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11.
This study reports findings from the pathological examination of the forestomach of an 11-month-old Japanese Black steer with severely retarded growth (41% of expected weight) and chronic ruminal tympany. The ruminal papillae were weakly formed (0.3–0.5 cm long) and unevenly distributed. The cellulae and cristae reticuli were underdeveloped; the cristae were 0.4–0.7 cm in height and milky white. The keratinized layer in the stratified squamous epithelium was thickened. Ruminal pH was 5.25, and ruminal volatile fatty acid concentration was 11.7 mM. The steer’s severely retarded growth was considered to be caused by malnutrition due to developmental and functional failure of the forestomach.  相似文献   
12.
Hypothalamic gonadotropin-releasing hormone (GnRH) neurons govern reproductive function by controlling the release of gonadotropins from the pituitary. To facilitate identification of living GnRH neurons, here we attempted to generate transgenic rats that express enhanced green fluorescent protein (EGFP) in GnRH neurons. About 3 kb of rat GnRH promoter region was inserted into the EGFP reporter cassette, and the expression of EGFP fluorescence was confirmed in several cell lines following transient transfection. Then we successfully generated a transgenic rat by injecting linearized GnRH-EGFP transgene into the pronuclei of fertilized oocytes. The GnRH-EGFP transgenic rats expressed EGFP in the brain, but not in the ovary, testis or thymus. Immunohistochemical examination revealed that detectable EGFP fluorescence was confined to the cell body of GnRH-immunoreactive neurons in the septum and preoptic area, while no EGFP signal was discernible in the median eminence where abundant GnRH-immunoreactive fibers were observed. The mean percentage of EGFP-positive cells in the GnRH-positive cells was 76.3%. The GnRH-EGFP transgenic rats generated in the present study will enable characterization of properties of individual GnRH neurons.  相似文献   
13.
Congenital myasthenic syndromes (CMSs) are a group of inherited disorders of neuromuscular transmission characterized by fatigable muscle weakness. One major subgroup of patients shows a characteristic "limb girdle" pattern of muscle weakness, in which the muscles have small, simplified neuromuscular junctions but normal acetylcholine receptor and acetylcholinesterase function. We showed that recessive inheritance of mutations in Dok-7, which result in a defective structure of the neuromuscular junction, is a cause of CMS with proximal muscle weakness.  相似文献   
14.
About 70% of eggs of Cyprinus carpio reached the eyed stage in fertility tests with 1 ml of cryopreserved semen added to 1 g of eggs. When 1 ml of semen was added to 100 g of eggs, few eggs reached the eyed stage. In two fertility tests with sperm preserved for 342 days, using 5 g of eggs inseminated with 1 ml of semen, percentages of eyed eggs were 31.5 and 25.5, respectively. In a series of fertility tests, the chemical constituency of the medium in which fertilization was attempted influenced the fertility of cryopreserved sperm.  相似文献   
15.
The roots of soybean ( Glycine max [L.] Merr.) establish symbiosis with nodule-inducing rhizobia and arbuscular mycorrhizal (AM) fungi. The existing nodules systemically suppress subsequent nodule formation, a phenomenon known as autoregulation. Grafting experiments revealed that some forms of autoregulation are controlled by the shoot. In the present study, we examined shoot-controlled regulation of AM fungal colonization using a reciprocal grafting technique. Ten-day-old seedlings of wild-type soybean cv. Enrei and its hypernodulating mutant En6500 were cut below the cotyledons and the shoots were grafted to self or reciprocal roots. Grafted seedlings were inoculated with Bradyrhizobium japonicum and Gigaspora rosea and grown in a glasshouse for 60 days. The arbuscule abundance of the En6500 (shoot)/En6500(root) graft was 1.5-fold higher than that of the Enrei/Enrei graft. In grafts between Enrei and En6500, an increased arbuscule abundance was detected only when En6500 was used as the shoot. The arbuscule abundance of Enrei/En6500 when Enrei was used as the shoot was comparable to that of Enrei/Enrei. The intensity of AM fungal colonization was lower in Enrei/En6500 than in the other grafting treatments. From the results obtained, we suggest that soybean shoots systemically control arbuscule formation in both AM symbiosis and nodule formation.  相似文献   
16.
