Acrosome Research Articles

Intracellular Mg2+ concentrations are differentially regulated in the sperm head and mid-piece in acrosome reaction inducing conditions.

The sperm ability to fertilize involves the regulation of ATP levels. Because inside cells, ATP is complexed with Mg2+ ions, changes in ATP levels result in changes in intracellular Mg2+ concentration ([Mg2+]i), which can be followed using intracellular Mg2+ sensors such as Mag-520. In this work, we tested conditions known to decrease sperm ATP such as starvation and capacitation. As expected, in these conditions [Mg2+]i increased in all cell compartments. In contrast, when ATP increases, such as adding nutrients to starved sperm, [Mg2+]i significantly decreases in all compartments. On the other hand, when the acrosome reaction was induced, either with progesterone or with ionomycin, [Mg2+]i was differentially regulated in the head and mid-piece. While Mag-520 fluorescence increased in the sperm mid-piece, it decreased in the head. These changes were observed in capacitated as well as in starved sperm but not in sperm incubated in conditions that do not support capacitation. Changes in [Mg2+]i were still observed when the sperm were incubated in high extracellular Mg2+ suggesting that this decrease is not due to Mg2+ efflux. Interestingly, the progesterone and ionomycin effects on [Mg2+]i were abolished on sperm incubated in Ca2+-free media. Altogether, these results indicate that [Mg2+]i is regulated in sperm during capacitation and acrosomal reaction, and suggest that these measurements can serve to evaluate ATP levels in real time.

Protective effects of Sphaeranthus indicus floral extract against BPS-induced testicular damage in rats occurs through downregulation of RIPK1/3-MLK-driven necroptosis and Fas-FasL-mediated apoptosis

AbstractBisphenol S (BPS) is one of the monomers preferred in the manufacturing of polycarbonate plastics. Unfortunately, its estrogenic and genotoxic effects are similar to those of bisphenol A. The protective effects of Sphaeranthus indicus floral extract (SFE) against reprotoxic effects of BPS (50 µg/kg per body weight) in rats exposed to it via drinking water was investigated. Different SFE doses (25, 50, and 100 mg/kg) were administered via oral gavage for 10 weeks. High-performance liquid chromatography (HPLC) results indicated that SFE was rich in polyphenols, with rutin and quercetin being important bioactive molecules modulating BPS-induced necroptosis and apoptosis. Biochemical analyses unveiled that rats administered BPS only exhibited considerable elevation of biomarkers of nitro-oxidative stress, necroptotic (RIPK1/RIPK3 and MLKL), and apoptotic mediators (Fas/FasL and caspase 3/caspase-8). These events caused changes in sperm characteristics (sperm motility, sperm head, and sperm viability), sperm count, and hormonal profile (thyroid stimulating hormone, luteinizing hormone, and follicle-stimulating hormone) of the rats. Histological analysis suggested that there was pronounced sloughing of Sertoli cells, reduced spermatogenic cell density, increased levels of seminiferous tubules, and disorganized morphometric parameters related to seminiferous tubules. The SFE supplementation in rats with BPS-containing water restored nitro-oxidative stress biomarkers, which led to the reduction of necroptosis and apoptosis. Reinstatement of all the biomarkers of oxidative stress, inflammation, necroptosis, and apoptosis after SFE supplementations restored the hormonal profile and normal histoarchitecture of the testes. Virtual screening elucidated that the key regulators of the necroptosis are RIPK3-rutin and RIPK1-quercetin complexes. Further studies are needed to assess its pharmacodynamics, kinetics, and effective concentration for daily use in humans.

Effect of Probiotics on Sperm Quality in the Adult Mouse.

The administration of probiotics for the treatment of different diseases has gained interest in recent years. However, few studies have evaluated their effects on reproductive traits. The objective of this study was to examine the effect of two mixtures of probiotics, a commercial probiotic (Vivomixx®) and a mix of Lacticaseibacillus rhamnosus GG and Faecalibacterium duncaniae A2-165, on sperm quality in a mouse model. Adult male mice (8months old) were used for two experimental and one control groups (n = 5 each). The probiotics or physiological serum (control) was administered orally, twice a week, during 5weeks. Sperm were collected from the cauda epididymis, and their total number, motility, kinematics, morphology, and acrosome integrity were assessed in recently collected samples and after a 60-min in vitro incubation. Results showed a higher percentage of normal sperm in both experimental groups, with fewer head abnormalities than in the control. Differences were found among groups in the morphometry of sperm heads, being more elongated in mice treated with probiotics. Sperm from probiotic-treated mice showed similar total motility when compared to the controls, although the proportion of progressively moving sperm and their vigor of motility were lower. Sperm swimming descriptors were measured with a CASA system. Velocity parameters were similar among groups whereas linearity was higher in mice treated with the commercial probiotic. These results suggest that the administration of probiotics may increase the proportion of sperm with normal morphology and lead to modifications in sperm head shape that may enhance sperm swimming. Studies using a longer administration period would be useful in further characterizing the effect of these probiotic mixtures on sperm quality and fertilization capacity.

