Molecular Genetics of Glucosinolate Biosynthesis in Brassicas: Genetic Manipulation and Application Aspects

The Expanding Molecular Genetics Tool Kit in Chlamydia

Journal of Bacteriology ◽

10.1128/jb.00590-18 ◽

2018 ◽

Vol 200 (24) ◽

Cited By ~ 2

Author(s):

Raphael H. Valdivia ◽

Robert J. Bastidas

Keyword(s):

Genetic Engineering ◽

Molecular Genetics ◽

Genetic Manipulation ◽

Molecular Genetic ◽

Model System ◽

New Method ◽

Content Type ◽

Host Interactions ◽

Additional Tool ◽

Genomic Regions

ABSTRACT Chlamydia has emerged as an important model system for the study of host pathogen interactions, in part due to a resurgence in the development of tools for its molecular genetic manipulation. An additional tool, published by Keb et al. (G. Keb, R. Hayman, and K. A. Fields, J. Bacteriol. 200:e00479-18, 2018, https://doi.org/10.1128/JB.00479-18), now allows for custom genetic engineering of genomic regions that were traditionally recalcitrant to genetic manipulation, such as genes within operons. This new method will be an essential instrument for the elucidation of Chlamydia-host interactions.

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Genetic manipulation of rumen bacteria: from potential to reality

Australian Journal of Agricultural Research ◽

10.1071/ar9960247 ◽

1996 ◽

Vol 47 (2) ◽

pp. 247 ◽

Cited By ~ 7

Author(s):

K Gregg ◽

G Allen ◽

C Beard

Keyword(s):

Molecular Genetics ◽

Genetic Manipulation ◽

Bacterial Species ◽

Genetic Material ◽

Rumen Bacteria ◽

Butyrivibrio Fibrisolvens ◽

Prevotella Ruminicola ◽

The Stability

The development of techniques for manipulating the molecular genetics of bacteria led naturally to suggestions for using this technology to alter rumen function. Despite early difficulties, methods are now available to insert new genetic material into several rumen bacterial species, including Butyrivibrio fibrisolvens, Prevotella ruminicola, and Ruminococcus albus. One strain of B. fibrisolvens has been modified to detoxify a naturally occurring poison that causes major losses of livestock in Australia, Africa, and Central America. The stability of that modified organism has been demonstrated by its recolonization of the rumen and retention of its altered genotype over 5 months in vivo. Many of the persistent doubts about rumen bacterial genetic manipulation and the viability of altered organisms in a competitive environment have been shown to be capable of resolution, and interest in this area of research may be revitalized by these results. Apart from the achievement of specific metabolic improvements, the technology now available will allow extensive characterization of the molecular genetics of rumen bacteria with a precision that was not previously possible.

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Introduction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070266 ◽

1978 ◽

Vol 36 (3) ◽

pp. 543-544

Author(s):

W. Bernard

Keyword(s):

Molecular Weight ◽

Electron Microscope ◽

Nucleic Acid ◽

Gene Mapping ◽

Molecular Genetics ◽

Cell Biology ◽

Gene Activity ◽

Close Connection ◽

Basic Information ◽

Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

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Metabolic engineering of CHO cells to prepare glycoproteins

Emerging Topics in Life Sciences ◽

10.1042/etls20180056 ◽

2018 ◽

Vol 2 (3) ◽

pp. 433-442 ◽

Cited By ~ 1

Author(s):

Qiong Wang ◽

Michael J. Betenbaugh

Keyword(s):

Metabolic Engineering ◽

Cho Cells ◽

Genetic Manipulation ◽

Chinese Hamster ◽

Post Translational Modification ◽

Effector Functions ◽

Recombinant Glycoproteins ◽

Production Platform ◽

Chemical Inhibitors ◽

Amino Acid Mutations

As a complex and common post-translational modification, N-linked glycosylation affects a recombinant glycoprotein's biological activity and efficacy. For example, the α1,6-fucosylation significantly affects antibody-dependent cellular cytotoxicity and α2,6-sialylation is critical for antibody anti-inflammatory activity. Terminal sialylation is important for a glycoprotein's circulatory half-life. Chinese hamster ovary (CHO) cells are currently the predominant recombinant protein production platform, and, in this review, the characteristics of CHO glycosylation are summarized. Moreover, recent and current metabolic engineering strategies for tailoring glycoprotein fucosylation and sialylation in CHO cells, intensely investigated in the past decades, are described. One approach for reducing α1,6-fucosylation is through inhibiting fucosyltransferase (FUT8) expression by knockdown and knockout methods. Another approach to modulate fucosylation is through inhibition of multiple genes in the fucosylation biosynthesis pathway or through chemical inhibitors. To modulate antibody sialylation of the fragment crystallizable region, expressions of sialyltransferase and galactotransferase individually or together with amino acid mutations can affect antibody glycoforms and further influence antibody effector functions. The inhibition of sialidase expression and chemical supplementations are also effective and complementary approaches to improve the sialylation levels on recombinant glycoproteins. The engineering of CHO cells or protein sequence to control glycoforms to produce more homogenous glycans is an emerging topic. For modulating the glycosylation metabolic pathways, the interplay of multiple glyco-gene knockouts and knockins and the combination of multiple approaches, including genetic manipulation, protein engineering and chemical supplementation, are detailed in order to achieve specific glycan profiles on recombinant glycoproteins for superior biological function and effectiveness.

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