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61.
During mammalian fertilization, sperm is fused with the oocyte's membrane, triggering the resumption of meiosis from the metaphase II arrest, the extrusion of the second polar body, and the exocytosis of cortical granules; these events are collectively called 'oocyte activation.' In all species studied to date, the transient rise in the cytosolic level of calcium (in particular, the repeated calcium increases called 'calcium oscillations' in mammals) is required for these events. Researchers have focused on identifying the factor(s) that can induce calcium oscillations during fertilization. Sperm‐specific phospholipase C, i.e., PLC zeta (PLCζ), is a strong candidate of the factor(s), and several research groups using different species obtained evidence that PLCζ is a sperm factor that can induce calcium oscillations during fertilization. However, postacrosomal sheath Tryptophan‐Tryptophan (WW)—domain‐binding protein (PAWP) was recently shown to have a pivotal role in inducing calcium oscillations in some species. In this review, we focus on PLCζ and PAWP as sperm factors, and we discuss this controversy: Which of these two molecules survives as a sperm factor?  相似文献   
62.
Myostatin is a member of the transforming growth factor-β family with a key role in inhibition of muscle growth by negative regulation of both myoblast proliferation and differentiation. Recently, a genomic region on ECA18, which includes the MSTN gene, was identified as a candidate region influencing racing performance in Thoroughbreds. In this study, four SNPs on ECA18, g.65809482T>C, g.65868604G>T, g.66493737C>T, and g.66539967A>G, were genotyped in 91 Thoroughbred horses-in-training to evaluate the association between genotype and body composition traits, including body weight, withers height, chest circumference, cannon circumference, and body weight/withers height. Of these, statistically differences in body weight and body weight/withers height were associated with specific genotypes in males. Specifically, body weight/withers height showed statistically significant differences depending on genotype at g.658604G>T, g.66493737C>T, and g.66539967A>G (P<0.01) in males during the training period. Animals with a genotype associated with suitability for short-distance racing, C/C at g.66493737C>T, had the highest value (3.17 ± 0.05 kg·cm(-1)) for body weight/withers height in March, while those with a genotype associated with suitability for long-distance racing, T/T, had the lowest (2.99 ± 0.03 kg·cm(-1)). In females, the trends in the association of body weight/withers height with genotypes were similar to those observed in males. As the SNPs are not believed to be linked to coding variants in MSTN, these results suggest that regulation of MSTN gene expression influences skeletal muscle mass and hence racing performance, particularly optimum race distance, in Thoroughbred horses.  相似文献   
63.
A factor responsible for progression to pregnancy establishment in the mare has not been definitively characterized. To identify factors possibly involved in the establishment of equine pregnancy, the endometrium was collected from day 13 (day 0=day of ovulation) cyclic and day 13, 19 and 25 pregnant animals. From initial subtractive hybridization studies, a calcium regulating factor, Stanniocalcin-1 (STC1) mRNA, was found as a candidate molecule expressed uniquely in the pregnant endometrium. Endometrial expression of STC1 mRNA was noted on day 19 and was markedly increased in the day 25 gravid endometrium. STC1 protein was found in the extracts of day 25 gravid endometrium and immunochemically localized in the uterine glands. In addition, STC1 protein was detected in uterine flushing media collected from day 25 pregnant mares. High concentrations of estradiol-17 β (E(2)) were detected in day 25 conceptuses. E(2) levels were much higher in the gravid endometrium than in other regions, whereas progesterone levels did not differ among the samples from different endometrial regions. Expression of STC1 mRNA, however, was not significantly upregulated in cultured endometrial explants treated with various concentrations of E(2) (0.01-100 ng/ml) with or without 10 ng/ml progesterone. These results indicate that an increase in STC1 expression appears to coincide with capsule disappearance in the conceptus, and suggest that STC1 from the uterine glands likely plays a role in conceptus development during the pregnancy establishment period in the mare.  相似文献   
64.
65.
Sleep is believed to play an important role in memory consolidation. We induced sleep on demand by expressing the temperature-gated nonspecific cation channel Transient receptor potential cation channel (UAS-TrpA1) in neurons, including those with projections to the dorsal fan-shaped body (FB). When the temperature was raised to 31°C, flies entered a quiescent state that meets the criteria for identifying sleep. When sleep was induced for 4 hours after a massed-training protocol for courtship conditioning that is not capable of inducing long-term memory (LTM) by itself, flies develop an LTM. Activating the dorsal FB in the absence of sleep did not result in the formation of LTM after massed training.  相似文献   
66.
Canine calicivirus (CaCV) No. 48 strain isolated from a dog with fatal diarrhea is known to be able to replicate in MDCK and primary dog kidney cells. In this study, two new canine cell lines, MCM-B2 and MCA-B1, were determined to be permissive for CaCV No. 48, whereas other cell lines, including one canine cell line, A-72, were non-permissive. Flow cytometric analysis indicated that CaCV No. 48 binds efficiently to the permissive cells and to some degree also to Vero cells that are non-permissive for the virus, but does not bind to the other non-permissive cells tested. Both the permissive and non-permissive cells could be transfected with genomic RNA from CaCV No. 48, resulting in the appearance of CPE, production of capsid antigen and release of infectious progeny. These results suggested that the early interaction of the virus with cells, probably by binding to a virus receptor on the cell membrane, is the major determinant of CaCV No. 48 cell tropism in vitro.  相似文献   
67.
