In a paper published online in advance in PNAS this week, researchers in Italy and Austria show that "transgene-mediated cosuppression and RNA interference enhance germ-line apoptosis in Caenorhabditis elegans," and hypothesize that the mechanism through which it occurs "may trigger the elimination of germ cells that have undergone viral infection or transposon activation."
Investigators at the Commonwealth Scientific and Industrial Research Organization Plant Industry in Australia and their collaborators this week discuss trans-chromosomal methylation and trans-chromosomal demethylation — "where the methylation level of one parental allele alters to resemble that of the other parent," the authors write — in Arabidopsis hybrids. "Epigenetic controls can be important in the generation of altered transcription levels that may contribute to the increased biomass of the hybrids," the team writes.
Elsewhere in this week's Early Edition, an international team led by researchers at University of Missouri Hospital and Clinics reports on its array-based analysis of group A streptococci grown in the presence of Center for Chemical Genomics compound 2979, or CCG-2979, which "showed down-regulation of a number of important virulence factors in addition to SK [streptokinase], suggesting disruption of a general virulence gene regulatory network." The authors say their data suggest "that the class of compounds represented by CCG-2979 may be of therapeutic value for the treatment of GAS [group A streptococci] and potentially other Gram-positive infections in humans."
Also in PNAS this week, researchers at the University of California, San Francisco, report on their creation of transgenic mice expressing wild-type bank vole prion protein. The UCSF group says its transgenic mouse model "may be useful for studying the spontaneous formation of prions," and therefore may help researchers come to understand the etiology of sporadic Creutzfeldt-Jakob disease.