排序方式： 共有33条查询结果，搜索用时 234 毫秒
1.
Yukinori YOSHIMURA 《Animal Science Journal》2004,75(3):183-191
The current paper describes aspects of local immunity in the ovary and oviduct, and the significance of immunity to reproductive functions in hens. The immunocompetent cell populations in the ovary and oviduct change with a positive correlation to sexual activity, and gonadal steroid is one of the key factors in the increase. Local immune responses mediated by major histocompatibility complex class II and T cell subsets occur in response to infection by Salmonella enteritidis, which may contaminate eggs. In the ovary, immunocompetent cells are also suggested to play roles in the regulation of ovarian functions. Macrophages and T cells are likely to enhance the regression of atretic follicles to maintain the ovarian tissue microenvironment. Autoantibodies to ovarian tissues appeared in the hens with low egg laying frequency, suggesting that the auto‐antibodies may be one of the factors in the decline of egg production. In the oviduct, local immunity possibly has a role in the selection of sperm, though the immunoreactions may also affect sperm survival leading to the decline in fertility. The concentration of yolk IgY, which plays a role in maternal immunity transmission, significantly decreases with the aging of birds, whereas it is significantly increased by estrogen. Therefore, the immune system plays significant roles not only in defense against infection, but also in the functions of reproductive organs. Investigations on the local immune system in the reproductive organs and factors affecting it are of importance for the production of sterile eggs and improvement of reproductive functions. 相似文献
2.
Hideki ASAI Noboru HAYASHI Naoharu TAKAI Yoshihisa YOSHIMURA Yutaka NAKAMURA Hiroomi YOKOTA Kazumi KITA 《Animal Science Journal》2005,76(1):51-54
In the present study, the daily excretion of potassium (K) in urine (urinary K(UK)) was estimated from a 6 h urine sample using urinary creatinine (UC) as the index substance. All urine was collected from six pregnant Holstein cows at 6 h intervals for 24 h on 3 days of the 4th, 2nd and final week before the expected date of parturition. In total, 72 6 h urine samples were obtained. Daily UC excretion (mg/day per kg bodyweight (BW)) was almost the same for the three sampling days. Daily UC excretion varied among cows from 22.1 to 24.3 mg/day per kg BW with a mean of 22.8 mg/day per kg BW with no significant difference. Thus, daily UC excretion was confirmed to be constant throughout the prepartum period with no differences among individuals. The concentration ratios of K to creatinine ((UK mg/dL)/(UC mg/dL) (UK/UC)) correlated strongly to the hourly K excretions (mg/h per kg BW) (r = 0.952, P < 0.01) in the 6 h urine samples. The differences in the UK/UC ratio between sampling periods were not significant within each cow. Therefore, daily UK excretion (mg/day) can be estimated using the equation: daily UK excretion (mg/day) = daily UC excretion (mg/day per kg BW) × BW (kg) × 6 h urine sample UK/UC, where daily UC excretion can be a given value. 相似文献
3.
The goal of this study was to determine whether in the Japanese quail the male genital tract contains receptors for progesterone, androgen and estrogen (PR, AR and ER, respectively), which have significant roles in reproductive functions, and whether their localization changes during sexual maturation. The epididymis and ductus deferens (middle and ampulla regions) of immature (approximately 30-day-old) and mature male Japanese quail were collected and frozen sections of them were immunostained for PR, AR and ER. The immunoreaction products for AR and PR were found in the nuclei of epithelial cells in the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens of mature and immature birds. In the mature birds, the epithelial cells of the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens were positive for ER, although some of the cells in the ductus deferens were negative. The epithelial cells of the ductules in the epididymis stained positive for ER, but the immunoreactions were negligible in the ductus deferens of immature birds. These results suggest that the epididymis and ductus deferens in quail possesses PR, AR and ER receptors. Each receptor is expressed before sexual maturation, although enhancement of ER expression may occur during maturation. 相似文献
4.