植物表皮蜡中链烷含量测定方法的研究   总被引:3,自引:0,他引:3  
植物细胞壁中链烷含量测定分析研究的目的是不降低测定分析精度的同时,节约时间和费用以便将来用于大量样品的分析。本研究首次把链烷分析提纯过程中省略用作纯化的硅胶,直接将含有链烷但未经硅胶提纯的原提取液注入气相色谱仪中测定,将世界通用的两种链烷分析法作为对照。结果表明,硅胶能否省略应根据不同牧草而定。本实验中所用的三种牧草,以省硅胶而简化的链烷分析可用于多年生黑麦草和瓦,而不能用于日本结缕草中链烷的测定。  相似文献   
68.
Antioxidant activities of freeze-dried preparations of a 70% acetone extract of pomegranate (Punica granatum L.) and its three major anthocyanidins (delphinidin, cyanidin, and pelargonidin) were evaluated. Free radical scavenging activities were examined using an ESR technique with spin trapping; DMPO for hydroxyl (.OH) and superoxide (O(2)(.-) ) radicals; and [(MGD)(2)Fe(2+)] for nitric oxide (NO). Inhibitory effects on lipid peroxidation were estimated by the levels of malonaldehyde and 4-hydroxyalkenals in rat brain homogenates. Pomegranate extract exhibited scavenging activity against.OH and O(2)(.-). Anthocyanidins inhibited a Fenton reagent.OH generating system possibly by chelating with ferrous ion. Anthocyanidins scavenged O(2)(.)- in a dose-dependent manner. The ID(50) values of delphinidin, cyanidin, and pelargonidin were 2.4, 22, and 456 microM, respectively. In contrast, anthocyanidins did not effectively scavenge NO. Anthocyanidins inhibited H(2)O(2)-induced lipid peroxidation in the rat brain homogenates. The ID(50) values of delphinidin, cyanidin, and pelargonidin for them were 0.7, 3.5, and 85 microM, respectively. These findings suggest that the above anthocyanidins contribute to the antioxidant activity of pomegranate fruits.  相似文献   
69.
Concentrations of ozone and nitrogen oxides, together with air temperature and solar radiation intensity, were measured at several heights on a tower standing through the canopy of a red pine forest in summer and in autumn. In the summer observation, the diurnal variation patterns of ozone concentration both above and below the canopy were all similar and parallel to the solar radiation intensity. Using the data collected immediately above the canopy, deviation from the Leighton relationship and variations of concentration sums [O3] + [NO] and [NO2] + [NO] were examined, and as a result, it was supposedthat ozone was photochemically formed there in the daytime, probably because hydrocarbons emitted from pine trees broke the photostationary state among ozone and nitrogen oxides. The vertical temperature profile exhibited an inversion at the leaf-layer, which must have hindered vertical mixing of the air and made the trunk space more or less isolated from the upper atmosphere. These observations led to an idea that the similarity of the ozone variation pattern at every height was caused by the photochemical formation that proceeded simultaneously above and below the canopy rather than by vertical transport. Such situations of ozone formation were supported by observation of two maximums in the ozone vertical profile, one immediately above the canopy and another in the trunk space. Another feature of the ozone profile was a deep minimum in the leaf layer, which indicated ozone deposition onto leaf surfaces. This study thus revealed concurrence of ozone formation and deposition, and left two potentially important implications worthy of further investigation: (1) a forest is not always a sink but can be a source of ozone in sunlit conditions, and (2) deposition of ozone to trees can take place not only from outside but also from inside of a forest. In the autumn observation, however, the ozone formation was barely recognizable above the canopy and no longer found in the trunk space; in addition, the ozone concentration minimum in the leaf layer disappeared, suggesting that the deposition or removal was dependent on temperature.  相似文献   
70.
Abstract: An 8‐week‐old, male, German Shepherd‐cross puppy found in southeastern Ohio was presented to The Ohio State University Veterinary Teaching Hospital for evaluation of lameness and lethargy. Fever and joint effusion involving multiple joints were identified on physical examination. Results of a CBC included mild anemia, mature neutrophilia, monocytosis, and hyperglobulinemia. Rickettsial morulae were identified within neutrophils in joint fluid and peripheral blood. Both initial and convalescent serum titers were negative for Ehrlichia sp.; however, PCR analysis was strongly positive for Ehrlichia ewingii. The patient's clinical signs resolved within several days of beginning doxycycline treatment. Resolution of infection was confirmed by negative PCR results after 18 days of treatment and again after 3 years. This is the first reported case of E. ewingii in Ohio. More importantly, this case demonstrates the importance of PCR in making a definitive diagnosis of tick‐borne disease and the potential pitfalls of relying on serologic testing alone in making a diagnosis.  相似文献   
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