Contribucion de los ramos ventrales cervicales a la inervacion de los Mm. rhomboideus, serratus ventralis y trapezius en los mamiferos domesticos. Part I: perro, gato y cerdo

In consideration of the sparcity of data regarding the anatomic organization of the innervation of the Rhomboideus, Serratus ventralis and Trapezius muscles in the general veterinary literature, a study of the innervation of these muscles was carried out. This work was done in the dog, the cat and the pig. Nerves supplying these muscles were studied through gross dissection, and described in regard to their origin, distribution and termination. The conclusions present a discussion of the relationship of muscle innervation to the ascending and descending branches of the ventral rami of spinal nerves. The pattern of innervation is discussed in relationship to the embryologic development and function of these muscles.     

Development and characterization of rifampicin-resistant mutants from high virulent strains of Flavobacterium columnare

Flavobacterium columnare is divided into three genetic groups or genomovars, genomovar II being highly virulent for channel catfish. A modified live vaccine is currently available to prevent columnaris disease under the licensed name Aquavac‐Col^®. The strain of F. columnare used to generate the avirulent rifampicin‐resistant mutant used in Aquavac‐Col^® belonged to genomovar I, the less virulent group towards channel catfish. In this study, we describe the generation and characterization of rifampicin‐resistant mutants from genomovar II strains. A total of 13 new mutants were obtained, and eight of them (two from each parent strain) were genetically and phenotypically characterized. Highly conserved regions within the ribosomal operons were identical between parent and mutant strains. Genetic differences between mutants and their parent strains were revealed by amplified fragment length polymorphism (AFLP). Genetic changes were distinctive among different mutants. Analysis of the lipopolysaccharide (LPS) showed that while some mutants lacked a few molecular bands of the LPS, some exhibited the same LPS profiles as their parent strains. Comparison between immunogenic proteins from mutants and parents was carried out by immunoblot analysis and further confirmed the uniqueness of individual mutants. A complete set of rifampicin‐resistant mutants with different genetic and immunogenic properties from the highly virulent genomovar II has been created. These mutants may have the potential of becoming vaccine candidates against columnaris disease.     

Isolation and characterization of strains of Flavobacterium columnare from Brazil

Flavobacterium columnare is an important pathogen of freshwater fish, implicated in skin and gill disease, often causing high mortality. An outbreak of skin disease in fingerling and adult Nile tilapia, Oreochromis niloticus (L.), cultivated in a recirculation system, was investigated. Four strains were isolated and characterized by biochemical reactions, enzyme production, fatty acid profile and analysis of the 16S-23S rDNA intergenic spacer region. All strains were identified as F. columnare. Experimental infection assays with one of these strains (BZ-5-02) were conducted and pathogenicity (by intramuscular route) was demonstrated in Nile tilapia and channel catfish, Ictalurus punctatus (Rafinesque). This is the first report of characterization of Brazilian strains of F. columnare.     

Ability of NIRS technology to determine pesticides in liquid samples at maximum residue levels

BACKGROUND: Pesticide residues remaining on food represent a potential risk to consumer's health. Determination of these pesticide residues involves tedious procedures of analysis with regard to time and laboratory work. Near‐infrared spectroscopy (NIRS) is a possible alternative to these methods. The aim of this research was to evaluate the ability of NIRS to classify two pesticides used for controlling apple fruit pests according to their concentration. Different solutions were prepared, based on the dose recommended by the pesticide producers for apple pest treatments. Spectra were acquired on a spectrophotometer from liquid samples belonging to these solutions. RESULTS: Calibration models were developed from liquid samples, following the soft independent modelling of class analogy (SIMCA) analysis method. These models classified between 99 and 100% of the validation samples belonging to different pesticide concentration solutions even at the maximum residue limit level of these products in apple fruit. CONCLUSIONS: NIRS technology shows a high potential for identifying pesticides in liquid samples, according to their concentration, at the levels required by the legislation. © 2012 Society of Chemical Industry     

Role of Gene Interactions in Hybrid Speciation: Evidence from Ancient and Experimental Hybrids

The origin of a new diploid species by means of hybridization requires the successful merger of differentiated parental species' genomes. To study this process, the genomic composition of three experimentally synthesized hybrid lineages was compared with that of an ancient hybrid species. The genomic composition of the synthesized and ancient hybrids was concordant (rs = 0.68, P < 0.0001), indicating that selection to a large extent governs hybrid species formation. Further, nonrandom rates of introgression and significant associations among unlinked markers in each of the three synthesized hybrid lineages imply that interactions between coadapted parental species' genes constrain the genomic composition of hybrid species.     

Genetic diversity assessment and genotype identification in sugarcane based on DNA markers and morphological traits

Sugarcane is known for its highly complex genetics and more knowledge is needed for better use and conservation of genetic materials. In order to identify genotypes and to assess genetic diversity, diverse data sets such as morphological and molecular markers are used as a general approach. To evaluate the usefulness of different markers, important sugarcane genotypes in Argentina were characterized by AFLP, SSR and morphological traits. All genotypes characterized were grouped in one main cluster in dendrograms using two independent softwares. Interestingly, local genotypes grouped together with USA varieties and no clear genetic differentiation could be found probably due to intensive germplasm exchange between these breeding programs. The molecular markers tested were useful for genetic diversity assessment as well as for genotype identification. These markers should be included in the internationally established characters for sugarcane variety protection as they give a better view on whole genome complexity. Additionally, genetic similarities obtained from molecular markers will provide more accurate information to breeders than the pedigree method, especially when considering the asymmetric genetic inheritance of sugarcane. Morphological traits are valuable tools to identify genotypes since they reflect external resemblance more than genetic relatedness. When they were combined with molecular markers the dendogram obtained revealed genetic relationships and the genetic diversity was better estimated. In summary, both methods appear to be useful, complementing each other and should be used together to assist sugarcane breeders in estimating genetic diversity, electing parents for crossings, identifying superior lines and to protect intellectual property rights.     

Cell death induced by fumonisin B1 in two maize hybrids: correlation with oxidative status biomarkers and salicylic and jasmonic acids imbalances

European Journal of Plant Pathology - Fusarium graminearum and Zymoseptoria tritici cause economically important diseases of wheat. F. graminearum is one of the primary causal agents of Fusarium...     

Revegetation of burnt areas: relative effectiveness of native and commercial seed mixtures

The efficiency of revegetation of burnt areas was put to the test with two different mixes of grasses, one comprising native species and the other, including Lolium multiflorum, sown by hand. Runoff generation and soil loss were studied over the first 20 months after the fire in seeded plots (two plots for each seed mix) and in an unseeded plot (considered as the control). The seeded plots showed a marked increase in vegetation, and 6 months after the fire ground cover was about 60 per cent in the plots seeded with native species. This ground cover value (considered to be the cover necessary for good protection against soil erosion) was reached in plots seeded with the commercial mix after 8 months and in the control plot after 14 months. Runoff volume was similar in all plots, but the soil erosion was reduced in both seeded plots by a factor of 6·5. Copyright © 2000 John Wiley & Sons, Ltd.