There are concerns that genetically modified soybean might threaten the genetic diversity of the wild soybean populations that are distributed in East Asia because genetically modified soybean has no crossing barrier with wild soybean. A simple and effective method to prevent hybridization via pollen flow is spatial separation between the two species because their hybridization occurs only when they grow in close proximity. Therefore, the invasiveness of wild soybean needs to be known in order to secure the appropriate distances. As wild soybean seeds are dispersed mechanically by pod dehiscence, an experiment was conducted in which white sheets were placed on the ground, concentric circles were drawn around the parent plants, and the number of dispersed seeds within each 0.5 m‐wide zone were counted. About 40% of the produced seeds were dispersed and the number of dispersed seeds gradually declined as the distance from the parent plants increased. The model that explained the relationship between the number and distance of the dispersed seeds was produced by using a generalized linear model procedure. More than 95, 99, and 99.9% of the produced seeds stayed within 3.5, 5.0, and 6.5 m after natural pod dehiscence. Knowing these values is useful for evaluating the level of invasive risk by mechanical seed dispersal. The goal of the work is to efficiently and deliberately prevent hybridization by isolating genetically modified soybean fields and wild soybean populations by vegetation management, including weeding and setting up specific‐width buffer zones. 相似文献
5.
Tatsuyuki YOSHIDA Makoto SEKI Norio WATANABE Hiroki FURUTA Itaru YOSHIMURA Masahiro OSADA Koji CHIBA Konosuke OKADA Koh KAWASUMI Hitoshi USHIJIMA 《Animal Science Journal》2012,83(3):207-212
Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP‐based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1 ± 3.1 mm on US and a mean P4 concentration of 8.1 ± 2.3 ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4 ± 5.4 mm, 4.0 ± 2.8 ng/mL) (P < 0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18–25 days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P < 0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7 days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P < 0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post‐estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL. 相似文献
6.
Ichiro YAMAMOTO Yukinori YOSHIMURA Akira TSUKADA Norio KANSAKU Nobumichi TSUSHIMA Minoru TANAKA 《Animal Science Journal》2008,79(1):116-121
To examine the involvement of ghrelin in growth hormone (GH) synthesis in the chicken pituitary, the regional distribution of GH secretagogue receptor (GHS‐R)/ghrelin receptor was investigated. Quantitative real‐time polymerase chain reaction (Q‐PCR) analysis revealed that the expression levels of GHS‐R and GH mRNA in the caudal lobe were about fourfold and sevenfold higher in the cephalic lobe of 7 day‐old chickens, respectively. Immunohistochemical analysis showed that GHS‐R immunoreactivity was more abundant in the caudal lobe than in the cephalic lobe, as was the case for GH immunoreactivity. By Q‐PCR, parallel increases were observed in the expression levels of ghrelin mRNA in the proventriculus and GH mRNA in the pituitary from embryonic day 17 to day 7 after hatching, whereas no significant change was found in the expression levels of GHS‐R mRNA in the pituitary during this period. These results suggest that proventriculus‐derived ghrelin may participate in pituitary GH synthesis by acting on its receptor during late embryonic development and the early post‐hatching period in chickens. 相似文献
7.
Lingual antimicrobial peptide (LAP), a member of the β-defensin family in cows, is involved in the innate immune system and plays a crucial role in killing a large variety of microorganisms. The aim of the present study was to demonstrate the immunolocalization of LAP in the mammary glands of cows. A LAP antibody was raised in a rabbit by immunity with a synthetic 11 amino acid sequence out of a 42-amino acid sequence of the mature form of LAP. The specificity of the LAP antibody was checked using a competitive immunoassay and Western blotting. Paraffin sections of the mammary gland were immunostained with LAP antibody. In the competitive immunoassay, an increase of synthetic LAP concentration suppressed the optical density. Western blotting analysis for LAP revealed the presence of the LAP peptide in mammary alveolar tissue. When the mammary gland was immunostained with LAP antibody, epithelial cells of both infected and non-infected alveoli were immunopositive. These results indicate that LAP is localized in the epithelium of non-infected as well as infected alveolus in the mammary gland in cows. 相似文献
8.
