Distinct regional profiles of trace element content in muscle of Japanese eel Anguilla japonica from Japan, Taiwan, and China

Trace element distribution patterns were examined in Japanese eel from five Asian regions for the purpose of identifying the elements and patterns that could be used to determine provenance. Distinctive patterns were found in eels from the Japanese prefectures of Miyazaki, Kagawa, and Shizuoka, and from Taiwan and China. The levels of six trace elements, selenium, mercury, copper, manganese, zinc, and arsenic, in muscle tissue varied among eels of different origins, and factorial analysis of the elemental patterns showed that Factor 1 was attributable to selenium and mercury levels and Factor 2 to zinc and copper levels. Multivariate analysis showed that the patterns of elemental composition in fish muscle were mainly differentiated by these two factors.     

Parental Contributions in a Japanese Flounder Hatchery Inferred from Mitochondrial DNA Haplotypes

We analyzed a portion of the mitochondrial genome of hatchery Japanese flounder Paralichthys olivaceus to compare the genetic characteristics between maternal parents and their offspring. The maternal parents consisted of 11 subcultured fish (broodstock taken from hatchery-raised fish) and 41 wild fish. A 1098 base pair region extending from the 3'half of the cytochrome b gene to the central domain of the control region of mtDNA was amplified by PCR and analyzed using 11 restriction endonucleases. We also analyzed the number of copies of tandem repeats in the control region from the sizes of the PCR products. Each female parent had a unique haplotype, but only 31 of them were observed among the 66 offspring examined. From these results, we estimated that about 60% of the maternal parents in the hatchery contributed to the offspring we surveyed. The distribution of the family sizes of the wild fish was Poisson, which is consistent with expectation from a randomly mating population. In contrast, the distribution of family sizes of the subcultured fish deviated from a Poisson distribution. One of the sources of the deviation was that none of the six oldest fishes contributed to offspring production, which is consistent with observation that the spawning peaks later in the spawning season for older fish in flounder hatcheries. Uneven contribution of the female flounders in the hatchery has the potential to reduce substantially the genetic diversity in the offspring. Our results suggest that the misuse of subcultured fish as broodstock is an important cause of reduced genetic diversity in hatchery-raised flounder juvenile.     

Mechanisms of synthesis and action of 17α,20β-dihydroxy-4-pregnen-3-one,a teleost maturation-inducing substance

This article briefly reviews the current status of investigations, mainly based on the amago salmon,Oncorhynchus rhodurus, on the mechanisms of synthesis and action of 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-diOHprog). Pituitary gonadotropin is of primary importance in triggering meiotic maturation in teleost oocytes. However, the maturational action of gonadotropin is not direct, but is mediated by the follicular production of maturation-inducing substance (MIS). It is now well established that 17α,20β-diOHprog is the major MIS of salmonids. Production of this steroid occursvia the interaction of two distinct cell layers, the thecal and granulosa cell layers (2-cell type model). The first step of the stimulating effect of gonadotropin in both layers is the receptor-mediated activation of adenylate cyclase and formation of cAMP. Our findings suggest that the major stimulating action of gonadotropin on 17α,20β-diOHprog biosynthesis is due to the stimulation of 17α-hydroxyprogesterone production by the thecal layer and the selective induction of thede novo synthesis of 20β-hydroxysteroid dehydrogenase in the granulosa layer. 17α,20β-diOHprog acts at the surface of the oocyte. The early steps following 17α,20β-diOHprog action involve the formation of the major cytoplasmic mediator of this steroid, maturation-promoting factor (MPF). It was shown that goldfish MPF induces meiotic maturation inXenopus oocytes andvice versa. The chemical characterization of fish MPF is important for our understanding of the precise mode of maturational action of 17α,20β-diOHprog.     

Seasonal changes in the distribution of black sea bream Acanthopagrus schlegelii estimated by environmental DNA

Fisheries Science - This study aimed at characterizing the distribution of black sea bream Acanthopagrus schlegelii, a major target fish of commercial and recreational fishing, using environmental...     

First report of <Emphasis Type="Italic">Impatiens necrotic spot virus</Emphasis> infecting chrysanthemum (<Emphasis Type="Italic">Chrysanthemum morifolium</Emphasis>) in Japan

In 2009, chlorotic mottle and necrosis were observed on chrysanthemums (cv. Jimba) in Aomori Prefecture, Japan. A virus was isolated from the chrysanthemum plants by serial local-lesion transfer. The symptoms exhibited by the test plants, the particle morphology, the features of the protein and the potential for transmission by thrips were similar to those for Impatiens necrotic spot virus (INSV). The partial nucleotide sequences of the nucleocapsid protein gene and the 3′-untranslated sequence of the S RNA shared 99% identity with that of an INSV isolate. This report is the first of INSV infection of chrysanthemums in Japan.     

Mitochondrial DNA analysis reveals cytoplasmic variation within a single cultivar of perennial ryegrass (Lolium perenne L.)

