Male infertility and the genesis of mature sperm cells

BackgroundMultiple morphological abnormalities of the flagella (MMAF) consistently lead to male infertility due to a reduced or absent sperm motility defined as asthenozoospermia. Despite numerous genes recently described to be recurrently associated with MMAF, more than half of the cases analysed remain unresolved, suggesting that many yet uncharacterised gene defects account for this phenotypeMethodsExome sequencing was performed on 167 infertile men with an MMAF phenotype. Immunostaining and transmission electron microscopy (TEM) in sperm cells from affected individuals were performed to characterise the ultrastructural sperm defects. Gene inactivation using RNA interference (RNAi) was subsequently performed in Trypanosoma.ResultsWe identified six unrelated affected patients carrying a homozygous deleterious variants in MAATS1, a gene encoding CFAP91, a calmodulin-associated and spoke-associated complex (CSC) protein. TEM and immunostaining experiments in sperm cells showed severe central pair complex (CPC) and radial spokes defects. Moreover, we confirmed that the WDR66 protein is a physical and functional partner of CFAP91 into the CSC. Study of Trypanosoma MAATS1’s orthologue (TbCFAP91) highlighted high sequence and structural analogies with the human protein and confirmed the axonemal localisation of the protein. Knockdown of TbCFAP91 using RNAi impaired flagellar movement led to CPC defects in Trypanosoma as observed in humans.ConclusionsWe showed that CFAP91 is essential for normal sperm flagellum structure and function in human and Trypanosoma and that biallelic variants in this gene lead to severe flagellum malformations resulting in astheno-teratozoospermia and primary male infertility.

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Olfactory receptors are displayed on dog mature sperm cells.

The Journal of Cell Biology ◽

10.1083/jcb.123.6.1441 ◽

1993 ◽

Vol 123 (6) ◽

pp. 1441-1452 ◽

Cited By ~ 123

Author(s):

P Vanderhaeghen ◽

S Schurmans ◽

G Vassart ◽

M Parmentier

Keyword(s):

Olfactory Receptor ◽

Germ Line ◽

Receptor Gene ◽

Olfactory Receptors ◽

Olfactory Mucosa ◽

Mature Sperm ◽

Sperm Cells ◽

Olfactory Receptor Gene ◽

Mammalian Sperm ◽

Expression Site

Olfactory receptors constitute a huge family of structurally related G protein-coupled receptors, with up to a thousand members expected. We have shown previously that genes belonging to this family were expressed in the male germ line from both dog and human. The functional significance of this unexpected site of expression was further investigated in the present study. We demonstrate that a few dog genes representative of various subfamilies of olfactory receptors are expressed essentially in testis, with little or no expression in olfactory mucosa. Other randomly selected members of the family show the expected site of expression, restricted to the olfactory system. Antibodies were generated against the deduced amino acid sequence of the most abundantly expressed olfactory receptor gene in dog testis. The purified serum was able to detect the gene product (DTMT receptor) in late round and elongated spermatids, as well as in the cytoplasmic droplet that characterizes the maturation of dog sperm cells, and on the tail midpiece of mature spermatozoa. Western blotting further confirmed the presence of a 40-kD immunoreactive protein in the membrane of mature sperm cells. Altogether , these results demonstrate that the main expression site of a subset of the large olfactory receptor gene family is not olfactory mucosa but testis. This expression correlates with the presence of the corresponding protein during sperm cell maturation, and on mature sperm cells. The pattern of expression is consistent with a role as sensor for unidentified chemicals possibly involved in the control of mammalian sperm maturation, migration, and/or fertilization.

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Subcellular Localization of a Novel Alternative Splicing of IIIG9 and Colocalization with PPP1gamma Isoforms

Microscopy and Microanalysis ◽

10.1017/s143192760808968x ◽

2008 ◽

Vol 14 (S3) ◽

pp. 141-143

Author(s):

C. Sousa ◽

A.P. Vintém ◽

M. Fardilha ◽

O. da Cruz e Silva ◽

E. da Cruz e Silva

Keyword(s):

Alternative Splicing ◽

Male Infertility ◽

Cell Types ◽

Sperm Cells ◽

Regulatory Subunits ◽

Specific Antibodies ◽

Fluorescent Microscope ◽

Bovine Sperm ◽

Spermatogonia Cells ◽

Different Cell Types

In testis we find mainly PPP1gamma2 isoform. We hypothesize that in different cell types we can find different regulatory subunits that may constitute targets for therapeutics of diseases such as male infertility, cancer and Alzheimer's disease. We identified a novel alternative splicing isoform of IIIG9 in testis, a known regulator of PPP1, IIIG9sT, and the aim of this study was its further characterization. We used a specific antibody for IIIG9sT in order to characterize its localization in bovine sperm cells. We also transfected IIIG9sT-GFP construct in mouse spermatogonia cells (GC-1 cells) and we used specific antibodies for each PPP1 isoform for the colocalization studies. We observed them under a fluorescent microscope and a LSM and quantified a high co-localization with PPP1gamma1 and 2 isoforms.

