe Leboulch

doi:10.1038/srep39760

Abstract

Despite progress in human reproductive biology, the cause of male infertility often remains unknown, due to the lack of appropriate and convenient in vitro models of meiosis. Induced pluripotent stem cells (iPSCs) derived from the cells of infertile patients could provide a gold standard model for generating primordial germ cells and studying their development and the process of spermatogenesis. We report the characterization of a complex chromosomal rearrangement (CCR) in an azoospermic patient, and the successful generation of specific-iPSCs from PBMC-derived erythroblasts. The CCR was characterized by karyotype, fluorescence in situ hybridization and oligonucleotide-based array-comparative genomic hybridization. The CCR included five breakpoints and was caused by the inverted insertion of a chromosome 12 segment into the short arm of one chromosome 7 and a pericentric inversion of the structurally rearranged chromosome 12. Gene mapping of the breakpoints led to the identification of a candidate gene, SYCP3. Erythroblasts from the patient were reprogrammed with Sendai virus vectors to generate iPSCs. We assessed iPSC pluripotency by RT-PCR, immunofluorescence staining and teratoma induction. The generation of specific-iPSCs from patients with a CCR provides a valuable in vitro genetic model for studying the mechanisms by which chromosomal abnormalities alter meiosis and germ cell development.

Highlights

Spermatogenesis is a complex process by which haploid gametes are formed through a specific type of cell division called meiosis
Fluorescence in situ hybridization (FISH) analysis was performed with two probes, one binding to the short arm of chromosome 12 in the 12p13.1 region and the other binding to the long arm of chromosome 12 in the 12q24.11 region: the 12q24.11 probe signal was detected in its normal position on the normal and der(12), whereas the 12p13.1 probe signal was located on the long arm of chromosome 12 (Fig. 1D)
These results indicate that a pericentric inversion of the der(12) had occurred in addition to the insertion event

Summary

Introduction

Spermatogenesis is a complex process by which haploid gametes are formed through a specific type of cell division called meiosis. Chromosomal abnormalities, including aneuploidies, deletions, microdeletions of the AZF region of the Y chromosome, duplications, small supernumerary marker chromosomes, translocations, insertions, and inversions, may be the underlying cause of the failure to complete meiosis[4,5,6,7,8,9,10,11,12,13,14,15,16] Such chromosomal aberrations have been shown to affect meiotic synapsis and chromosome pairing[17], resulting in both infertility and spontaneous abortions. Induced pluripotent stem cells have recently been generated from the fibroblasts of azoospermic men carrying deletions in the AZF region[31] and from patients with Klinefelter syndrome (47, XXY)[32,33]

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Results

Conclusion