Effect of Oxidative Stress on Sperm TERRA Expression and Chromatin Function in Infertile Males: A Preliminary Finding

Telomeres are vital for cellular function. Oxidative stress is detrimental to telomere function as it causes telomere attrition. Increase in oxidative stress has a negative impact on sperm telomere and chromatin integrity and therefore, on sperm function and male fertility. TERRA, a long non-coding RNA is a fundamental component required for telomere length homeostasis. Aim: The present work aimed to study the effect of H2O2 induced oxidative stress on sperm TERRA expression and chromatin function. Methodology: 5 infertile and 5 fertile males were selected for the study. Baseline semen analysis was done as per WHO manual 2021. Sperm TERRA expression was assessed by real time qPCR. To assess chromatin function nuclear chromatin decondensation test was done. Results: Study showed that 500µM H2O2 increased TERRA expression as compared to untreated groups and the difference was found to be statistically significant. As compared to controls, cases showed more fold increase in TERRA expression. When treated samples of control and cases were compared, cases had more TERRA expression than controls however, the baseline TERRA expressions in untreated samples were less in cases as compared to controls. Both comparisons yielded statistically nonsignificant results. When nuclear chromatin decondensation was compared before and after H2O2 treatment, the percentage of sperm head decondensation decreased in both cases and controls. When treated and untreated samples of cases and controls were compared, the difference was statistically nonsignificant. Conclusion: Oxidative stress led to an increase in the expression of sperm TERRA and had a negative impact on nuclear chromatin decondensation. Similar studies with greater sample size can provide much more insight into TERRA mediated regulation of telomere function and chromatin integrity and how it is affected by oxidative stress.

Male reproductive system of the deep-sea acorn worm Quatuoralisia malakhovi (Hemichordata, Enteropneusta, Torquaratoridae) from the Bering Sea

BackgroundThe deep-sea acorn worm Quatuoralisia malakhovi belongs to the phylum Hemichordata, class Enteropneusta, family Torquaratoridae, which was described in 2005. Owing to their epibenthic lifestyle and deep-sea habitat features, torquaratorids differ anatomically from shallow-water acorn worms; however, their morphology and fine structure are poorly studied. We have the opportunity to make three complete detailed series of histological sections of Q. malakhovi and to study the microscopic anatomy, histology and fine structure of the reproductive system of this acorn worm using scanning and transmission electron microscopy.ResultsThe sexes of Q. malakhovi are separate and indistinguishable externally. The lobed testes occupy the dorsal side of the genital wings and distinctly bulge into the peribranchial cavity by their mature lobes. The central part of the testis is always submerged into the genital wing and opens via a single gonad pore. The monociliary muscle cells stretch along the external wall of the testis and surround the gonad pore, probably taking part in the contraction of the testis lobes for spawning. The germinative epithelium of the testis contains spermatogenic cells at different stages of development and interstitial cells. Yolk cells are not found. Interstitial cells embrace the spermatogonia and spermatogenic columns, providing horizontal compartmentalization of the germinative epithelium, and contain numerous phagosomes with remnants of degenerating spermatogenic cells. The testis wall contains haemal lacunae, which are usually located on the side opposite the gonad pore. We describe the fine structure of spermatogonia, spermatocytes clustered in spermatogenic columns, spermatids, and spermatozoa. Spermatozoa are of the ectaquasperm type and consist of an acorn-shaped head and a flagellum 18–25 µm long. The sperm head includes a beak-shaped acrosomal part, a spherical nucleus and a midpiece containing a ring of 5 or rarely 6 mitochondria.ConclusionsThe male reproductive system and sperm structure of Q. malakhovi, a representative of the family Torquaratoridae, have a number of differences from shallow-water acorn worms; however, the spermatogenesis and sperm structure of Q. malakhovi generally follow the pattern of the other three enteropneust families, and the phylogenetic significance of these deviations should be the subject of further research.

