Composition of forage and grain from second-generation insect-protected corn MON 89034 is equivalent to that of conventional corn (Zea mays L.)

Insect-protected corn hybrids containing Cry insecticidal proteins derived from Bacillus thuringiensis have protection from target pests and provide effective management of insect resistance. MON 89034 hybrids have been developed that produce both the Cry1A.105 and Cry2Ab2 proteins, which provide two independent modes of insecticidal action against the European corn borer ( Ostrinia nubilalis ) and other lepidopteran insect pests of corn. The composition of MON 89034 corn was compared to conventional corn by measuring proximates, fiber, and minerals in forage and by measuring proximates, fiber, amino acids, fatty acids, vitamins, minerals, antinutrients, and secondary metabolites in grain collected from 10 replicated field sites across the United States and Argentina during the 2004-2005 growing seasons. Analyses established that the forage and grain from MON 89034 are compositionally comparable to the control corn hybrid and conventional corn reference hybrids. These findings support the conclusion that MON 89034 is compositionally equivalent to conventional corn hybrids.     

Widespread selective sweeps affecting microsatellites in Drosophila populations adapting to captivity: Implications for captive breeding programs

Many threatened species are being maintained in captivity to save them from extinction, often with the eventual aim of reintroduction. The objective of genetic management in captivity is to ‘freeze’ evolution i.e. to avoid genetic adaptation to captivity and to retain genetic diversity. Most current genetic management of threatened species addresses the latter, but does not explicitly address the former. The theory underlying current genetic management and its practical implementation assumes neutrality of loci. However, genetic adaptation in captive populations may cause non-neutral behavior at neutral loci due to selective sweeps (hitchhiking) caused by rapid allele frequency changes at linked fitness loci. We compared changes in microsatellite genetic diversity at eight non-coding loci with neutral predictions in 23 pedigreed captive populations of Drosophila melanogaster maintained with effective sizes of 25 (eight replicates), 50 (6), 100 (4), 250 (3) and 500 (2) for 48 generations. Loss of microsatellite heterozygosity was significantly faster (by 12%) than predicted by neutral theory, as assessed by regressing proportion of heterozygosity retained on pedigree inbreeding coefficients. Further, greater than neutral changes were observed for both variances in allele frequencies across replicates (by 25%), and for temporal changes in allele frequencies (by 33%). All eight microsatellite loci showed signals of selectively-driven changes. Rather than having their evolution ‘frozen’, captive populations are undergoing major genome-wide selective sweeps that affect not only fitness loci but linked neutral loci. Captive genetic management for threatened species destined for reintroduction requires modification to explicitly minimize genetic adaptation to captivity.     

Evaluation of gait kinetics in puppies with coxofemoral joint laxity

OBJECTIVE: To characterize ground reaction forces (GRFs) and determine whether there were correlations between forces and passive coxofemoral joint laxity in puppies. ANIMALS: Fifty-one 16-week-old hound-breed dogs. PROCEDURE: Force-plate gait evaluation and distraction radiographic imaging were performed. Ground reaction forces evaluated included x (mediolateral), y (craniocaudal breaking and propulsion), and z (vertical) peak force and impulse. Z-plane limb loading and unloading rates, loading interval, and weight distribution and y-plane stance time breaking and propulsion percentages were calculated. One-way ANOVA with the Duncan multiple range test was used to evaluate differences in gait variables among limbs. The relationships of left, right, highest, and mean distraction index (DI) with individual limb data of each dog were evaluated with the Spearman rank correlation. Left and right DIs were compared by means of linear regression analysis. RESULTS: Mean +/- SEM DI was 0.67 +/- 0.02. Left and right DIs were strongly correlated, but there were no significant relationships between DIs and gait variables. Most fore- and hind limb gait variables differed significantly, whereas paired fore- and hind limb gait variables did not. Asymmetry was most pronounced in the x- and y-planes. CONCLUSIONS AND CLINICAL RELEVANCE: GRFs were consistent with those of clinically normal mature dogs, supporting an absence of association between GRF and DI in young dogs. The GRFs and elucidation of the relationship between GRFs and DI may be useful for future studies in immature dogs.     

