Molecular Biology Blog
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Bacterial Regulatory Networks book available very soon
 | Edited by: Alain A.M. Filloux ISBN: 978-1-908230-03-4 Publisher: Caister Academic Press Publication Date: June 2012 Cover: hardback |
Identification of Mobile Genetic Elements in Metagenomes
from Peter Mullany and Adam P. Roberts writing in Horizontal Gene Transfer in Microorganisms:
Mobile genetic elements are discrete segments of nucleic acid that can translocate from one part of the genome to another, and in the case of conjugative elements between genomes in different cells. The vast majority of our knowledge of mobile genetic elements is derived from experimentation on cultivable bacteria and is therefore incomplete. In this chapter we will discuss the methods available for identifying and isolating these elements from metagenomic samples.
Further reading: Horizontal Gene Transfer in Microorganisms
Studying Microbial Gene Expression in Environmental Matrices Using RT-qPCR
from Vijay J. Gadkar and Martin Filion writing in Quantitative Real-time PCR in Applied Microbiology:
Environmental matrices are highly diverse in their composition and range from simple (e.g. water) to highly complex (e.g. organic soils/biosolids). Analysis of microbial gene expression from such substrates is done for variety of purposes which could range from bio-surveillance to elucidation of biological function of a target microbe. Quantitative real-time PCR (RT-qPCR) has become a technique of choice for studying such bio-processes, due to its unique ability to both detect and quantify a target transcript in real-time. Challenges in extracting inhibitor-free, structurally intact RNA, amenable for a sensitive technique like RT-qPCR, has however proved to be a major impediment in our ability to rigorously implement this highly versatile technology. Despite these "substrate defined" limitations, many attempts have been made to implement the RT-qPCR technology. Efforts like these have given us invaluable insight into the expression status of a particular transcript and hence, the biological functioning of the microbe, specifically under natural in situ conditions. As a result, it has enhanced our understanding of the role and diversity of many microbial populations which, previously was not possible using conventional molecular approaches. In this chapter, we have sought to summarize such technical problems faced by molecular environmental microbiologist and solutions developed to mitigate those challenges.
Further reading: Quantitative Real-time PCR in Applied Microbiology Related publications
Real-Time PCR in Food Science
Written by experts in the field, this book is an indispensable manual for scientists in the food industry. The first section provides an introduction to real-time PCR, discusses the use of PCR diagnostics in food science, describes the principles and methods of sample preparation, and covers the verification and control of PCR procedures. The eleven chapters in the second section cover the use of real-time PCR to detect various pathogens including Salmonella, Listeria, E. coli, Campylobacter, Yersinia, Staphylococcus, Clostridium, viruses and parasites. Also included is a chapter on the standardisation of real-time PCR methods in food microbiology. In the final section authors cover the use of real-time PCR for the analysis of genetically modified organisms, food allergens and for identification of animal or plant species. An invaluable book for anyone involved in food microbiology or the detection of foodborne pathogens and a recommended volume for all microbiology laboratories read more ...
 | Edited by: David Rodriguez-Lazaro read more ...ISBN: 978-1-908230-15-7 Publisher: Caister Academic Press Publication Date: January 2013 Cover: hardback |
The Evolution of Horizontally Transferred Genes
from Iñaki Comas and Fernando González-Candelas writing in Horizontal Gene Transfer in Microorganisms:
Horizontal gene transfer is a pervasive evolutionary process which has developed and is still developing an essential role in shaping biodiversity through providing opportunities for innovation, moving determinants of functions among taxa, opening opportunities for colonization of new niches, or acting as a catalyst for adaptation. However, its importance in evolution has only recently begun to be recognized. Reasons for this relatively late recognition of HGT and its relevance stem from two main sources. One is the availability, or rather the lack thereof, of appropriate information to infer the existence of HGT. This shortcoming has now been widely overcome with the large, and still growing at a very fast rate, number of completely sequenced genomes, which allow for precise phylogenetic reconstructions, along with the deployment of theoretical models necessary for inferring evolutionary events in deep-time. The second source is the appreciation that HGT does not leave an indelible stamp on the transferred genes because these continue evolving under a different genomic, and often ecological, environment which usually act synergistically to erase the initially clear marks that go along with those genes. In this chapter we provide an overview of these processes along with a model proposal that will help to better understand the consequences of the continuous evolution of laterally transferred genes at different evolutionary time-scales.
Further reading: Horizontal Gene Transfer in Microorganisms
The Extent and Regulation of Lateral Gene Transfer in Natural Microbial Ecosystems
from Rustam I. Aminov writing in Horizontal Gene Transfer in Microorganisms:
The importance of horizontal gene transfer (HGT) in bacterial evolution is evident from the retrospective analyses of bacterial genomes, which suggest that a substantial part of bacterial genomes is of foreign origin. Another line of evidence that supports the possibility of rapid adaptation of bacteria through lateral gene exchange is the history of antibiotic use by humans. Within a very brief period of the "antibiotic era" many bacterial pathogens were able to acquire the mechanisms allowing them to withstand the selective pressure of antibiotics. And finally, the field and microcosm studies allowed monitoring HGT events in situ. In this chapter, a brief overview of the milestones of mobile genetic elements (MGEs) research is given, followed by discussion of the conceptual framework development. Then the occurrence and diversity of MGEs as well as the frequencies of HGT in terrestrial, aquatic, intestinal and biofilm communities are described. The role of environmental factors that may affect MGE-mediated HGT in these ecosystems is also discussed.
Further reading: Horizontal Gene Transfer in Microorganisms