Mapping of quantitative trait loci controlling seedling vigor in rice (Oryza sativa L.) under submergence

Submergence-induced suppression of seedling vigor is a serious constraint particularly in the direct seeding rice cultivation system. To identify quantitative trait loci (QTLs) associated with seedling vigor in rice under submergence, a mapping population of 98 Backcross Inbred Lines derived from a cross of Nipponbare/Kasalath//Nipponbare was used. Phenotypic evaluation of seedling vigor under submergence was based on shoot length (SHL), root length (RTL) and shoot fresh weight (SFW) using a test tube bioassay method. Thirty-two putative QTLs were detected among which 7 were for SHL, 11 for RTL and 14 for SFW. Phenotypic evaluation was also made of the parental lines and a set of 54 chromosome segment substitution lines in which Nipponbare segments were substituted for by their homologous Kasalath segments covering the entire rice genome. Two QTLs with more than 10 % contribution to the total phenotypic variance were verified for SHL, and at least one for RTL and six for SFW on chromosomes 1, 3, 4, 6 and 7 at the 1 % significance level. Among these, all but two showed reductions in one, two or all three traits. Our present and previous results suggest that the Nipponbare genome has a potential to improve seedling vigor under submergence and that japonica germplasms can be used to breed for this important trait in indica rice.     

Turbid water induces refuge behaviour of a commercially important ayu: A field experiment for interstream movement using multiple artificial streams

Riverine systems are inherently dendritic in nature, and turbid water may not necessarily flow equally throughout an entire catchment. Tributaries have the potential to serve as refugia from temporarily turbid water in the main stem. As ayu (Plecoglossus altivelis) are one of the important species for the inland fisheries industry and recreational fishing, their behaviour in a branched river network is a primary concern. We released ayu with radio‐transmitting tags into two experimental streams that joined at a downstream pool. Turbid water was released into one of the streams, and we identified whether avoidance movement of ayu between the two experimental streams was triggered by flowing turbid water. The suspended solid concentration elevated rapidly after adding the turbid water and was maintained at more than 400 mg/L for 3 hr. Avoidance movement of ayu was triggered when the suspended solid concentration exceeded approximately 200 mg/L. Then, most ayu moved from the turbid stream to the nonturbid one, leading to a difference in ayu density between the two streams. Therefore, we demonstrated that turbid water induced interstream movement of a commercially important ayu as refuge behaviour, suggesting that river connectivity is important for the persistence of the ayu.     

B‐cell intestinal lymphoma with Mott cell differentiation in a 1‐year‐old miniature Dachshund

Abstract: A 1‐year‐old intact female miniature Dachshund was presented with hematochezia, vomiting, and diarrhea of more than 1‐week duration. An abdominal mass was palpated, which at exploratory surgery was found to be a 7‐cm‐long thickened section of ileum. The thickened ileum was resected. Impression smears revealed numerous small‐ to medium‐sized lymphocytes, with a smaller number of cells resembling Mott cells. The Mott‐like cells contained multiple pale vacuoles that were positive for periodic acid‐Schiff (PAS) in wet‐fixed smears, consistent with Russell bodies. Histologic evaluation of the surgically excised ileum revealed 2 populations of neoplastic lymphoid cells. The majority were uniform medium‐sized lymphocytes with hyperchromatic oval or round nuclei and inconspicuous nucleoli. The remaining cells resembled Mott cells, which contained several PAS‐positive eosinophilic globules in the cytoplasm, occasionally compressing the nucleus. The majority of neoplastic cells stained positively for vimentin, CD20, CD79a, and Pax‐5, but were negative for CD3 and lysozyme; 43.5% of cells stained positively for Ki‐67. The Mott cells were strongly positive for immunoglobulin but were negative for Pax‐5. Using electron microscopy, a homogenous substance of intermediate electron density was observed frequently in the cisternae of rough endoplasmic reticulum in the cytoplasm of the Mott cells, and rarely in the perinuclear cisternae of the lymphoid cells, corresponding to the site of immunoglobulin staining. Monoclonal rearrangement of immunoglobulin heavy‐chain (IgH) gene was observed by PCR testing for lymphocyte–antigen receptor rearrangement. The morphologic features, immunophenotype, and IgH gene rearrangement verified the lymphoid cells were neoplastic (mature cell type) and had a B‐cell phenotype, with evidence of immunoglobulin production and differentiation into Mott cells. This case was unusual because of the age of the dog and because most intestinal lymphomas are T‐cell phenotype. The Mott cell morphology also differed from typical mature B‐cell lymphoma types and may be a unique B‐cell lymphoma variant.     