Sodium iodide I 131 treatment of dogs with nonresectable thyroid tumors: 39 cases (1990-2003)

OBJECTIVE: To determine outcome for dogs with nonresectable thyroid carcinomas treated with sodium iodide I 131 and identify factors associated with outcome. DESIGN: Retrospective case series. Animals-39 dogs. PROCEDURES: A definitive or presumptive diagnosis of thyroid tumor was made on the basis of cytologic or histologic examination, abnormal accumulation of sodium pertechnetate Tc 99m during scintigraphy, or both, and dogs were treated with sodium iodide I 131. Dogs with cervical thyroid tumors were evaluated 3 to 6 weeks after 131I therapy, and residual tumor was resected when feasible. RESULTS: Prior to 131I therapy, 32 dogs had a solitary mass and 7 had metastases; 21 were hyperthyroid, 16 were euthyroid, and 2 were hypothyroid. Median survival time for dogs with local or regional tumors (ie, stage II or III) was significantly longer (839 days) than median survival time for dogs with metastasis (366 days). Tumor site (cervical vs ectopic), dose of sodium iodide I 131, age, body weight, treatment (131I therapy alone vs 131I therapy followed by surgery), and serum T4 concentration prior to 131I therapy were not significantly associated with survival time. Three dogs died of radioiodine-associated myelosuppression within 3 months after treatment, but no specific factor associated with development of toxicosis was identified. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that 131I therapy may result in prolonged survival times in dogs with nonresectable thyroid tumors, regardless of serum thyroxine concentration prior to treatment. Dogs undergoing 131I therapy should be monitored for signs of bone marrow suppression.     

Genetic relationships of boxwood (<Emphasis Type="Italic">Buxus</Emphasis> L.) accessions based on genic simple sequence repeat markers

Boxwoods (Buxus L., Buxaceae) are popular woody landscape shrubs grown for their diverse forms and broad-leaved evergreen foliage. We used genic simple sequence repeat (genic-SSR) markers to assess genetic diversity and relatedness of 275 accessions from the National Boxwood Collection at the U.S. National Arboretum. Flow cytometry was conducted to determine the relative ploidy of each accession. Genic-SSR loci were highly variable among the accessions, detecting an average of 6.7 alleles per locus based on 17 primer pairs. Data were analyzed with a distance matrix based on Jaccard’s similarity index, followed by Unweighted Pair Group Method with Arithmetic Mean clustering. Two major clusters were identified, with four subclusters consisting of individual accessions from B. balearica Lam., B. bodinieri Lévl., B. harlandii Hance, B. microphylla Siebold et Zuccarini, B. sempervirens L., B. sinica (Rehd. et Wils.) M. Cheng, and their putative interspecific hybrids. The accessions generally clustered by cultivar, provenance, or species. Clustering within each group typically reflected breeding pedigrees, when known, and the clusters were supported by bootstrap results. This information will be used for breeding programs and collection management, and for identifying possible sources of disease tolerance for boxwood blight and other diseases and pests.     

Antioxidant 1 copper chaperone gene expression and copper levels in dog osteosarcoma patients

Twenty-four dogs with OS underwent limb amputation. Serum, OS tumour, and normal bone were harvested at time of surgery. RNA was extracted and gene expression was performed using quantitative polymerase chain reaction (qPCR). Tissue and blood copper concentrations were also determined with spectrophotometry. Compared to bone, tumour samples had significantly higher expressions of antioxidant 1 copper chaperone (ATOX1, p = .0003). OS tumour copper levels were significantly higher than that of serum (p < .010) and bone (p = .038). Similar to our previous observations in mouse and human OS, dog OS demonstrates overexpression of genes that regulate copper metabolism (ATOX1), and subsequent copper levels. Dogs with OS may provide a robust comparative oncology platform for the further study of these factors, as well as potential pharmacologic interventions.