OBJECTIVETo observe the ultrastructural changes of sperm flagella in patients with severe idiopathic asthenospermia.

METHODSUsing the transmission electron microscope, we examined the ultrastructure of sperm flagella from 22 patients with severe idiopathic asthenospermia.

RESULTSUltrastructural anomalies were found in all the 22 patients, 6 with partial or complete absence of internal and external dynamic arms in dedicative of primary ciliary dyskinesia, 1 with hyperplasia, hypertrophy and disordered organization of the fibrous sheath usually referred to as dysplasia of the fibrous sheath, and the other 15 with non-specific flagellar anomalies.

CONCLUSIONExamination of the ultrastructure of sperm flagella in severe idiopathic asthenospermia patients can help to distinguish congenital from acquired flagellar structural anomalies and give valuable guidance in the treatment.

Adult ; Asthenozoospermia ; pathology ; Humans ; Male ; Sperm Tail ; ultrastructure

SUMMARY: To investigate the influences on semen parameters and fertilizing capacity of immuno- globulin(Ig) isotypes and regional distribution of antisperm antibody (ASA) on the human sperm surface. Sixty-seven ASA-positive patients were compared with 96 ASA-negative donors. ASAs in semen showed significant negative effects on both semen parameters and fertilizing capacity; in those with ASAs in the sperm head and/or tail, the reductions were significant. In the head as well as the tail, there was close correlation between fertilizing capacity and both IgG and IgA. Both semen parameters and fertilizing capacity are significantly affected by the presence of ASA in semen. In particular, antibodies IgG to sperm head and/or tail, and antibodies IgA to sperm tail appeared to have a highly detrimental effect on fertilizing capacity.
Antibodies* ; Head ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Semen* ; Sperm Head ; Sperm Tail ; Spermatozoa ; Tissue Donors

To determine the role of outer dense fiber (ODF) in multiple morphological abnormalities of the sperm flagella in Akap4 gene defect mice.
 Methods: Akap4 knock-out (KO) mouse model was established by using gene editing technology. Akap4-KO male mice were identified by genotype. Seven sexually mature male Akap4-KO mice served as an experimental group, and 7 sexually mature wild-type (WT) male mice served as a control group. The changes in body weight and testicular weight were measured. Computer aided sperm analysis (CASA) was used to detect sperm motility. Sperm morphology was detected by modified Periodic Acid-Schif (PAS) staining. The ultra-structure of sperm was observed under the scanning and transmission electron microscope. Sperm flagella associated protein expression and localization were detected by immunofluorescence. Spermatogenesis function of testis was evaluated by HE and PAS staining. Ultra-structure of seminiferous tubules was observed under the transmission electron microscope.
 Results: Akap4-KO mice had no natural fertility. The sperm motility of Akap4-KO male mice was lower than that of WT male mice (8.81% vs 46.02%, P<0.01). In Akap4-KO male mice the percentage of sperm, with shortened tail and coiled tail was 91.18% which was higher than that of WT male mice (P<0.01). There was no statistically significance in the testicular weight, spermatogensis function, and sperm count between the 2 groups (P>0.01). The longitudinal column of fibrous sheath in Akap4-KO male mice was absent, and the residues of transverse rib remained, which was consistent with the immunofluorescence localization of AKAP3 protein. No. 3 and No. 8 ODF in the principal piece were disordered, which was in consistent with ectopic localization of ODF2 protein.
 Conclusion: Multiple morphological abnormalities of the sperm flagella in mice are resulted from disorder of "9+2" microtubules and the abnormally expanded lumen at the proximal of the principal piece via causing dysplasia of the transverse rib due to Akap4 gene defect, and separation of the ODF of No. 3 and No. 8 via loss of longitudinal column.
A Kinase Anchor Proteins ; Animals ; Fluorescent Antibody Technique ; Infertility, Male ; Male ; Mice ; Sperm Motility ; Sperm Tail ; Spermatozoa

OBJECTIVETo investigate the feasibility and clinical application value of selecting viable spermatozoa by noncontact diode laser.

METHODSWe obtained immotile spermatozoa from 2 infertile men with obstructive azoospermia or severe asthenospermia and selected viable spermatozoa using a single laser shot at the sperm tail. Those that responded to the laser shot by a curling reaction of the tail were regarded as presumably viable and used for intracytoplasmic sperm injection (ICSI).

RESULTSThe mean fertilization rate was 88.89% after ICSI with the laser-selected viable spermatozoa. Both of the embryo transfers resulted in a single pregnancy.

CONCLUSIONNoncontact diode laser is a useful alternative for the assessment of sperm viability, which may help to achieve successful pregnancy.

Embryo Transfer ; Female ; Fertilization ; Humans ; Infertility, Male ; therapy ; Male ; Pregnancy ; Pregnancy Outcome ; Sperm Injections, Intracytoplasmic ; Sperm Motility ; Sperm Tail ; physiology

The ultrastructural abnormalities of human sperm flagella can cause sperm movement disorders. Dysplasia of the fibrous sheath (DFS) is an autosomal recessive genetic disease. The affected sperm in 95-100% of the patients display short, thick and irregular tails. Transmission electron microscopy can be used to confirm the diagnosis, which reveals gross abnormal flagella, with hypertrophy and hyperplasia of the fibrous sheath, without orderly disposition in longitudinal columns and transversal ribs. The axoneme shows variable distortion or almost complete obliteration. Microtubular doublets may exhibit partial or total lack of dynein arms. The genetic etiology of DFS is not yet clear. DFS does not affect the rates of fertilization and clinical pregnancy in ICSI, but due attention should be paid to the genetic risks in the offspring of the patient.
Humans ; Hyperplasia ; complications ; pathology ; Hypertrophy ; complications ; pathology ; Infertility, Male ; Male ; Microscopy, Electron ; Sperm Motility ; physiology ; Sperm Tail ; pathology ; ultrastructure ; Spermatozoa

