tailieunhanh - Báo cáo y học: " T4 genes in the marine ecosystem: studies of the T4-like cyanophages and their role in marine ecology"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: T4 genes in the marine ecosystem: studies of the T4-like cyanophages and their role in marine ecology | Clokie et al. Virology Journal 2010 7 291 http content 7 1 291 VIROLOGY JOURNAL REVIEW Open Access T4 genes in the marine ecosystem studies of the T4-like cyanophages and their role in marine ecology Martha RJ Clokie1 Andrew D Millard2 Nicholas H Mann2 Abstract From genomic sequencing it has become apparent that the marine cyanomyoviruses capable of infecting strains of unicellular cyanobacteria assigned to the genera Synechococcus and Prochlorococcus are not only morphologically similar to T4 but are also genetically related typically sharing some 40-48 genes. The large majority of these common genes are the same in all marine cyanomyoviruses so far characterized. Given the fundamental physiological differences between marine unicellular cyanobacteria and heterotrophic hosts of T4-like phages it is not surprising that the study of cyanomyoviruses has revealed novel and fascinating facets of the phage-host relationship. One of the most interesting features of the marine cyanomyoviruses is their possession of a number of genes that are clearly of host origin such as those involved in photosynthesis like the psbA gene that encodes a core component of the photosystem II reaction centre. Other host-derived genes encode enzymes involved in carbon metabolism phosphate acquisition and ppGpp metabolism. The impact of these host-derived genes on phage fitness has still largely to be assessed and represents one of the most important topics in the study of this group of T4-like phages in the laboratory. However these phages are also of considerable environmental significance by virtue of their impact on key contributors to oceanic primary production and the true extent and nature of this impact has still to be accurately assessed. Background The cyanomyoviruses and their hosts In their review on the interplay between bacterial host and T4 phage physiology Kutter et al 1 stated that efforts to understand the infection process and evolutionary pressures in the