Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella (MMAF). Distinct projections encircling the central microtubules of the spermatozoal axoneme play pivotal roles in flagellar bending and spermatozoal movement. Mammalian sperm-associated antigen 17 ( SPAG17 ) encodes a conserved axonemal protein of cilia and flagella, forming part of the C1a projection of the central apparatus, with functions related to ciliary/flagellar motility, skeletal growth, and male fertility. This study investigated two novel homozygous SPAG17 mutations (M1: NM_206996.2, c.829+1G>T, p.Asp212_Glu276del; and M2: c.2120del, p.Leu707*) identified in four infertile patients from two consanguineous Pakistani families. These patients displayed the MMAF phenotype confirmed by Papanicolaou staining and scanning electron microscopy assays of spermatozoa. Quantitative real-time polymerase chain reaction (PCR) of patients' spermatozoa also revealed a significant decrease in SPAG17 mRNA expression, and immunofluorescence staining showed the absence of SPAG17 protein signals along the flagella. However, no apparent ciliary-related symptoms or skeletal malformations were observed in the chest X-rays of any of the patients. Transmission electron microscopy of axoneme cross-sections from the patients showed incomplete C1a projection and a higher frequency of missing microtubule doublets 1 and 9 compared with those from fertile controls. Immunofluorescence staining and Western blot analyses of spermatogenesis-associated protein 17 (SPATA17), a component of the C1a projection, and sperm-associated antigen 6 (SPAG6), a marker of the spring layer, revealed disrupted expression of both proteins in the patients' spermatozoa. Altogether, these findings demonstrated that SPAG17 maintains the integrity of spermatozoal flagellar axoneme, expanding the phenotypic spectrum of SPAG17 mutations in humans.
Humans ; Male ; Infertility, Male/pathology* ; Sperm Tail/ultrastructure* ; Homozygote ; Microtubule-Associated Proteins/genetics* ; Axoneme/genetics* ; Spermatozoa/ultrastructure* ; Adult ; Mutation ; Sperm Motility/genetics* ; Pedigree ; Microtubules ; Microtubule Proteins/genetics*

Male infertility is a worldwide health issue, affecting 8%-12% of the global population. Oligoasthenoteratozoospermia (OAT) represents a severe type of male infertility, characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology. Using whole-exome sequencing, this study identified a novel missense mutation (c.848C>A, p.A283E) in the coiled-coil domain-containing 34 gene (CCDC34) in a consanguineous Pakistani family. This rare mutation was predicted to be deleterious and to affect the protein stability. Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms. These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms, thus expanding the phenotypic spectrum of CCDC34 missense mutations.
Humans ; Male ; Mutation, Missense/genetics* ; Pakistan ; Consanguinity ; Asthenozoospermia/genetics* ; Pedigree ; Infertility, Male/genetics* ; Adult ; Oligospermia/genetics* ; Exome Sequencing ; Axoneme/ultrastructure* ; Spermatozoa/ultrastructure*

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

Giardia lamblia is a protozoan that causes diarrheal diseases in humans. Cytoskeletal structures of Giardia trophozoites must be finely reorganized during cell division. To identify Giardia proteins which interact with microtubules (MTs), Giardia lysates were incubated with in vitro-polymerized MTs and then precipitated by ultracentifugation. A hypothetical protein (GL50803_8405) was identified in the precipitated fraction with polymerized MTs and was named GlMBP1 (G. lamblia microtubule-binding protein 1). Interaction of GlMBP1 with MTs was confirmed by MT binding assays using recombinant GlMBP1 (rGlMBP1). In vivo expression of GlMBP1 was shown by a real-time PCR and western blot analysis using anti-rGlMBP1 antibodies. Transgenic G. lamblia trophozoites were constructed by integrating a chimeric gene encoding hemagglutinin (HA)-tagged GlMBP1 into a Giardia chromosome. Immunofluorescence assays of this transgenic G. lamblia, using anti-HA antibodies, revealed that GlMBP1 mainly localized at the basal bodies, axonemes, and median bodies of G. lamblia trophozoites. This result indicates that GlMBP1 is a component of the G. lamblia cytoskeleton.
Antibodies ; Axoneme ; Basal Bodies ; Blotting, Western ; Cell Division ; Cytoskeleton ; Fluorescent Antibody Technique ; Giardia lamblia* ; Giardia* ; Hemagglutinins ; Humans ; Microtubules ; Polymers ; Real-Time Polymerase Chain Reaction ; Trophozoites

