Subcellular localization of DNA-binding protein BA by immunofluorescence and immunoelectron microscopy

Nonhistone protein BA has been shown to decrease in amount in the chromatin of growth- stimulated normal rat liver (Yeoman et al. 1975. Cancer Res. 35:1249-1255) and in mitogen-stimulated normal human lymphocytes (Yeoman et al. 1976. Exp. Cell Res. 100:47- 55.). Subsequently, protein BA was purified and was shown to prefer to bind to double- stranded A-T-rich DNAs (Catino et al. 1978. Biochemistry. 17:983-987.). Immunization of rabbits with highly purified protein BA has resulted in the production of a specific antibody. A specific immunoreactivity for chromosomal protein BA has been demonstrated by immunoelectrophoresis and double antibody immunoprecipitation analysis with rabbit anti-BA immunoglobulin and IgG fractions. Light microscope examination of normal rat liver crysections by the indirect immunofluorescence procedure has demonstrated a cytoplasmic as well as a nuclear localization for protein BA with a pronounced perinucleolar fluorescence. Immunoelectron microscopy employing the peroxidase antiperoxidase method of antigen localization has confirmed the immunofluorescence data and has show a heterochromatin localization for protein BA. The relationship of the localization of protein BA to gene control in quiescent cells or to configurations of heterochromatin as well as the marked reduction in the amounts of protein BA which occur in stimulated growth states remains to be defined.     

A genetic linkage map of red drum,Sciaenops ocellatus

Second‐generation, sex‐specific genetic linkage maps were generated for the economically important estuarine‐dependent marine fish Sciaenops ocellatus (red drum). The maps were based on F₁ progeny from each of two single‐pair mating families. A total of 237 nuclear‐encoded microsatellite markers were mapped to 25 linkage groups. The female map contained 226 markers, with a total length of 1270.9 centiMorgans (cM) and an average inter‐marker interval of 6.53 cM; the male map contained 201 markers, with a total length of 1122.9 cM and an average inter‐marker interval of 6.03 cM. The overall recombination rate was approximately equal in the two sexes (♀:♂ = 1.03:1). Recombination rates in a number of linkage intervals, however, differed significantly between the same sex in both families and between sexes within families. The former occurred in 2.4% of mapped intervals, while the latter occurred in 51.2% of mapped intervals. Sex‐specific recombination rates varied within chromosomes, with regions of both female‐biased and male‐biased recombination. Original clones from which the microsatellite markers were generated were compared with genome sequence data for the spotted green puffer, Tetraodon nigroviridis; a total of 43 matches were located in 17 of 21 chromosomes of T. nigroviridis, while seven matches were in unknown portions of the T. nigroviridis genome. The map for red drum provides a new, useful tool for aquaculture, population genetics, and comparative genomics of this economically important marine species.     

Parthenogenesis in a whitetip reef shark Triaenodon obesus involves a reduction in ploidy

Genetic analysis of a female whitetip reef shark Triaenodon obesus and her stillborn pup, assumed to be of parthenogenetic origin, revealed that the pup was homozygous at all 24 nuclear‐encoded microsatellites assayed, consistent with the idea that diploidy in the pup had been restored via terminal fusion. Flow cytometric analysis, however, indicated that the genome size of the pup was no more than half that of the mother, and microscopy revealed that nuclear volume was c. 1·73 times larger in the mother than in the pup. Together these data suggest that the pup was genetically haploid, developing directly from an unfertilized egg; as far as is known, this is the first observation of a spontaneously produced haploid vertebrate.     

Lessons learned from the 1918–1919 influenza pandemic

The 1918 influenza pandemic was one of the most virulent strains of influenza in history. Phylogenic evidence of the novel H1N1 strain of influenza discovered in Mexico last spring (2009) links it to the 1918 influenza strain. With information gained from analyzing viral genetics, public health records and advances in medical science we can confront the 2009 H1N1 influenza on a global scale. The paper analyses the causes and characteristics of a pandemic, and major issues in controlling the spread of the disease. Wide public vaccination and open communication between government and health sciences professionals will be an essential and vital component in managing the 2009 H1N1 pandemic and any future pandemics.