水稻耐冷性研究Ⅲ.特定颖花结实率作为耐冷性指标的分子依据

以云南稻种耐冷性资源昆明小白谷及弱耐冷性的日本品种十和田配制的杂交F2代为材料,采用159个RFLP及SSR分子标记构建的连锁图和STATISTIC等分析软件,以单株结实率作为耐冷性评价指标.分析结果显示单株结实率与单株特定颖花结实率之间的相关系数(r)为0.8364;与耐冷性(以单株结实率为指标)相关的分子标记有43个,分布在8条染色体     

Horizontal distribution and seasonal variability of the epipelagic chaetognath Sagitta elegans in relation to hydrography in the western subarctic Pacific Ocean

The spatial distribution and seasonal variability of epipelagic chaetognaths along the Kurile Islands and off south-east Hokkaido, in the western subarctic Pacific Ocean. were investigated during the period from May 1990 to October 1992. Sagitta elegans was the dominant species among the epipelagic chaetognaths in the study area. Juvenile S. elegans were distributed mainly along the path of the mixed water which was determined by the acceleration potential anomaly (APA) at the iso-pycnal density surface of 26.6 σθ. The location of the path of The mixed water meandered around cyclonic and anticyclonic eddies. Catches of S. elegans were made at temperatures ranging from 4.5 to 22.2C. The juvenile distribution, however, was mostly restricted to between 1 and 4C of the potential temperature determined at the isopycnal density surface of 26.6 σθ. Variability in the juvenile abundance within the path of the mixed water could be caused by predation rather than by food limitation because microzooplankton, which are known to he prey for juveniles, were abundant enough to meet the food requirements of juveniles in the study area. Adults occurred in spring (April-May) and young individuals (juvenile and stage 1) were abundant in summer (June-July), when a strong thermocline developed. The main spawning period appears to be during April-May, with a possible second spawning period in the autumn.     

Variability in timing and magnitude of spring bloom in the Oyashio region, the western subarctic Pacific off Hokkaido, Japan

The spring bloom of phytoplankton is a well-established, regular, seasonal event in the western subarctic Pacific and is considered one of the most important conditions of massive production of pelagic fishes. A series of 12 cruises was conducted from 1990 to 1992 to examine the timing and magnitude of the spring phytoplankton bloom in the Oyashio region, the western subarctic Pacific off Hokkaido, Japan. An interannual variability in the bloom events was also analysed. On the basis of hydrographical characteristics, the study area was divided into three water masses: the Oyashio Water Mass, the Mixed Water Mass, and the Coastal Water Mass. Spring blooms were observed first in April in the Oyashio and the Coastal Water Masses, and continued to May in 1991 and 1992. However, no bloom was recorded in the Mixed Water Mass. High nutrient supply into the surface mixed layer during winter is likely to be one of the factors supporting an intense spring bloom in the Oyashio Water Mass. A significant positive relationship between log-transformed surface chlorophyll a concentration and maximum density gradient (MDG) within the euphotic layer was obtained in April, indicating the importance of vertical stability of the water column in the initiation of spring blooms in the Oyashio and the Coastal Water Masses. The spring blooms in 1991 were much more extensive and lasted longer than in 1990. It is suggested that meteorological conditions and abundance of grazers were responsible for this interannual difference.     

Age, growth and hatching season of the diamond squid Thysanoteuthis rhombus estimated from statolith analysis and catch data in the western Sea of Japan

Age, growth and hatching season were estimated for the diamond squid (Thysanoteuthis rhombus) migrating into the Sea of Japan based on analyses of statolith growth increments and length–frequency data of the catch in 1999–2004. Growth rates did not differ significantly between the sexes. The oldest squid was 306 days old, which provides further evidence that T. rhombus has a 1-year life span. The hatching season extended from January to September, with a peak in February–March, and the spawning grounds were suggested to extend from the far southwestern Pacific to the East China Sea. Using aging results from statolith analysis, growth was well described by a logistic formula, which also closely corresponded with the sequential progress of the mean mantle length in size–frequency distribution of the catch. Growth rates varied depending on the time of hatching; earlier-hatched squid grew faster than later-hatched ones, suggesting that the former hatched in warmer upper-stream areas of the Tsushima Current or the Kuroshio region and the latter hatched in colder mid- or downstream areas of the Tsushima Current.     

Effect of temperature, age class, and growth on induction of aestivation in Japanese sandeel (Ammodytes personatus) in Ise Bay, central Japan

We investigated the effects of temperature, age class, and growth on induction of aestivation in the Japanese sandeel (Ammodytes personatus) by means of rearing experiments and field surveys in Ise Bay, central Japan. Acoustic surveys and sampling of shoaling and aestivating sandeels indicated that the sandeels completed aestivation when the water temperature increased to 17–20°C. A rearing experiment showed that the mortality of sandeels reared without sand was greater than it was with sand, under replete feeding conditions. In a non‐aestivation rearing experiment without sand, the condition factor of the sandeels decreased when water temperatures exceeded 20°C, although they were fed to repletion. These results suggest that aestivation is induced by rising seawater temperature and plays an important role in energy conservation. The age‐1 group tended to start aestivation earlier than the age‐0 group in the field. Within the age‐0 group, larger sandeels tended to enter aestivation earlier. These observations indicate that fat reserves are an important cue to start aestivation.     

