Single-cell transcriptomics uncovers distinct molecular signatures of stem cells in chronic myeloid leukemia

Recent advances in single-cell transcriptomics are ideally placed to unravel intratumoral heterogeneity and selective resistance of cancer stem cell (SC) subpopulations to molecularly targeted cancer therapies. However, current single-cell RNA-sequencing approaches lack the sensitivity required to reliably detect somatic mutations. We developed a method that combines high-sensitivity mutation detection with whole-transcriptome analysis of the same single cell. We applied this technique to analyze more than 2,000 SCs from patients with chronic myeloid leukemia (CML) throughout the disease course, revealing heterogeneity of CML-SCs, including the identification of a subgroup of CML-SCs with a distinct molecular signature that selectively persisted during prolonged therapy. Analysis of nonleukemic SCs from patients with CML also provided new insights into cell-extrinsic disruption of hematopoiesis in CML associated with clinical outcome. Furthermore, we used this single-cell approach to identify a blast-crisis-specific SC population, which was also present in a subclone of CML-SCs during the chronic phase in a patient who subsequently developed blast crisis. This approach, which might be broadly applied to any malignancy, illustrates how single-cell analysis can identify subpopulations of therapy-resistant SCs that are not apparent through cell-population analysis

Rrp5 binding at multiple sites coordinates pre-rRNA processing and assembly

In vivo UV crosslinking identified numerous preribosomal RNA (pre-rRNA) binding sites for the large, highly conserved ribosome synthesis factor Rrp5. Intramolecular complementation has shown that the C-terminal domain (CTD) of Rrp5 is required for pre-rRNA cleavage at sites A0–A2 on the pathway of 18S rRNA synthesis, whereas the N-terminal domain (NTD) is required for A3 cleavage on the pathway of 5.8S/25S rRNA synthesis. The CTD was crosslinked to sequences flanking A2 and to the snoRNAs U3, U14, snR30, and snR10, which are required for cleavage at A0–A2. The NTD was crosslinked to sequences flanking A3 and to the RNA component of ribonuclease MRP, which cleaves site A3. Rrp5 could also be directly crosslinked to several large structural proteins and nucleoside triphosphatases. A key role in coordinating preribosomal assembly and processing was confirmed by chromatin spreads. Following depletion of Rrp5, cotranscriptional cleavage was lost and preribosome compaction greatly reduced

Evolutionary Conservation of the Ribosomal Biogenesis Factor Rbm19/Mrd1 : Implications for Function

Ribosome biogenesis in eukaryotes requires coordinated folding and assembly of a pre-rRNA into sequential pre-rRNA-protein complexes in which chemical modifications and RNA cleavages occur. These processes require many small nucleolar RNAs (snoRNAs) and proteins. Rbm19/Mrd1 is one such protein that is built from multiple RNA-binding domains (RBDs). We find that Rbm19/Mrd1 with five RBDs is present in all branches of the eukaryotic phylogenetic tree, except in animals and Choanoflagellates, that instead have a version with six RBDs and Microsporidia which have a minimal Rbm19/Mrd1 protein with four RBDs. Rbm19/Mrd1 therefore evolved as a multi-RBD protein very early in eukaryotes. The linkers between the RBDs have conserved properties; they are disordered, except for linker 3, and position the RBDs at conserved relative distances from each other. All but one of the RBDs have conserved properties for RNA-binding and each RBD has a specific consensus sequence and a conserved position in the protein, suggesting a functionally important modular design. The patterns of evolutionary conservation provide information for experimental analyses of the function of Rbm19/Mrd1. In vivo mutational analysis confirmed that a highly conserved loop 5-β4-strand in RBD6 is essential for function.funding agencies|Swedish Research Council||Carl Tryggers Stiftelse||Linkoping University||</p

