The municipal markets of Calcutta : Three case studies.

This thesis deals with the municipal markets of Calcutta City hut examines in detail only three of these institutions - Hogg Market, Gariahat Market and Manicktala Market. These three markets have been chosen as representing markets of different scales and rather different types. The study discusses first the historical and spatial context of the three markets by examining their historical evolution and the marketing geography of Calcutta City as a whole. There follows a detailed description of the three chosen markets, using published and unpublished material and presenting the author's field research. The impact of the markets on their respective neighbourhoods is noted and an attempt is made to determine the related shopping area around each market. Comparisons are then drawn to show the similarities and dissimilarities between the three markets and between the municipal and non-municipal markets of Calcutta. The thesis also looks at the future prospects of the municipal markets of Calcutta in general and of Hogg Market in particular. Finally, some of the ideas and suggested lines of inquiry which seem to emerge from the thesis are indicated

Genomic DNA transposition induced by human PGBD5

Transposons are mobile genetic elements that are found in nearly all organisms, including humans. Mobilization of DNA transposons by transposase enzymes can cause genomic rearrangements, but our knowledge of human genes derived from transposases is limited. In this study, we find that the protein encoded by human PGBD5, the most evolutionarily conserved transposable element-derived gene in vertebrates, can induce stereotypical cut-and-paste DNA transposition in human cells. Genomic integration activity of PGBD5 requires distinct aspartic acid residues in its transposase domain, and specific DNA sequences containing inverted terminal repeats with similarity to piggyBac transposons. DNA transposition catalyzed by PGBD5 in human cells occurs genome-wide, with precise transposon excision and preference for insertion at TTAA sites. The apparent conservation of DNA transposition activity by PGBD5 suggests that genomic remodeling contributes to its biological function. DOI: http://dx.doi.org/10.7554/eLife.10565.00

Summary table of DNA transposon integration loci

Spreadsheet listing human genome and transposon coordinate positions of transposon integrations, integration type (ITR transposition vs non-ITR transposition), and DNA sequences surrounding the genomic integration sites

Transposon reporter plasmid sequence: pb-ef1-neo

Plasmid sequence of NEO reporter flanked by PiggyBac ITRs. Reads from FLEA PCR were mapped to a hybrid genome consisting of this sequence and the hg19 human genome reference

Data from: Genomic DNA transposition induced by human PGBD5

Transposons are mobile genetic elements that are found in nearly all organisms, including humans. Mobilization of DNA transposons by transposase enzymes can cause genomic rearrangements, but our knowledge of human genes derived from transposases is limited. In this study, we find that the protein encoded by human PGBD5, the most evolutionarily conserved transposable element-derived gene in vertebrates, can induce stereotypical cut-and-paste DNA transposition in human cells. Genomic integration activity of PGBD5 requires distinct aspartic acid residues in its transposase domain, and specific DNA sequences containing inverted terminal repeats with similarity to piggyBac transposons. DNA transposition catalyzed by PGBD5 in human cells occurs genome-wide, with precise transposon excision and preference for insertion at TTAA sites. The apparent conservation of DNA transposition activity by PGBD5 suggests that genomic remodeling contributes to its biological function

Mycobacteriophages BPs, angel and halo: Comparative genomics reveals a novel class of ultra-small mobile genetic elements

Mycobacteriophages BPs, Angel and Halo are closely related viruses isolated from Mycobacterium smegmatis, and possess the smallest known mycobacteriophage genomes, 41 901 bp, 42 289 bp and 41 441 bp, respectively. Comparative genome analysis reveals a novel class of ultra-small mobile genetic elements; BPs and Halo each contain an insertion of the proposed mobile elements MPME1 and MPME2, respectively, at different locations, while Angel contains neither. The close similarity of the genomes provides a comparison of the pre- and post-integration sequences, revealing an unusual 6 bp insertion at one end of the element and no target duplication. Nine additional copies of these mobile elements are identified in a variety of different contexts in other mycobacteriophage genomes. In addition, BPs, Angel and Halo have an unusual lysogeny module in which the repressor and integrase genes are closely linked. The attP site is located within the repressor-coding region, such that prophage formation results in expression of a C-terminally truncated, but active, form of the repressor. © 2009 SGM

Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes.

Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response

Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes

Research in autophagy continues to accelerate, and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose. There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.