Evaluation of biomarkers of kidney injury following 4% succinylated gelatin and 6% hydroxyethyl starch 130/0.4 administration in a canine hemorrhagic shock model

Objective : To investigate the association between synthetic colloids and biomarkers of acute kidney injury (AKI) in dogs with hemorrhagic shock. Design : Experimental interventional study. Setting : University. Animals : Twenty‐four healthy ex‐racing Greyhounds. Interventions : Anesthetized Greyhounds subjected to hemorrhage for 60 min were resuscitated with 20 mL/kg of fresh whole blood (FWB), 6% hydroxyethyl starch (HES) 130/0.4, 4% succinylated gelatin (GELO), or 80 mL/kg of isotonic crystalloid (CRYST) over 20 min (n = 6 per treatment). Concentrations of biomarkers of AKI were measured at baseline, end of hemorrhage, and at 40 (T60), 100 (T120), and 160 (T180) min after fluid bolus. Biomarkers included neutrophil gelatinase‐associated lipocalin in urine and serum (uNGAL; sNGAL), and urine cystatin C (uCYSC), kidney injury molecule‐1 (uKIM), clusterin (uCLUST), osteopontin, gamma‐glutamyl transferase, monocyte chemoattractant protein‐1 (uMCP), interleukin‐6, interleukin‐8, protein (uPROT), hyaluronan, and F₂‐isoprostanes. Renal histology was scored for tubular injury and microvesiculation. Biomarker fold‐change from baseline was compared between groups using mixed effects models (Bonferroni–Holm corrected P<0.05). Frequencies of histology scores were compared by Fisher's exact test. Measurements and main results : In dogs treated with GELO, uNGAL fold‐change was markedly greater compared with all other groups at T60, T120, and T180 (all P<0.001), and uCYSC was greater at T60 compared with CRYST (P<0.001), and at T120 and T180 compared with all other groups (all P<0.001). Smaller, albeit significant, between‐group differences in uKIM, uCLUST, uMCP, and urine protein concentration were observed across the FWB, GELO, and HES groups, compared with CRYST. The GELO group more frequently had marked tubular microvesiculation than the other groups (P = 0.015) although tubular injury scores were comparable. Conclusion : In dogs with hemorrhagic shock, GELO was associated with greater magnitude increases in urine biomarkers of AKI and more frequent marked tubular microvesiculation, compared with FWB, CRYST, and HES.     

Transcriptomic profile reveals molecular events associated to focal adhesion and invasion in canine mammary gland tumour cell lines

The prevalence of cancer in animals has increased significantly over the years. Mammary tumours are the most common neoplasia in dogs, in which around 50% are presented in the malignant form. Hence, the development and characterization of in vitro models for the study of canine tumours are important for the improvement of cancer diagnosis and treatment. Thus, the aim of this study was to characterize cell lines derived from canine mammary gland neoplasias which could be further used for basic and applied oncology research. Samples of canine mammary carcinomas were taken for cell culture and 2 cell lines were established and characterized in terms of cell morphology, tumourigenicity and global gene expression. Both cell lines presented spindle‐shape morphology and shown common malignant features as in vitro invasion potential and expression of epithelial and mesenchymal proteins. Also, we found gene expression patterns between the 2 cell cultures in comparison to the normal mammary gland tissue. Cells from M25 culture showed a higher invasion and in vivo tumourigenic potential, associated to the overexpression of genes involved in focal adhesion and extracellular matrix communication, such as FN1, ITGA8 and THBS2. The phenotypic characterization of these cells along with their global gene expression profile potentially determine new therapeutic targets for mammary tumours.     

Spatial distribution pattern of attack of the oak borer,Platypus quercivorus (Murayama) (Coleoptera: Platypodidae), and scolytid ambrosia beetles (Coleoptera: Scolytidae) on fresh logs

The spatial distribution patterns of the attack on fresh logs ofPasania edulis was studied for the oak borer,Platypus quercivorus (Murayama), and two species of Scolytid ambrosia beetles,Xylosandrus crassiusculus (Motschulsky) andXyleborus attenuatus Blanford, in 1994 and 1995. On the logs where onlyP. quercivorus attacked, the entry holes were distributed uniformly when attack intensity was low. However, the distribution pattern became more aggregated with the increase in attack intensity. On logs where bothP. quercivorus and the two Scolytid species attacked, there was a negative association between the spatial distribution of the entry holes ofP. quercivorus and that of scolytids. Simultaneous attack of two scolytids also increased the degree of aggregation of the entry holes ofP. quercivorus. The entry holes of scolytids were distributed in groups irrespective of the attack intensity of scolytids andP. quercivorus. These results suggest an asymmetrical interspecific relationship betweenP. quercivorus and scolytids. Concentration of the entry holes ofP. quercivorus in a small area may cause a considerable decline in the reproductive success in the galleries constructed there.     

Effect of dietary lipid-lowering drugs upon plasma lipids and egg yolk cholesterol levels of laying hens.

To evaluate the effect of lipid-lowering agents upon egg quality, reproductive performance, plasma lipids, and egg yolk cholesterol levels, 30-week-old Shaver laying hens were fed a basal diet (commercial ration) supplemented with 0.1% probucol (PROB), 0.025% gemfibrozil (GEMF), or lovastatin at 0.0005% (LOV1), 0.001% (LOV2), or 0.0015% (LOV3) for a 12-week experimental period. It was observed that the supplementation of the drugs did not impair albumen and shell quality. Hen performance was not adversely affected. The depression in triglyceride concentrations approached statistical significance only in LOV2 (38.5%), and total cholesterol was significantly depressed in LOV2 (36.0%), LOV3 (36.8%), PROB (29.6%), and GEMF (30.4%) treatments. Egg cholesterol content, expressed per gram of yolk, was significant lowered in LOV1 (7.5%) and LOV3 (12. 7%).