The objective of this study was to examine the relationship between the insulin-like peptide 3 (INSL3) receptor (RXFP2) expression levels on spermatozoa and INSL3 concentrations in the seminal plasma of fresh semen from beef bulls with different levels of sperm morphological normality. Ejaculates (n = 44) were collected from 21 yearling Japanese Black beef bulls and categorized into three groups based on the levels of sperm morphological normality: High (normal morphology ≥ 80%; n = 23), Mid (< 80% & ≥ 65%; n = 10) and Low (< 65%; n = 11). Immunofluorescence was used to determine the localization and expression levels of RXFP2 in spermatozoa.
View Article and Find Full Text PDFThis study aimed to characterize calyculin A (CL-A)-induced and thimerosal-induced hyperactivation of cryopreserved bovine spermatozoa. Hyperactivation was effectively induced by treating with 10 nM CL-A for 60 min in the presence of cyclic AMP analogs, extracellular Ca, and albumin or with 12.5 µM thimerosal briefly in the absence of these capacitation-supporting factors.
View Article and Find Full Text PDFThis study aimed to verify the effects of polyvinyl alcohol (PVA) and bovine serum albumin (BSA) on the induction of full-type hyperactivation in boar spermatozoa treated with a cyclic AMP analog (cBiMPS). Washed spermatozoa were treated with cBiMPS (100 μM) for 180 min. As shown in the assessment of sperm motility, PVA (0.
View Article and Find Full Text PDFFor a successful natural regeneration of Japanese white birch ( var. ), competitive vegetation should be managed. Here, we clarified how soil water condition modifies the competitiveness of Japanese white birch against perennial weeds, species, based on an ecophysiological approach combining a glasshouse experiment and a field survey.
View Article and Find Full Text PDFIn cattle, cryopreserved spermatozoa are generally used for artificial insemination (AI). Many of these specimens exhibit helical movement, although the molecular mechanisms underlying this phenomenon remain unclear. This study aimed to characterize helically motile spermatozoa, investigate the involvement of Ca-ATPase in suppressing the appearance of these spermatozoa prior to cryopreservation, and examine the potential of helical movement as an index of sperm quality.
View Article and Find Full Text PDFIn mammals, hyperactivation is essential for sperm fertilization with oocytes in vivo. Two types of hyperactivation "full-type and nonfull-type patterns" can be observed in the spermatozoa from boars, bulls, and mice. We have a hypothesis that the full-type hyperactivation is a physiological (in vivo) pattern and are elucidating its molecular bases.
View Article and Find Full Text PDFBenzpyrimoxan (5-(1,3-dioxan-2-yl)-4-{[4-(trifluoromethyl)phenyl]methoxy}pyrimidine, NNI-1501) was discovered as a novel insecticide structurally characterized by a pyrimidine derivative substituted with 1,3-dioxanyl and 4-trifluoromethylbenzyloxy groups. The compound showed remarkable activity against nymphs of rice planthoppers, including strains resistant to existing insecticides. Furthermore, benzpyrimoxan had low adverse effects on pollinators and beneficial arthropods.
View Article and Find Full Text PDFConstant mesophyll conductance (g), and two-resistance g model (involved in resistances of cell wall and chloroplast), where g reaches maximum under higher CO concentrations, cannot describe the phenomenon that g decreases with increasing intercellular CO concentration (C) under relatively higher CO concentrations. Yin et al. (2020) proposed a g model, according to which the ratio of chloroplastic CO concentration (C) to C is constant in the two-resistance g model, which can describe the decreasing g with increasing C.
View Article and Find Full Text PDFJapanese larch ( (Lamb.) Carr.) and its hybrid are economically important coniferous trees widely grown in the Northern Hemisphere.
View Article and Find Full Text PDFPrevious researches of our laboratory reported that addition of cAMP analog cBiMPS and protein phosphatase inhibitor calyculin A (stimulators of cAMP signaling cascades) improved the capacity of incubation medium to induce full-type hyperactivation in bovine ejaculated spermatozoa. However, this modified medium was valid only for samples with relatively good survivability for incubation with stimulators of cAMP signaling cascades. Thus, it is necessary to make further modified medium for evaluation of potentials to exhibit full-type hyperactivation in bovine sperm samples with relatively lower survivability.
View Article and Find Full Text PDFAn atypical distribution of sperm acrosomal tyrosine-phosphorylated proteins [which include sperm acrosome associated 1 (SPACA1) proteins] may be related to the relatively lesser pregnancy rates when semen of some bulls are used for artificial insemination (AI). There may also be these associations with bull SPACA1 proteins that are translocated from the equatorial segment to the anterior part in the acrosomes during sperm maturation in the normally functioning epididymis. The aim of the present study, therefore, was assessment of the characteristics of bull SPACA1 proteins.
View Article and Find Full Text PDFThe density and architecture of leaf veins determine the network and efficiency of water transport within laminae and resultant leaf gas exchange and vary widely among plant species. Leaf hydraulic conductance ( K) can be regulated by vein architecture in conjunction with the water channel protein aquaporin. However, our understanding of how leaf veins and aquaporins affect leaf hydraulics and stomatal conductance ( g) remains poor.
View Article and Find Full Text PDFAccumulated evidence show that reactive species play a dual role in plants as well, with likely biphasic responses. This suggests that photoprotective mechanisms may also show similar patterns because they are highly related to reactive species. The nonphotochemical quenching (NPQ) is an index of heat dissipation of excitation energy in the antenna system.