碎石填方坡面乔灌草植物群落构建方法的实验研究

碎石填方边坡是山区公路常见的一种坡面类型。表层为以碎石为主的土石混合体,土壤含量极少甚至没有,立地条件恶劣,导致坡面植被恢复非常困难。针对这一难题,以北京市门头沟区百花山旅游公路11 km处的45°碎石填方边坡为研究对象,采用"客土+保育块苗移栽"技术,在坡面上重建了乔灌草植物群落。施工4 a后,坡面草本植物群落的总覆盖度约为50%,平均高度约为40 cm;坡面木本植物生长状况良好,主根粗壮、根系发达且已深入碎石缝隙之中,其中山桃保育块苗的成活率为78%,高度为82 cm,地径为7.9 mm。实验结果表明,该方法可以在比较陡峭的碎石覆盖边坡上有效地构建乔灌草植物群落。     

Uterine Carcinosarcoma in a 2-year-old Female Wistar Hannover GALAS Rat

Carcinosarcomas are rare tumors in humans as well as rats and most commonly occur in the uterus. Recently, we observed a case of incidental carcinosarcoma of the uterus in a female Wistar Hannover GALAS [BrlHan:WIST@ Jcl (GALAS)] rat at 2 years of age. Histopathologically, the tumor was characterized by an admixture of malignant epithelial and nonepithelial elements. The carcinomatous components represented a type of endometrial carcinoma, consisting of glandular and solid proliferation of large-sized tumor cells. Prominent mitoses and tumor cell invasion were observed. The sarcomatous components were characterized by multifocal proliferation of severe atypical cells with cartilage matrix and were diagnosed as chondrosarcoma. Transitions between carcinomatous and sarcomatous components were observed, and many tumor cells in the solid lesion showed immunohistochemical reactivity with both cytokeratin and vimentin. Based on these findings, this tumor was diagnosed as a uterine carcinosarcoma. This is the first report of uterine carcinosarcoma in Wistar Hannover GALAS [BrlHan:WIST@Jcl (GALAS)] rats.     

Functional study of the central nervous system for farm animal husbandry

The purpose of this mini-review is to describe the recent approaches for revealing the function of the central nervous system in farm animals. The sensory organs are the first sites to gain environmental information. The behavior of the animals is outputted as a result of changes in the integrated neuronal systems, and is largely influenced by the external environment. Therefore, it is necessary to know how farm animals catch and recognize environmental changes. To understand the mechanisms of sensing and behavioral output, approaches for analyzing the brain function are required. Neuroscientific approaches are able to give cues for resolving abnormal behaviors such as stereotypy, and may lead to the improved housing and management of farm animals.     

Rapid activation of Mac-1(CD11b/CD18) molecules on macrophages by a new chemotactic factor 'Gasserokine' produced by Lactobacillus gasseri JCM1131T

The chemoattractant activity of a new chemotactic factor, 'Gasserokine' produced by Lactobacillus gasseri JCM1131^T, has been proposed as a novel immunological function of probiotic lactic acid bacteria. The focus of the present study was to understand the mechanism of the chemotaxis induced by Gasserokine, using activation of an adhesion molecule, Mac-1 (CD11b/CD18) on macrophages. The macrophage chemotaxis to Gasserokine was abolished by preincubation of macrophages with the anti-Mac-1 mAb. Gasserokine induced rapid serine phosphorylation of CD18 molecules within 1 min of stimulation, but the effect was short-lived. Substantial tyrosine phosphorylation was observed in CD18-associated protein of macrophages stimulated by Gasserokine. The tyrosine phosphorylation was confirmed in macrophages stimulated with Gasserokine and also serine/threonine phosphorylation was detected on CD18 molecules by laser microscopy using a double immunostaining method. These results suggest that selective activation of intracellular signaling cascades, such as the mitogen-activated protein kinase pathway, are related to the macrophage chemotaxis induced by Gasserokine.     

Histological comparison of malignant epithelioid mesothelioma in young and adult cattle

The histology and immunohistochemistry of pleomorphic and conventional epithelioid mesotheliomas were examined. The former was detected in two young calves aged 2 and 4 months and was characterized by pleomorphic and atypical cells with decreased expression of cytokeratin 7 (CK7). In contrast, the latter was found in a 31-month-old heifer, consisting of tumor cells uniform in size and shape with CK7 expression in nearly all cells. Production of collagen by tumor cells was demonstrated in both histological types, and was considered to be characteristic of bovine epithelioid mesothelioma. Pleomorphic mesothelioma is far more pleomorphic and mitotically active than conventional mesothelioma, and its normal counterpart may be immature mesothelial cells with high proliferation potential, which exist in fetal life and early calfhood.