The population explosion and unintended pregnancies resulting in elective abortions continue to be the major public health issues in spite of availability of current methods of contraception. There is an urgent need for a better method of contraception that is accepted, effective, and available. Various targets are being investigated that can be used for contraception. The gene knockout technol...

Little is known regarding the biological roles of archaeal proteases. The haloarchaeon Haloferax volcanii is an ideal model for understanding these enzymes, as it is one of few archaea with an established genetic system. In this report, a series of H. volcanii mutant strains with markerless and/or conditional knockouts in each known proteasome gene was systematically generated and characterized...

We previously described a method for targeted homologous recombination at the yellow gene of Drosophila melanogaster. Because only a single gene was targeted, further work was required to show whether the method could be extended to become generally useful for gene modification in Drosophila. We have now used this method to produce a knockout of the autosomal pugilist gene by homologous recombi...

Pullulanase, an enzyme that catalyzes the hydrolysis of polysaccharides, has been identified in a broad range of organisms, including bacteria, yeasts, fungi, and animals. The pullulanase (pulB; FTT_0412c) of F. tularensis subspecies tularensis Schu S4 is considered to be a homologue of the type I pullulanase (pulA) of the other Francisella subspecies. The significance of Francisella pullulanas...

Mutations in the NSMF gene have been related to Kallmann syndrome. Conflicting results have been reported on the subcellular localization of Jacob/NELF, the protein encoded by the NSMF gene. Some reports indicate an extracellular localization and a function as a guidance molecule for migration of GnRH-positive neurons from the olfactory placode to the hypothalamus. Other studies have shown prot...

Cisplatin (cDDP) is effective against some human tumors, but many are intrinsically resistant and, even among initially sensitive tumors, acquired resistance develops commonly during treatment. It has not been possible to prove which biochemical mechanisms control sensitivity to cDDP. Gene knockout studies in yeast, Dictyostelium discoideum, and mammalian cells have begun to unambiguously ident...

Deleteagene (Delete-a-gene) is a deletion-based gene knockout system for plants. To obtain deletion mutants for a specific gene, random deletion libraries created by fast neutron mutagenesis are screened by polymerase chain reaction (PCR) using primers flanking the target gene. By adjusting the PCR extension time to preferentially amplify the deletion alleles, deletion mutants can be identified...

The complete genome sequences of 36 microorganisms have now been published and this wealth of genome data has enabled the development of comparative genomic and functional genomic approaches to investigate the biology of these organisms. Comparative genomic analyses of membrane transport systems have revealed that transporter substrate specificities correlate with an organism's lifestyle. The t...

An asd-deleted (Deltaasd) mutant of Salmonella enterica serovar Pullorum (SP) was constructed using an improved method of gene knockout by combining the pi-suicide plasmid system with the Red Disruption system. The asd gene was efficiently knocked out by the recombinant suicide vector, which replaced the asd gene with the CmR gene. Based on the balanced lethal host-vector system, the phenotype ...

Bifidobacterium longum 105-A shows high transformation efficiency and allows for the generation of gene knockout mutants through homologous recombination. Here, we report the complete genome sequence of strain 105-A. Genes encoding at least four putative restriction-modification systems were found in this genome, which might contribute to its transformation efficiency.