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DNA topoisomerases I and II in human mature sperm cells: characterization and unique properties

Human Reproduction ◽

10.1093/humrep/dem170 ◽

2007 ◽

Vol 22 (8) ◽

pp. 2183-2189 ◽

Cited By ~ 23

Author(s):

I. Har-Vardi ◽

R. Mali ◽

M. Breietman ◽

Y. Sonin ◽

S. Albotiano ◽

...

Keyword(s):

Mature Sperm ◽

Sperm Cells ◽

Dna Topoisomerases

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Genome architecture in human sperm cells: possible implications for male infertility and prediction of pregnancy outcome

Male Infertility ◽

10.3109/9780203090626-13 ◽

2007 ◽

pp. 101-112

Keyword(s):

Male Infertility ◽

Pregnancy Outcome ◽

Human Sperm ◽

Genome Architecture ◽

Sperm Cells

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P–015 Characterization of ultrastructural morphology of human sperms by field-emission scanning electron microscopy using the NanoSuit method

Human Reproduction ◽

10.1093/humrep/deab130.014 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

S So ◽

Y Takaku ◽

I Ohta ◽

F Tawara ◽

T Hariyama

Keyword(s):

Electron Microscopy ◽

Male Infertility ◽

Freeze Drying ◽

Sperm Morphology ◽

Sperm Head ◽

Fixation Method ◽

Sperm Cells ◽

Sem Observation ◽

Optical Micrographs ◽

Scanning Electron

Abstract Study question Can the NanoSuit method to observe sperm cells in wet conditions help treat male infertility using a field emission scanning electron microscope (FE-SEM)? Summary answer Compared with the conventional fixation method, the NanoSuit method can easily prepare FE-SEM samples without causing contraction and denaturation of human sperm cells. What is known already Evaluation of sperm morphology by optical microscopy is important for identifying male infertility. FE-SEM observation is useful for a more detailed evaluation of sperm morphology; however, a lot of the morphological information of the cells is lost by chemical fixation, dehydration, and freeze-drying. The NanoSuit method enables FE-SEM observation of unfixed cells under a high vacuum environment by electron beam polymerization of extracellular substances called NanoSuit. It has been reported that a sample prepared by the NanoSuit method retains the morphological information of live cells better than a sample prepared by the conventional fixation method. Study design, size, duration This laboratory study was conducted with informed consent and IRB approval. Semen parameters were within the WHO normal reference range. Participants/materials, setting, methods The conventional fixation method sample was prepared by fixing (glutaraldehyde and osmium), dehydration (ethanol and t-butyl alcohol), and freeze-drying. The NanoSuit method sample was introduced into the FE-SEM directly without conducting the above treatments. For observation, a JSM–7100F (JEOL, Japan) was used at an acceleration voltage of 1.0 kV. The vacuum level of the observation chamber was 10–3 to 10–6 Pa. Main results and the role of chance Sperm head segmentation (acrosome, equatorial segment, and post acrosome), midpiece, and tail including endpiece could be clearly identified in the FE-SEM sample prepared by the NanoSuit method. Transmission electron microscopy revealed the existence of a thin polymerized extra layer, the NanoSuit, on the surface of the sperm. It is suggested that the presence of the NanoSuit layer enables FE-SEM observation of the unfixed sperm. The conventional fixation method causes a statistically significant contraction in the sperm head size compared to that calculated from optical micrographs (13.5 μm2 vs. 11.6 μm2, p < 0.001). Furthermore, wheat germ agglutinin (WGA), a lectin, which is known to have the ability to bind to the sperm surface, did not bind to the fixed FE-SEM samples. This means that the original cell surface properties are lost in the fixed sperm sample. On the other hand, the FE-SEM sample prepared by the NanoSuit method did not show a statistically significant contraction of the sperm head compared to that calculated from optical micrographs (13.2 μm2 vs 12.9 μm2, p = 0.416); it also revealed a detailed binding pattern of gold-labelled WGA to the sperm surface. These results indicate that the NanoSuit method can prepare FE-SEM samples without sperm contraction and denaturation. Limitations, reasons for caution Characteristic sperm morphology in patients with male infertility should be investigated in future studies. Wider implications of the findings: The NanoSuit method does not use chemical carcinogens and can prepare an FE-SEM sample in a shorter time than the conventional fixation method. The evaluation of ultrastructural morphology of unfixed sperms by this method may be useful for the identification of new morphological features and the evaluation of male infertility. Trial registration number Not applicable

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Mitochondrial Membrane Potential and DNA Stainability in Human Sperm Cells: A Flow Cytometry Analysis with Implications for Male Infertility

Experimental Cell Research ◽

10.1006/excr.1998.4064 ◽

1998 ◽

Vol 241 (2) ◽

pp. 384-393 ◽

Cited By ~ 107

Author(s):

Leonarda Troiano ◽

Antonio R.M. Granata ◽

Andrea Cossarizza ◽

Galina Kalashnikova ◽

Rita Bianchi ◽

...

