Evaluation of commonly used ectoderm markers in iPSC trilineage differentiation.

Patient-derived induced pluripotent stem cells (iPSCs) have become a promising resource for exploring genetics of complex diseases, discovering new drugs, and advancing regenerative medicine. Increasingly, laboratories are creating their own banks of iPSCs derived from diverse donors. However, there are not yet standardized guidelines for qualifying these cell lines, i.e., distinguishing between bona fide human iPSCs, somatic cells, and imperfectly reprogrammed cells. Here, we report the establishment of a panel of 30 iPSCs from CD34+ peripheral blood mononuclear cells, of which 10 were further differentiated in vitro into all three germ layers. We characterized these different cell types with commonly used pluripotent and lineage specific markers, and showed that NES, TUBB3, and OTX2 cannot be reliably used as ectoderm differentiation markers. Our work highlights the importance of marker selection in iPSC authentication, and the need for the field to establish definitive standard assays

A computational analysis of Turkish makam music based on a probabilistic characterization of segmented phrases

This study targets automatic analysis of Turkish makam music pieces on the phrase level. While makam is most simply defined as an organization of melodic phrases, there has been very little effort to computationally study melodic structure in makam music pieces. In this work, we propose an automatic analysis algorithm that takes as input symbolic data in the form of machine-readable scores that are segmented into phrases. Using a measure of makam membership for phrases, our method outputs for each phrase the most likely makam the phrase comes from. The proposed makam membership definition is based on Bayesian classification and the algorithm is specifically designed to process the data with overlapping classes. The proposed analysis system is trained and tested on a large data set of phrases obtained by transferring phrase boundaries manually written by experts of makam music on printed scores, to machine-readable data. For the task of classifying all phrases, or only the beginning phrases to come from the main makam of the piece, the corresponding F-measures are.52 and.60 respectively.Scientific and Technological Research Council of Turkey, TUBITAK (112E162

Ly6cLo non-classical monocytes promote resolution of rhesus rotavirus-mediated perinatal hepatic infammation

Perinatal hepatic inflammation can have devastating consequences. Monocytes play an important role in the initiation and resolution of inflammation, and their diverse functions can be attributed to specific cellular subsets: pro-inflammatory or classical monocytes (Ly6c(Hi)) and pro-reparative or non-classical monocytes (Ly6c(Lo)). We hypothesized that inherent differences in Ly6c(Hi) classical monocytes and Ly6c(Lo) non-classical monocytes determine susceptibility to perinatal hepatic inflammation in late gestation fetuses and neonates. We found an anti-inflammatory transcriptional profile expressed by Ly6c(Lo) non-classical monocytes, and a physiologic abundance of these cells in the late gestation fetal liver. Unlike neonatal pups, late gestation fetuses proved to be resistant to rhesus rotavirus (RRV) mediated liver inflammation. Furthermore, neonatal pups were rendered resistant to RRV-mediated liver injury when Ly6c(Lo) non-classical monocytes were expanded. Pharmacologic inhibition of Ly6c(Lo) non-classical monocytes in this setting restored susceptibility to RRV-mediated disease. These data demonstrate that Ly6c(Lo) monocytes promote resolution of perinatal liver inflammation in the late gestation fetus, where there is a physiologic expansion of non-classical monocytes, and in the neonatal liver upon experimental expansion of these cells. Therapeutic strategies directed towards enhancing Ly6c(Lo) non-classical monocyte function may mitigate the detrimental effects of perinatal liver inflammation

The P22 Xis Protein: Regulation of Bacteriophage P22 Site -Specific Recombination

136 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Mutants of P22 Xis were isolated and assayed for excision system in vivo, to quantify their excision activity relative to wild-type Xis. Mutants S18F, R19A, G29S, G29D, A33P, R35C, D37G, S43F, S43P, P44L, L46F, A51T, and A51V were found to be defective in stimulating excision. Additionally, truncation mutants S66Z, K76Z, and D97Z were decreased in function about five-fold. In contrast, truncation mutants Q57Z and a mutant with the first 21 amino acids deleted were completely defective. Substitution mutants at R105, K107, and R109 revealed that this region stimulates the reactaion. A subset of Xis mutants were purified and assayed by EMSA and crosslinking studies. All purified mutants formed multimers by crosslinking, but L15F, K16E, A33P, S43F, and A55T were defective in DNA binding. Furthermore, L46F bound DNA with a weaker affinity but still formed specific complexes.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

