Middle Piece Research Articles

The ultrastructural features of embryonic and early larval development in Yesso scallop, Mizuhopecten yessoensis.

Fine structural features of Mizuhopecten yessoensis in different embryonic and larval developmental stages from oocyte to early veliger have been studied. Spermatozoa have a conical head, consisting of a short acrosome, nucleus, and 4 mitochondria in the middle piece. The flagellum is approximately 40 μm in length. Oocyte cytoplasm contains numerous yolk granules, which are gradually expended during the larval development and disappear at the early veliger stage. Gastrula has two invaginations: shell gland anlage on the dorsal side and ventral side archenteron. Prototroch of a trochophore consists of two ciliary rings. Telotroch is absent. Myoblasts containing bundles of myofilaments are found in the blastocoel of trochophore. Velum and shell begin forming at the late trochophore stage. Cells of gut epithelium form numerous microvilli, organized into a brush border structure on the surface of enterocytes. A suggestion is made that larvae at the late trochophore stage are capable of digesting food and feeding. The structure of a M. yessoensis veliger is typical for pectinids. The velar retractor muscles have cross striation with a period of 1 μm. The digestive system of an 8-day-old veliger consists of the esophagus, stomach (with subdivided gastric shield and style sac), and short intestine. The digestive gland (with no discernible loops at this stage) is a part of the stomach epithelium with two types of digestive enzyme-producing cells.

HISTOLOGICAL AND ULTRASTRUCTURAL STUDIES OF SPERMATOGENESIS OF FRESHWATER MITE, UNIONICOLA AEGYPTIACA (ACARI, UNIONICOLIDAE)

The male genital system of the water mite, Unionicola aegyptiaca consists of an accessory gland, two spherical testes, two vasa deferentia, common vas deferens, an ejaculatory complex and spermatopositor (penis) and is supported with the male genital skeleton. It is evident that each testis is enclosed in a very thin amorphous layer (basal lamina) and consists of a germinal part, in which spermatogenesis take place for sperms development, and a glandular part which consists of a massive complex of glandular cells. The glandular cells of the accessory gland and glandular part of each testis secret testicular secretions which delivered into the lumen of the testis and contribute to sperm cell aggregation and sperm movement. The sperm development of Unionicola aegyptiaca includes spermatogonia, primary and secondary spermatocytes, spermatids and sperms. Fine structures of these stages show mitochondria, rough endoplasmic reticulum, free ribosomes and cytoplasmic vacuoles in their cytoplasm. Transmission electron micrographs show that the mature sperm consists of three parts; head, middle piece and a short tail.

TMEM16A inhibition impedes capacitation and acquisition of hyperactivated motility in guinea pig sperm

Ca2+ -activated Cl- channels (CaCCs) are anionic channels that regulate many important physiological functions associated with chloride and calcium flux in some somatic cells. The molecular identity of CaCCs was revealed to be TMEM16A and TMEM16B (also known as Anoctamin or ANO1 and ANO2, respectively) in all eukaryotes. A recent study suggests the presence of TMEM16A in human sperm and a relationship with the rhZP-induced acrosome reaction. However, to the best of our knowledge, little is known about the role of TMEM16A in other spermatic processes such as capacitation or motility. In this study, we evaluated the effects of two TMEM16A antagonists on capacitation, acrosome reaction, and motility in guinea pig sperm; these antagonists were T16Ainh-A01, belonging to a second generation of potent antagonists of TMEM16A, and niflumic acid (NFA), a well-known antagonist of TMEM16A (CaCCs). First of all, we confirmed that the absence of Cl- in the capacitation medium changes motility parameters, capacitation, and the progesterone-induced acrosome reaction. Using a specific antibody, TMEM16A was found as a protein band of ∼120 kDa, which localization was in the apical crest of the acrosome and the middle piece of the flagellum. Inhibition of TMEM16A by T16Ainh-A01 affected sperm physiology by reducing capacitation, blocking the progesterone-induced acrosome reaction under optimal capacitation conditions, inhibiting progressive motility, and the acquisition of hyperactivated motility, diminishing [Ca2+ ]i, and increasing [Cl- ]i. These changes in sperm kinematic parameters provide new evidence of the important role played by TMEM16A in the production of sperm capable of fertilizing oocytes.

