The Anatomy, Movement and Functions of Human Sperm Tail: An Evolving Mystery

Author(s):  
Naina Kumar ◽  
Amit Kant Singh

Abstract Sperms have attracted the attention of many researchers since it was discovered by Antonie van Leeuwenhoek in 1677. Though a small cell, its every part has complex structure and a different function to play in carrying life further. Sperm tail is the most complicated structure with more than 1000 proteins involved in its functioning. With advent of advanced three-dimensional microscopes, many studies are still undergoing to understand the exact mechanism of sperm tail movement. Most recent studies have shown that sperms move by spinning rather than swimming. Furthermore, each small subunit of tail including axonemal and peri-axonemal structures play essential roles in sperm motility, capacitation, hyperactivation, fertilization. Methodology: Relevant literature (from 1982 till 2020) on sperm tail anatomy, movement and functions were searched from various English language full length and review articles using PUBMED, SCOPUS or Google database. Conclusion: There is still a lot needed to be discovered about human sperm tail movement and its role in male fertility. Sperm tail has a complex anatomy with surrounding axoneme having 9+2 microtubules (9 outer doublet and one central doublet) arrangement along its entire length and additional peri-axonemal structures that all contribute in sperm motility and fertilization. In future various sperm tail proteins and its subunits can be used as markers of male fertility.

2020 ◽  
Vol 21 (20) ◽  
pp. 7796
Author(s):  
Deborah Allouche-Fitoussi ◽  
Haim Breitbart

Several studies proposed the importance of zinc ion in male fertility. Here, we describe the properties, roles and cellular mechanisms of action of Zn2+ in spermatozoa, focusing on its involvement in sperm motility, capacitation and acrosomal exocytosis, three functions that are crucial for successful fertilization. The impact of zinc supplementation on assisted fertilization techniques is also described. The impact of zinc on sperm motility has been investigated in many vertebrate and invertebrate species. It has been reported that Zn2+ in human seminal plasma decreases sperm motility and that Zn2+ removal enhances motility. Reduction in the intracellular concentration of Zn2+ during epididymal transit allows the development of progressive motility and the subsequent hyper activated motility during sperm capacitation. Extracellular Zn2+ affects intracellular signaling pathways through its interaction with the Zn2+ sensing receptor (ZnR), also named GPR39. This receptor was found in the sperm tail and the acrosome, suggesting the possible involvement of Zn2+ in sperm motility and acrosomal exocytosis. Our studies showed that Zn2+ stimulates bovine sperm acrosomal exocytosis, as well as human sperm hyper-activated motility, were both mediated by GPR39. Zn2+ binds and activates GPR39, which activates the trans-membrane-adenylyl-cyclase (tmAC) to catalyze cAMP production. The NHE (Na+/H+-exchanger) is activated by cAMP, leading in increased pHi and activation of the sperm-specific Ca2+ channel CatSper, resulting in an increase in [Ca2+]i, which, together with HCO3−, activates the soluble adenylyl-cyclase (sAC). The increase in [cAMP]i activates protein kinase A (PKA), followed by activation of the Src-epidermal growth factor receptor-Pphospholipase C (Src-EGFR-PLC) cascade, resulting in inositol-triphosphate (IP3) production, which mobilizes Ca2+ from the acrosome, causing a further increase in [Ca2+]i and the development of hyper-activated motility. PKA also activates phospholipase D1 (PLD1), leading to F-actin formation during capacitation. Prior to the acrosomal exocytosis, PLC induces phosphadidylinositol-4,5-bisphosphate (PIP2) hydrolysis, leading to the release of the actin-severing protein gelsolin to the cytosol, which is activated by Ca2+, resulting in F-actin breakdown and the occurrence of acrosomal exocytosis.


2020 ◽  
Vol 35 (3) ◽  
pp. 494-503
Author(s):  
Yi-min Cheng ◽  
Zhen Peng ◽  
Hou-yang Chen ◽  
Ting-ting Pan ◽  
Xiao-nian Hu ◽  
...  

