Kinetic scaffolding mediated by a phospholipase C-beta and Gq signaling complex

Transmembrane signals initiated by a broad range of extracellular stimuli converge on nodes that regulate phospholipase C (PLC)-dependent inositol lipid hydrolysis for signal propagation. We describe how heterotrimeric guanine nucleotide-binding proteins (G proteins) activate PLC-βs and in turn are deactivated by these downstream effectors. The 2.7-angstrom structure of PLC-β3 bound to activated Gα(q) reveals a conserved module found within PLC-βs and other effectors optimized for rapid engagement of activated G proteins. The active site of PLC-β3 in the complex is occluded by an intramolecular plug that is likely removed upon G protein-dependent anchoring and orientation of the lipase at membrane surfaces. A second domain of PLC-β3 subsequently accelerates guanosine triphosphate hydrolysis by Gα(q), causing the complex to dissociate and terminate signal propagation. Mutations within this domain dramatically delay signal termination in vitro and in vivo. Consequently, this work suggests a dynamic catch-and-release mechanism used to sharpen spatiotemporal signals mediated by diverse sensory inputs.     

Defense induced by a bis-aryl methanone compound leads to resistance in potato against Phytophthora infestans

Plants recognize certain microbial compounds as elicitors of their active defense mechanisms. In the present study, NUBS-4190, a synthetic bis-aryl-methanone compound elicited NO and ROS generation in potato suspension cultured cells and intact potato leaves. Hypersensitive cell death was found in these cultured cells and in potato leaves without the accumulation of phytoalexins in the tubers. Defense-related genes such as StrbohB, StrbohC, StNR1, StNR5, Sthsr203J and StPR1 were expressed in potato suspension cultured cells treated with NUBS-4190. Resistance against Phytophthora infestans also increased in NUBS-4190-treated potato leaves.     

Estimated amount of carbon accumulation of hybrid larch in three 31-year-old progeny test plantations

Hybrids generated by crossing Kuril larch (Larix gmelinii var. japonica) and Japanese larch (L. kaempferi) are expected to have high carbon accumulation ability because of fast growth and high wood density in Hokkaido, Japan. We estimated the amount of carbon accumulation of the hybrid larch in three progeny test plantations consisting of 21 full-sib families and compared the results to the carbon accumulation of open-pollinated progenies of Japanese larch plus-trees (improved Japanese larch). Gene-environment interactions were not observed for tree height and diameter at breast height but were seen for wood density (area-weighted density, AWD). The amount of carbon accumulated per unit area (C_stand) positively correlated with the stand volume. The AWD did not correlate with the C _stand; therefore, families with high wood density can be selected independent of the C _stand. The C _stand of the best full-sib family, female parent half-sib family, and male parent half-sib family at three sites were 106.1, 84.6, and 93.2 Cton·ha⁻¹, respectively. All these values exceed the mean for the improved Japanese larch, which has a C _stand value of 82.5 Cton·ha⁻¹.     

Monoblastic leukemia (M5a) with chronic basophilic leukemia in a cat

A cat was presented with depression and anorexia. The complete blood cell count (CBC) revealed non-regenerative anemia (PCV, 8.5%), marked thrombocytopenia (2,400/µl), and leukocytosis (32,090/µl). In the peripheral blood, proliferation of blast cells (85%; 27,276/µl) and basophils (7.7%; 2,460/µl) was observed. Bone marrow aspirate showed hyperplasia with 8.8% blasts and 90.2% basophils of all nucleated cells. The blast cells were negative for myeloperoxidase staining and positive for alpha-naphthol butyrate esterase staining, indicating the agranular blasts are monoblasts. Thus, acute monoblastic leukemia (M5a) with chronic basophilic leukemia was diagnosed. Basophils accounted for more than 40% of the bone marrow, and we diagnosed secondary basophilic leukemia. Secondary basophilic leukemia should be included in the differential list when abnormal basophil increases are observed in feline bone marrow.     