PWWP3A deficiency accelerates testicular senescence in aged mice.

The PWWP domain-containing proteins are involved in chromatin-associated biological processes, including transcriptional regulation and DNA repair, and most of them are significant for gametogenesis and early embryonic development in mammals. PWWP3A, one of the PWWP domain proteins, is a reader of H3K36me2/H3K36me3 and a response factor to DNA damage. However, the physiological role of PWWP3A in spermatogenesis and fertility remains unclear. The goal of this study was to explore the function and mechanism of PWWP3A in the process of spermatogenesis. We generated V5-Pwwp3a KI mice and PWWP3A polyclonal antibody to observe the localization of PWWP3A in vivo. Meanwhile, Pwwp3a KO mice was used to explore the function in spermatogenesis. We reported that PWWP3A is a predominant expression in the testis of mice. During spermatogenesis, PWWP3A exhibits the temporal expression from early-pachytene to the round spermatids. The results of spermatocyte spreading and immunostaining showed that PWWP3A aggregated on the XY body, which then diffused as the XY chromosome separated at late-diplotene. Although the depletion of PWWP3A had no obvious reproductive defects in young male mice, there were observed morphological abnormalities in sperm heads. Immunoprecipitation demonstrated the interaction of PWWP3A with DNA repair proteins SMC5/6; however, PWWP3A deficiency did not result in any meiotic defects. Notably, the testes of aged male Pwwp3a KO mice displayed pronounced degeneration, and were characterized by the presence of vacuolated seminiferous tubules. Furthermore, RNA-seq analysis revealed an upregulation in the expression of genes which may be involving in immunoregulatory and inflammatory response pathways in aged Pwwp3a KO mice with testicular degeneration. Our study showed that PWWP3A was highly enriched in the mouse testis, and the Pwwp3a KO mice were fertile. However, the aged Pwwp3a KO male mice displayed testicular atrophy that may be due to changes in the immune micro-environment or abnormal repair of DNA damage.

Soma-to-germline BMP signal is essential for Drosophila spermiogenesis

In the Drosophila testis, developing germ cells are encapsulated by somatic support cells throughout development. Soma-germline interactions are essential for successful spermiogenesis. However, it is still not fully understood what signaling events take place between the soma and the germline. In this study, we found that a Bone Morphogenetic Protein (BMP) ligand, Glass bottom boat (Gbb), secreted from somatic cyst cells (CCs), signals to differentiating germ cells to maintain proper spermiogenesis. Knockdown of Gbb in CCs or the type I BMP receptor Saxophone (Sax) in germ cells leads to a defect in sperm head bundling and decreased fertility. Our Transmission Electron Microscopy (TEM) analyses revealed that the mutant germ cells have aberrant morphology of mitochondria throughout the stages of spermiogenesis and exhibit a defect in nebenkern formation. Elongating spermatids show uncoupled nuclei and elongating mitochondrial derivatives, suggesting that improper mitochondrial development may cause sperm bundling defects. Taken together, we propose a new role of soma-derived BMP signaling, which is essential for spermiogenesis.

Rat copper transport protein 2 (CTR2) is involved in fertilization through interaction with IZUMO1 and JUNO

In mammalian reproduction, testis-specific protein IZUMO1 and its receptor JUNO on the oocyte surface are essential for sperm-oocyte recognition, binding, and membrane fusion. However, these factors alone are insufficient to accomplish cytoplasmic membrane fusion. It is believed that other gametic proteins interact with them to facilitate sperm-oocyte interaction on the head and mid-tail of rat spermatozoa as well as on the surface of oocytes. In this study, Copper Transport Protein 2 (CTR2) has been identified on the head and mid-tail of rat spermatozoa as well as on the surface of oocytes. CTR2 directly interacts with both IZUMO1 and JUNO, colocalizing with IZUMO1 on the sperm head and with JUNO on the oocyte membrane. Treatment of the capacitated sperm and zona pellucida-free oocytes with anti-CTR2 antibody resulted in a significant decrease in fertilization rates in IVF experiments. These findings suggest that CTR2 plays an important role in mammalian fertilization by interacting with IZUMO1 and JUNO, providing new insights into the molecular mechanisms of mammalian sperm-oocyte adhesion and fusion.

