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The emergence of the middle class in countries such as Brazil, Russia, India, and China is resulting in increasing global demand for animal-based food products. This increase represents a unique opportunity for Canadian livestock producers to export their products to new markets and expand Canada's reputation as a global provider of safe and highest quality food items. This article has two major themes. First, current Canadian contributions to livestock genomics in the cattle and swine industries are outlined. Second, important future opportunities are discussed, including the high throughput collection of phenotypic data, development of environmentally friendly livestock, emergence of decision support software, and the use of Web 2.0. Through the use of genomic technologies, livestock producers can not only ensure that the nutritional demands of Canada are secured, but also play a pivotal role in ensuring the rest of the world is fed as well. Furthermore, investment through initiatives led by Genome Canada has ensured that Canada is favorably positioned to contribute cutting-edge solutions to meet this global challenge. Ultimately, genomic-based innovations will enable producers to increase efficiency, lower production costs, decrease the use of prophylactics, and limit the expenditure of resources. Key words: genomics, single nucleotide polymorphisms, genomic selection, livestock, cattle, swine. L'emergence d'une classe moyenne dans des pays comme le Bresil, la Russie, l'Inde et la Chine entraine une demande globale croissante en produits alimentaires d'origine animale. Cet accroissement represente une occasion unique pour les producteurs canadiens de betail d'exporter leurs produits sur de nouveaux marches et d'accroitre la reputation du Canada en tant que fournisseur mondial de produits alimentaires des plus securitaires et de la plus haute qualite. Cet article porte sur deux themes. D'abord, les auteurs decrivent les contributions canadiennes actuelles en matiere de genomique animale dans les industries bovine et porcine. Deuxiemement, les auteurs discutent des principales opportunites futures, incluant la collecte de donnees phenotypiques a grande echelle, le developpement de pratiques d'elevage durables, l'emergence de logiciels d'appui a la decision et l'utilisation du web 2.0. En faisant appel aux technologies genomiques, les producteurs de betail peuvent non seulement s'assurer que les besoins alimentaires des Canadiens sont rencontres, mais aussi contribuer a nourrir le reste du monde. De plus, les investissements rendus possibles grace aux initiatives menees par Genome Canada ont permis d'assurer que le Canada se trouve en position favorable pour contribuer des solutions dernier cri pour relever ces defis globaux. Ultimement, les innovations basees sur la genomique permettront aux producteurs d'augmenter leur efficacite, d'abaisser leurs couts de production, de reduire le recours aux prophylactiques et de limiter l'utilisation des ressources. [Traduit par la Redaction] Mots-cles: genomique, polymorphisme mononucleotidique, selection genomique, betail, bovins, porcs., Introduction With an average of 220 000 people added to the global population every 24 h, it is projected that the Earth will be comprised of nearly 9.2 billion inhabitants [...]

Francisella tularensis is a highly virulent, intracellular pathogen that causes the disease tularaemia. A research surrogate for F. tularensis is Francisella novicida, which causes a tularaemia-like disease in mice, grows similarly in macrophages, and yet is unable to cause disease in humans. Both Francisella species contain a cluster of genes referred to as the Francisella pathogenicity island (FPI). Pathogenicity determinant protein A (PdpA), encoded by the pdpA gene, is located within the FPI and has been associated with the virulence of Francisella species. In this work we examined the properties of PdpA protein expression and localization as well as the phenotype of a F. novicida pdpA deletion mutant. Monoclonal antibody detection of PdpA showed that it is a soluble protein that is upregulated in iron-limiting conditions and undetectable in an mglA or mglB mutant background. Deletion of pdpA resulted in a strain that was highly attenuated for virulence in chicken embryos and mice.