Abstract STUDY QUESTION Does lysine 2-hydroxyisobutyrylation, a newly identified protein posttranslational modification (PTM), occur in human sperm and affect human sperm function? SUMMARY ANSWER Lysine 2-hydroxyisobutyrylation mainly occurs in human sperm tail proteins, and excessive lysine 2-hydroxyisobutyrylation affects human sperm motility. WHAT IS KNOWN ALREADY PTM is regarded as an important pathway in regulating sperm function since mature sperm are almost transcriptionally silent. However, only phosphorylation was extensively studied in mature sperm to date. Lysine 2-hydroxyisobutyrylation, a newly characterised PTM, is broadly conserved in both eukaryotic and prokaryotic cells. Although histone lysine 2-hydroxyisobutyrylation has been shown to be associated with active gene expression in spermatogenic cells, the presence, regulatory elements and function of lysine 2-hydroxyisobutyrylation have not been characterised in mature sperm. STUDY DESIGN, SIZE, DURATION Sperm samples were obtained from normozoospermic men and asthenozoospermic men who visited the reproductive medical centre at Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi, China, between May 2017 and November 2018. In total, 58 normozoospermic men and 65 asthenozoospermic men were recruited to participate in this study. PARTICIPANTS/MATERIALS, SETTING, METHODS Lysine 2-hydroxyisobutyrylation was examined using immunoblotting and immunofluorescence assays using a previously qualified pan anti-lysine 2-hydroxyisobutyrylation antibody. The immunofluorescence assay was imaged using super-resolution structured illumination microscopy. Sperm viability was examined by using the eosin staining method, and sperm motility parameters were assessed by computer-assisted sperm analysis. Sperm penetration ability was determined by evaluating the ability of the sperm to penetrate a 1% (w/v) methylcellulose solution. The level of intracellular adenosine triphosphate (ATP) was detected using a rapid bioluminescent ATP assay kit. MAIN RESULTS AND THE ROLE OF CHANCE Lysine 2-hydroxyisobutyrylation was present in several proteins (20–100 kDa) mainly located in the tail of human sperm. Sperm lysine 2-hydroxyisobutyrylation was derived from 2-hydroxyisobutyrate (2-Hib) and was regulated by acyltransferase P300 and nicotinamide adenine dinucleotide-dependent lysine deacylase sirtuins. Elevation of sperm lysine 2-hydroxyisobutyrylation by 2-Hib decreased total motility, progressive motility, penetration ability and ATP level of human sperm. Interestingly, the level of sperm lysine 2-hydroxyisobutyrylation was higher in asthenozoospermic men than that in normozoospermic men and was negatively correlated with the progressive motility of human sperm. Furthermore, high levels of lysine 2-hydroxyisobutyrylation in asthenozoospermic men accompanied decreased ATP levels. LIMITATIONS, REASONS FOR CAUTION Although the present study indicated the involvement of sperm lysine 2-hydroxyisobutyrylation in regulating human sperm motility, the underlying mechanism needs to be further illustrated. WIDER IMPLICATIONS OF THE FINDINGS The findings of this study provide insight into the novel role of lysine 2-hydroxyisobutyrylation in human sperm and suggest that abnormality of sperm lysine 2-hydroxyisobutyrylation may be one of the causes for asthenozoospermia. STUDY FUNDING/COMPETING INTEREST(S) National Natural Science Foundation of China (81771644 to T.L. and 81871207 to H.C.); Natural Science Foundation of Jiangxi province (20171ACB21006). The authors have no conflicts of interest to declare.


Reproduction ◽  
2018 ◽  
Vol 155 (4) ◽  
pp. 383-392 ◽  
Author(s):  
Yali Xu ◽  
Yong Fan ◽  
Weimin Fan ◽  
Jia Jing ◽  
Ke Xue ◽  
...  

Asthenozoospermia is one of the leading causes of male infertility owing to a decline in sperm motility. Herein, we determined if there is a correlation between RNASET2 content on human spermatozoa and sperm motility in 205 semen samples from both asthenozoospermia patients and normozoospermia individuals. RNASET2 content was higher in sperm from asthenozoospermia patients than in normozoospermia individuals. On the other hand, its content was inversely correlated with sperm motility as well as progressive motility. Moreover, the inhibitory effect of RNASET2 on sperm motility was induced by incubating normozoospermic sperm with RNase T2 protein. Such treatment caused significant declines in intracellular spermatozoa PKA activity, PI3K activity and calcium level, which resulted in severely impaired sperm motility, and the sperm motility was largely rescued by cAMP supplementation. Finally, protein immunoprecipitation and mass spectrometry identified proteins whose interactions with RNASET2 were associated with declines in human spermatozoa motility. AKAP4, a protein regulating PKA activity, coimmunoprecipated with RNASET2 and they colocalized with one another in the sperm tail, which might contribute to reduced sperm motility. Thus, RNASET2 may be a novel biomarker of asthenozoospermia. Increases in RNASET2 can interact with AKAP4 in human sperm tail and subsequently reduce sperm motility by suppressing PKA/PI3K/calcium signaling pathways.


