鸡源株与人源株H9N2流感病毒血凝素受体结合位点氨基酸比较与分析

H19N2病毒可以感染多种禽类和哺乳动物，包括人类。流感病毒血凝素受体结合位点的氨基酸可以影响受体结合特性。为了解鸡源株与人源株H19N2病毒受体结合部氨基酸的差异，作者对二者进行了比较与分析，结果表明，鸡源株与人源株血凝素受体结合部位氨基酸的第137、183、190、226位点存在差异，鸡源株在这些位点分别为K、N、AorVorT、LorQ而人源株则分别为R、H、E、L。虽然尚不清楚这些位点的改变对病毒与细胞亲和力及宿主范围的影响，但由于H9N2在我国养鸡业的普遍存在，加强H9N2病毒的分子流行病学监测有重要意义。     

Pueruli of Panulirus longipes bispinosus (Crustacea, Decapoda, Palinuridae) stranded on the beach of Kuroshima Island, Ryukyu Archipelago, southern Japan

ABSTRACT: Stranded organisms were observed on the sandy beach of Kuroshima Island, Ryukyu Archipelago, in the early morning of 28 January 1993. Stranded organisms of 525 individuals were classified into 74 species. These organisms included 13 individuals of Panulirus pueruli, which were identical to P. longipes bispinosus. Kuroshima Island is located near Ishigakijima and Iriomote islands, Ryukyu Archipelago, where coral reefs develop. Coral reefs are common and develop in the Ryukyu Archipelago, southern Japan, with the exception of Yakushima and Tanegashima islands. Panulirus japonicus in Japanese waters has not been found in coral reef regions where P. longipes bispinosus are mainly found. The present study describes and identifies to species level puerulus specimens that were stranded on the beach of Kuroshima Island.     

家蚕肾形卵的荧光差异显示分析

Liang等建立的mRNA的荧光差异显示法 (flourescentdifferentialdisplay,FDD)具有高效、安全、有用信息多等特点。利用这一方法在mRNA水平上探讨了肾形卵 (ki)与正常卵在初期胚胎阶段的基因表达 ,回收了差异片段 10条 ,并对其差异进行了验证。其中之一的片段序列分析表明为低分子量热激蛋白基因 (smallheatshockgene)。     

Fatigue property of high-performance polyethylene netting twine

Tensile and knot fatigue property of high-performance polyethylene (HPPE), regular polyethylene (PE), nylon multifilament (PAmu), and nylon monofilament (PAmo) under cyclic loading conditions were investigated. The durability of HPPE under tensile fatigue testing was largest, followed by PAmo, PAmu and PE. In knot fatigue, the largest was PAmo, followed by HPPE, PAmu, and PE. High resistance by HPPE to the cyclic loads was also confirmed by scanning electron microscopy, which showed that HPPE suffered the least damage from abrasion compared with the other twines. From the measurement of elongation changes during the cyclic loading, HPPE had very small changes. The low elongation value of HPPE was probably the result of its better fatigue property because there was less damage from abrasion.     

Prey selection of common minke (Balaenoptera acutorostrata) and Bryde's (Balaenoptera edeni) whales in the western North Pacific in 2000 and 2001

A study of common minke and Bryde's whales was conducted in the western North Pacific in the 2000 and 2001 summer seasons to estimate prey selection of cetaceans as this is an important parameter in ecosystem models. Whale sighting and sampling surveys and prey surveys using quantitative echosounder and mid‐water trawl were carried out concurrently in the study. Biomasses of Japanese anchovy, walleye pollock and krill, which were major prey species of common minke and Bryde's whales, were estimated using an echosounder. The results suggested that common minke whale showed prey selection for Japanese anchovy while they seemed to avoid krill in both the offshore and coastal regions and walleye pollock in the continental shelf region. Selection for shoaling pelagic fish was similar to that in the eastern North Atlantic. Bryde's whale showed selection for Japanese anchovy in August 2000 and July 2001, while it showed prey selection for krill in May and June in 2001.     

Use of parasites as biological tags for separating stocks of the starspotted dogfish Mustelus manazo in Japan and Taiwan

ABSTRACT:   The parasite fauna of Mustelus manazo from seven localitiesin Japan and Taiwan was assessed for the feasibility of using parasitesas biological tags for the identification of different host stocks.Examination of 1038 host specimens resulted in 13 parasite speciesrecorded: one nematode, two myxosporeans, two copepods and eightcestodes. Although relatively low overall prevalence of the firstfive species at different localities showed some significant differences,the samples collected in Tokyo Bay bore the lowest similarity (19.2%).These results support previous studies, which suggested the existenceof a unique host stock in Tokyo Bay. Accordingly, combinations ofprevalence data may provide useful information on stock identification.Cestodes probably have the greatest potential for use as biologicaltags. Detailed examination of 25 specimens of M .  manazo fromAomori and Tokyo Bay disclosed eight species of intestinal cestodes.A canonical discriminant analysis based on these species separatedthe two localities clearly.     

Mass spectrometric detection of proopiomelanocortin (POMC)-related peptides following molecular cloning of POMC cDNA in bigeye tuna Thunnus obesus

Several pituitary hormones, including adrenocorticotropin (ACTH), melanotropin (MSH) and β-endorphin, are generated from a common precursor protein, proopiomelanocortin (POMC). In fish, in addition to steroidogenesis of ACTH and melanogenesis of MSH, immunomodulating activity has been found in some POMC-related peptides. To investigate the functions of these peptides in the homologous system, it is necessary to establish a convenient detection method for the peptides. The present study aimed to establish a method for the detection of POMC-related peptides in bigeye tuna Thunnus obesus using a small amount of tissue sample, but not requiring peptide purification. We first determined the nucleotide sequence of tuna POMC cDNA. The cDNA was composed of 1084 base pairs (excluding the poly A tail) that encoded POMC consisting of 222 amino acids. We then fractionated an acid-acetone extract of one pituitary by reverse-phase high performance liquid chromatography (HPLC) and determined the molecular weight of each separated peptide by mass spectrometry. Consequently, we detected eight POMC-related peptides by comparing the values to the deduced amino acid sequence. Thus, the present study enabled the detection of POMC-related peptides from a small amount of tissue without the use of several purification steps.     

Effects of Rhizopus extract administration on somatic growth and sexual maturation in lacustrine sockeye salmon Oncorhynchus nerka

ABSTRACT: The filamentous fungi Rhizopus , like many fungal species, possesses physiologically active substances. Rhizopus extract (RU) is reported to be effective for various aspects of growth and reproduction in many vertebrates. The effects of RU administration on body growth and plasma levels of steroid hormones were investigated in lacustrine sockeye salmon Oncorhynchus nerka . One-year-old fish were fed daily with RU (20 mg/kg feed) from July 1999 to October 2000 for 15 months. Fish were sampled every month and plasma levels of testosterone (T), 11-ketotestosterone (11-KT), estradiol-17β (E₂) and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) were measured by time-resolved fluoroimmunoassay. Body growth of RU-fed fish of both sexes increased significantly in 1⁺ and 2⁺ October, and 2⁺ January–March and July. All RU-fed males and one female matured in 2⁺ October. RU-fed 1⁺ precociously mature males showed increased plasma levels of T, 11-KT and DHP in 1⁺ October. In 2⁺ males, RU significantly elevated plasma levels of T from May to June, 11-KT from June to July, and DHP in October. In sockeye salmon, administration of RU accelerated body growth of both sexes and sexual maturation in males, suggesting physiologically active substances present in RU enhance somatic growth and sexual maturation by sex-specific mechanisms.