The IRREGULAR TRICHOME BRANCH loci regulate trichome elongation in Arabidopsis

The proper control of cell expansion is vital to plant development. It is responsible for shaping individual cells and, together with cell division, it plays a lead role in shaping plant organs. Much of the underlying mechanism by which plant cells expand anisotropically is not understood. We are taking a genetic approach to cell expansion by isolating mutants that affect the branching pattern of Arabidopsis trichomes. Here we report the identification of four new loci that control trichome morphogenesis. These loci were named the IRREGULAR TRICHOME BRANCH (ITB) loci because of the deleterious effects on branch position and length in the mutants. Our analysis of branch expansion in itb mutants shows that the ITB genes act as positive regulators of branch elongation, and that the branch position defects are caused by altered expansion of the trichome stalk. The itb mutations display synergistic effects in double mutant combinations with certain branch number mutations, suggesting that the ITB genes also play key roles in branch initiation. These results demonstrate that the ITB genes are key regulators of anisotropic cell expansion in trichomes.     

Treatment of separation anxiety in dogs with clomipramine: results from a prospective, randomized, double-blind, placebo-controlled, parallel-group, multicenter clinical trial

The efficacy and tolerability of clomipramine in the treatment of separation anxiety in dogs was tested in a prospective, randomized, double-blind, placebo-controlled, parallel-group, international multicenter clinical trial. For a diagnosis of separation anxiety, dogs had to exhibit at least one of the following signs in the absence of their owner: destruction, defecation, urination and/or vocalization, as well as the behaviour suggestive of "hyper-attachment" to their owner. A total of 95 dogs were randomized to receive one of the three treatments for 2-3 months: "standard-dose" clomipramine (1 to <2 mg/kg, PO, q. 12 h); "low-dose" clomipramine (0.5 to <1 mg/kg, PO, q. 12 h); and placebo (PO, q. 12 h). All dogs received behavioural therapy. Dogs were examined at four time points (days 0, 28, 56 and 84) after the initiation of therapy. Improvement in each dog's behaviour at days 28, 56 and 84 was evaluated in comparison to its behaviour at day 0.The results showed that, compared to placebo, dogs receiving standard-dose clomipramine were rated improved at least three times faster for the signs destruction, defecation and urination. At most time points, more dogs in the standard-dose clomipramine group were rated improved for the signs destruction, defecation and urination, and in an owner's global assessment of the dog's overall behaviour (p<0.05 at certain time points). However, there were no statistically significant differences at any time point between the standard dose and the placebo groups in the sign vocalization. The low-dose clomipramine group produced no statistically significant effect when compared with placebo. Mild and transient vomiting was noted as a side effect of clomipramine in a small number of dogs.It is concluded that addition of standard-dose (1 to <2 mg/kg, PO, q. 12 h) clomipramine to conventional behavioural therapy for 2-3 months ameliorated the signs of separation anxiety in dogs.     

Nasal allergy to fungi in guinea pigs

Sensitized guinea pigs produced specific IgG and IgE antibodies toward Cladosporium and Alternaria. In presence of fungal extracts, nasal mast cells degranulate. Ultrastructural modifications of the cells during degranulation have been established. The ciliary epithelium and the ciliary beating are not affected by fungal allergens.     