Pathological features of hepatic portal venous gas in a cat

An 8-year 8-month-old castrated male Munchkin presented with vomiting, anorexia and hypoactivity. Computed tomography revealed excessive gas accumulation within the intestinal lumen and gas bubbles in the liver, spleen, and portal venous system, indicating hepatic portal venous gas. The cat died without any significant improvement, and mild splenomegaly was found at necropsy. Histologically, multiple gas vacuoles were diffusely observed in the liver and spleen. In the stomach, multiple gas vacuoles and scattered focal ulcers were detected within the mucosa. Multifocal hemorrhage was noted in the small and large intestines, whereas gas vacuoles were not present. Based on these findings, a gastric ulcer under high gas pressure may have provided an entry point for gas into the portal venous system.     

Anatomical evaluation of hepatic vascular system in healthy beagles using X-ray contrast computed tomography

Liver contrast X-ray computed tomography (CT) has been used for evaluation of hepatic vessels for liver transplantation, liver lobectomy, interventional radiology and diagnosis of hepatocellular carcinoma in humans. However, there remains scant available anatomical information on normal hepatic vessels in the veterinary field. In this study, visualization of hepatic vessels was evaluated in 32 normal beagle dogs by X-ray contrast CT using triple phase images. The following hepatic vessels were clearly visualized: arterial, portal and hepatic veins. With regards to the running patterns of the portal vein and hepatic vein, there were no significant differences between the dogs. However, the hepatic artery exhibited some differences in each dog. In particular, the hepatic artery of the quadrate lobe and the right lateral lobe had many running patterns. The results of the present study could be useful for veterinary diagnosis, surgery and interventional radiology.     

SGT1 and HSP90 are essential for age-related non-host resistance of Nicotiana benthamiana against the oomycete pathogen Phytophthora infestans

The oomycete pathogen, Phytophthora infestans, is the causal agent of potato late blight, which is one of the most destructive and economically important plant diseases. We investigated the interaction between P. infestans and Solanaceous model plant Nicotiana benthamiana. Mature N. benthamiana plants were resistant to 8 isolates of P. infestans, whereas relatively young plants were susceptible to all isolates. Analysis with virus-induced gene silencing (VIGS) indicated that NbSGT1 and NbHSP90, genes essential for the function of R proteins, are required for the resistance of N. benthamiana to P. infestans. NbSGT1 was also required for the production of reactive oxygen species (ROS), hypersensitive cell death and expression of NbEAS, a gene for phytoalexin biosynthesis, induced by INF1, a secretory protein derived from P. infestans. These results suggested that N. benthamiana possibly possesses a broad-spectrum R protein against P. infestans, which requires an SGT1/HSP90-dependent mechanism, for the recognition of a conserved molecular pattern of P. infestans.     

Occurrence of two distinct Theileria lineages in sika deer (Cervus nippon) of Iwate Prefecture, Japan

In the present study, we tried to detect protozoan blood parasites from the liver or blood of 141 Japanese sika deer (Cervus nippon) in Iwate Prefecture of Japan by polymerase chain reaction. Approximately 500-bp amplicons were obtained in 76 (53.9%) of 141 samples by amplification for V4 hyper-variable regions of the 18S rRNA gene, and the amplicons were considered to be DNA of Theileria species. The complete nucleotide sequences (1701-bp) of the 18S rRNA gene were determined in 25 samples and were divided into 8 genotypes that were phylogenetically separated into two distinct lineages showing a monophyletic relation. The two lineages of Theileria were detected in different rates (12 and 88%) from sika deer in Iwate Prefecture.     

Malignant mixed tumor in the salivary gland of a cat

The presence of a malignant mixed tumor, also known as a carcinosarcoma, in the salivary gland is very rare. Such tumors, which are typically aggressive, are characterized by the presence of carcinomatous and sarcomatous components. A 9-year-old neutered female domestic short-haired cat presented with swelling in the right mandibular lesion that had rapidly enlarged over the previous 3 weeks. Physical examination revealed a large, fluctuated and painless subcutaneous swelling that was associated with a firm mass. Radiographs of the head revealed a soft-tissue density that involved faint circular calcific opacity. Contrast-enhanced computed tomography revealed that the peripheral capsulated cystic area had a contrast enhanced region without bone lysis. The cat received a total excision of the mass and postoperative radiotherapy. Histopathological analysis of the mass revealed that it was a malignant mixed tumor. Metastasis to the lung was discovered 7 weeks later, at which time treatment was stopped.