Ciliogenesis was investigated in the tracheal epithelium of human fetus at mid trimester of gestation (15~22 weeks), and the substructure of basal body was studied with serial, cross sections. The ciliogenic cells were long columnar cells with an electron -lucent cytoplasm, and contained rich free ribosomes and smooth endoplasmic reticulum. Apical cytoplasm of these cells contained various structures related to ciliogenesis including fibrous granules, procentrioles, centrioles and basal bodies. Basal bodies were located near apical plasma membrane and had basal foot and striated rootlets. In cross section, alar sheets appeared at transitional area between distal portion of basal body and axoneme, and basal foot at distal portion of basal body. Alar sheets arouse from each peripheral triplets of basal body and projected radially clockwise in apex to base view. Basal foot was a cone shaped structure with cross striation which base attached to two or three of the peripheral triplet sets and apex converged to basal foot cap. Three dimentional reconstruction by serial cross section of the basal body showed a structural relationship of alar sheets and basal feet with basal body. By immunohistochemistry, alpha -tubulin label was seen in both basal and surface ciliated cells, and gamma-tubulin label was seen in the apical region of surface cilated cells. These results indicate that ciliogenesis of tracheal epithelium of human fetus is performed mainly by acentriolar ciliogenesis, and suggest the ciliogenesis and ciliary movement at mid trimester of gestation are active.
Axoneme ; Basal Bodies ; Cell Membrane ; Centrioles ; Cytoplasm ; Endoplasmic Reticulum, Smooth ; Epithelium* ; Fetus* ; Foot ; Humans* ; Immunohistochemistry ; Pregnancy ; Ribosomes ; Triplets ; Tubulin

Primary ciliary dyskinesia encompasses a heterogenous group of inherited condition characterized by clinical, functional, and ultrastructural features. The transmission electronmicroscopic findings of nasal cilia in a 14-year old girl with primary ciliary dyskinesia were studied. The ultrastructure of axonemes showed normal outer membrane, dynein arms, microtubules, and nexin links but partial lack of radial spokes. The nature of the defective spoke is not clear and further studies will be necessary to determine how the radial spokes and central sheath interact and coordinate ciliary movement.
Adolescent ; Arm ; Axoneme ; Cilia ; Dyneins ; Female ; Humans ; Kartagener Syndrome* ; Membranes ; Microtubules

Kartagener's syndrome, a congenital disease transmitted as an autosomal recessive illness with a prevalence of approximately 1:20,000 persons, is characterized by the triple association of situs inversus, bronchiectasis, and sinusitis. Affected persons have an incoordination of ciliary motility that leads to defective mucociliary transport, chronic bronchial infections. Kartagener's syndrome is a subset of the immotile cilia syndrome and therefore all patients with Kartagener's syndrome have immotile cilia with obvious ultrastructural defects in the ciliary axoneme. In the respiratory tract this inability presumably causes impaired clearance of mucus and inhaled particles and results in the chronic infections of the sinuses and bronchial trees that are characterized of the disease. The end-stage phenomenon in Kartagener's syndrome, respiratory or heart failure is a less common event and heart-lung transplantation is becoming an accepted therapy for patients with end-stage pulmonary disease in Kartagener's syndrome in many institutes. We report one case of Kartagener's syndrome in a 25-year-old young woman who was presented as respiratory and right heart failures, with review of literatures.
Academies and Institutes ; Adult ; Ataxia ; Axoneme ; Bronchiectasis ; Cilia ; Ciliary Motility Disorders ; Female ; Heart Failure ; Heart* ; Heart-Lung Transplantation ; Humans ; Kartagener Syndrome* ; Lung Diseases ; Mucociliary Clearance ; Mucus ; Prevalence ; Respiratory Insufficiency ; Respiratory System ; Sinusitis ; Situs Inversus ; Trees