Multiple morphological abnormalities of the sperm flagella (MMAF) is a severe form of asthenozoospermia categorized by immotile spermatozoa with abnormal flagella in ejaculate. Whole-exome sequencing (WES) is used to detect pathogenic variants in patients with MMAF. In this study, a novel homozygous frameshift variant (c.6158_6159insT) in dynein axonemal heavy chain 8 (DNAH8) from two infertile brothers with MMAF in a consanguineous Pakistani family was identified by WES. Reverse transcription-polymerase chain reaction (RT-PCR) confirmed DNAH8 mRNA decay in these patients with the DNAH8 mutation. Hematoxylin-eosin staining and transmission electron microscopy revealed highly divergent morphology and ultrastructure of sperm flagella in these patients. Furthermore, an immunofluorescence assay showed the absence of DNAH8 and a reduction in its associated protein DNAH17 in the patients' spermatozoa. Collectively, our study expands the phenotypic spectrum of patients with DNAH8-related MMAF worldwide.
Humans ; Male ; Consanguinity ; Pakistan ; Infertility, Male/metabolism* ; Semen/metabolism* ; Sperm Tail/metabolism* ; Spermatozoa/metabolism* ; Flagella/pathology* ; Mutation

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

Cilium, an organelle with a unique proteome and organization, protruding from the cell surface, generally serves as a force generator and signaling compartment. During ciliogenesis, ciliary proteins are synthesized in cytoplasm and transported into cilia by intraflagellar transport (IFT) particles, where the inner counterparts undergo reverse trafficking. The homeostasis of IFT plays a key role in cilial structure assembly and signaling transduction. Much progress has been made on the mechanisms and functions of IFT; however, recent studies have revealed the involvement of IFT particle subunits in organogenesis and spermatogenesis. In this review, we discuss new concepts concerning the molecular functions of IFT protein IFT25 and how its interactions with other IFT particle subunits are involved in mammalian development and fertility.
Animals ; Biological Transport ; Carrier Proteins/metabolism* ; Cilia/metabolism* ; Flagella/metabolism* ; Male ; Mammals/metabolism* ; Organogenesis ; Proteins/metabolism* ; Signal Transduction

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*

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

Multiple morphological abnormalities of the sperm flagella (MMAF) is a specific type of asthenoteratozoospermia, presenting with multiple morphological anomalies in spermatozoa, such as absent, bent, coiled, short, or irregular caliber flagella. Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins (CFAPs; e.g., CFAP43, CFAP44, CFAP65, CFAP69, CFAP70, and CFAP251) responsible for the MMAF phenotype in infertile men from different ethnic groups. However, none of them have been identified in infertile Pakistani males with MMAF. In the current study, two Pakistani families with MMAF patients were recruited. Whole-exome sequencing (WES) of patients and their parents was performed. WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families (Family 1: ENST00000357060.3, p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state; Family 2: ENST00000357060.3, p.Thr526Serfs*43 in a homozygous state). Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype. Semiquantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was carried out to detect the effect of the mutation on mRNA of the affected gene. Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients. To the best of our knowledge, this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype. This study will help researchers and clinicians to understand the genetic etiology of MMAF better.
Adolescent ; Adult ; Humans ; Infertility, Male/epidemiology* ; Loss of Function Mutation/genetics* ; Male ; Microtubule Proteins/genetics* ; Middle Aged ; Pakistan/epidemiology* ; Sperm Tail/physiology*

sperm motility process, microtubules ascertain functional capacity of sperm. Also, microtubule based structures such as axoneme and manchette are crucial for sperm head and tail formation. This review (a) presents a concise, yet detailed structural overview of the microtubules, (b) analyses the role of microtubule structures in various male reproductive functions, and (c) presents the association of microtubular dysfunctions with male infertility. Considering the immense importance of microtubule structures in the formation and maintenance of physiological functions of sperm cells, this review serves as a scientific trigger in stimulating further male infertility research in this direction.]]>
Actin Cytoskeleton ; Axoneme ; Cytoskeleton ; Humans ; Infertility, Male ; Kartagener Syndrome ; Male ; Male ; Microtubule-Associated Proteins ; Microtubules ; Organelles ; Sperm Head ; Sperm Motility ; Spermatogenesis ; Spermatozoa ; Tail

Cilia and flagella on eukaryotic cells are polarized organelles extending from the surfaces of cells, which participate not only in cell motility, but also in signal transduction and other processes. Structural or functional abnormalities of cilia can cause various human diseases, termed ciliopathies. Bardet-Biedl syndrome (BBS) is a ciliopathic human genetic disorder, and the pathogenesis is that mutated BBS genes result in abnormal cilia function. In order to study the pathogenic genes BBS8, we screened bbs8 mutant in Chlamydomonas reinhardtii and did a lot of physiology and biochemistry experiments. We affirmed that BBS8 protein was a cilia protein and had specific localization in the basal body by immunofluorescence (IF). The bbs8 mutant lost photokinesis, and it was defective in flagella shortening with drug induction. The results of silver staining and mass spectrometric analysis showed aberrant accumulation of flagellar proteins in the mutant flagella. We concluded that the BBS8 protein plays a significant role in flagellar membrane proteins transport, and the BBS8 protein might mediate retrograde transport to exert physiological function in the process.
Bardet-Biedl Syndrome ; Chlamydomonas reinhardtii ; Cilia ; Flagella ; Humans ; Protein Transport

OBJECTIVE: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. METHODS: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. RESULTS: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. CONCLUSION: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.
Acrosome ; Chromatin ; Cryopreservation ; DNA Fragmentation ; DNA ; Freezing ; Humans ; Infertility, Male ; Male ; Membranes ; Reproductive Techniques, Assisted ; Semen ; Semen Analysis ; Sperm Head ; Sperm Motility ; Spermatozoa ; Tail

OBJECTIVE: The aim of this study was to investigate DNA fragmentation status in human spermatozoa according to specific tail swelling patterns determined via hypo-osmotic swelling test (HOST).METHODS: Frozen semen samples from 21 healthy donors were thawed and prepared by the swim-up technique for use in intracytoplasmic sperm injection. The semen samples were treated for 5 minutes as part of the HOST procedure and then underwent the sperm chromatin dispersion test using a Halosperm kit. DNA fragmentation status (large halo, medium halo, small halo, no halo, or degraded) and the specific tail swelling pattern (“a”–“g”) were assessed at the level of a single spermatozoon. A total of 42,000 spermatozoa were analyzed, and the percentage of spermatozoa without DNA fragmentation (as evidenced by a large or medium halo) was assessed according to the specific tail swelling patterns observed.RESULTS: The HOST examinations showed that >93% of spermatozoa across all types displayed no DNA fragmentation. The percentage of spermatozoa without DNA fragmentation was 100% in type “d”, 98.67% in type “g”, and 98.17% in type “f” spermatozoa.CONCLUSION: We found that the type “d” spermatozoa displayed no DNA fragmentation, but the other types of spermatozoa also displayed very low rates of DNA fragmentation. This result may be associated with the processing of the spermatozoa by density gradient centrifugation and the swim-up technique.
Centrifugation, Density Gradient ; Chromatin ; DNA Fragmentation ; DNA ; Humans ; Infertility ; Semen ; Semen Preservation ; Sperm Head ; Sperm Injections, Intracytoplasmic ; Spermatozoa ; Tail ; Tissue Donors