Molecular characterization of voltage-gated potassium channel (Kv) and its importance in functional dynamics in bull spermatozoa

Present study was undertaken to characterize the voltage gated potassium channel (Kv 1.1) in bull spermatozoa using sixty four ejaculates collected from four Hariana bulls. Functional characterization was undertaken using a selective blocker of Kv channel, 4-Aminopyridine (4-AP) while molecular presence of Kv on bull spermatozoa by immunoblotting and indirect immunofluorescence. Three sets of 100 μL diluted sperm samples namely-negative control (100 μL of sperm dilution medium (SDM) containing 10 × 106 cells), vehicle control (99 μL of SDM containing 10 × 106 cells, and DMSO- 1 μL) and 4-AP treatment group (99 μL of SDM containing 10 × 106 cells, and drug 1 μL 4-AP) were used in the study. Immunoblotting identified a single band of 56 kDa corresponding to Kv1.1 in Hariana bull spermatozoa. Immunolocalization showed the positive immunoreactivity at head, middle piece and principal piece of the spermatozoa for Kv 1.1. Blocking of Kv using 4-AP resulted in significant (p < 0.05) reduction in sperm progressive motility, per cent capacitated spermatozoa (B-pattern) and acrosome reacted (AR-pattern) spermatozoa, while significant (P < 0.05) increase in per cent swollen spermatozoa. Blocking of Kv channels resulted in significantly (P < 0.05) increased percentage of spermatozoa with lower mitochondrial transmembrane potential. Computer assisted semen analysis (CASA) of motion and kinematic parameters in 4-AP treated spermatozoa indicated reduction in sperm motion parameters like LIN, STR, VSL and VAP and higher ALH, VCL, and BCF indicating hyperactivity of spermatozoa. Based on our findings, it may be concluded that voltage-gated potassium channel (Kv) are present on bull spermatozoa and these are associated with functional dynamics of spermatozoa. However, based on our limited study, it is not possible to deduce that how these channels are associated with induction of hyperactivity. Therefore, further studies are warranted to unravel the mechanistic signaling pathways involved in Kv-mediated alterations in functional dynamics of spermatozoa.

Ultrastructure of Sperm Development and Mature Sperm Morphology inSpondylus calciferandS. Princeps(Bivalvia: Spondylidae)

The entire spermatogenesis process and the presence of accessory cells in sperm development in Spondylus princeps Broderip, 1833, and S. calcifer Carpenter, 1857, were described for the first time. Spermatogenesis in both species showed similar anatomical and ultrastructural features. The testis contained amoeboid somatic cells inside the acini, frequently associated with developing gametes. Overall, spermatogenesis followed the typical pattern reported for other bivalve species, except for a few specific details. In S. princeps, intercellular bridges between spermatogonia, as well as one spermatocyte with seven mitochondria were observed. Both species had mature sperm of the ect-aquasperm type, consisting of a head, which contains a spherical-pyriform nucleus and a conical acrosome bounded by two regions of different density, four spherical mitochondria and two centrioles in the middle piece; the flagellum showed a standard 9 2 microtubule arrangement.

Glutathione treatment of Japanese Black bull sperm prior to intracytoplasmic sperm injection promotes embryo development

Intracytoplasmic sperm injection (ICSI) was expected to enable more efficient use of sperm from sires with preferable genetic traits and result in a generation containing a larger number of offspring with superior genetic characteristics in livestock. However, the efficiency of the early development of embryos produced by ICSI is still far from satisfactory in cattle. The present study aimed to investigate the effects of the treatment of cryopreserved sperm with glutathione (GSH) on the early development of embryos produced by ICSI in Japanese Black cattle. Moreover, the disulfide bond state and mitochondrial function were investigated in the sperm treated with GSH to confirm the effectiveness of the abovementioned treatment. We also investigated the effect of 7% ethanol activation treatment on the developmental ability of ICSI embryos using GSH-treated sperm. There was no effect on the blastocyst rate from the activation treatment. When sperm-injected oocytes were cultured in vitro, the treatment with GSH significantly improved the early development of embryos. Specifically, the rates of embryos reaching the 4–8-cell stage and blastocyst stage were significantly higher in ICSI with GSH-treated sperm (71.4% and 31.0%, respectively) than that with the control sperm (36.6% and 7.0%, respectively). Moreover, the GSH-treated sperm treatment significantly decreased the number of disulfide bonds in the sperm head (as shown by monobromobimane staining) and enhanced the mitochondrial function in the sperm middle piece (as shown by Rhodamine 123 staining and the adenosine triphosphate-dependent bioluminescence assay). Based on these results, we suggest that the treatment of cryopreserved sperm with GSH might contribute to the improvement of ICSI techniques for the production of blastocysts in Japanese Black cattle.