Expression of TLR7/8 in canine sperm and evaluation of the effect of ligand R848 on the sorting of canine X/Y sperm

The aim of this study was to analyze the expression pattern of Toll receptor 7/8 (TLR7/8) in canine sperm, and explore the feasibility of using TLR7/8 ligand resiquimod(R848)to separate canine X and Y sperm. In this study, cellular immunofluorescence was used to analyze the expression of TLR7/8 in canine sperm, real-time fluorescence quantitative PCR was used to calculate the proportion of X sperm in the lower layer of the incubation solution with R848 to evaluate the sorting effect of R848 on canine X/Y sperm, and sperm quality detection system was used to analyze the effect of R848 on the motility of canine sperm. The mechanism of effect of R848 on canine sperm motility was analyzed by Western blot. The results showed that TLR8 was not expressed in all canine sperm, while TLR7 was expressed in all canine sperm and was localized in the head and tail of sperm. When 0.4 μM R848 was incubated with canine sperm for 1 h, the total motility, average path velocity (VAP), average straight-line velocity (VSL), and average curved-line velocity (VCL) of canine sperm were significantly decreased(P<0.05). There was no significant difference between the lower and upper layers of the R848 treatment group and the control group(P>0.05), and the proportion of X sperm was nearly half. The levels of NF-κB and GSK3α/β phosphorylation of sperm in R848 treatment group were significantly increased compared with control group(P<0.05). The above results showed that TLR7/8 was not differentially expressed in canine X and Y sperm. R848 could decrease the motility of canine spermatozoa and inhibit sperm motility by the GSK3α/ β-hexokinase pathway through the phosphorylation of NFκB and GSK3α/β, while could not separate X and Y spermatozoa. The method of sorting X/Y sperm based on TLR7/8 is not feasible for dogs.

The size of the sperm head influences the gynogenetic success in teleost fish

Gynogenesis is a phenomenon in which only the maternal genome contributes to offspring development. Artificial gynogenesis induced using genetically inactivated sperm is a useful technique for sex control and rapid production of inbred lines in aquaculture and breeding. For gynogenesis induction, eggs require fertilization stimulus from the sperm; however, the effects of sperm characteristics on gynogenetic success remain unexplored. In this study, we investigated the induction of gynogenesis in medaka embryos by sperm from distant species and the correlation of sperm head size relative to the micropyle with success in gynogenesis. Results revealed that sperm heads of Nile tilapia and rainbow trout had smaller areas than those of the medaka micropyle, and thus, the sperm successfully activated medaka eggs for development. Furthermore, gynogenetic haploid embryos could be induced using genetically inactivated sperm from these species, which were viable after diploidization using heat shock treatment. In contrast, goldfish and zebrafish sperm, with larger head areas than that of medaka micropyle, could not activate medaka eggs for development, suggesting that sperm entry into medaka micropyle was inhibited. Therefore, we propose that the relative physical features of sperm and eggs influence the success of gynogenesis. The findings provide new insights into the application of gynogenesis in aquacultural fish. We developed an automatic method for measuring sperm head size, which can facilitate the recording of physical characteristics of sperm and predicting gynogenesis success.

Unraveling the role of sperm retained histones in bull fertility and daughter fertility

During spermatogenesis, a substantial proportion of histones are substituted by protamine to condense the genome within the sperm head. Studies indicate that a minority of histones, typically ranging from 1 to 15 %, persist in mammalian sperm post-substitution. The persistence of histones in the zygote facilitates chromatin accessibility to transcription factors in regions crucial for early embryonic development. Nevertheless, the potential causal relationship between retained histones and fertility phenotypes remains uncertain. This study seeks to investigate this relationship. The results indicate that in mature bovine sperm, regions of DNA associated with fertility that bind to histones are primarily concentrated in promoters and transcription start sites, potentially impacting bull fertility and offspring fertility through the regulation of relevant genes. Furthermore, microRNAs and estradiol/ESR are suggested to be the main regulators of the canonical pathways identified, highlighting the need for additional research to investigate their potential utility as biomarkers.