SHINSUKE TOMITA EIJI NAWATA YASUYUKI KONO TATSUYA INAMURA YOSHIKATSU NAGATA CHAIRAT NOICHANA AKKADET SRIBUTTA 《Weed Biology and Management》2003,3(2):68-76
In north-east Thailand where rainfed paddy cultivation is commonplace, direct dry seeding is replacing transplanting to increase the frequency of successful plantings and to save labor. The present study shows the impact of this change on paddy vegetation from agricultural and ecological viewpoints. One hundred and seventy-nine paddy fields from a wide range of climatic, topography, soil and hydrological conditions were used in this study. Authors visited these fields every 3 weeks during the rainy seasons of 1996–1998 to collect data about water conditions, rice growth, progress of cultivation, paddy vegetation and roughness (unevenness) of the soil surface. Analysis of this data revealed that direct dry seeded fields are resource-poor and have a wider range of water conditions within a field than transplanted fields due to a rougher soil surface. This results in lower productivity of total vegetation for rice growing in direct dry seeded fields. However, weed productivity was not significantly different between the direct dry seeding and transplanted fields. Direct dry seeded fields have more species-rich vegetation and greater diversity than the transplanted fields. Previous planting methods for particular fields did not influence productivity and diversity of paddy vegetation. It is concluded that the use of direct dry seeding increases biomass production of rice and the diversity of the paddy vegetation. The present results also suggest that an analytical framework be used to integrate agricultural and ecological studies of paddy vegetation in order to harmonize agricultural productivity with biological diversity. 相似文献
9.
SHUNJI KUROKAWA NORIHIRO SHIMIZU SUNAO UOZUMI YOSHINORI YOSHIMURA 《Weed Biology and Management》2003,3(1):28-36
The source of the velvetleaf spreading its distribution rapidly and causing serious problems in forage fields all over Japan since the mid 1980s was thought to be a new accidental introduction of seeds from velvetleaf mingled in some imported grains from the USA and Australia. However, velvetleaf used to be cultivated as a fiber crop until the 1880s. We examined the intraspecies variations, such as morphological characteristics and growth habits, using accessions previously collected and obtained from imported grains. Using principal component analysis (PCA), the accessions were classified into crop type and weed type. The crop type capsule was mostly an ivory color, and the weed type was mostly an ebony color. The crop type showed characteristics of a fiber crop, such as an erect form, uniform flowering and a low seed dormancy rate. Conversely, the imported grains were classified into the weed type which showed a strong weedy nature, such as branched form, long flowering period, high reproductive ability and a high dormancy rate. These results suggest that the new introduction is different from the indigenous fiber crop, and may possibly be the source of the present invasive velvetleaf because of its strong weedy nature. However, further studies comparing the new introduction directly with the present velvetleaf are necessary. 相似文献
10.
The aim of this study was to determine whether the population of lymphocytes expressing CD4 and CD8 molecules changed in the white follicles during atresia in chickens. Frozen sections of healthy, early atretic, advanced atretic and late atretic follicles were immunostained for CD4 and CD8, and the populations of positive cells were analyzed under a light microscope. In the healthy, early atretic and advanced atretic follicles both CD4+ and CD8+ cells were localized in the theca layer, but not in the granulosa layer. However, an influx of CD4+ and CD8+ cells was observed not only in the theca but also in the follicular cavity that was formed by disintegration of the oocyte in late atretic follicles. The frequency of CD4+ T cells in the theca layer did not differ among healthy, early atretic and advanced atretic follicles, but was significantly increased in the late atretic follicles (P < 0.05). The frequency of CD8+ cells showed a pattern of change that resembled that of CD4+ T cells, with a significantly greater population in late atretic follicles than the other follicles (P < 0.05). These results suggest that CD4+ and CD8+ cells are increased in the late atretic follicles, probably to promote the tissue regression. 相似文献