Assessing the Effectiveness of Functional Genetic Screens for the Identification of Bioactive Metabolites     

Anahit Penesyan  Francesco Ballestriero  Malak Daim  Staffan Kjelleberg  Torsten Thomas  Suhelen Egan 《Marine drugs》2013,11(1):40-49

A common limitation for the identification of novel activities from functional (meta) genomic screens is the low number of active clones detected relative to the number of clones screened. Here we demonstrate that constructing libraries with strains known to produce bioactives can greatly enhance the screening efficiency, by increasing the “hit-rate” and unmasking multiple activities from the same bacterial source.  相似文献   

Embryonal recombination and germline inheritance of recombined FRT loci mediated by constitutively expressed FLP in tobacco     

David Gidoni  Moshe Bar  Baruch Leshem  Nehama Gilboa  Anahit Mett  Julia Feiler 《Euphytica》2001,121(2):145-156

FLP site-specific recombination has been shown in transgenic plants to excise DNA sequences between target FRT sites, and thereby activate transgenes in plants. In previous reports, crossing of tobacco plants expressing FLP recombinase from a CaMV-35s promoter with plants containing the target FRT sites, hybrid plants with deletion sectors were generated, which were infrequently transmitted to progeny. In this report we evaluate the occurrence of recombination in F₁ hybrid seed derived from crosses of different FLP and FRT-reporter target lines and the germinal transmission of recombined loci from these hybrids to F₂ progeny. Twenty hybrids were generated from crosses of independent five FLP-active lines and four FRT-reporter target lines. In one hybrid, FLP deletions occurred at an early stage, prior to seed maturation, and the deletions from this hybrid were more efficiently transmitted to F₂ progeny. The demonstration of FLP-mediated recombination activity and germinal inheritance of the recombined FRT loci are supported by both molecular and enzymatic evidence. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Identification of the antibacterial compound produced by the marine epiphytic bacterium Pseudovibrio sp. D323 and related sponge-associated bacteria     

Penesyan A  Tebben J  Lee M  Thomas T  Kjelleberg S  Harder T  Egan S 《Marine drugs》2011,9(8):1391-1402

Surface-associated marine bacteria often produce secondary metabolites with antagonistic activities. In this study, tropodithietic acid (TDA) was identified to be responsible for the antibacterial activity of the marine epiphytic bacterium Pseudovibrio sp. D323 and related strains. Phenol was also produced by these bacteria but was not directly related to the antibacterial activity. TDA was shown to effectively inhibit a range of marine bacteria from various phylogenetic groups. However TDA-producers themselves were resistant and are likely to possess resistance mechanism preventing autoinhibition. We propose that TDA in isolate D323 and related eukaryote-associated bacteria plays a role in defending the host organism against unwanted microbial colonisation and, possibly, bacterial pathogens.  相似文献