View Article and Find Full Text PDFIn bull spermatozoa, extracellular Ca-dependent full-type hyperactivation, which is characterized by the asymmetrical beating in whole parts of the middle/principal pieces, is suppressed by calyculin A-sensitive protein phosphatases. The aim of this study was to identify isoforms of these protein phosphatases. Ejaculated spermatozoa were used for the investigation on effects of protein phosphatase inhibitors (calyculin A with high specificity for both of protein phosphatases 1 and 2A, and okadaic acid with relatively higher specificity for protein phosphatase 2A than protein phosphatase 1) on the induction of extracellular Ca-dependent full-type hyperactivation by incubation with CaCl and cAMP analog (cBiMPS).
View Article and Find Full Text PDFBackground: In mammals, flagellar hyperactivation is indispensable to sperm fertilization with oocytes in vivo, although there are species differences in regulatory mechanisms for this event. In this study, I reviewed researches regarding hyperactivation of bull and boar spermatozoa, in comparison with those of spermatozoa from other species.
Methods: Recent publications regarding sperm hyperactivation were collected and summarized.
Progressive movement of spermatozoa has conventionally been regarded as a good indicator of motility. However, bull spermatozoa exhibit two types of progressive movement: progressive/planar movement without rotation and progressive/helical movement with rotation. The aim of this study was to reconsider the evaluation criteria of bull ejaculated sperm motility in the context of rotation.
View Article and Find Full Text PDFA clear-cutting of canopy trees during winter often causes severe foliar damage during the following spring in forest floor seedlings of Abies sachalinensis, a typical shade-tolerant evergreen coniferous species. The maximum photochemical efficiency of photosystem II after an overnight dark adaptation showed a temporary decrease immediately before budbreak in 1-year-old shoots of A. sachalinensis seedlings grown under full sunlight in a nursery, suggesting "springtime photoinhibition" related to the phenology of evergreen coniferous species.
View Article and Find Full Text PDFAs photoinhibition primarily reduces the photosynthetic light use efficiency at low light, sunfleck-induced photoinhibition might result in a fatal loss of carbon gain in the shade leaves within a canopy with barely positive carbon balance. We hypothesized that shade leaves at the lower canopy might retain a certain amount of leaf nitrogen (N) to maintain energy consumption via electron transport, which contributes to circumventing photoinhibition during sunflecks to keep efficient utilization of low light during the rest period of daytime. We investigated excess energy production, a potential measure of susceptibility to photoinhibition, as a function of N distribution within a Japanese oak canopy.
View Article and Find Full Text PDFBackground: Although artificial insemination (AI) technique is an established biotechnology for bovine reproduction, the results of AI (conception rates) have a tendency to decline gradually. To our annoyance, moreover, AI-subfertile bulls have been occasionally found in the AI centers. To resolve these serious problems, it is necessary to control the sperm quality more strictly by the examinations of sperm molecules.
View Article and Find Full Text PDFWe propose a novel approach to determine the coefficient of CO diffusional leakage (k ) in the chamber of a portable open gas exchange system (Li-6400, Li-Cor Inc., NE, USA) using intact leaves. Assuming that dark respiration rate (R ) is constant at various CO concentrations, at least in a short term, k should be the value that makes the leak-corrected R constant.
View Article and Find Full Text PDFEjaculated 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 CaCl 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 [Ca ] (cBiMPS/CaCl , thimerosal, procaine, and 4-aminopyridine) to characterize the regulatory mechanism of extracellular Ca -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.
View Article and Find Full Text PDFTo obtain basic information of bull IZUMO1 (a sperm protein essential for sperm-egg fusion) and disclose possible causes for the impaired fertilizing ability in bull cryopreserved spermatozoa, we investigated this protein in bull spermatozoa collected from various regions of epididymides, freshly ejaculated spermatozoa, acrosome-reacted spermatozoa, and cryopreserved spermatozoa by Western blotting and the triple staining with the anti-IZUMO1 antibody, fluorescein isothiocyanate-peanut agglutinin, and 4',6-diamidino-2-phenylindole. In the cauda epididymal spermatozoa and freshly ejaculated spermatozoa, bull IZUMO1 was detected mainly as a 45-kDa major form. This major form was derived probably from a 52-kDa precursor form in the epididymis.
View Article and Find Full Text PDFThe leaf economics spectrum has given us a fundamental understanding of the species variations in leaf variables. Across plant species, tight correlations among leaf mass per area (LMA), mass-based nitrogen (N m) and photosynthetic rate (A m) and leaf lifespan have been well known as trade-offs in leaf carbon economy. However, the regional or biome-level correlations may not be necessary to correspond with the global-scale analysis.
View Article and Find Full Text PDFThe aims of this study were to investigate changes in the distribution and molecular mass of boar sperm acrosome-associated 1 (SPACA1) proteins during the acrosome reaction and to discuss validity of SPACA1 proteins as indicators for occurrence of the true acrosome reaction. Boar ejaculated spermatozoa were used for induction of the extracellular Ca(2+)-dependent acrosome reaction (true acrosome reaction) or acrosomal damages (false acrosome reaction) and then subjected to double staining with the anti-SPACA1 protein antibody and FITC-PNA and Western blotting. Extracellular Ca(2+)-dependently acrosome-reacted spermatozoa were characterized by appearance of SPACA1 proteins in the postacrosomal region (; these spermatozoa were classified into SP-3&AR pattern of double staining).
View Article and Find Full Text PDFIn Japanese black cattle, AI severely subfertile males have occasionally been found. In order to solve this problem, we previously asserted the need for exact examinations of acrosomal tyrosine-phosphorylated proteins and acrosome morphology in cryopreserved spermatozoa. In the present study, we further investigated acrosomal tyrosine-phosphorylated proteins in spermatozoa before cryopreservation and examined possible relationships between these phosphoproteins and acrosome stability.
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