The expression of the new epididymal luminal protein of PDZ domain containing 1 is decreased in asthenozoospermia.

Spermatozoa are not mature until they transit the epididymis where they acquire motility and the ability to fertilize an egg through sequential modifications. The epididymis has three functional regions, caput, corpus, and cauda, and the luminal proteins of the epididymis play important roles in the above modifications. However, the proteins with differential enrichment between the caput and cauda are still largely unknown. To reveal the functions of the caput and cauda during sperm maturation, luminal proteins from caput and cauda of mice were analyzed by isobaric tag for relative and absolute quantitation (iTRAQ). Overall, 128 differentially enriched proteins were found, of which 46 were caput enriched and 82 were cauda enriched. Bioinformatic analysis showed that lipid metabolism was active in the caput; while anion- and cation-binding activity and phosphorus and organophosphate metabolism were active in the cauda. A new epididymal luminal protein, the caput-enriched PDZ domain containing 1 (Pdzk1), also named Na+/H+ exchange regulatory cofactor 3 (NHERF3), which plays a critical role in cholesterol metabolism and carnitine transport, was found in the lipid metabolism. Western blotting and immunofluorescence analyses showed that Pdzk1 was expressed in the epididymis but not in the testis, and localized at the middle piece of the sperm tail. Pdzk1 protein level was also reduced in the spermatozoa in case of asthenozoospermic patients compared with that in normozoospermic men, suggesting that Pdzk1 may participate in sperm maturation regulation and may be associated with male infertility. These results may provide new insights into the mechanisms of sperm maturation and male infertility.

Shape transition of water-in-CO2 reverse micelles controlled by the surfactant midpiece.

Designing CO2-philic surfactants for generating wormlike reverse micelles (RMs) is an effective approach to enhance the viscosity of supercritical CO2 (scCO2), however this remains challenging. Modifying the middle piece (midpiece) of surfactant tails is a potential method to generate wormlike RMs, but the underlying mechanism is still unclear. Herein, by adopting molecular dynamics simulations, the self-assembly of the hybrid surfactant FC6-HC5 in scCO2 was investigated. It was found that the FC6-HC5 with an alkyl midpiece could form spherical RMs. By introducing phenyl on the surfactant midpiece, a transformation of the RMs from a spherical shape to a wormlike shape was achieved. The improved fusion free energy was demonstrated to promote the fusion of the spherical RMs to form wormlike RMs. Further analysis indicated that, originating from the π-π interaction, the introduced phenyl assists the parallel arrangement of FC6-HC5, resulting in the improved fusion ability. Moreover, according to the analysis on interfacial properties, introducing phenyl had little effect on the surfactant CO2-philicity. Therefore, modifying the midpiece is a great method for designing hybrid surfactants to generate wormlike RMs while maintaining their high CO2-philicity. This strategy of generating wormlike RMs is expected to facilitate the application of scCO2 meeting industrial requirements.

Single-cell-based evaluation of sperm progressive motility via fluorescent assessment of mitochondria membrane potential

Sperm cells progressive motility is the most important parameter involved in the fertilization process. Sperm middle piece contains mitochondria, which play a critical role in energy production and whose proper operation ensures the reproductive success. Notably, sperm progressive motility is strictly related to mitochondrial membrane potential (MMP) and consequently to mitochondrial functionality. Although previous studies presented an evaluation of mitochondrial function through MMP assessment in entire sperm cells samples, a quantitative approach at single-cell level could provide more insights in the analysis of semen quality. Here we combine laser scanning confocal microscopy and functional fluorescent staining of mitochondrial membrane to assess MMP distribution among isolated spermatozoa. We found that the sperm fluorescence value increases as a function of growing progressive motility and that such fluorescence is influenced by MMP disruptors, potentially allowing for the discrimination of different quality classes of sperm cells in heterogeneous populations.