The P22 Xis Protein: Regulation of Bacteriophage P22 Site -Specific Recombination

136 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Mutants of P22 Xis were isolated and assayed for excision system in vivo, to quantify their excision activity relative to wild-type Xis. Mutants S18F, R19A, G29S, G29D, A33P, R35C, D37G, S43F, S43P, P44L, L46F, A51T, and A51V were found to be defective in stimulating excision. Additionally, truncation mutants S66Z, K76Z, and D97Z were decreased in function about five-fold. In contrast, truncation mutants Q57Z and a mutant with the first 21 amino acids deleted were completely defective. Substitution mutants at R105, K107, and R109 revealed that this region stimulates the reactaion. A subset of Xis mutants were purified and assayed by EMSA and crosslinking studies. All purified mutants formed multimers by crosslinking, but L15F, K16E, A33P, S43F, and A55T were defective in DNA binding. Furthermore, L46F bound DNA with a weaker affinity but still formed specific complexes.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Purification and Characterization of Bacteriophage P22 Xis Protein▿

The temperate bacteriophages λ and P22 share similarities in their site-specific recombination reactions. Both require phage-encoded integrase (Int) proteins for integrative recombination and excisionase (Xis) proteins for excision. These proteins bind to core-type, arm-type, and Xis binding sites to facilitate the reaction. λ and P22 Xis proteins are both small proteins (λ Xis, 72 amino acids; P22 Xis, 116 amino acids) and have basic isoelectric points (for P22 Xis, 9.42; for λ Xis, 11.16). However, the P22 Xis and λ Xis primary sequences lack significant similarity at the amino acid level, and the linear organizations of the P22 phage attachment site DNA-binding sites have differences that could be important in quaternary intasome structure. We purified P22 Xis and studied the protein in vitro by means of electrophoretic mobility shift assays and footprinting, cross-linking, gel filtration stoichiometry, and DNA bending assays. We identified one protected site that is bent approximately 137 degrees when bound by P22 Xis. The protein binds cooperatively and at high protein concentrations protects secondary sites that may be important for function. Finally, we aligned the attP arms containing the major Xis binding sites from bacteriophages λ, P22, L5, HP1, and P2 and the conjugative transposon Tn916. The similarity in alignments among the sites suggests that Xis-containing bacteriophage arms may form similar structures

IntDOT Interactions with Core- and Arm-Type Sites of the Conjugative Transposon CTnDOT

CTnDOT is a Bacteroides conjugative transposon (CTn) that has facilitated the spread of antibiotic resistances among bacteria in the human gut in recent years. Although the integrase encoded by CTnDOT (IntDOT) carries the C-terminal set of conserved amino acids that is characteristic of the tyrosine family of recombinases, the reaction it catalyzes involves a novel step that creates a short region of heterology at the joined ends of the element during recombination. Also, in contrast to tyrosine recombinases, IntDOT catalyzes a reaction that is not site specific. To determine what types of contacts IntDOT makes with the DNA during excision and integration, we first developed an agarose gel-based assay for CTnDOT recombination, which facilitated the purification of the native IntDOT protein. The partially purified IntDOT was then used for DNase I footprinting analysis of the integration site attDOT and the excision sites attL and attR. Our results indicate that CTnDOT has five or six arm sites that are likely to be involved in forming higher-order nucleoprotein complexes necessary for synapsis. In addition, there are four core sites that flank the sites of strand exchange during recombination. Thus, despite the fact that the reaction catalyzed by IntDOT appears to be different from that typically catalyzed by tyrosine recombinases, the protein-DNA interactions required for higher-order structures and recombination appear to be similar