2020 ◽  
Author(s):  
Yuanjin Zhou ◽  
Avery O’Hara ◽  
Emily Ishado ◽  
Soo Borson ◽  
Tatiana Sadak

Abstract Background and Objectives Caring for a person living with dementia requires resilience, the capacity to recover and grow from challenging situations. Despite the increasing interest in assessing and promoting resilience for dementia care partners, behaviors that indicate this attribute are not well known. The goal of this study is to synthesize the literature to identify resilience-related behaviors and develop a new framework for future validation and intervention research. Research Design and Methods We searched English-language peer-reviewed articles (January 1991 – June 2019) reporting qualitative or quantitative descriptions of resilience-related behaviors among dementia care partners. Thematic analysis was used to categorize behaviors into domains, identify the relationships among them, and generate a thematic map. Results Sixteen articles were identified according to predefined inclusion criteria. Four domains emerged: (1) problem-response behaviors (problem-solving, problem-distancing); (2) self-growth behaviors (self-care activities, spiritual-related activities, and developing and maintaining meaningful social relationships); (3) help-related behaviors (help-seeking and help-receiving), and (4) learning-related behaviors (learning from others and reflection). Definitions of each domain, identification of corresponding behaviors, and formulation of Care Partner Resilience (CP-R) behavioral framework were informed by this mixed research synthesis and other relevant literature. Discussion and Implications The CP-R framework emerged as a result of a new focus on identifying and cultivating strengths instead of evaluating strain and burden. It serves as a useful foundation for understanding the impact of specific behaviors on dementia care partner resilience. Once validated, this framework will inform the development of future measures, research, interventions, and policies for dementia care partners.


2012 ◽  
Vol 97 (1) ◽  
pp. 39-45.e2 ◽  
Author(s):  
Conrado Avendaño ◽  
Ariela Mata ◽  
César A. Sanchez Sarmiento ◽  
Gustavo F. Doncel

2008 ◽  
Vol 179 (4S) ◽  
pp. 620-620
Author(s):  
Shingo Hatakeyama ◽  
Noritaka Kamimura ◽  
Takuya Koie ◽  
Kazuyuki Mori ◽  
Yasuhiro Hashimoto ◽  
...  

1983 ◽  
Vol 36 (4) ◽  
pp. 333 ◽  
Author(s):  
A RJones

Non-steroidal chemicals that affect male fertility have been known for over 25 years but only one compound, oc-chlorohydrin, possesses most of the attributes of an ideal male contraceptive. In the male rat, for example, continuous daily oral administration of low doses produces an almost immediate and continuous antifertility response that ceases when treatment is withdrawn. Such a dose regime does not interfere with libido, is apparently not toxic and the action is specific towards mature sperm. Furthermore, the action of the compound is species-specific: it is effective in the rat, ram, boar, guinea pig, hamster,rhesus monkey and upon ejaculated human sperm but it is ineffective in the mouse and the rabbit. High doses of oc-chlorohydrin can be neurotoxic, nephrotoxic and, in rats, lead to prolonged or permanent infertility. However, the antifertility response and the toxicity of racemic oc-chlorohydrin may be due, respectively, to the separate enantiomers. No other antifertility chemical has been investigated to such an extent as oc-chlorohydrin; this article reviews the progress that has been achieved with oc-chlorohydrin during the past six years.


1997 ◽  
Vol 25 (03n04) ◽  
pp. 301-306 ◽  
Author(s):  
Hellen Jeng ◽  
Chao Mei Wu ◽  
Shuen-Jiing Su ◽  
Wen-Chang Chang

The effects of a Chinese herb, Cornus officinalis, on the motility of human sperm was studied. An aqueous extract was prepared from the dried fruits of the herb and used in this study. The crude extract at a final concentration of 0.5 μg/μl in phosphate buffered saline (pH 7.4) increased sperm motility from 25.8 ± 7.7% to 42.8 ± 10.3% (i.e. 68% increase, n = 7), as determined by the computer-aided-sperm-analysis (CASA) method. The crude extract was fractionated by high-performance liquid chromatography (HPLC) into four fractions: Cl , C2, C3 and C4. Their effects on sperm motility were further studied by CASA. Only the C4 fraction showed substantial stimulatory effects on sperm motility. At a concentration of 5 ng/μl, C4 increased the sperm motility from 15.7 ± 3.8% to 34.5 ± 6.4% (i.e. 120% increase, n = 6) by CASA and from 14.9 ± 4.3 to 28.5 ± 8.1 (i.e. 91% increase, n = 8) by transmembrane migration ratio (TMMR) method. This result suggests that C4 is the active component in Cornus officinalis that enhances sperm motility.


1990 ◽  
Vol 24 (2) ◽  
pp. 121-124 ◽  
Author(s):  
J. W. Graczykowski ◽  
M. Vermesh ◽  
M. S. Siegel ◽  
A. Davidson ◽  
R. A. Lobo

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