ABSTRACT
Bacteriophages Shambre1 and Renna12 were isolated from soil in Bismarck, ND, using Arthrobacter globiformis. Genomic characterization and analyses allowed Renna12 to be assigned to phage cluster AS3, while Shambre1, which is not closely related to any phage, is a singleton.
ABSTRACT
The course-based research experience (CRE) with its documented educational benefits is increasingly being implemented in science, technology, engineering, and mathematics education. This article reports on a study that was done over a period of 3 years to explicate the instructional processes involved in teaching an undergraduate CRE. One hundred and two instructors from the established and large multi-institutional SEA-PHAGES program were surveyed for their understanding of the aims and practices of CRE teaching. This was followed by large-scale feedback sessions with the cohort of instructors at the annual SEA Faculty Meeting and subsequently with a small focus group of expert CRE instructors. Using a qualitative content analysis approach, the survey data were analyzed for the aims of inquiry instruction and pedagogical practices used to achieve these goals. The results characterize CRE inquiry teaching as involving three instructional models: 1) being a scientist and generating data; 2) teaching procedural knowledge; and 3) fostering project ownership. Each of these models is explicated and visualized in terms of the specific pedagogical practices and their relationships. The models present a complex picture of the ways in which CRE instruction is conducted on a daily basis and can inform instructors and institutions new to CRE teaching.
Subject(s)
Models, Educational , Students , Engineering , Faculty , Humans , Mathematics , TeachingABSTRACT
Mycobacteriophage CrystalP is a newly isolated phage infecting Mycobacterium smegmatis strain mc2155. CrystalP has a 76,483-bp genome and is predicted to contain 143 protein-coding and 2 tRNA genes, including repressor and integrase genes consistent with a temperate lifestyle. CrystalP is related to the mycobacteriophages Toto and Kostya and to other Cluster E phages.
ABSTRACT
Mutations affecting the Tec kinases Itk and Rlk decrease T cell receptor-induced Ca(2+) mobilization and Erk kinase activation and impair both positive and negative thymic selection. Itk(-/-) and Rlk(-/-)Itk(-/-) mice also have decreased CD4:8 T cell ratios, suggestive of altered CD4:8 lineage commitment. Nonetheless, we find that CD8 single-positive (SP) thymocytes and peripheral CD8(+) T cells in these mice do not resemble conventional CD8(+) T cells. Instead, these cells express memory markers, rapidly produce interferon-gamma, and can be selected on hematopoietically derived cells, similar to MHC class Ib-restricted "innate-type" lymphocytes. Itk deficiency also greatly increases the number of cells selected by MHC class Ib. Expression of a hypersensitive Erk2 mutant partially corrects the CD8(+) T cell phenotypes in Itk(-/-) mice, arguing that altered signaling permits development of this innate-type CD8(+) cell population. Our results suggest that Tec kinases differentially regulate development of conventional versus nonconventional lymphocytes.
Subject(s)
CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/enzymology , Cell Differentiation , Cell Lineage , Protein-Tyrosine Kinases/deficiency , Animals , CD8-Positive T-Lymphocytes/immunology , Histocompatibility Antigens/metabolism , Mice , Mice, Knockout , Organ Culture Techniques , Phenotype , Protein-Tyrosine Kinases/classification , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Signal Transduction , Thymus Gland/cytology , Thymus Gland/immunology , Thymus Gland/metabolism , Time FactorsABSTRACT
The generation of CD4 and CD8 alphabeta T-cell lineages from CD4+ CD8+ double-positive (DP) thymocyte precursors is a complex process initiated by engagement of major histocompatibility complex (MHC) by T-cell receptor (TCR) and coreceptor. Quantitative differences in TCR signaling induced by this interaction impose an instructional bias on CD4/CD8 lineage commitment that must be reinforced by MHC recognition and TCR signaling over subsequent selection steps in order for the thymocyte to progress and mature in the adopted lineage. Our studies show that the transmembrane receptor Notch plays a role in this process by modifying TCR signal transduction in DP thymocytes. In this review, we consider the functional relationship of TCR and Notch signaling pathways in the selection and specification of CD4 and CD8 T-cell lineages.