Modulation of voltage-gated sodium channels induces capacitation in bull spermatozoa through phosphorylation of tyrosine containing proteins

In our previous study, we have reported the molecular presence of Nav 1.8 in bull spermatozoa and its potential involvement in regulation of sperm functions. With the selective blocking of Nav 1.8 using A-803467, alterations in sperm functions were observed, therefore, we envisaged of investigating the involvement of Nav in regulating sperm function and the mechanism(s) involved in it using veratridine, a selective opener of Nav channels. Forty ejaculates were collected from four Hariana bulls and semen samples were pooled in view of the non-significant variations between the different ejaculates. Treatment of sperm cells with veratridine (6, 8, and 10 μM) resulted in concentration- and time-dependent increase in forward progressive sperm motility and it persisted up to 6 h. However, hyperactive motility was induced by veratridine at higher concentrations (8 and 10 μM) and after 2 h of incubation, which was confirmed by subjective assessment followed by chlortetracycline staining showing the increased B-pattern spermatozoa, and thereby suggesting the involvement of Nav in regulation of capacitation in spermatozoa. To substantiate the functional study observations especially veratridine-induced capacitation, immunoblotting and indirect immune fluorescence assays were performed for detection of the tyrosine-phosphorylated proteins. The immune blot study revealed the presence of five tyrosine phosphorylated proteins, namely-p17, p30, p54, p90 and p100. The p17 protein showed the highest band intensity compared to other protein bands indicating its potential involvement in the process of capacitation. Immunolocalization study revealed positive immunoreactivity for tyrosine phosphorylated proteins in the middle piece, post acrosomal region (high fluorescence) and tail of the spermatozoa (low fluorescence). From the results of present study, it is evident that activation of NaV by veratridine, especially at higher concentrations, induced capacitation which is evidently mediated through phosphorylation of the tyrosine containing proteins localized in the post acrosomal regions, middle piece and tail of the spermatozoa. However, further studies will help in unraveling the involvement of Nav and other ion channels regulating different physiological functions of sperm.

Species difference in the expression of Fas and Fas ligand in mature mammalian spermatozoa

Although it has been proposed that the Fas and Fas ligand (FasL) may protect ejaculated spermatozoa against apoptosis induced by lipoperoxidative damage and against lymphocytes present in the female genital tract, studies reported conflicting results on the presence of Fas receptors in ejaculated human spermatozoa. Furthermore, the expression of Fas/FasL on mature spermatozoa has not been observed in several important mammals. Using seven species, we observed the possibility for species difference in Fas/FasL expression on mature spermatozoa by both immunofluorescence microscopy and western blot analysis. Whereas intensive signals of Fas immunolabelling were detected in sperm head and middle piece and weak signals observed in the tail in 86–100% of the mouse, rat, bull, ram, and buck spermatozoa, only weak signals were detected on the whole body of 27% boar spermatozoa and in the head of 21% human spermatozoa. The pattern of FasL localization was identical to that of Fas in spermatozoa from human, mouse, rat, ram, and buck, but boar and bull spermatozoa showed weak and intensive FasL signals, respectively, only in the head. Western blotting further confirmed the Fas and FasL expression in mouse, rat, bull, ram, and buck, but not in human and boar spermatozoa. Taken together, the results revealed a marked species difference in Fas/FasL expression and an extensive co-expression of Fas and FasL among mature mammalian spermatozoa, suggesting that whereas spermatozoa from most species may be protected by Fas/FasL, those from human and boar may not use the Fas system for protection.

Characterization of extracellular Ca2+ -dependent full-type hyperactivation in ejaculated boar spermatozoa preincubated with a cAMP analog.

Ejaculated boar spermatozoa exhibit two types of hyperactivation: full and non-full. Full-type hyperactivation is characterized by the asymmetrical bending of the entire middle piece-principal piece and a twisting/figure-eight-like trajectory, and can be induced by simple incubation with CaCl2 after preincubation with a cAMP analog (Sp-5,6-dichloro-1-β-D-ribofuranosyl-benzimidazole-3',5'-cyclic monophosphorothioate [cBiMPS]). Here, we compared the sperm flagellar motility after treatments with elevators of [Ca2+ ]i (cBiMPS/CaCl2 , thimerosal, procaine, and 4-aminopyridine) to characterize the regulatory mechanism of extracellular Ca2+ -dependent, full-type hyperactivation in ejaculated boar spermatozoa, and examined the possible involvement of Transient receptor potential cation channel subfamily C member 3 (TRPC3) in this event using the specific inhibitor Pyr3. Full-type hyperactivation was induced by a 60-min incubation with CaCl2 following a 180-min preincubation with cBiMPS but without Ca2+ . Thimerosal-treated spermatozoa exhibited full-type hyperactivation in a manner independent of extracellular Ca2+ ; conversely, this was not observed in procaine- or 4-aminopyridine-treated spermatozoa. A 20-min treatment with Pyr3 between preincubation with cBiMPS and incubation with CaCl2 , significantly suppressed the normal phenotype. These observations indicated that mechanisms underlying full-type hyperactivation in spermatozoa incubated with CaCl2 after preincubation with cBiMPS are different from those in the thimerosal-treated spermatozoa. Furthermore, indirect immunofluorescence localized TRPC3 in the upper segment of the middle piece, which bends asymmetrically during full-type hyperactivation but not in non-full-type hyperactivation, suggesting that TRPC3 may be involved in the extracellular Ca2+ -dependent full-type hyperactivation in ejaculated boar spermatozoa.

