In this week's PNAS Early Edition, a team led by investigators at Cold Spring Harbor Laboratory in New York shows that "mice harboring deletion of the chromosomal region corresponding to 16p11.2 as well as mice harboring the reciprocal duplication," show dosage-dependent changes in "gene expression, viability, brain architecture, and behavior." The team says its study shows that 16p11.2 copy-number variants provide "insight into human neurodevelopmental disorders," like autism.
Elsewhere, Harvard University's Daniel Hartl et al. show that "interspecific Y chromosome introgressions disrupt testis-specific gene expression and male reproductive phenotypes in Drosophila." More specifically, by comparing "genome-wide gene expression and male reproductive phenotypes between heterospecific and conspecific Y chromosomes," Hartl and his colleagues found that genes "down-regulated in males with heterospecific Y chromosomes are significantly biased toward testis-specific expression patterns."
In another PNAS paper published online in advance this week, investigators at Johns Hopkins University School of Medicine show that SOD1G93A glial-restricted precursor cells transplanted into the cervical spinal cords of wild-type rats "survived and differentiated efficiently into astrocytes," which later induced motor neuron death. "These findings show that mSOD1 astrocytes alone can induce WT MN death and associated pathological changes in vivo," the Johns Hopkins team writes.
Researchers at the University of Massachusetts Medical School and the University of Washington report on their expression analysis of the photoinducible and rhythmic clock genes Period 1 and 2 in the in the mammalian hypothalamic suprachiasmatic nucleus, in which they found evidence to suggest "the underlying molecular mechanisms of circadian entrainment differ with morning (advancing) or evening (delaying) light exposure, and such differences may reflect how entrainment takes place in nocturnal animals under natural conditions."