Knockdown of the Ribosomal Protein eL38 in HEK293 Cells Changes the Translational Efficiency of Specific Genes

The protein eL38 is one of the smallest proteins of the mammalian ribosome, which is a component of its large (60S) subunit. The haploinsufficiency of eL38 in mice leads to the Tail-short mutant phenotype characterized by defects in the development of the axial skeleton caused by the poor translation of mRNA subsets of Hox genes. Using the ribosome profiling assay applied to HEK293 cells knocked down of eL38, we examined the effects of the lack of eL38 in 60S subunits on gene expression at the level of translation. A four-fold decrease in the cell content of eL38 was shown to result in significant changes in the translational efficiencies of 150 genes. Among the genes, whose expression at the level of translation was enhanced, there were mainly those associated with basic metabolic processes; namely, translation, protein folding, chromosome organization, splicing, and others. The set of genes with reduced translation efficiencies contained those that are mostly involved in the processes related to the regulation of transcription, including the activation of Hox genes. Thus, we demonstrated that eL38 insufficiency significantly affects the expression of certain genes at the translational level. Our findings facilitate understanding the possible causes of some anomalies in eL38-deficient animals

Archaeological evidence for two separate dispersals of Neanderthals into southern Siberia

Neanderthals were once widespread across Europe and western Asia. They also penetrated into the Altai Mountains of southern Siberia, but the geographical origin of these populations and the timing of their dispersal have remained elusive. Here we describe an archaeological assemblage from Chagyrskaya Cave, situated in the Altai foothills, where around 90,000 Middle Paleolithic artifacts and 74 Neanderthal remains have been recovered from deposits dating to between 59 and 49 thousand years ago (age range at 95.4% probability). Environmental reconstructions suggest that the Chagyrskaya hominins were adapted to the dry steppe and hunted bison. Their distinctive toolkit closely resembles Micoquian assemblages from central and eastern Europe, including the northern Caucasus, more than 3,000 kilometers to the west of Chagyrskaya Cave. At other Altai sites, evidence of earlier Neanderthal populations lacking associated Micoquian-like artifacts implies two or more Neanderthal incursions into this region. We identify eastern Europe as the most probable ancestral source region for the Chagyrskaya toolmakers, supported by DNA results linking the Neanderthal remains with populations in northern Croatia and the northern Caucasus, and providing a rare example of a long-distance, intercontinental population movement associated with a distinctive Paleolithic toolkit