17 research outputs found
Functional Analysis of LINC Complexes in the Skin
The genome in eukaryotic cells is encased by two intricate and interconnected concentric membranes, which together with the underlying nuclear lamina form the nuclear envelope (NE). Two fundamental macromolecular structures are embedded within the nuclear envelope: the nuclear pore (NPC) and the LINC complex. The former perforates the nucleus controlling biomolecule trafficking between the nucleoplasm and the cytoplasm, while the latter integrates the nucleus via the cytoskeleton to the extracellular matrix. LINC complex structural and functional integrity is of utmost importance for various fundamental cellular functions. Mechanical forces are relayed into the nuclear interior via the LINC complex, which controls lamina organization, chromosome dynamics, and genome organization and stability. Thus, LINC constituents play pivotal roles in cellular architecture including organelle positioning, cell movement, tissue assembly, organ homeostasis, and organismal aging. The LINC complex oligomeric core contains several multi-isomeric, multifunctional, and often tissue-specific proteins. Therefore, for a proper functional analysis, genetic mouse models are an invaluable resource. Herein, we focus on the LINC complex roles in the skin and describe methods that enable the successful isolation of primary embryonic fibroblast and newborn skin cells, which can be then investigated functionally in vitro
Active pathways of anaerobic methane oxidation across contrasting riverbeds.
Anaerobic oxidation of methane (AOM) reduces methane emissions from marine ecosystems but we know little about AOM in rivers, whose role in the global carbon cycle is increasingly recognized. We measured AOM potentials driven by different electron acceptors, including nitrite, nitrate, sulfate, and ferric iron, and identified microorganisms involved across contrasting riverbeds. AOM activity was confined to the more reduced, sandy riverbeds, whereas no activity was measured in the less reduced, gravel riverbeds where there were few anaerobic methanotrophs. Nitrite-dependent and nitrate-dependent AOM occurred in all sandy riverbeds, with the maximum rates of 61.0 and 20.0 nmol CO2 g-1 (dry sediment) d-1, respectively, while sulfate-dependent and ferric iron-dependent AOM occurred only where methane concentration was highest and the diversity of AOM pathways greatest. Diverse Candidatus Methylomirabilis oxyfera (M. oxyfera)-like bacteria and Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like archaea were detected in the sandy riverbeds (16S rRNA gene abundance of 9.3 × 105 to 1.5 × 107 and 2.1 × 104 to 2.5 × 105 copies g-1 dry sediment, respectively) but no other known anaerobic methanotrophs. Further, we found M. oxyfera-like bacteria and M. nitroreducens-like archaea to be actively involved in nitrite- and nitrate/ferric iron-dependent AOM, respectively. Hence, we demonstrate multiple pathways of AOM in relation to methane, though the activities of M. oxyfera-like bacteria and M. nitroreducens-like archaea are dominant
Journey to the East : intercultural adaptation of international students in China
The number of international students studying in Mainland China was comparatively small three decades ago. However, more international students have chosen to study Chinese language and culture in Mainland China due to its booming economy and flourishing employment opportunities in the last ten years. Bevis (2014) informs that the number of American students choosing to study in colleges and universities across Mainland China is quickly rising. Many international students have become interested in studying and living in Mainland China especially after the 2008 Beijing Olympic
SAR11 bacteria linked to ocean anoxia and nitrogen loss.
Bacteria of the SAR11 clade constitute up to one half of all microbial cells in the oxygen-rich surface ocean. SAR11 bacteria are also abundant in oxygen minimum zones (OMZs), where oxygen falls below detection and anaerobic microbes have vital roles in converting bioavailable nitrogen to N2 gas. Anaerobic metabolism has not yet been observed in SAR11, and it remains unknown how these bacteria contribute to OMZ biogeochemical cycling. Here, genomic analysis of single cells from the world's largest OMZ revealed previously uncharacterized SAR11 lineages with adaptations for life without oxygen, including genes for respiratory nitrate reductases (Nar). SAR11 nar genes were experimentally verified to encode proteins catalysing the nitrite-producing first step of denitrification and constituted ~40% of OMZ nar transcripts, with transcription peaking in the anoxic zone of maximum nitrate reduction activity. These results link SAR11 to pathways of ocean nitrogen loss, redefining the ecological niche of Earth's most abundant organismal group