Effect of Japanese catfish Silurus asotus lipid intake on the lipid components of plasma and liver in adult mice

SUMMARY: The effect of Japanese catfish Silurus asotus lipid intake on the lipid metabolism of male adult mice was determined by measuring the total cholesterol, triacylglycerol, phospholipid, and fatty acid content of plasma and liver. Mice were fed diets containing 5% lard, 5% Thai catfish oil, 5% Japanese catfish lipids, or 5% sardine lipids for 4 weeks. The arachidonic acid (20 : 4n-6) content was highest in the livers of mice fed the Japanese catfish lipid diet and docosahexaenoic acid (22 : 6n-3) content was higher in livers of the Japanese catfish lipid and sardine lipid diet groups than those of the lard and Thai catfish diet groups. However, no significant differences were observed in the 22 : 6n-3 levels in either plasma or liver between the Japanese catfish lipid and sardine lipid diet groups. Although the Japanese catfish lipid diet contains, by far, the highest cholesterol content (143 mg/100 g), there was no significant difference in the plasma cholesterol levels between the lard, Thai catfish oil and Japanese catfish lipid diet groups. However, the liver cholesterol levels of mice fed the Japanese catfish lipid diet were lower than those of mice fed the Thai catfish oil diet, and were similar to those of animals fed a sardine lipid diet. These results suggest that Japanese catfish lipids are suitable components of the diet for ingestion of 20 : 4n-6 and 22 : 6n-3, and for decreasing the cholesterol content of liver.     

Cultivar and anatomical analysis of corolla enlargement of petunia (Petunia hybrida Vilm.) by cytokinin application

We found that the corolla of petunia (Petunia hybrida Vilm.) could be conspicuously enlarged by the separate application of three cytokinins: forchlorfenuron (CPPU), N⁶-benzylaminopurine (BA), and zeatin. To obtain the same enlargement as that achieved by CPPU, approximately 30 and 900 times the concentration of BA and zeatin, respectively, were required. CPPU at 3.2 μmol/L increased the limb area of the corollas of 15 cultivars to between 1.3 and 2.4 times (1.8 times on average) the size of the control area. The increase was negatively correlated (R = 0.58) with the “genetic” limb area (i.e., that of the untreated plant). The enlargement of the corolla caused by cytokinin application was mainly attributed to an increase in cell number in most cultivars. This increase resulted from a high rate of cell proliferation and from prolongation of the cell proliferation phase during corolla development. This anatomical change caused by cytokinin application was similar to the anatomical difference among cultivars because genetic differences in limb area resulted mainly from differences in cell number.     

Different cross-reactivity of human and rodent sera to Tula virus and Puumala virus

Tula virus (TULV) and Puumala virus (PUUV) are hantaviruses carried by the bank vole (Myodes glareolus) and European common vole (Microtus arvalis), respectively. PUUV is a causative agent of hemorrhagic fever with renal syndrome (HFRS), while TULV is thought to be apathogenic to humans. The N-terminal regions of the N proteins from TULV and PUUV were expressed and applied as enzyme-linked immunosorbent assay (ELISA) antigens. Colonized Japanese grass voles (Microtus montebelli) and BALB/c mice were used for experimental inoculation of the vole-borne hantaviruses TULV and PUUV. Voles and mice showed significant antibody production toward both viruses, but these antisera showed little cross-reactivity between TULV and PUUV in the immunofluorescence antibody assay and ELISA. In contrast, sera from patients with HFRS caused by PUUV exhibited high cross-reactivity against the TULV antigen, and sera from a natural rodent reservoir showed moderate cross-reactivity against the heterologous antigen, indicating that the antigenic cross-reactivity between TULV and PUUV differs in sera from rodents and humans.     

Generation of recombinant bovine interferon tau in the human embryonic kidney cell line and its biological activity

The objective of this study was to generate recombinant bovine interferon tau (rbIFNT) in mammalian hosts. The complementary DNA encoding bovine IFNT2 was cloned for the construction of pRcRSV‐bIFNT2 expression vector. The expression vector was transfected to 293 cells. Transfected cells harboring expression vector were selected with G418. Highly expressing clonal line was adapted to serum‐free suspension culture in a spinner flask. The recombinant protein had 24 kDa apparent molecular mass, suggesting being expressed as a glycoprotein, and was purified from serum‐free conditioned medium by the combination of Diethylaminoethanol Sepharose ion exchange and Sephacryl S‐200 HR gel filtration. A total of 7.3 mg rbIFNT was obtained from 13.5 L conditioned medium. Generated rbIFNT was biologically active in terms of antiviral activity measured by the plaque inhibition assay with Madin‐Darby bovine kidney cells and the vesicular stomatitis virus. The recombinant protein was also utilized for immunization to raise antibodies in the rabbit. The generated antibody was capable of use in both Western blotting and the binding assay. The results in the present study suggest that a certain amount of rbIFNT is raised in mammalian hosts by using conventional plasmid vector and its antibody provides useful tools for studies in the biology of bovine IFNT.     

Uterine and ovarian blood flow in a Holstein Friesian cow with aplasia of one uterine horn

The ovarian dynamics and uterine and ovarian blood flows of a 6-year-old (2 parturitions) Holstein Friesian cow with right uterine horn aplasia were observed during two estrous cycles. In one estrous cycle, a corpus luteum (CL) formed in the right ovary, but regression of the CL and subsequent ovulation were not observed. In the other estrous cycle, a CL formed in the left ovary and delayed regression of the CL and subsequent ovulation were observed. The blood velocity of the right uterine artery was lower than that of the left uterine artery throughout both estrous cycles when a CL formed in either the right and left ovary. The blood velocities of the right and left ovarian arteries were unaffected by right uterine horn aplasia and changed depending on the presence of a CL. These results indicated that the blood flow of the right uterine artery was very weak and that aplasia of one uterine horn affects the estrous cycle, especially CL regression.     

Effect of food amount and temperature on growth rate and aerobic scope of juvenile chum salmon

Offshore migration of Pacific salmon Oncorhynchus spp. is partly triggered by increasing body size and high motility in the early stages of life. The survival of juvenile salmon may depend on their growth rate during the first few months in the sea, and this factor partly regulates the dynamics of adult populations. Here, we assessed the effects of water temperature and food availability on the growth of juvenile chum salmon O. keta. In addition, by combining the measurements of metabolic performance for growth and activity (Absolute Aerobic Scope: AAS) with a bioenergetics model, we estimated the energy allocation for different activities in the juveniles. Under high temperatures (14 °C), juveniles reared at low food levels (1% body weight) allocated less than half their energy for growth than those reared at high food levels (4% body weight). These findings suggest that high temperature and low food level constrain the growth of juveniles, providing an insight into the effect of the recent increase in warm and low-nutrient water masses on survival of juveniles and catches of adult chum salmon on the Pacific side of Honshu Island, Japan.