Clinical efficacy of treatments against non-obstructive azoospermia (NOA), which affects 1% of men, are currently limited by the incomplete understanding of NOA pathogenesis and normal spermatogenic microenvironment. Here, we profile >80,000 human testicular single-cell transcriptomes from 10 healthy donors spanning the range from infant to adult and 7 NOA patients. We show that Sertoli cells, which form the scaffold in the testicular microenvironment, are severely damaged in NOA patients and identify the roadmap of Sertoli cell maturation. Notably, Sertoli cells of patients with congenital causes (Klinefelter syndrome and Y chromosome microdeletions) are mature, but exhibit abnormal immune responses, while the cells in idiopathic NOA (iNOA) are physiologically immature. Furthermore, we find that inhibition of Wnt signaling promotes the maturation of Sertoli cells from iNOA patients, allowing these cells to regain their ability to support germ cell survival. We provide a novel perspective on the development of diagnostic methods and therapeutic targets for NOA.

The corpus cavernosum is the most important structure for penile erection, and its dysfunction causes many physiological and psychological problems. However, its cellular heterogeneity and signalling networks at the molecular level are poorly understood because of limited access to samples. Here, we profile 64,993 human cavernosal single-cell transcriptomes from three males with normal erection and five organic erectile dysfunction patients. Cell communication analysis reveals that cavernosal fibroblasts are central to the paracrine signalling network and regulate microenvironmental homeostasis. Combining with immunohistochemical staining, we reveal the cellular heterogeneity and describe a detailed spatial distribution map for each fibroblast, smooth muscle and endothelial subcluster in the corpus cavernosum. Furthermore, comparative analysis and related functional experiments identify candidate regulatory signalling pathways in the pathological process. Our study provides an insight into the human corpus cavernosum microenvironment and a reference for potential erectile dysfunction therapies.

In the 1960s, sperm cryopreservation was developed as a method to preserve fertility. Currently, techniques for the cryopreservation of human spermatozoa have been widely used in assisted reproduction. However, although sperm cryobiology has made notable achievements, the optimal method for the recovery of viable spermatozoa after cryopreservation remains elusive. Postthawing sperm quality can be affected by cryoprotectants, ice formation, storage conditions, and osmotic stress during the freezing process. This review discusses recent advances in different cryopreservation techniques, cryoprotectants, and freezing and thawing methods during cryopreservation and new indications for the use of cryopreserved spermatozoa.

Numerous genes have been associated with multiple morphological abnormalities of the sperm flagella (MMAF), which cause severe asthenozoospermia and lead to male infertility, while the causes of approximately 50% of MMAF cases remain unclear. To reveal the genetic causes of MMAF in an infertile patient, whole-exome sequencing was performed to screen for pathogenic genes, and electron microscope was used to reveal the sperm flagellar ultrastructure. A novel heterozygous missense mutation in the outer dense fiber protein 2 (ODF2) gene was detected, which was inherited from the patient's mother and predicted to be potentially damaging. Transmission electron microscopy revealed that the outer dense fibers were defective in the patient's sperm tail, which was similar to that of the reported heterozygous Odf2 mutation mouse. Immunostaining of ODF2 showed severe ODF2 expression defects in the patient's sperm. Therefore, it was concluded that the heterozygous mutation in ODF2 caused MMAF in this case. To evaluate the possibility of assisted reproductive technology (ART) treatment for this patient, intracytoplasmic sperm injection (ICSI) was performed, with the help of a hypo-osmotic swelling test and laser-assisted immotile sperm selection (LAISS) for available sperm screening, and artificial oocyte activation with ionomycin was applied to improve the fertilization rate. Four ICSI cycles were performed, and live birth was achieved in the LAISS-applied cycle, suggesting that LAISS would be valuable in ART treatment for MMAF.

Background: The genetic causes of human idiopathic non-obstructive azoospermia (NOA) with meiotic arrest remain unclear. Methods: Two Chinese families with infertility participated in the study. In family 1, two brothers were affected by idiopathic NOA. In family 2, the proband was diagnosed with idiopathic NOA, and his elder sister suffered from infertility. Whole-exome sequencing (WES) was conducted in the two patients in family 1, the proband in family 2 and 362 additional sporadic patients with idiopathic NOA. Sanger sequencing was used to verify the WES results. Periodic acid–Schiff (PAS), immunohistochemistry (IHC) and meiotic chromosomal spread analyses were carried out to evaluate the stage of spermatogenesis arrested in the affected cases. Results: We identified compound heterozygous loss of function (LoF) variants of SHOC1 (c.C1582T:p.R528X and c.231_232del:p.L78Sfs*9, respectively) in both affected cases with NOA from family 1. In family 2, homozygous LoF variant in SHOC1 (c.1194delA:p.L400Cfs*7) was identified in the siblings with infertility. PAS, IHC and meiotic chromosomal spread analyses demonstrated that the spermatogenesis was arrested at zygotene stage in the three patients with NOA. Consistent with the autosomal recessive mode of inheritance, all of these SHOC1 variants were inherited from heterozygous parental carriers. Intriguingly, WES of 362 sporadic NOA cases revealed one additional NOA case with a bi-allelic SHOC1 LoF variant (c.1464delT:p.D489Tfs*13). Conclusion: To the best of our knowledge, this is the first report identifying SHOC1 as the causative gene for human NOA. Furthermore, our study showed an autosomal recessive mode of inheritance in the NOA caused by SHOC1 deficiency.