Keyword(s):

Flow Cytometry ◽

Membrane Potential ◽

Male Infertility ◽

Mitochondrial Membrane Potential ◽

Mitochondrial Membrane ◽

Human Sperm ◽

Sperm Cells ◽

Flow Cytometry Analysis

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Male Infertility and Its Causes in Human

Advances in Urology ◽

10.1155/2012/384520 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 26

Author(s):

Toshinobu Miyamoto ◽

Akira Tsujimura ◽

Yasushi Miyagawa ◽

Eitetsu Koh ◽

Mikio Namiki ◽

...

Keyword(s):

Environmental Factors ◽

Male Infertility ◽

Effective Treatment ◽

Genetic Predisposition ◽

Social Problems ◽

Male Partner ◽

Mature Sperm ◽

Nonobstructive Azoospermia

Infertility is one of the most serious social problems facing advanced nations. In general, approximate half of all cases of infertility are caused by factors related to the male partner. To date, various treatments have been developed for male infertility and are steadily producing results. However, there is no effective treatment for patients with nonobstructive azoospermia, in which there is an absence of mature sperm in the testes. Although evidence suggests that many patients with male infertility have a genetic predisposition to the condition, the cause has not been elucidated in the vast majority of cases. This paper discusses the environmental factors considered likely to be involved in male infertility and the genes that have been clearly shown to be involved in male infertility in humans, including our recent findings.

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Oral Ascorbic Acid And α-Tocopherol Protect On Di-(2-Ethyl Hexyl) Phthalate (DEHP) Induced Effects On Gonadotoxicity In The Adult Male Wistar Rats

European Journal of Medical and Health Sciences ◽

10.24018/ejmed.2020.2.3.322 ◽

2020 ◽

Vol 2 (3) ◽

Author(s):

Sunday Adakole Ogli ◽

Samuel O. Odeh

Keyword(s):

Oxidative Stress ◽

Ascorbic Acid ◽

Male Infertility ◽

Sperm Motility ◽

Wistar Rats ◽

Sperm Morphology ◽

Serum Testosterone ◽

Sperm Cells ◽

Testosterone Concentration ◽

Male Wistar Rats

Environmental pollutants such as di-(2-ethylhexyl) phthalate (DEHP) adversely affect reproductive system tissue differentiation and functions with exposure at intrauterine, neonatal or adult stages of life, thereby potentiating male infertility later in life. World health organization estimates a global infertility prevalent rate of 10-15%, and 20-30% among Nigerians, with male factor constituting about 40-50% of infertility cases. This study was designed to investigate the effect(s) of oral vitamins C and E on DEHP induced changes in some semen parameters and serum testosterone concentration in adult Wistar rats. Seventy (70) adult male Wistar rats weighing between 156-250 g were randomised into 7 experimental groups 1, 2, 3, 4, 5, 6 and 7 (group n=10). Animals in groups 1, 2 and 3 were treated with 0.02 mg, 20 mg, 200 mg oral DEHP/kg bw daily respectively, while those in groups 4, 5 and 6, in addition to the above DEHP treatments, were treated with 100 mg ascorbic acid and 67.5 mg α-tocopherol per kg bw daily respectively. Rats in group 7 served as Control and were treated with vehicle. All treatments lasted for 60 days. After, over night fasting, samples of semen and serum were obtained for analysis. Results obtained were expressed as mean ± standard deviation and analyzed for significant differences in means using one way ANOVA and Post Hoc test. Relative to the control reference values, groups exposed to oral DEHP had significant (p<0.05) reduction in sperm count, total sperm motility, active sperm motility, normal sperm morphology, serum testosterone concentration and serum super oxide dismutase levels to 31.70±18.68x106 cells/mL, 38.60±24.78%, 8.50±5.66%, 38.00±18.00%, 9.56±1.34 ng/mL and 0.017±0.0013 units respectively. Sluggish sperm motility and abnormal sperm morphology significantly (p˂0.01) increased to 39.70±13.05% and 68.50±18.42% respectively. In the groups that had DEHP co-treatments with oral ascorbic acid and α-tocopherol, all studied parameters tended to comparative indifference statistically, with the Controls values. This indicates a protective function against DEHP effects on the studied parameters. The study has shown therefore, that DEHP inflicts oxidative stress in the reproductive system which potentially suppresses serum testosterone concentration with attendant derangements in the qualitative and quantitative sperm cells in adult Wistar rats, and thereby enhancing male infertility. However, the antioxidants ascorbic acid and α-tocopherol protects the gonadal and sperm cells from the harmful effects of DEHP by ameliorating oxidative stress and improving male fertility. This implies that there is need to avoid prolonged exposure to DEHP while encouraging the daily intake of oral ascorbic acid and α-tocopherol.

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