Exploring sperm cell rheotaxis in microfluidic channel: the role of flow and viscosity

Rheotaxis is a fundamental mechanism of sperm cells that guides them in navigating towards the oocyte. The present study investigates the phenomenon of sperm rheotaxis in Newtonian and non-Newtonian fluid media, which for the first time explores a viscosity range equivalent to that of the oviductal fluid of the female reproductive tract in rectilinear microfluidic channels. Three parameters, the progressive velocity while performing rheotaxis, the radius of rotation during rheotaxis, and the percentage of rheotactic sperm cells in the bulk and near-wall regions of the microfluidic channel were measured. Numerical simulations of the flow were conducted to estimate the shear rate, flow velocity, and the drag force acting on the sperm head at specific locations where the sperms undergo rheotaxis. Increasing the flow velocity resulted in a change in the position of rheotactic sperm from the bulk center to the near wall region, an increase and subsequent decrease in the sperm's upstream progressive velocity, and a decrease in the radius of rotation. We observed that with an increase in viscosity, rheotactic sperms migrate to the near wall regions at lower flow rates, the upstream progressive velocity of the sperm decreases for Newtonian and increases for non-Newtonian media, and the radius of rotation increases for Newtonian and decreases for non-Newtonian media. These results quantify the effects of fluid properties such as viscosity and flow rate on sperm rheotaxis and navigation, thereby paving the way for manipulating sperm behavior in microfluidic devices, potentially leading to advancements in assisted reproduction techniques.

WDR64, a testis-specific protein, is involved in the manchette and flagellum formation by interacting with ODF1

The WD40 repeat (WDR) domain is present in a wide range of proteins, providing sites for protein‒protein interactions. Recent studies have shown that WDR proteins play indispensable roles in spermatogenesis, such as in spermatocyte division, sperm head formation and flagellar assembly. In this study, we identified a novel testis-specific gene, WDR64, which has the typical characteristics of WD40 proteins with two β-propellers, and is highly conserved in Mammalia. RT-PCR and Western blot results revealed that WDR64 was highly expressed in testis. WDR64 protein was weakly expressed at postnatal Day 7, increased substantially at postnatal Day 28 and maintained at high levels thereafter. Further immunofluorescence demonstrated that WDR64 was localized posterior to the nucleus in steps 8–14 spermatids in line with the dynamic localization of manchette, moved to the flagella in steps 15–16 spermatids, and localized at the midpiece of the flagellum in mature spermatozoa. To explore the function of WDR64, we performed immunoprecipitation‒mass spectrometry (IP‒MS) to screen its interacting proteins and found that WDR64 interacted with ODF1 to form a complex. The WDR64/ODF1 complex is located at the manchette during nucleus shaping and finally at the midpiece of the mature spermatozoa tail, suggesting that it may be involved in the assembly of the manchette and flagella during spermiogenesis. Our findings provide the first understanding of the expression pattern of WDR64 and its potential molecular mechanism in spermiogenesis.

Tire Rubber Based Microplastic Particles Cause Adverse on Quality Parameters of Rainbow Trout Sperm Cells.

In the present study, we aimed to determine the parameters of oxidative stress markers, motility and kinematics of rainbow trout (Oncorhynchus mykiss) sperm cells exposed to different doses (0.001, 0.01, 0.1, 1.0, and 10mg/L, in vitro 4h) of tire rubber based microplastic particles (TRMP-Ps) the leachates procedure of rubber pieces. First of all, TRMP-Ps were prepared by abrasion method in accordance with the literature. Structural and morphological features of TRMP-Ps were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) methods, respectively. Energy dispersive X-ray (EDX) analysis technique was used to characterize the elemental composition of TRMP-Ps. Particle size of microplastic structures was measured hydrodynamically with dynamic light scattering analysis (DLS). After exposure, the effect of TRMP-Ps was defined by the observations of kinematics and antioxidant activities in sperm cells. Our findings showed that the straight line velocity, the curvilinear velocity, the angular path velocity, and the amplitude of lateral displacement of sperm cells decreased. Moreover, while the level of superoxide dismutase decreased dose-dependently against the toxicity of TRMP-Ps, no significant change was observed in the levels of malondialdehyde and total glutathione. The 4-h median effective concentrations (EC50) of TRMP-Ps based on mobility parameters of sperm ranged from 0.31mg/L for reduced straight line velocity of sperm cells to 0.51mg/L for reduced amplitude of lateral displacement of the spermatozoa head. Therefore, we concluded that TRMP-Ps can be a risk for the reproduction cycle of fish in aquatic environments.

Loss of CCDC188 causes male infertility with defects in the sperm head-neck connection in mice.

