Hemoglobin switching is believed to have evolved to enable efficient transfer of oxygen from the mother's hemoglobin to the higher oxygen affinity fetal hemoglobin in the placenta during fetal life.
(S.C. McConnell, Y. Huo, S. Liu, and T.M. Ryan, 2011. Human globin knock-in mice complete fetal-to-adult hemoglobin switching in postnatal development. Mol. Cell. Biol. 31:876-883.)
Host Genetics Plays Unexpected Role in Dance with Pathogen
A new study suggests that differences in the host's genetics can make a big difference in susceptibility bacterial infection. In a study in the February 2011 Infection and Immunity, Virginia L. Miller of the University of North Carolina, Chapel Hill, and her collaborators show that the virulence of a strain of Yersinia pestis, notable for causing bubonic plague, varies drastically among mice strains with different genetic backgrounds. These findings carry major implications for vaccine development, says Miller.
A number of earlier reports dating back 20 years had suggested that removing this bacterium's capsule--an envelope of a loose protein gel surrounding the bacterial cellhad no effect on its virulence. Then, Miller and her collaborators performed the same experiment, with opposite results.
Searching for an explanation for the conflicting results, the only difference in the experiments that Miller could find was in the strains of mice, and so it occurred to her that their susceptibilities might be different. Her team tested that hypothesis by infecting two different strains of mice with Y. pestis in which the capsule had been removed. In one strain, the bacteria were nearly normally virulent, while in the o
|Contact: Jim Sliwa|
American Society for Microbiology