Personnel Selection in the Public Sector: Case Study of Latvia and Estonia

Pēc Padomju Savienības sabrukuma un neatkarības atjaunošanas 1991.gadā, Igaunijā un Latvijā kā viens no uzdevumiem tika izvirzīts izveidot savas valsts civildienestu, kas būtu balstīts uz demokrātiskiem principiem, kur civildienests būtu neitrāls un bez jebkādas ideoloģiskas kontroles. Savukārt civildienesta personāla atlasei būtu jābalstās uz nopelnu principiem, lai panāktu to, ka ierēdņi spēj nodrošināt profesionālu un kompetentu civildienesta darbu un balstītos uz augstiem ētiskiem standartiem. Lai noskaidrotu, vai abām valstīm ir izdevies nodrošināt to, ka personāla atlase balstās uz nopelnu sistēmas pamatprincipiem par bakalaura darba mērķi ir izvirzīts izpētīt pastāvošās civildienesta rekrutācijas sistēmas Latvijas un Igaunijas civildienestos, kā arī noskaidrot, kura no šīm sistēmām dominē civildienestos. Galvenais jautājums ir noskaidrot, vai personāla atlase balstās uz nopelnu principiem. Savukārt jānoskaidro arī tas, vai ir vērojama politisko spēku ietekme uz personāla atlases procesiem Latvijā un Igaunijā, kas liecinātu par to, ka tiek izmantoti patronāžas sistēmas elementi civildienestā? Saistībā ar jautājumiem par to, kādas rekrutācijas sistēmas tiek izmantotas personāla atlasē, darbā tika izvirzīta hipotēze: Lai gan, vadoties no tiesību aktos atrunātajiem principiem, Latvijā un Igaunijā civildienesta personāla atlasē darbojas nopelnu sistēmas modelis, abu valstu civildienesta personāla izvēlē novērojami arī patronāžas sistēmas elementi. Darbā tika izdarīti galvenie secinājumi par to, ka gan Latvijas, gan Igaunijas civildienestā formāli tiek uzskatīts, ka personāla atlases procesā tiek izmantoti nopelnu sistēmas elementi, kur ierēdņa amata pretendenta zināšanas, atbilstoša izglītība, darba pieredze ir kā galvenie priekšnoteikumi atlases procesā, kas tādējādi var nodrošināt efektīvu un profesionālu civildienesta darbību, tomēr civildienesta likumi pieļauj to, ka tiek izmantoti un var tikt izmantoti arī patronāžas sistēmas elementi, kas nosaka politisko spēku ietekmi pār civildienesta ierēdņu personāla atlases procesiemAfter the breakdown of the Soviet Union and independence declaration on 1991, one of the most important challenge for Latvia and Estonia was the construction of the civil service where emphasis was put on legalistic aspects and democratic principles. In order to guarantee a neutrality from political control and providing effectiveness and productivity in the civil service work, the selection for personnel required to be uphold on the merit principles. The aim of this research is to find out what kind of recruitation principles are used in personnel selection and which principles are dominated. Whether the personnel recruitation in Latvia and Estonia is based on merit principles or patronage when politicians play great role in personnel selection process and made the civil service work too much politicized. The hypothesis of this research is: Despite that in legislation there is written that personnel selection is based on the merit principles in Latvia and Estonia, there exist also a patronage in both countries. The main conclusions are that the civil service laws in both countries allow to use patronage in personnel selection process in spite of the proposals that they are selecting their personnel on merit principles in order to form a effective and neutral civil service

SM-Omics: An automated platform for high-throughput spatial multi-omics

QCR 20210128</p

SM-Omics: An automated platform for high-throughput spatial multi-omics

QCR 20210128</p

Phylogenetic tree of eukaryotic lineages showing Rbm19/Mrd1 proteins containing five or six RBDs.

<p>The tree is redrawn from <a href="http://tolweb.og/Eukaryotes/" target="_blank">http://tolweb.og/Eukaryotes/</a>. Blue lines indicate organisms with five RBDs and green lines those with six RBDs. Grey lines indicate branches for which no completely sequenced genome is known yet. Dashed lines indicate uncertainties in the tree topology. Microsporidia are fungi, but exceptionally have only four RBDs.</p

Properties of the linker regions.

<p>A. Disorder prediction of Rbm19 (human) and Mrd1 (<i>S. cerevisiae</i>). Grey areas indicate the RBDs: the red line represents the 0.05 threshold above which values are considered to indicate disorder. RBDs (RBD1–6) and linkers (L1–5) are indicated. B. Consensus sequence of linker 3. Conserved residues are ordered according to frequency, with the most common residue at the top. Rbm19 (human) residues are in bold. The secondary structure prediction given above the sequence (H = α-helix) is for linker 3 in Rbm19 (human).</p