The polyovules phenomenon in sugar beet has the same importance for breeding as multigermity, because only mono-ovulic monogerm plants can be used for mechanized cultivation. The polyovules trait was investigated in two Japanese lines, mono-ovulic line NK-219-O and polyovulic line NK-183-cms. Plants of the former had three pistil lobes (stigmatic rays) in each flower, a single ovule per ovary, a single seed in the mature fruit and a single seedling germinated in subsequent tests. Plants of the latter had 5–6 pistil lobes in each flower, 2–3 ovules per ovary, double-seeds and double-seedlings. The correlations between a Pistil Lobes Index (PLI) and thenumber of ovules per ovary, percentage of double-seeds inan X-ray test, and percentage of double-seedlings in germination tests were 0.885, 0.838, and 0.749, respectivelyindicating close associations. These results are important both in sugar beet breeding for indirect selection to eliminate the undesirable polyovules trait and for botanicalinvestigations of the relationship among different parts of the gynoecium.  相似文献   
17.
18.
In the present study, we investigated the regulatory mechanisms underlying sperm hyperactivation enhanced by 5-hydroxytryptamine (5-HT) in hamsters. First, we examined the types of 5-HT receptors that regulate hyperactivation. Hyperactivation was significantly enhanced by 5-HT2A and 5-HT4 receptor agonists. Moreover, the results of the motility assay revealed that 5-HT2A, 5-HT3, and 5-HT4 receptor agonists significantly decreased the velocity and/or amplitude of sperm. Under 5-HT2 receptor stimulation, hyperactivation was associated with phospholipase C (PLC), inositol 1,4,5-trisphosphate (IP3) receptor, soluble adenylate cyclase (sAC), and protein kinase A (PKA). In contrast, under 5-HT4 receptor stimulation, hyperactivation was associated with transmembrane adenylate cyclase (tmAC), sAC, PKA, and CatSper channels. Accordingly, under the condition that sperm are hyperactivated, 5-HT likely stimulates PLC/IP3 receptor signals via the 5-HT2A receptor and tmAC/PKA/CatSper channel signals via the 5-HT4 receptor. After sAC and PKA are activated by these stimulations, sperm hyperactivation is enhanced.  相似文献   
19.
Populations of large mammals have been dramatically increasing in Japan, resulting in damage to agriculture, forestry, and ecosystems. However, their effects on tick-borne diseases have been poorly studied. Here, we focused on the relationship between Japanese spotted fever (JSF), a tick-borne disease caused by Rickettsia japonica, and populations of large mammals. To explore factors that affected the area in which JSF cases occur, we used generalized linear mixed models (GLMMs). We demonstrated that the expansion of the area of JSF occurrence can be predicted by deer density and geographical factors, which is likely due to differences in landscape structure. However, the associated models have limitations because of the lack of information about the distribution of vectors and reservoirs. To reduce the risk of humans contracting JSF, potential reservoirs should be confirmed.  相似文献   
20.
Analytical methods were investigated for the discrimination of ‘nori’, the dried laver Porphyra spp. sheet products, which were organoleptically judged as excellent-grade for commercial distribution. Volatile compounds of nori were analyzed with an electronic nose and a gas chromatography-mass spectrometer (GC/MS) with headspace solid-phase micro-extraction. Each chopped dry nori sample was sealed in a vial and the headspace gas at 40 °C was analyzed. Excellent-grade nori product of ‘Akime’, first autumn shoots, of one season could be discriminated from other products by using principal component analyses (PCA) for the electronic nose response. PCA using a peak area of 32 compounds detected in the GC/MS analysis clearly discriminated all excellent-grade samples from all other samples. Excellent-grade products were considered to be characterized by higher total contents of 6-methyl-5-hepten-2-one, octanal and trimethylamine, and by lower total volatile contents, especially 1-pentanol, 2-pentenal, (E)-2-hexenal, acetoin, 2-methyl-2-butenal, 3-methyl butanal and others. These findings revealed the possibility of analytical discrimination of excellent-grade nori products as a substitution for organoleptic testing.  相似文献   
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