Summary The extent of mitochondrial DNA restriction fragment length polymorphisms among individual plant samples of perennial ryegrass was determined. A total of 72 plants from three cultivars Yorktown II, S23 and Riikka were surveyed using three restriction enzymes (BamHI,EcoRI andHindIII) and three mitochondrial gene probes (coxI, coxIII andnad9). Polymorphisms were noted within each of the two cultivars Yorktown II and S23, whereas in Riikka no variation was detected. It seems most likely that the mitochondrial genome diversity within the same cultivar has resulted from non-homogeneous ancestor cytoplasms. The hybridization-based assay employed is simple to perform, gives unambiguous results, and may thus be used in mass screening of perennial ryegrass populations for breeding purpose.     

A black soybean seed coat extract prevents obesity and glucose intolerance by up-regulating uncoupling proteins and down-regulating inflammatory cytokines in high-fat diet-fed mice

Black soybean seed coat extract (BE) is a polyphenol-rich food material consisting of 9.2% cyanidin 3-glucoside, 6.2% catechins, 39.8% procyanidins, and others. This study demonstrated that BE ameliorated obesity and glucose intolerance by up-regulating uncoupling proteins (UCPs) and down-regulating inflammatory cytokines in C57BL/6 mice fed a control or high-fat diet containing BE for 14 weeks. BE suppressed fat accumulation in mesenteric adipose tissue, reduced the plasma glucose level, and enhanced insulin sensitivity in the high-fat diet-fed mice. The gene and protein expression levels of UCP-1 in brown adipose tissue and UCP-2 in white adipose tissue were up-regulated by BE. Moreover, the gene expression levels of major inflammatory cytokines, tumor necrosis factor-α and monocyte chemoattractant protein-1 were remarkably decreased by BE in white adipose tissue. BE is a beneficial food material for the prevention of obesity and diabetes by enhancing energy expenditure and suppressing inflammation.     

Cutaneous lymphoplasmacytic lymphoma with systemic metastasis in a cat

A lymphoplasmacytic lymphoma was diagnosed in a 12- year-old domestic cat that had a primary cutaneous mass involving the stomach, liver, kidneys, heart, abdominal wall, diaphragm, bone marrow and several lymph nodes. Histopathologically, the most characteristic feature of this tumor was the heterogeneity of cell components, such as small lymphocytes, well-differentiated plasma cells and plasmacytoid transformed lymphocytes. Amyloid was deposited in the skin, stomach, and several lymph nodes. Immunohistochemically, neoplastic small lymphocytes were positive for CD20, and well-differentiated plasma cells and plasmacytoid transformed lymphocytes were positive for λ-Ig light chains and MUM1/IRF-4. These results emphasize the importance of lymphoplasmacytic lymphoma as a differential diagnosis of extramedullary cutaneous plasmacytoma in cats.     

Characterisation of the carboxylesterase enzyme cauxin in the seminal fluid of the cat

The carboxylesterase cauxin is a major urinary protein in cats that is also found in seminal fluid (SF). This study investigated cauxin in feline SF including biochemical features, concentration, distribution and gene expression in epididymal tissue, and its reaction with acylglycerol substrates.Monomeric, dimeric, and/or multimeric forms of cauxin carrying N-glycosylations were detected on Western blots of feline SF but most were monomeric. Cauxin concentrations were markedly lower in SF (0.042 ± 0.020 mg/mL) than in urine (∼0.5 mg/mL) and cauxin gene expression was 60-fold lower in the epididymis than in the kidney. Immunohistochemical examination localised cauxin within the stereocilia and cytoplasm of epithelial cells lining the caput and corpus epididymis. Cauxin-positive spermatozoa were detected in the lumen of the cauda epididymis but not in the cytoplasm of the epithelial cell lining. Using an in vitro assay, cauxin hydrolysed saturated 1-mono- but not di- and tri-acylglycerols. The results suggest that cauxin secreted from the caput and corpus epididymis acts as an esterase on lipid within feline SF.     

Efficacy of some biodegradable films as pre-harvest covering material for guava

To produce guavas with good commercial or industrial potential, fruit farmers use phytosanitary practices such as fruit bagging. Bagging protects the fruit mainly from the attack of pests, such as the fruit fly (Anastrepha spp.) and the guava weevil (Conotrachelus psidii), and reduces the use of insecticides and fungicides. This investigation aimed to develop and produce biodegradable films from cassava starch and poly(butylene adipate-co-terephthalate) (PBAT) by extrusion for application in pre-harvest guava fruit bagging. After the fruit harvest, for 6–9 weeks all films were more fragile and rigid, but did not present cracks. BF70 was the most fragile and had the greatest tendency to tear; however, it remained whole until harvesting. Fruit bagged with films BF30, BF50, BF70 was analyzed for fruit quality and compared with PSF control and non-bagged fruit. There was no difference between the treatments relative to physical and chemical characteristics, indicating that biodegradable film did not influence fruit development when compared to the PSF control.