Comparison of Insulin-like Growth Factor-I and Insulin-like Growth Factor Binding Protein Concentrations of the Palmetto and Sunshine Bass and the Effects of Gender and Stress

Abstract— Plasma concentrations of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) were compared between market sized sunshine and palmetto bass. Differences between male and female fish were examined and both hybrids were sampled before and after a low-water confinement stress. There was no difference in body weight between the hybrid types, however, females were significantly heavier than males in both hybrids. Plasma IGF-I concentrations were significantly higher in pre-stressed palmetto bass when compared with sunshine bass, and male palmetto bass had significantly higher IGF-I concentrations than females. Two hours after a 15-min low-water stress, a significant decrease in palmetto bass IGF-I occurred, but there was no change in sunshine bass IGF-I concentrations. Levels of a 33-kDa IGFBP were similar in pre-stressed palmetto bass when compared with sunshine bass; however, no differences due to gender were evident for either hybrid. Two hours after a 15-min low-water exposure, there was no change in the levels of a 33-kDa IGFBP in palmetto or sunshine bass. A more complete understanding of IGF-I, IGFBPs, and IGF-I receptors may be necessary to explain the role of IGF-I in regulating fish growth.     

Multi-Locus DNA Fingerprinting of Channel Catfish Ictalurus punctatus

Abstract.— Similarities among multi-locus DNA fingerprints of five channel catfish Ictalurus punctatus strains and the ability to identify the strain of a fish based on its fingerprint pattern were investigated. Five restriction enzymes and 13 multi-locus DNA probes were screened to identify enzyme-probe combination useful for DNA fingerprinting channel catfish. Restriction enzymes Hinf I and Dpn II, in combination with probes (CAC)n, (CGC)n, (CTC)n, (ATCC)n, and (GATA)n, produced useful fingerprints (20–30 resolvable bands for each enzyme-probe combination). Thirty individuals (3 pools of 10 individuals each) from each of five channel catfish strains (albino, Mississippi normal, USDA-102, USDA-102 select, and USDA-103) were fingerprinted with all useful enzyme-probe combinations. Band sharing among samples was higher within strains than among strains and band sharing among strains was higher for strains whose breeding history indicated a high degree of relatedness. Individual fingerprints of 18 fish from each of the USDA-102 select and USDA-103 strains revealed no strain-specific bands, but several diagnostic bands (present at high frequencies in either USDA-102 select or USDA-103 strains and at a low frequencies in other strains) were identified. Band sharing at diagnostic bands was used to correctly identify fish as USDA-102 select or USDA-103 strains with 82% accuracy from fingerprints of 17 USDA-102 select strain fish, 18 USDA-103 strain fish, and 38 fish collected from three commercial farms.     

Corynebacterium pseudotuberculosis infections (Pigeon Fever) in horses in Western Colorado: An epidemiological investigation

Following reports of an increase in the number of Corynebacterium pseudotuberculosis infections in horses in the western counties of Colorado in 1997, an epidemiological assessment of the problem was conducted using a survey of premises with affected horses. No gender, age or breed predilections were found. Most diagnoses of disease were made in the summer or fall of 1997. Abscesses were reported to occur in various locations with a mean healing time of 77 days. A majority of premises owners reported potential contact of horses with sheep or goats. The days of lost use and treatment costs per case had a mean of 13 days and $139, respectively.     

Antigenic diversity in the major merozoite antigens ofTheileria parasites

Tropical Animal Health and Production -     

Use of computed tomography to evaluate pathologic changes in the lungs of calves with experimentally induced respiratory tract disease

