In a paper published in Genome Research online in advance this week, researchers across Europe show that the intra-mitochondrial dynamin OPA1 works to maintain mitochondrial genome integrity. Using "siRNAs specific to OPA1 alternate spliced exons," the team found that "silencing of the OPA1 variants including exon4b leads to mtDNA depletion, secondary to inhibition of mtDNA replication, and to marked alteration of mtDNA distribution," and that a 10 kDa peptide that results from OPA1-exon4b isoform cleavage is responsible for this process.
In another Genome Research preprint, investigators at the University of Liege in Belgium and Utah State University report their use of high-throughput sequencing to determine the effect of the CLPG mutation on skeletal muscle-associated miRNAs in sheep. Additionally, the researchers "highlight the quantitative limitations of high-throughput sequencing for digital gene expression profiling as a result of biased and inconsistent amplification of specific miRNA species."
Elaine Mardis and her colleagues at Washington University in St. Louis this week describe the murine natural killer cell miRNA transcriptome. Using two next-generation sequencing platforms, Mardis et al. mapped the "miRNA transcriptomes of resting and cytokine-activated primary murine NK cells," and confirmed their results using qRT-PCR and microarrays. In their analysis, the researchers identified 302 known and 21 novel mature miRNAs, which, they write, are "expressed over a broad range and exhibit isomiR complexity."
Researchers at the University of Wisconsin-Madison and the University of North Carolina, Chapel Hill, have inferred variation in the recombination rate of the house mouse species using between two whole-genome F2 genetic linkage maps. In a Genome Research paper, the team identifies "numerous orthologous genomic regions with significant map length differences between" two crosses of Mus musculus, which are "suggestive of variation in broad-scale recombination rate." Taken together, the researchers write, "divergent intervals span 19 percent of the house mouse genome," and are disproportionately aggregated on the X chromosome.