Ganglioside GD3 sensitizes human hepatoma cells to cancer therapy

Ganglioside GD3 (GD3) has emerged as a modulator of cell death pathways due to its ability to interact with mitochondria and disable survival pathways. Because NF-kappaB activation contributes to cancer therapy resistance, this study was undertaken to test whether GD3 modulates the response of human hepatoblastoma HepG2 cells to radio- and chemotherapy. NF-kappaB was activated in HepG2 cells shortly after therapeutic doses of ionizing radiation or daunorubicin treatment that translated into up-regulation of kappaB-dependent genes. These effects were accompanied by minimal killing of HepG2 cells by either ionizing radiation or daunorubicin. However, GD3 pretreatment blocked the nuclear translocation of active kappaB members, without effect on Akt phosphorylation, induced by either treatment. The suppression of kappaB-dependent gene induction by GD3 was accompanied by enhanced apoptotic cell death caused by these therapies. Furthermore, the combination of GD3 plus ionizing radiation stimulated the formation of reactive species followed by the mitochondrial release of cytochrome c and Smac/Diablo and caspase 3 activation. Pretreatment with cyclosporin A before radiotherapy protected HepG2 cells from the therapeutic combination of GD3 plus ionizing radiation. These findings underscore a key role of mitochondria in the response of tumor cells to cancer therapy and highlight the potential relevance of GD3 to overcome resistance to cancer therapy by combining its dual action as a mitochondria-interacting and NF-kappaB-inactivating agent.     

Native parasitoids and recovery of Spathius agrili from areas of release against emerald ash borer in eastern Tennessee,USA

The parasitoid Spathius agrili Yang, introduced in the USA to suppress populations of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, has been recovered at a release site for the first time in eastern Tennessee after a single year of releases. Other native parasitoids, including Spathius floridanus Ashmead, undetermined species of Spathius (possibly Spathius elegans Matthews and Spathius parvulus Matthews) and Atanycolus cappaerti Marsh & Strazanac, also known to be associated with EAB, were recovered. These recoveries represent the first documentation of these four species, including the introduced S. agrili, associated with EAB in the southern USA. Implications for biological control efforts against EAB are discussed.     

Genomic organisation of the <Emphasis Type="Italic">Mal d 1</Emphasis> gene cluster on linkage group 16 in apple

European populations exhibit progressive sensitisation to food allergens, and apples are one of the foods for which sensitisation is observed most frequently. Apple cultivars vary greatly in their allergenic characteristics, and a better understanding of the genetic basis of low allergenicity may therefore allow allergic individuals to increase their fruit intake. Mal d 1 is considered to be a major apple allergen, and this protein is encoded by the most complex allergen gene family. Not all Mal d 1 members are likely to be involved in allergenicity. Therefore, additional knowledge about the existence and characteristics of the different Mal d 1 genes is required. In the present study, we investigated the genomic organisation of the Mal d 1 gene cluster in linkage group 16 of apple through the sequencing of two bacterial artificial chromosome clones. The results provided new information on the composition of this family with respect to the number and orientation of functional and pseudogenes and their physical distances. The results were compared with the apple and peach genome sequences that have recently been made available. A broad analysis of the whole apple genome revealed the presence of new genes in this family, and a complete list of the observed Mal d 1 genes is supplied. Thus, this study provides an important contribution towards a better understanding of the genetics of the Mal d 1 family and establishes the basis for further research on allelic diversity among cultivars in relation to variation in allergenicity.     

Dmrt1 polymorphism and sex‐chromosome differentiation in Rana temporaria

Sex‐determination mechanisms vary both within and among populations of common frogs, opening opportunities to investigate the molecular pathways and ultimate causes shaping their evolution. We investigated the association between sex‐chromosome differentiation (as assayed from microsatellites) and polymorphism at the candidate sex‐determining gene Dmrt1 in two Alpine populations. Both populations harboured a diversity of X‐linked and Y‐linked Dmrt1 haplotypes. Some males had fixed male‐specific alleles at all markers (“differentiated” Y chromosomes), others only at Dmrt1 (“proto‐” Y chromosomes), while still others were genetically indistinguishable from females (undifferentiated X chromosomes). Besides these XX males, we also found rare XY females. The several Dmrt1 Y haplotypes differed in the probability of association with a differentiated Y chromosome, which we interpret as a result of differences in the masculinizing effects of alleles at the sex‐determining locus. From our results, the polymorphism in sex‐chromosome differentiation and its association with Dmrt1, previously inferred from Swedish populations, are not just idiosyncratic features of peripheral populations, but also characterize highly diverged populations in the central range. This implies that an apparently unstable pattern has been maintained over long evolutionary times.