Primary and secondary structure of black beetle virus RNA2, the genomic messenger for BBV coat protein precursor

The nucleotide sequence of black beetle virion (BBV) RNA2 has been determined. RNA2 is 1399 b long. Its 5' terminus is capped. Its 3' terminus has an unidentified moiety that renders the RNA resistent to polyadenylation and ligation. The first AUG codon at base 23 is followed by an open reading frame for a protein 107 amino acids long, the predicted size of coat protein precursor. A second open reading frame for a putative protein 72 amino acid residues long begins at base 1110. No other large open reading frames exist. The 5' half of the RNA can be folded into a long, imperfect hairpin of high predicted stability. The 3' half of the RNA can fold into a complex set of multiply bifurcated stem and loop regions

Individual plumage and integument scoring of laying hens on commercial farms: correlation with severe feather pecking and prognosis by visual scoring on flock level

Various plumage and integument scoring methods are commonly used to deduce the occurrence of severe feather pecking and cannibalism in laying hens. The aim of our study was to provide evidence of correlations between the occurrence of severe feather pecking and our individual plumage scoring system used under practical conditions on commercial farms with non–beak-trimmed and beak-trimmed layers (study I). In second step, we aimed to verify whether the results of the elaborate individual scoring may be predicted with a visual scoring method based on the total body scores of groups of birds (study II). For study I we observed the pecking behavior and performed an individual plumage scoring at the beginning, in the middle, and at the end of a laying period on 8 commercial farms. For study II we performed both an individual and a visual plumage scoring on 49 flocks on 45 farms at the beginning of the laying period and on 43 flocks on 41 farms at the end of the laying period. Spearman's Rho revealed a correlation of the mean feather pecking rate with the total plumage score, the neck–back plumage score, and the total cannibalism score in all observation periods. A high feather pecking rate was correlated with severe plumage damage and the frequent occurrence of skin injuries. We conclude that both the total plumage score and the neck–back plumage score constitute a reliable indicator of the occurrence of severe feather pecking in the flocks assessed in this study. The results of study II suggest that the percental assessment of plumage damage on flock level in 3 categories (“visual score”) leads to a good prognosis of the actual, individually assessed plumage score. Therefore, the application (and documentation) of the visual score on a regular basis can provide a good evaluation of the development of the plumage condition of the flock. The visual score presented in this study is suggested as a suitable instrument for self-evaluation programs on farms

The Adsorption of Bacteriophage ϕX174 to its Host

The adsorption of purified ϕX174 to E. coli C and to E. coli C cell walls was investigated. Adsorption was measured by assaying for unadsorbed plaque formers. The amount of irreversible and reversible adsorption depends upon pH and divalent ion concentration. Maximum irreversible adsorption occurs in 0.1 M CaCl(2) at 36°C. There is no detectable reversible adsorption at conditions of pH and CaCl(2) concentration optimum for irreversible adsorption. Under these optimum conditions, diffusion is not the rate-limiting factor, and the encounter efficiency appears to be low. The rate constant is 1.0 × 10(-10) ml/sec. Phages adsorbed irreversibly to live cells cause infection and to the isolated cell walls apparently cause release of DNA. There is a specific ϕX174 receptor site on the mucocomplex portion of the cell wall