Acephalic spermatozoa syndrome (ASS) represents a rare genetic and reproductive disease, which is defined as semen composed of mostly headless spermatozoa. The connecting piece in the neck region, also known as the head-to-tail coupling apparatus (HTCA), plays a crucial role in the tight linkage between the sperm head and tail. Dysfunction of this structure can lead to separation of sperm heads and tails, and male infertility. Using the mouse as an experimental model, several proteins have been identified as associated with the HTCA and disruption of these proteins causes acephalic spermatozoa. However, the molecular mechanism underlying this morphologic anomaly and HTCA remains elusive. In this study, we focused on coiled-coil domain containing 188 (Ccdc188), which shows testis-enriched expression. To elucidate the physiological role of CCDC188, we generated a knockout (KO) mouse line using the CRISPR/Cas9 system. Ccdc188 KO male mice were sterile, indicating that CCDC188 is indispensable for male fertility. Most Ccdc188-null spermatozoa were acephalic. Transmission electron microscopy revealed that while the sperm HTCA could assemble properly without CCDC188, the HTCA failed to attach to the nucleus during spermiogenesis, leading to sperm head and neck separation. In addition, we found almost all of the spermatozoa in the cauda epididymis lacked a mitochondrial sheath. Taken together, we demonstrated that CCDC188 plays a crucial role in forming a tight sperm head-neck junction.

TMC7 deficiency causes acrosome biogenesis defects and male infertility in mice.

Transmembrane channel-like (TMC) proteins are a highly conserved ion channel family consisting of eight members (TMC1-TMC8) in mammals. TMC1/2 are components of the mechanotransduction channel in hair cells, and mutations of TMC1/2 cause deafness in humans and mice. However, the physiological roles of other TMC proteins remain largely unknown. Here, we show that Tmc7 is specifically expressed in the testis and that it is required for acrosome biogenesis during spermatogenesis. Tmc7-/- mice exhibited abnormal sperm head, disorganized mitochondrial sheaths, and reduced number of elongating spermatids, similar to human oligo-astheno-teratozoospermia. We further demonstrate that TMC7 is colocalized with GM130 at the cis-Golgi region in round spermatids. TMC7 deficiency leads to aberrant Golgi morphology and impaired fusion of Golgi-derived vesicles to the developing acrosome. Moreover, upon loss of TMC7 intracellular ion homeostasis is impaired and ROS levels are increased, which in turn causes Golgi and endoplasmic reticulum stress. Taken together, these results suggest that TMC7 is required to maintain pH and ion homeostasis, which is needed for acrosome biogenesis. Our findings unveil a novel role for TMC7 in acrosome biogenesis during spermiogenesis.

Quantitative assessment of Nigella sativa and conjugated silver nanoparticles against hexavalent chromium toxic effects on sperm function

BackgroundInfertility has been observed as one of the major issues in humans, one known risk factor is heavy metals. MethodsThe main focus of the present research was to assess the toxic effect of hexavalent chromium (Cr (VI)) on sperm and its mitigation by Nigella sativa seed extract (NS) and its conjugated silver nanoparticles (NS + NP). In the present study, we administered 1.5 mg/kg body of Cr (VI) orally in mice for 60 days routinely, to induce toxicity in testes and effect on sperm production and motility in male mice. NS and NS + NP (50 mg/kg body weight) were administered to evaluate protective action against Cr (VI). The sperm were analyzed by computer-assisted semen analysis (CASA) and chromium concentration in testicular tissue was measured via the atomic absorption spectrophotometer. ResultsThe CASA analysis showed that Cr (VI) was directly linked with a decline in sperm concentration, motility, distance, velocity, straightness, and head beat frequency attributes. However, the administration of Nigella sativa seed extract and its green synthesized silver nanoparticles improved sperm concentration, motility, distance, velocity, straightness, and head beat frequency. The chromium content in the testes of Cr-exposed animals significantly increased, which negatively affected sperm parameters. However, Nigella sativa and Nigella sativa conjugated silver nanoparticles appeared to help in the removal of Cr content from testes hence improving the sperm parameters in exposed mice. ConclusionThe decrease in Cr concentration improved sperm quality and quantity, hence, improve male fertility.

Exploring the potential of selenium nanoparticles and fabricated selenium nanoparticles @vitamin C nanocomposite in mitigating nicotine-induced testicular toxicity in rats.