Stereological study of the mid piece of ductus epididymis In human and other animal species

A stereological study of a (middle piece) of ductus epididymis between normal adult human, bulls, rams, goats and buffalos was conducted using routine histological techniques. The following stereological parameters were determined; Stereocilia height, epithelial height, muscular wall thickness, lumen and tube diameters. The human epididymal stereocilia height is shorter than in goat only and higher than bulls and goats in both the epithelial height and muscular wall thickness. Human ductile diameter is smaller than in other animals. In conclusion, all human epididymal mid piece parameters in the present study differ significantly than in the other animals. Because human epididymis differs from other animals in fine structure and luminal contents, the present stereological study shows how structural data obtained from histological micrographs of the intact tissue and cells can be different between human and other animals mid peiece ductus epididymis.

Lower buffet prices lead to less taste satisfaction

Lower buffet prices lead to less taste satisfaction

The performance of heat-treated silcrete backed pieces in actualistic and controlled complex projectile experiments

The origins of complex projectile weaponry provides insight into cultural and biological changes associated with the origins and spread of modern human populations. Middle Stone Age backed pieces are often thought to be components of such armaments, however our limited understanding of their functional characteristics as projectiles precludes understanding the adaptive problems they may have solved. Despite acknowledgment of raw material differences and intra-assemblage variability, whether variability in backed piece form reflects functional, economic, or stylistic variation has a paucity of empirical support. Here, the functional differences in backed piece form (size and shape) while hafted transversely and obliquely as high-velocity complex projectile armatures are examined. If there are performance tradeoffs simply in how backed pieces are arranged at the end of armaments that can influence effectiveness, then identifying the archaeological arrangement can provide insight into what variables were being prioritized in prehistoric technological systems. How variation in backed piece size, elongation, and hafting arrangement influences complex projectile performance is tested using experimental and actualistic projectile replications with a calibrated crossbow against animal and ballistics gelatin targets. The results of this study show that, within the size and shape variation of silcrete backed pieces examined, tool form plays a relatively limited role in their performance as projectile armatures. However, hafting orientation has very different performance characteristics for complex projectiles shot at ballistics gelatin compared to animal targets. We demonstrate that transversely hafted tools have more lethal internal wounds, but obliquely hafted backed pieces have greater puncture reliability. These functional differences represent different technological design emphasis: transversely hafted tools create large, deep wounds, while obliquely hafted arrows and darts create a puncture more reliably. Although obliquely hafted armaments cause less internal trauma, they are more likely to penetrate the hide of ungulate prey. Variability in MSA hunting tactics may have played a role in the design of weapon systems to optimize these performance tradeoffs. Despite similarities in shape with ethno-historic technologies, based on these results, MSA-sized backed pieces hafted as projectile armatures were unlikely to have been used with small, low-powered bows - but would have been lethal with a high-velocity delivery system.

Effect of reduced glutathione supplementation in semen extender on tyrosine phosphorylation and apoptosis like changes in frozen thawed Hariana bull spermatozoa