OBJECTIVE: To optimize methods for the use of computed tomography (CT) to assess pathologic changes in the lungs of calves and to determine the effect of treatment on lung consolidation. ANIMALS: 10 male Holstein calves. PROCEDURES: Calves were anesthetized to facilitate CT imaging of the thorax. After initial images were obtained, pneumonia was induced in the calves by inoculation through a bronchoscope. Two calves were used in a preliminary study to refine the inoculation dose and optimize CT images. Four calves were administered florfenicol and 4 calves were untreated control animals. Serial images were obtained 24, 48, and 72 hours after inoculation. After final images were obtained, calves were euthanized, and lung consolidation was estimated by use of lung surface area scoring and water displacement. These estimates were compared with estimated lung consolidation obtained by use of CT. RESULTS: Calves had rapid disease progression. Percentage of lung consolidation was not significantly different between treatment groups for any of the estimation methods. Results of an ANOVA of the 3 assessment methods indicated significant differences among methods. Estimates of the percentage of lung consolidation obtained by use of surface area scoring and CT correlated well, whereas water displacement estimates correlated poorly with other methods of consolidation estimation. CONCLUSIONS AND CLINICAL RELEVANCE: Because of the correlation with other methods for estimation of lung consolidation, CT has the potential to be used to monitor disease progression in calves with experimentally induced respiratory tract disease.     

Analysis of durable resistance to stem rust in barley

Summary Since the mid-1940's, barley cultivars grown in the northern Great Plains of the USA and Canada have been resistant to stem rust caused byPuccinia graminis f. sp.tritici. This durable resistance is largely conferred by a single gene,Rpg1, derived from a single plant selection of the cultivar Wisconsin 37 and an unimproved Swiss cultivar. At the seedling stage, barley genotypes withRpg1 generally exhibit low mesothetic reactions at 16–20° C and slightly higher mesothetic reactions at 24–28° C to many stem rust pathotypes. This resistance is manifested by a low level of rust infection and mostly incompatible type uredia on adult plants.Rpg1 reacts in a pathotype-specific manner since some genotypes ofP. g. f. sp.tritici are virulent on cultivars carrying this gene in the field. Several factors may have contributed to the longevity of stem rust resistance in barley, a) since barley is planted early and matures early, it can sometimes escape damage from stem rust inoculum carried from the south; b) one or more minor genes may augment the level of resistance already provided byRpg1; c) the cultivation of resistant wheat cultivars and eradication of barberry have reduced the effective population size and number of potential new pathotypes ofP. g. f. sp.tritici, respectively; and d) virulent pathotypes ofP. g. f. sp.tritici andP. g. f. sp.secalis have not become established. This situation changed in 1989 when a virulent pathotype (Pgt-QCC) ofP. g. f. sp.tritici became widely distributed over the Great Plains. However,Rpg1 may still confer some degree of resistance to pathotype QCC because stem rust severities have been low to moderate and yield losses light on barley cultivars carrying the gene during the last four seasons (1989–1992). Several sources of incomplete resistance to pathotype QCC have been identified in barley. To facilitate the transfer of resistance genes from these sources into advanced breeding lines, molecular marker assisted selection is being employed.     

Mutation genetics of salt tolerance in barley: An assessment of Golden Promise and other semi-dwarf mutants

A review of research at the Scottish Crop Research Institute (SCRI) on the effects of semi-dwarfing genes on salt tolerance in barley is given. Work began in1993 with the fortuitous and unexpected result that the cultivar ‘Golden Promise’ showed considerable tolerance to salt. Golden Promise is a gamma-ray induced semi-dwarf mutant of the cultivar ‘Maythorpe’. The parent and mutant cultivars are presumed to be isogenic, but show significant differences in their responses to salt stress. The positive and pleiotropic effects of the mutant gene, commonly known as GPert were found to be effective in a number of genetic backgrounds. Earlier, in 1991 Frackowiak showed that the GPert mutation was allelic to the ari-e mutants in barley. The ari-emutants were salt tested and found to show the same positive responses to salt stress as Golden Promise. This supported the allelism tests, and consequently the GPert symbol was changed to ari-e.GP. The semi-dwarf mutant sdw1 (also known as denso) and the erectoides semi-dwarf mutant,ert-k ³² were also tested for their effects on tolerance to salt, but did not show any positive effects. Salt tolerance was therefore not a general phenomenon of semi-dwarf stature but specific to mutations at the Ari-e locus in these lines. Genetic markers (RAPDs, AFLPs and SSRs) have been used for fingerprinting, genetic mapping, and QTL analysis. The markers have helped 1) confirm the isogenic relationship between Maythorpe and Golden Promise, 2)clarify the confusion over the pedigree of Golden Promise, and 3) genetically map the ari-e.GPlocus and examine its pleiotropic effects. This revised version was published online in August 2006 with corrections to the Cover Date.