Screen of Genes Linked to High-Sugar Content in Stems by Comparative Genomics

One of the great advantages of the fully sequenced rice genome is to serve as a reference for other cereal genomes in particular for identifying genes linked to unique traits. A trait of great interest is reduced lignocellulose in the stem of related species in favor of fermentable sugars as a source of biofuels. While sugarcane is one of the most efficient biofuel crops, little is known about the underlying gene repertoire involved in it. Here, we take advantage of the natural variation of sweet and grain sorghum to uncover genes that are conserved in rice, sorghum, and sugarcane but differently expressed in sweet versus grain sorghum by using a microarray platform and the syntenous alignment of rice and sorghum genomic regions containing these genes. Indeed, enzymes involved in carbohydrate accumulation and those that reduce lignocellulose can be identified.     

Molecular Markers for Sweet Sorghum Based on Microarray Expression Data

Using an Affymetrix sugarcane genechip, we previously identified 154 genes differentially expressed between grain and sweet sorghum. Although many of these genes have functions related to sugar and cell wall metabolism, dissection of the trait requires genetic analysis. Therefore, it would be advantageous to use microarray data for generation of genetic markers, shown in other species as single-feature polymorphisms (SFPs). As a test case, we used the GeSNP software to screen for SFPs between grain and sweet sorghum. Based on this screen, out of 58 candidate genes, 30 had single-nucleotide polymorphisms (SNPs) from which 19 had validated SFPs. The degree of nucleotide polymorphism found between grain and sweet sorghum was in the order of one SNP per 248 base pairs, with chromosome 8 being highly polymorphic. Indeed, molecular markers could be developed for a third of the candidate genes, giving us a high rate of return by this method.     

Aelurostrongylus abstrusus (cat lungworm) infection in five cats from Italy

Infection by the cat lungworm Aelurostrongylus abstrusus is considered uncommon. Here, the authors report the clinical, diagnostic and therapeutic features of five infections recently observed in Italy. All cats were under 12 months of age. All except one cat had symptomatic infections, with cough, dyspnea, and weight loss with radiographic signs of broncopneumonia. All cats were eosinophilic. Larvae were present in fresh fecal smears and on flotation exam in all cats. Baermann larval recovery permitted definitive identification and, in one case, larvae per gram of feces (lpg) counts. One dose of ivermectin (400 microg/kg) was not effective in one cat, while one dose of selamectin (6 mg/kg) was effective in one of three cases and fenbendazole at 50 mg/kg given daily for 15 days was effective in four of four cases.     

Disseminated histoplasmosis in a cat in Europe

A cat was presented with a history of vomiting, decreased appetite and weight loss. Abnormal findings were poor body condition, pale mucous membranes, dehydration and a palpable abdominal mass. Abdominal ultrasound showed lymph node enlargement, a mass of uncertain origin, thickening of the muscularis layer of the small bowel, focal thickening of the ileum with loss of layering and free peritoneal fluid. Cytology revealed a piogranulomatous infiltrate and numerous macrophages containing oval or round yeast-like cells 2 to 5 µm diameter with a central, spherical, lightly basophilic body surrounded by a clear halo, compatible with Histoplasma capsulatum, within the cytoplasm. Post-mortem examination revealed cavity effusions, granulomatous nodules in lungs, intestine and omentum, thickened intestinal walls and intestinal perforation. Staining with Grocott and immunohistochemistry (IHC) revealed numerous organisms within the granulomatous reaction. H. capsulatum has a worldwide distribution in temperate and subtropical climates. To the author’s knowledge, this is the first report of feline histoplasmosis in Europe.     

Immunity to Leishmania infantum in the Dog: Resistance and Disease

Veterinary Research Communications -     

Effect of dietary avoparcin on performances and carcass composition in rainbow trout, Oncorhynchus mykiss (Walbaum)

Two levels (40 or 80 mg kg^?1) of avoparcin were tested as a growth promoter in rainbow trout, Oncorhynchus mykiss (Walbaum), fed for 14 weeks. At 80 mg kg-¹ the weight gain was higher (P <0.05) than in the unsupplemented control or at the 40 mg kg-¹ dose. At either dose, the feed conversion rate and the protein efficiency ratio were more favourable (P <0.05) than in the control. Inclusion of the antibiotic significantly improved (P < 0.05) the apparent digestibility of lipids. The lipid content of flesh was significantly increased by inclusion of avoparcin in the diet; moreover, at the high level of inclusion the content of some unsaturated fatty acids (18:3ω3 and 20:5ω3) appeared to be significantly increased. No avoparcin residues were detected in the flesh.     

Losartan, an AT1 antagonist, prevents aortic aneurysm in a mouse model of Marfan syndrome

Aortic aneurysm and dissection are manifestations of Marfan syndrome (MFS), a disorder caused by mutations in the gene that encodes fibrillin-1. Selected manifestations of MFS reflect excessive signaling by the transforming growth factor-beta (TGF-beta) family of cytokines. We show that aortic aneurysm in a mouse model of MFS is associated with increased TGF-beta signaling and can be prevented by TGF-beta antagonists such as TGF-beta-neutralizing antibody or the angiotensin II type 1 receptor (AT1) blocker, losartan. AT1 antagonism also partially reversed noncardiovascular manifestations of MFS, including impaired alveolar septation. These data suggest that losartan, a drug already in clinical use for hypertension, merits investigation as a therapeutic strategy for patients with MFS and has the potential to prevent the major life-threatening manifestation of this disorder.