Intraspecific response of Pinus taeda L. to Grosmannia huntii and Leptographium terebrantis infection

We examined intraspecific and inter‐year variation in tolerance of Pinus taeda to two ophiostomatoid fungi, Leptographium terebrantis and Grosmannia huntii. Containerized seedlings of P. taeda from 27, 32, 17 and 23 different elite genetic families were artificially inoculated with L. terebrantis and G. huntii in years 2013, 2014, 2016 and 2017, respectively. Six connector families were inoculated every year. Eight weeks post‐inoculation, lesion and occlusion were measured on each seedling to determine the relative susceptibility/tolerance of families to these fungi. Pinus taeda families widely differed in these parameters suggesting intraspecific variation in the susceptibility/tolerance to the inoculated pathogens. The overall tolerance of the connector families to these fungi varied among the experimental years. These results showed that intraspecific variation to L. terebrantis and G. huntii exists among P. taeda families and it could be possible to select tolerant families to minimize the potential impact due to these fungi.     

Evaluation of the genetic basis of tricuspid valve dysplasia in Labrador Retrievers

OBJECTIVE: To quantify inheritance of tricuspid valve dysplasia (TVD) in a population of Labrador Retrievers and evaluate the possibility of the effect of a major locus on TVD. ANIMALS: 521 Labrador Retrievers (345 with known phenotypes and 176 related dogs with unknown phenotypes). PROCEDURES: Dogs were considered normal, equivocal, and affected for TVD on the basis of echocardiographic appearance of the tricuspid valves. Information on related dogs was collected for estimation of heritability of the 3 categories of phenotype, using a threshold model. Complex segregation analysis was performed to evaluate the possibility of the effect of a major locus on TVD. RESULTS: Heritability of TVD in this population of dogs was found to be 0.71, a value sufficiently large to suggest a segregating major locus. Subsequent complex segregation analysis did not provide sufficiently strong evidence to indicate influence of a major locus on the prevalence of TVD. However, complex segregation analysis for 2 categories of phenotype (eg, equivocal dogs were grouped with affected dogs) suggested that there was a single recessive allele with a substantial impact on the expression of TVD. CONCLUSIONS AND CLINICAL RELEVANCE: In Labrador Retrievers, TVD is a heritable disorder. Affected dogs and dogs closely related to affected dogs should not be used for breeding. There was insufficient evidence to suggest the influence of a major locus on TVD, although this conclusion was affected by the classification of dogs for diagnosis of the condition.     

Applied animal behavior and obedience training course: a model for veterinary curricula

Animal behavior problems often have detrimental effects on the relationships between pets and their owners and are one of the most frequently given reasons for canine relinquishment. The stressful environment of animal shelters can exacerbate behavior problems; yet most shelters do not have the staff necessary to address this issue adequately. Veterinary students may provide an untapped resource for solving this dilemma. As a service component of the curriculum, Veterinary schools can join with local humane societies to expose students to behavioral issues and concurrently build relationships within the community and perhaps even offer shelter animals a better chance of successful adoption. The following paper describes a "hands-on" undergraduate animal behavior and obedience training psychology course, created as a model to address these needs.     

Molecular neurobiology: Implications for insecticide action and resistance

Recent advances in molecular neurobiology have provided an unprecedented insight into the structure and function of the three principal target sites for neurotoxic insecticides: acetylcholinesterase, the 4-aminobutyric acid (GABA) receptor–chloride ionophore complex, and the voltage-sensitive sodium channel. This paper reviews some of these advances and their current or potential application to problems in insecticide resistance. It particularly emphasizes studies of the molecular biology of voltage-dependent sodium channels in the context of resistance to DDT and pyrethroids resulting from reduced neuronal sensitivity.