The tobacco epidemic signifies a major public health threat. Nicotine (NIC), a major active constituent in tobacco, impedes male fertility and semen quality. This work is implemented to explore the potential of selenium nanoparticles (SeNPs) and the newly fabricated SeNPs @vitamin C (SeNPs@VITC) nanocomposite in mitigating testicular toxicity induced by NIC. The six groups of 48 adult Wistar rats were designed as follows: the control group injected intraperitoneally with normal saline, the SeNPs group treated orally with 2mg/kg of SeNPs, the SeNPs@VITC nanocomposite group treated orally with 2mg/kg of SeNPs@VITC nanocomposite, the NIC group injected intraperitoneally with 1.25mL/kg of NIC, the NIC+ SeNPs group received SeNPs plus NIC, and the NIC+ SeNPs@VITC nanocomposite group received SeNPs@VITC nanocomposite plus NIC. Treatments were administered over a 28-day period. NIC treatment significantly caused poor sperm quality, decreased serum testosterone, increased follicle-stimulating hormone (FSH), luteinizing hormone (LH) concentrations, reduced hemoglobin levels, leukocytosis, disrupted testicular oxidant/antioxidant balance, and disorganized testicular structure. The construction of the novel SeNPs@VITC nanocomposite, compared to NIC plus SeNPs alone, demonstrated a more potent ameliorative effect on NIC-induced reproductive toxicity in adult rats. The SeNPs@VITC nanocomposite significantly increased sperm count, reduced the percentage of sperm head abnormalities, lowered both serum FSH and LH concentrations, and improved the hemoglobin response. Both SeNPs and SeNPs@VITC nanocomposite alleviated the testicular toxicity induced by NIC, but the SeNPs@VITC nanocomposite exhibited superior efficacy. The SeNPs@VITC nanocomposite could be employed to advance enhanced therapeutic strategies for addressing male infertility.

The proximal centriole-like structure maintains nucleus-centriole architecture in sperm.

Proper connection between the sperm head and tail is critical for sperm motility and fertilization. Head-tail linkage is mediated by the head-tail coupling apparatus (HTCA), which secures the axoneme (tail) to the nucleus (head). However, the molecular architecture of the HTCA is poorly understood. Here, we use Drosophila to investigate formation and remodeling of the HTCA throughout spermiogenesis by visualizing key components of this complex. Using structured illumination microscopy, we demonstrate that key HTCA proteins Spag4 and Yuri form a 'centriole cap' that surrounds the centriole (or basal body) as it invaginates into the surface of the nucleus. As development progresses, the centriole is laterally displaced to the side of the nucleus while the HTCA expands under the nucleus, forming what we term the 'nuclear shelf'. We next show that the proximal centriole-like (PCL) structure is positioned under the nuclear shelf, functioning as a crucial stabilizer of centriole-nucleus attachment. Together, our data indicate that the HTCA is a complex, multi-point attachment site that simultaneously engages the PCL, the centriole and the nucleus to ensure proper head-tail connection during late-stage spermiogenesis.

Lead Acetate Provokes Poor Sperm Quality and Reduced Sperm Concentration in Male Wistars Rats

Background: Lead acetate, a toxic heavy metal, adversely affects male reproductive health in both humans and animals. However, its specific impact on sperm quality and concentration in Wistar rats remains understudied. Objectives: This study aimed to examine the effects of lead acetate on sperm quality and concentration in male Wistar rats, assessing motility, viability, total sperm count, and morphology. Additionally, it evaluated whether a recovery period could mitigate these adverse effects. Methods: Thirty male Wistar rats were divided into three groups of 10 each: Control (1 mL/kg BW distilled water), Lead Acetate (60 mg/kg BW orally for 28 days), and Recovery (28 days lead acetate followed by 28 days distilled water). Sperm samples were assessed for various parameters. Statistical analysis was performed using ANOVA with significance set at P &lt; 0.05, using GraphPad Prism 8. Results: The lead acetate-exposed group (Group 2) showed significantly reduced sperm motility, viability, and total sperm count compared to the control group (Group 1). Additionally, Group 2 exhibited a higher incidence of sperm head abnormalities (P &lt; 0.05). The recovery group (Group 3) demonstrated some improvement in sperm parameters compared to Group 2, but these improvements were not statistically significant. Conclusions: This study provides evidence that exposure to lead acetate has a substantial negative impact on the capacity of sperm to move, survive, and reproduce in male Wistar rats.