Yield responses of crops to changes in environment and management practices: Model sensitivity analysis. I. Maize

YIELD, a parametric crop production model, employs climatic data to calculate actual and potential yield for various crops and includes formulations for specific crop and growth stage effects. The objective was to demonstrate the sensitivity of YIELD for grain corn (maize) to changes in various environmental and decision-making inputs. Five temperature, five solar radiation, six relative humidity regimes, five water application schemes, and four irrigation frequencies were included in this study. The effects of different soil types and wind regimes on crop water requirements were investigated. The model output includes crop yield, water use efficiency, and management efficiency. Among the results, yield decreased on the average by 3.9% per one degree (C) increase in air temperature. A 1% change in solar radiation resulted in an average of 1% change in yield. Similar changes in relative humidity caused a yield change of about 0.8%.     

Monitoring Hip and Elbow Dysplasia Achieved Modest Genetic Improvement of 74 Dog Breeds over 40 Years in USA

Hip (HD) and Elbow Dysplasia (ED) are two common complex developmental disorders of dogs. In order to decrease their prevalence and severity, the Orthopedic Foundation for Animals (OFA) has a voluntary registry of canine hip and elbow conformation certified by boarded radiologists. However, the voluntarily reports have been severely biased against exposing dogs with problems, especially at beginning period. Fluctuated by additional influential factors such as age, the published raw scores barely showed trends of improvement. In this study, we used multiple-trait mixed model to simultaneously adjust these factors and incorporate pedigree to derive Estimated Breeding Values (EBV). A total of 1,264,422 dogs from 74 breeds were evaluated for EBVs from 760,455 hip scores and 135,409 elbow scores. These EBVs have substantially recovered the reporting bias and the other influences. Clear and steady trends of genetic improvement were observed over the 40 years since 1970. The total genetic improvements were 16.4% and 1.1% of the phenotypic standard deviation for HD and ED, respectively. The incidences of dysplasia were 0.83% and 2.08%, and the heritabilities were estimated as 0.22 and 0.17 for hip and elbow scores, respectively. The genetic correlation between them was 0.12. We conclude that EBV is more effective than reporting raw phenotype. The weak genetic correlation suggested that selection based on hip scores would also slightly improve elbow scores but it is necessary to allocate effort toward improvement of elbow scores alone.     

Linkage and segregation analysis of black and brindle coat color in domestic dogs

Mutations of pigment type switching have provided basic insight into melanocortin physiology and evolutionary adaptation. In all vertebrates that have been studied to date, two key genes, Agouti and Melanocortin 1 receptor (Mc1r), encode a ligand-receptor system that controls the switch between synthesis of red-yellow pheomelanin vs. black-brown eumelanin. However, in domestic dogs, historical studies based on pedigree and segregation analysis have suggested that the pigment type-switching system is more complicated and fundamentally different from other mammals. Using a genomewide linkage scan on a Labrador x greyhound cross segregating for black, yellow, and brindle coat colors, we demonstrate that pigment type switching is controlled by an additional gene, the K locus. Our results reveal three alleles with a dominance order of black (K(B)) > brindle (k(br)) > yellow (k(y)), whose genetic map position on dog chromosome 16 is distinct from the predicted location of other pigmentation genes. Interaction studies reveal that Mc1r is epistatic to variation at Agouti or K and that the epistatic relationship between Agouti and K depends on the alleles being tested. These findings suggest a molecular model for a new component of the melanocortin signaling pathway and reveal how coat-color patterns and pigmentary diversity have been shaped by recent selection.     

Targeting glioblastoma multiforme with an IL-13/diphtheria toxin fusion protein in vitro and in vivo in nude mice

Fusion proteins composed of tumor binding agents and potent catalytic toxins show promise for intracranial therapy of brain cancer and an advantage over systemic therapy. Glioblastoma multiforme (GBM) is the most common form of brain cancer and overexpresses IL-13R. Thus, we developed an interleukin-13 receptor targeting fusion protein, DT(390)IL13, composed of human interleukin-13 and the first 389 amino acids of diphtheria toxin. To measure its ability to inhibit GBM, DT(390)IL13 was tested in vitro and found to inhibit selectively the U373 MG GBM cell line with an IC(50) around 12 pmol/l. Cytotoxicity was neutralized by anti-human-interleukin-13 antibody, but not by control antibodies. In vivo, small U373 MG glioblastoma xenografts in nude mice completely regressed in most animals after five intratumoral injections of 1 microg of DT(390)IL13 q.o.d., but not by the control fusion protein DT(390)IL-2. DT(390)IL13 was also tested against primary explant GBM cells of a patient's excised tumor and the IC(50) was similar to that measured for U373 MG. Further studies showed a therapeutic window for DT(390)IL13 of 1-30 microg/injection and histology studies and enzyme measurements showed that the maximum tolerated dose of DT(390)IL13 had little effect on kidney, liver, spleen, lung and heart in non-tumor-bearing immunocompetent mice. Together, these data suggest that DT(390)IL13 may provide an important, alternative therapy for brain cancer.     