Francisella tularensis is a highly infectious, facultative intracellular bacterial pathogen that is the causative agent of tularemia. Nearly a century ago, researchers observed that tularemia was often fatal in North America but almost never fatal in Europe and Asia. The chromosomes of F. tularensis strains carry two identical copies of the Francisella pathogenicity island (FPI), and the FPIs of North America-specific biotypes contain two genes, anmK and pdpD, that are not found in biotypes that are distributed over the entire Northern Hemisphere. In this work, we studied the contribution of anmK and pdpD to virulence by using F. novicida, which is very closely related to F. tularensis but which carries only one copy of the FPI. We showed that anmK and pdpD are necessary for full virulence but not for intracellular growth. This is in sharp contrast to most other FPI genes that have been studied to date, which are required for intracellular growth. We also showed that PdpD is localized to the outer membrane. Further, overexpression of PdpD affects the cellular distribution of FPI-encoded proteins IglA, IglB, and IglC. Finally, deletions of FPI genes encoding proteins that are homologues of known components of type VI secretion systems abolished the altered distribution of IglC and the outer membrane localization of PdpD.

Francisella tularensis is a gram-negative, facultative intracellular pathogen that causes the highly infectious zoonotic disease tularemia. We have discovered a ca. 30-kb pathogenicity island of F. tularensis (FPI) that includes four large open reading frames (ORFs) of 2.5 to 3.9 kb and 13 ORFs of 1.5 kb or smaller. Previously, two small genes located near the center of the FPI were shown to be needed for intramacrophage growth. In this work we show that two of the large ORFs, located toward the ends of the FPI, are needed for virulence. Although most genes in the FPI encode proteins with amino acid sequences that are highly conserved between high- and low-virulence strains, one of the FPI genes is present in highly virulent type A F. tularensis, absent in moderately virulent type B F. tularensis, and altered in F. tularensis subsp, novicida, which is highly virulent for mice but avirulent for humans. The G+C content of a 17.7-kb stretch of the FPI is 26.6%, which is 6.6% below the average G+C content of the F. tularensis genome. This extremely low G+C content suggests that the DNA was imported from a microbe with a very low G+C-containing chromosome.

Abstract Background Francisella tularensis is a gram negative, facultative intracellular bacterium that is the etiological agent of tularemia. F. novicida is closely related to F. tularensis but has low virulence for humans while being highly virulent in mice. IglA is a 21 kDa protein encoded by a gene that is part of an iglABCD operon located on the Francisella pathogenicity island (FPI). Results Bioinformatics analysis of the FPI suggests that IglA and IglB are components of a newly described type VI secretion system. In this study, we showed that IglA regulation is controlled by the global regulators MglA and MglB. During intracellular growth IglA production reaches a maximum at about 10 hours post infection. Biochemical fractionation showed that IglA is a soluble cytoplasmic protein and immunoprecipitation experiments demonstrate that it interacts with the downstream-encoded IglB. When the iglB gene was disrupted IglA could not be detected in cell extracts of F. novicida, although IglC could be detected. We further demonstrated that IglA is needed for intracellular growth of F. novicida. A non-polar iglA deletion mutant was defective for growth in mouse macrophage-like cells, and in cis complementation largely restored the wild type macrophage growth phenotype. Conclusion The results of this study demonstrate that IglA and IglB are interacting cytoplasmic proteins that are required for intramacrophage growth. The significance of the interaction may be to secrete effector molecules that affect host cell processes.

The emergence of the middle class in countries such as Brazil, Russia, India, and China is resulting in increasing global demand for animal-based food products. This increase represents a unique opportunity for Canadian livestock producers to export their products to new markets and expand Canada's reputation as a global provider of safe and highest quality food items. This article has two major themes. First, current Canadian contributions to livestock genomics in the cattle and swine industries are outlined. Second, important future opportunities are discussed, including the high throughput collection of phenotypic data, development of environmentally friendly livestock, emergence of decision support software, and the use of Web 2.0. Through the use of genomic technologies, livestock producers can not only ensure that the nutritional demands of Canada are secured, but also play a pivotal role in ensuring the rest of the world is fed as well. Furthermore, investment through initiatives led by Genome Canada has ensured that Canada is favorably positioned to contribute cutting-edge solutions to meet this global challenge. Ultimately, genomic-based innovations will enable producers to increase efficiency, lower production costs, decrease the use of prophylactics, and limit the expenditure of resources. [ABSTRACT FROM AUTHOR]

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