To provide new insights into the mechanisms through which reduced glutathione (GSH) is able to protect spermatozoa, we tested the hypothesis that cryocapacitation and apoptosis like changes can contribute to the negative effect of freezing and thawing on bull spermatozoa, and that GSH prevent this damage. Having known protective effects of GSH in terms of a potent antioxidant, we evaluated capacitation, tyrosine phosphorylation and apoptosis like changes in bull spermatozoa after freezing and thawing in egg yolk tris glycerol extender containing (0.5m M-GSH-T1 & 1mM GSH-T2) and without GSH serving as the control (C). Forty ejaculates were collected from four Hariana bulls and were pooled due to non significant variations among the bull ejaculates for the evaluation of sperm attributes. Capacitation like changes, tyrosine phosphorylation, localization of tyrosine phosphorylated proteins, apoptosis like changes in terms of mitochondrial transmembrane potential and DNA fragmentation after final dilution, 4h of equilibration at 4°C and 24h after freezing and thawing were evaluated. GSH supplementation at 0.5mM showed significant reduction in B- and AR- pattern spermatozoa during all stages of semen freezing and thawing. Immunoblot revealed six proteins which were tyrosine phosphorylated and protein of 30 and 75kDa (p30, p75) were the major tyrosine phosphorylted proteins. On further analysis, the p30 showed differential variation in intensity in all the three groups after freezing and thawing. Positive immune reactivity for tyrosine phosphorylated proteins was found in neck, middle piece and post-acrosomal regions of spermatozoa. Addition of 0.5mM GSH decreased percentage of spermatozoa showing fragmented DNA and increased the percentage of spermatozoa having high transmembrane mitochondrial potential (P<0.05). This study demonstrates that GSH favours survival of bull spermatozoa by interfering with apoptotic and cryocapacitation pathways, and thereby protects the spermatozoa from deleterious effects of cryopreservation. The findings of the study indicated that GSH at 0.5mM can be effectively used as an additive in bull semen extender for freezing and thawing.

Effect of cholesterol loaded cyclodextrin supplementation on tyrosine phosphorylation and apoptosis like changes in frozen thawed Hariana bull spermatozoa

The beneficial effects of cholesterol loaded cyclodextrin (CLC) addition were evaluated in cryopreserved bull semen. Forty ejaculates were collected from Hariana bulls (n = 4), pooled and divided into 4 aliquots. All the aliquots were initially diluted in to egg yolk tris citrate and supplemented with CLC @ 0.5 mg (Group-II), 1.0 mg (G-III) and 2.0 mg (G-IV) CLC/120 × 106 spermatozoa or without CLC (G-I) that served as control. Extended semen was cryopreserved at −196 °C for 24 h. Seminal attributes like motility, viability, cryocapacitation like changes, tyrosine phosphorylation, apoptosis like changes in terms of mitochondrial transmembrane potential and DNA integrity were evaluated after equilibration and thawing. Results showed a significant increase in the motility, viability and acrosome intact spermatozoa in Group II as compared to other three groups. Further, the proportion of spermatozoa showing capacitation and acrosome reaction was also decreased (P < 0.05) significantly in Group II as compared to Group I, III, and IV. Immunoblot demonstrated a 32 kDa (p32) protein showing differential variation in the band intensity in all the four groups being lower in Group II. Further, the immunolocalization study revealed positive immune reactivity for tyrosine phosphorylated proteins at middle piece and neck (high fluorescence), post-acrosomal region (medium fluorescence), and principal piece (low fluorescence) of spermatozoa. Addition of CLC significantly increased (P < 0.05) the percentage of spermatozoa showing high transmembrane mitochondrial potential, and also, CLC @ 0.5 mg/120 × 106 in semen extender significantly decreased (P < 0.05) spermatozoa showing fragmented DNA after thawing as compared to control. Results of the present study indicate beneficial effects of CLC supplementation on cryodamage of spermatozoa by reducing the cryocapacitation and apoptosis like changes.

Sociocultural factors associated with fish consumption in Lake Albert fishing community: Guidelines for lead and mercury.

Fish consumption in subsistence fishing community is a life style associated with lead and mercury uptake for humans. Fish consumption is influenced by sociocultural factors, exposure and health risks. Unfortunately, no sociocultural study in the Lake Albert fishing community in light of lead and mercury exists. A cross-sectional sociocultural study was carried out between March and June 2015. A total of 270 household heads in four landing sites in Hoima district completed structured questionnaires and data analyzed using SPSS version 20. The majority of the households (74.8%) had primary education or below, 51.1% drank unboiled water, and 30% perceived lake water safe for drinking. Children under five ate soup (15%) and middle piece of the fish (29%). The Poisson general linear model predicting weekly fish consumption amounts against sociocultural factors showed that household size (p = 0.047), male child presence (p = 0.007), methods of preparation i.e. salting (p < 0.0001), fish parts consumed by adults (p < 0.0001), fish preference (p < 0.0001), awareness about the beach management unit (p < 0.0001), and income from charcoal selling (p < 0.0001) were positive predictors. The negative predictors of weekly fish consumption amounts were awareness about fish consumption benefits (p < 0.0001), eating young fish (p = 0.002), donor agency presence (p < 0.0001), and frying as the method of fish preparation (p = 0.002). In conclusion, knowledge of the sociocultural factors associated with fish consumption determines the amounts and frequency of the predominant fish eaten. Therefore, to establish and adopt fish consumption guidelines for lead and mercury in the Lake Albert, the sociocultural factors should be integrated in the message disseminated.

