Monoaminergic Innervation of the Caudal Neurosecretory System of the Carp, Cyprinus carpio

Monoamine fluorescence was studied in the caudal neurosecretory system of eighty-four adult carp, Cyprinus carpio, of either sex. Some neurosecretory cells were surrounded with monoaminergic fluorescent varicosities, while others were not. The varicosities werc: also found adjacent to nerve terminals or capillaries in the urophysis. Noradrenaline, but not adrenaline or dopamine, was detected memically in the urophysis and the spinal cord. These results suggest that noradrenergic neurons seem to regulate both the synthesis and the release of neurosecretory material in the carp caudal neurosecretory system.     

Cytochrome oxidase I gene sequence of Hypoderma sinense infecting yaks in the Qinghai-Tibet high plateau of China

The previous scanning electron microscopy study of the Hypoderma species suggested that Hypoderma sinense Pleske (H. sinense) was different from Hypoderma bovis (H. bovis) and Hypoderma lineatum (H. lineatum). In this study, the mitochondrial cytochrome oxidase I (COI) gene sequence of H. sinense was compared with those of the other two species. The H. sinense sequence showed only 88.3% homology to H. bovis and 88.5% to H. lineatum. The results of the sequencing analysis confirm that H. sinense is a different species from H. bovis and H. lineatum.     

Migration of warble fly larvae in the yak and optimum timing of ivermectin treatment

Sixty yaks were autopsied to determine the migration pattern of warble fly larvae. In August, first instars were observed in the body of yak for the first time. These larvae peaked in number in October. From November to February, second instars were detected and their number peaked in January. Third instars appeared in January and peaked in March. Forty-five yaks were administered with ivermectin: 15 animals in September, 15 in October and 15 in November. Between December and June, the number of warbles was checked by palpation. Although some warbles were observed in the September- and November-treated groups, no warbles were detected in the October-treated group. Treatment of yaks with ivermectin was most effective for warble fly in October.     

Optimal conditions for visualizing water-conducting pathways in a living tree by the dye injection method

To elucidate the water-conducting pathways in living trees by the dye injection method, suitable sample preparation procedures are needed. We evaluated quantitatively the properties and concentrations of three dyes (acid fuchsin, basic fuchsin and safranin) widely used for this purpose, and determined the optimal conditions required to avoid artifacts after dye injection into the sap stream of Pieris japonica D. Don. Among the dyes tested, an aqueous solution of acid fuchsin at a concentration of 0.1% or more was the most useful for delineating water movement. In non-transpiring stem segments, the vertical movement of acid fuchsin by capillarity and diffusion from the dye injection site was limited. However, acid fuchsin moved rapidly in the horizontal direction by capillarity and diffusion, and most xylem cells were stained within 2 h. A delay of more than 2 h between dye injection and examination of the tissues greatly reduces the precision of the method. Use of the dye injection method without appropriate, well-defined experimental procedures may give rise to misleading information about the functional water-conducting pathway in living trees.     

Gene Expression and Fungal Morphology in Submerged Culture Using Whole Barley of Aspergillus kawachii

The authors described a novel submerged batch culture system that produced high levels of amylase by Aspergillus kawachii using whole barley （WB）, the surface of which is covered by its husk. In this study, detailed analyses determining the amylase activities, residual sugars, fungal morphology and expression levels of genes were performed in a submerged culture using WB to address the mechanism underlying high amylase productivity in A. kawachii. High levels of glucoamylase and acid-stable u-amylase were produced in this culture, and expression levels of amylases, as well as glucose-repressive genes including high-affinity glucose transporter and peroxidase/catalase were also high. On the other hand, the morphology of mycelia was altered, with swollen, bulbous, multi-septum hyphae and conidiophores that normally form in a solid culture being partially generated. Furthermore, cell cycle and post-translational modification-related gene expression levels were altered, and were similar to those in the solid culture. These findings suggest that high amylase productivity in the submerged culture using WB is accompanied by both the up-regulation of amylase genes and activation of post-translational modifications due to fungal morphological changes being brought closer to those in the solid culture.     

Dynamic interaction of stargazin-like TARPs with cycling AMPA receptors at synapses

Activity-dependent plasticity in the brain arises in part from changes in the number of synaptic AMPA receptors. Synaptic trafficking of AMPA receptors is controlled by stargazin and homologous transmembrane AMPA receptor regulatory proteins (TARPs). We found that TARPs were stable at the plasma membrane, whereas AMPA receptors were internalized in a glutamate-regulated manner. Interaction with AMPA receptors involved both extra- and intracellular determinants of TARPs. Upon binding to glutamate, AMPA receptors detached from TARPs. This did not require ion flux or intracellular second messengers. This allosteric mechanism for AMPA receptor dissociation from TARPs may participate in glutamate-mediated internalization of receptors in synaptic plasticity.     

Requirement for hippocampal CA3 NMDA receptors in associative memory recall

Pattern completion, the ability to retrieve complete memories on the basis of incomplete sets of cues, is a crucial function of biological memory systems. The extensive recurrent connectivity of the CA3 area of hippocampus has led to suggestions that it might provide this function. We have tested this hypothesis by generating and analyzing a genetically engineered mouse strain in which the N-methyl-D-asparate (NMDA) receptor gene is ablated specifically in the CA3 pyramidal cells of adult mice. The mutant mice normally acquired and retrieved spatial reference memory in the Morris water maze, but they were impaired in retrieving this memory when presented with a fraction of the original cues. Similarly, hippocampal CA1 pyramidal cells in mutant mice displayed normal place-related activity in a full-cue environment but showed a reduction in activity upon partial cue removal. These results provide direct evidence for CA3 NMDA receptor involvement in associative memory recall.     

Effects of low and high levels of maternal nutrition consumed for the entirety of gestation on the development of muscle,adipose tissue,bone, and the organs of Wagyu cattle fetuses

This study aimed to investigate the effects of high and low levels of energy intake during the entire gestation period on the skeletal muscle development, organ development, and adipose tissue accumulation in fetuses of Wagyu (Japanese Black) cows, a breed with highly marbled beef. Cows were allocated to a high-nutrition (n = 6) group (fed 120% of the nutritional requirement) or low-nutrition (n = 6) group (fed 60% of the nutritional requirement). The cows were artificially inseminated with semen from the same sire, and the fetuses were removed by cesarean section at 260 ± 8.3 days of fetal age and slaughtered. The whole-body, total muscle, adipose, and bone masses of the fetal half-carcasses were significantly higher in the high-nutrition group than the low-nutrition group (p = 0.0018, 0.009, 0.0004, and 0.0362, respectively). Fifteen of 20 individual muscles, five of six fat depots, nine of 17 organs, and seven of 12 bones that were investigated had significantly higher masses in the high-nutrition group than the low-nutrition group. The crude components and amino acid composition of the longissimus muscle significantly differed between the low- and high-nutrition groups. These data indicate that maternal nutrition during gestation has a marked effect on the muscle, bone, and adipose tissue development of Wagyu cattle fetuses.