OBJECTIVE: To explore the clinical feature and gene variant for two cases of primary male infertility caused by severe asthenospermia and to analyze the etiology of the disease. METHODS: Genomic DNA of peripheral blood samples of patients and their parents was extracted and gene variant analysis of the patients was conducted by using whole exome sequencing. Suspected pathogenic variant was verified by Sanger sequencing and pathogenic analysis. RESULTS: Whole exome sequencing showed that the DNAH1 gene of patient 1 had two heterozygous variants of c.2016T>G(p.Y672X) and c.6017T>G (p.V2006G). The DNAH1 gene of patient 2 had a homozygous variant of c.2610G>A(p.W870X), which were inherited from his father and mother, respectively. According to American College of Medical Genetics and Genomics standards and guidelines, the c.2016T>G (p.Y672X) and c.2610G>A (p.W870X) varaints of DNAH1 gene were predicted to be pathogenic (PVS1+PM2+PM3+PP3). CONCLUSION The two patients of multiple morphological abnormalities of the sperm flagella may be caused by DNAH1 gene variant, which has resulted in primary male infertility.
Dyneins/genetics* ; Genomics ; Humans ; Infertility, Male/genetics* ; Male ; Mutation ; Sperm Tail/pathology* ; Whole Exome Sequencing

Asthenoteratozoospermia is one of the most severe types of qualitative sperm defects. Most cases are due to mutations in genes encoding the components of sperm flagella, which have an ultrastructure similar to that of motile cilia. Coiled-coil domain containing 103 (CCDC103) is an outer dynein arm assembly factor, and pathogenic variants of CCDC103 cause primary ciliary dyskinesia (PCD). However, whether CCDC103 pathogenic variants cause severe asthenoteratozoospermia has yet to be determined. Whole-exome sequencing (WES) was performed for two individuals with nonsyndromic asthenoteratozoospermia in a consanguineous family. A homozygous CCDC103 variant segregating recessively with an infertility phenotype was identified (ENST00000035776.2, c.461A>C, p.His154Pro). CCDC103 p.His154Pro was previously reported as a high prevalence mutation causing PCD, though the reproductive phenotype of these PCD individuals is unknown. Transmission electron microscopy (TEM) of affected individuals' spermatozoa showed that the mid-piece was severely damaged with disorganized dynein arms, similar to the abnormal ultrastructure of respiratory ciliary of PCD individuals with the same mutation. Thus, our findings expand the phenotype spectrum of CCDC103 p.His154Pro as a novel pathogenic gene for nonsyndromic asthenospermia.
Asthenozoospermia/pathology* ; Dyneins/genetics* ; Homozygote ; Humans ; Male ; Microtubule-Associated Proteins ; Mutation ; Mutation, Missense ; Sperm Tail/metabolism*

In human reproduction, fertilization is the first step for successful pregnancy. From the perspective of sperm physiology, the progressive motility and capacitation, including hyperactivation and acrosome reaction, are the most important factors in the fertilization of oocytes. Numerous studies have demonstrated the roles of calcium ions, cyclic nucleotides, and bicarbonate in the acquisition of progressive motility and capacitation. Among these factors, calcium ion plays the most important role. Sperm possess several calcium channels, including voltage-gated calcium channel, cyclic nucleotide-gated calcium channel, transient receptor potential channel, and channels of the CatSper family The CatSper family is a newly-identified group of four sperm-specific cation channels. CatSper1 and CatSper2 proteins localize on the sperm tail and play a critical role in sperm motility and fertilization. In contrast, CatSper3 and CatSper4 proteinsare expressed only in the acrosomal region of sperm head, which implies that they may have a role in the acrosome reaction. Taken together, the CatSper family is the most important group of calcium channels for regulating sperm physiology and appear to be an attractive target for non-hormonal male contraceptives.
Acrosome Reaction ; Calcium ; Calcium Channels ; Contraceptive Agents, Male ; Fertilization ; Humans ; Ions ; Nucleotides, Cyclic ; Oocytes ; Physiology ; Pregnancy ; Reproduction ; Sperm Head ; Sperm Motility ; Sperm Tail ; Spermatozoa

The CatSper channel is known as one of the most important Ca²⁺ channels on the cell membrane of mammalian sperm and plays a key role in the motility, hyperactivation and fertilization function of sperm. The CatSper protein, expressed exclusively in the principal piece of the sperm tail, is composed of CatSper1-4 and 5 auxiliary unitsβ,γ,δ and ε, and has an essential part in the functional and structural domains of Ca²⁺as well as in the spatiotemporal regulation of the P-Tyr protein, sperm hyperactivation, efficient sperm migration in the oviduct, egg penetration, and normal fertility. Recent studies show that functional deficiency of CatSper seriously affects sperm function,and the loss of any one of its 9 subunits may lead to male reproductive dysfunction. This paper outlines recent advances in the studies of the CatSperprotein, focusing on its expression, location, structure, and regulation,as well as itsinfluence on sperm hyperactivation and male reproduction.
Animals ; Calcium Channels ; chemistry ; physiology ; Humans ; Infertility, Male ; etiology ; Male ; Sperm Motility ; physiology ; Sperm Tail ; metabolism ; Sperm-Ovum Interactions ; physiology ; Spermatozoa ; physiology

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.
Abnormalities, Multiple ; Animals ; Flagella ; Heat-Shock Proteins ; Humans ; Infertility, Male ; Male ; Mice ; Mutation ; Semen ; Sperm Tail ; Spermatozoa