Aquaporin-Mediated Water and Hydrogen Peroxide Transport Is Involved in Normal Human Spermatozoa Functioning

Different aquaporins (AQPs) are expressed in human sperm cells and with a different localization. Their function has been related to cell volume control in response to the osmotic changes encountered passing from the epididymal fluid to the cervical mucus or involved in the end stage of cytoplasm removal during sperm maturation. Recently, AQPs have also shown hydrogen peroxide (H2O2) permeability properties. Here, we investigate the expression, localization and functioning of AQPs in human sperm cells with particular attention to their role as peroxiporins in reactive oxygen species (ROS) scavenging in both normospermic and sub-fertile human subjects. Western blotting and immunocytochemistry were used to confirm and clarify the AQPs expression and localization. Water and H2O2 permeability was tested by stopped flow light scattering method and by the CM-H2DCFDA (5-(and-6)-chloromethyl-2′,7′-dichlorodihydro-fluorescein diacetate, acetyl ester) H2O2 fluorescence probe, respectively. AQP3, -7, -8, and -11 proteins were found in human sperm cells and localized in the head (AQP7), in the middle piece (AQP8) and in the tail (AQP3 and -11) in both the plasma membrane and in intracellular structures. Sperm cells showed water and H2O2 permeability which was reversibly inhibited by H2O2, heat stress and the AQP inhibitor HgCl2. Reduced functionality was observed in patients with compromised basal semen parameters. Present findings suggest that AQPs are involved in both volume regulation and ROS elimination. The relationship between sperm number and motility and AQP functioning was also demonstrated.

Functional and molecular characterization of voltage gated sodium channel Nav 1.8 in bull spermatozoa

The aim of our study was to characterize the voltage gated sodium channel Nav 1.8 in bull spermatozoa. Forty ejaculates were collected from four Hariana bulls and semen samples were pooled in view of the nonsignificant variations between different ejaculates. Functional characterization was undertaken using A-803467, a selective blocker of Nav1.8, and veratridine as an opener of the voltage gated sodium channels while molecular characterization was done using western blotting and indirect immunofluorescence assays. In vitro capacitation was induced using heparin, and to study the functional involvement of Nav 1.8 in regulation of capacitation induced hyper sperm motility, A-803467 was used. Selective blocking of NaV 1.8 by A-803467 at 6 and 8 μM concentration significantly (P < 0.05) decreased the forward progressive sperm motility in a time-dependent manner, while, blocking at higher concentrations (10 and 15 μM) resulted in fast forward motility in spermatozoa after 2 h of incubation and it was observed up to 3 h. Treatment of sperm cells with veratridine (6, 8, 10, 15, 20 μM) resulted in concentration- and time-dependent increase in forward progressive sperm motility and it persisted up to 4 h. However, hyperactive motility was induced by veratridine at higher concentrations (10 and 15 μM) after 2 h of incubation. In vitro capacitated spermatozoa treated with A-803467 revealed significant (P < 0.05) reduction in forward progressive motility after 2 h of incubation. Both A-803467 and veratridine altered the percentage of spermatozoa showing high mitochondrial transmembrane potential in concentration- and time-dependent manner. High concentrations (10 and 15 μM) of A-803467 and veratridine resulted in bent neck condition in spermatozoa along with significant (P < 0.05) reduction in membrane integrity (HOST negative). Immunoblot revealed the presence of a single protein band of 260 kDa molecular weight along with positive immunoreactivity (IR) in head, neck, middle piece and tail of the spermatozoa. Strongest IR was observed in the neck and middle piece whereas weak IR was observed in tail and acrosomal region of the spermatozoa. Results of our present study evidently revealed the presence of voltage gated sodium channel Nav1.8 in bull spermatozoa and its functional involvement in regulation of spermatozoa dynamics in terms of motility, membrane integrity, acrosome integrity, capacitation and mitochondrial transmembrane potential. Further studies are warranted to unravel their mechanistic pathways and/or their interaction with other ion channels in regulating sperm dynamics.