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Biomedical subjects

Yikang S Rong

Publications and source records attributed to Yikang S Rong.

3 recordsLinked to original sources

Targeting multi-cellular organisms.

For many years, biologists' efforts in achieving gene targeting by homologous recombination in multicellular organisms have been hampered by the difficulty in culturing pluripotent stem cells. Recent advances have eliminated this requirement for several animal species. For large mammals, cloning by nuclear transfer has led to the first knockout sheep and pigs. For Drosophila, whole organism gene targeting was accomplished by a method for the generation of linear DNA in vivo.

Animals↗

Gene targeting by homologous recombination: a powerful addition to the genetic arsenal for Drosophila geneticists.

A series of recent publications have firmly established the notion that Drosophila researchers now have a general method to subject genes for targeted modification by homologous recombination (HR) [Science 288 (2000) 2013; Genetics 157 (3) (2001) 1307; Genes Dev. 16 (12) (2002) 1568; Genetics 161 (2002) 1125-1136]. This method allows one to knockout essentially any gene starting with the DNA sequence of the gene. It has greatly enhanced studies of gene function as demonstrated by over 20 years of gene targeting practice in yeast and mouse. Here, I discuss the basic targeting methodology for eukaryotic organisms. I compare the Drosophila method with the traditional targeting scheme in yeast and mouse mainly to show that the targeting mechanism as well as many aspects of the experimental design remain unchanged, and that the Drosophila scheme differs only in the way in which the donor molecule for targeting is generated. I propose that the Drosophila method can be readily adapted in other organisms without culturable stem cells, since the mechanism for in vivo donor generation in Drosophila is likely to be functional in a variety of different organisms.

Animals↗

Targeted mutagenesis by homologous recombination in D. melanogaster.

We used a recently developed method to produce mutant alleles of five endogenous Drosophila genes, including the homolog of the p53 tumor suppressor. Transgenic expression of the FLP site-specific recombinase and the I-SceI endonuclease generates extrachromosomal linear DNA molecules in vivo. These molecules undergo homologous recombination with the corresponding chromosomal locus to generate targeted alterations of the host genome. The results address several questions about the general utility of this technique. We show that genes not near telomeres can be efficiently targeted; that no knowledge of the mutant phenotype is needed for targeting; and that insertional mutations and allelic substitutions can be easily produced.

Alleles↗