Action of acid on 6-thio-hexose derivatives. Synthesis of 1,6-epithio-hexofuranoses

Reaction of 5,6-anhydro-1,2-O-isopropylidene-3-O-methanesulfonyl-3-L-idofuranose+ ++ with thioacetic acid in pyridine gave 6-S-acetyl-1,2-O-isopropylidene-3-O-methanesulfonyl-6-thio-3-L-idofur anose, which was deacetylated and the resultant thiol was converted into 1,2-O:5,6-O,S-diisopropylidene-3-O-methanesulfonyl-3-L-idofuran ose. Alkaline cleavage of the mesyl group gave 1,2-O: 5,6-O,S-diisopropylidene-3-L-idofuranose, which on treatment with hot dilute hydrochloric acid gave, after acetylation, 2,3,5-tri-O-acetyl-1,6-dideoxy-1,6-epithio-alpha-L-idofuranose+ ++ and not the expected idopyranose isomer. 1,2:3,5-Di-O-isopropylidene-6-O-toluene-p-sulfonyl-alpha-D-glucofuranose was converted into 6-S-acetyl-1,2:3,5-di-O-isopropylidene-6-thio-alpha-D-glucofuranose; conversion into the 6-thiol and isomerisation in acidified acetone gave 1,2-O:5,6-O,S-diisopropylidene-6-thio-alpha-D-glucofuranose. Acid treatment of this diacetal, or the isomeric 1,2:3,5-di-O-isopropylidene-6-thio-alpha-D-glucofuranose, followed by acetylation gave 2,3,5-tri-O-acetyl-1,6-dideoxy-1,6-epithio-beta-D-glucofuranose. Similar treatment of 1,2:3,4-di-O-isopropylidene-6-thio-alpha-D-galactopyranose gave 2,3,5-tri-O-acetyl-1,6-dideoxy-1,6-epithio-alpha-D-galactofuranose .     

A random model for mapping imprinted quantitative trait loci in a structured pedigree: an implication for mapping canine hip dysplasia

Genetic imprinting may have played a more notable role in shaping embryonic development of plants, animals, and humans than previously appreciated. Quantitative trait loci that are imprinted (iQTL) exert monoallelic effects, depending on the parent of origin, which is an exception to the laws of Mendelian genetics. In this article, we present a modified random effect-based mapping model to use in a genome-wide scan for the distribution of iQTL that contribute to genetic variance for a complex trait in a structured pedigree. This model, implemented with the maximum likelihood method, capitalizes on a network of relatedness for maternally and paternally derived alleles through identical-by-descent sharing, thus allowing for the discrimination of the genetic variances due to alleles derived from maternal and paternal parents. The model was employed to map iQTL responsible for canine hip dysplasia in a multihierarchical canine pedigree, founded with seven greyhounds and six Labrador retrievers. Of eight significant QTL detected, three, located on CFA1, CFA8, and CF28, were found to trigger significant parent-of-origin effects on the age of femoral capital ossification measured at the left and right hips of a canine. The detected iQTL provide important candidate regions for fine-mapping of imprinted genes and for studying their structure and function in the control of complex traits.     

Cytology of polychrome-stained equine synovial fluid smears. Comparison with clinical findings, histologic specimens, Wright-Giemsa-stained smears and outcome.

Polychrome-stained equine synovial fluid specimens from 34 normal joints and 129 joints with clinical abnormalities were examined cytologically. The smears from joints with abnormalities were categorized as within normal limits (4.7%), slight abnormality (27.9%), proliferative synovitis (21.7%), neutrophilic pattern (20.2%), elongated cell pattern (10.1%), other moderate to marked abnormality (11.6%) and unsatisfactory (3.9%). Cytologic abnormalities that were not restricted to a single category included spindle cells, crystals, stellate cells and cartilage fragments. Multinucleate cells and mononucleate cells with dense cytoplasm and a delicate periphery were seen in smears from cases with clinical diagnoses of osteochondrosis or fracture; interpretation of these cells as osteoclasts and their mononucleate precursors was supported by positive staining with tartrate-resistant acid phosphatase. Smears within the same cytologic category were not found to correspond with a single clinical diagnosis. The identification of several cytologic patterns in cases with the same clinical diagnosis suggests that multiple stages of disease were sampled. Except in cases with the cytologic neutrophilic pattern, there was not a consistent relationship between the histologic features in synovial biopsy specimens and the cytologic findings; the morphologic variation within synovial membrane sections and between sections from different locations was sometimes marked. When compared with air-dried, Wright-Giemsa-stained smears, the polychrome-stained smears were more sensitive in the detection of cytologic abnormalities and were less often falsely negative or unsatisfactory. Following surgery, cases with clinical diagnoses of osteochondrosis (29 cases) and fracture (25 cases) were analyzed according to clinical outcome and cytologic category. While 80% of the horses with proliferative synovitis in cytologic specimens were sound, only 67% of those with the elongated cell pattern, 50% of those with slight abnormality and 33% of those with other moderate to marked abnormality were sound. A statistically significant relationship (P less than .02) was found in cases with a diagnosis of osteochondrosis: animals with a proliferative synovitis pattern were almost three times as likely to be sound as compared to those with slight abnormality. These findings indicate that polychrome-stained equine synovial fluid smears (1) provide information that is different from that found in corresponding histologic sections and (2) are superior to air-dried, Wright-Giemsa-stained smears for cytologic examination. The polychrome-stained equine synovial fluid smears were found to provide information supportive of clinical, radiographic and prognostic data.     

Modification of rat liver RNA polymerase I after in vivo stimulation by hydrocortisone or methylisobutylxanthine

Following in vivo administration of hydrocortisone or methylisobutylxanthine to rats, higher levels (1.5- to 2.3-fold) of RNA polymerase I activity are present in liver nuclei and nucleoli of the treated animals as compared to control animals. The elevated specific activity is retained after purification of the enzyme under conditions where the enzyme is dependent on exogenous template for activity. The elevated polymerase activity in nuclei, nucleoli, and soluble enzyme can be destroyed by mild trypsin treatment which results in a rapid decay of the specific activity to the control level. Under these conditions, the control polymerase I activity is stable. The results indicate that in vivo stimulation by hydrocortisone or methylisobutylxanthine results in a conversion of the enzyme to a form that is catalytically more active but has an increased sensitivity to proteolysis.