Junghuei Chen

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We explore the effects of p53 on strand exchange as well as regression of stalled replication forks promoted by human Rad51. We have found that p53 specifically inhibits strand exchange mediated by human Rad51, but not by Escherichia coli RecA. In addition, we provide in vitro evidence that human Rad51 can promote regression of a stalled replication fork,(More)
Kinetoplast DNA (kDNA) of trypanosomatid parasites is a network of approximately 5000 catenated DNA minicircles and approximately 25 maxicircles. We developed the following strategy to deduce the topological linkage of the minicircles of the Crithidia fasciculata network. First, we used graph theory to provide precise models of possible network structures.(More)
A DNA-based memory was implemented with in vitro learning and associative recall.The learning protocol stored the sequences to which it was exposed, and memories were recalled by sequence content through DNA-to-DNA template annealing reactions. Experiments demonstrated that biological DNA could be learned, that sequences similar to the training DNA were(More)
For an involution θ : Σ* → Σ* over a finite alphabet Σ we consider involution codes: θ-infix, θ-comma-free, θ-k -codes and θ-subword-k-codes. These codes arise from questions on DNA strand design. We investigate conditions under which both X and X+ are same type of involution codes. General methods for generating such involution codes are given. The(More)
Libraries of DNA oligonucleotides manufactured by an in vitro selection protocol were characterized for their non-crosshybridizing properties. Cloning and sequencing after several iterations of the protocol showed that the sequences, in general, became more non-crosshybridizing. Gel electrophoresis of protocol product, also, indicated(More)
Genetic algorithms, DNA computing, and in vitro evolution are brie y discussed. Elements of these are combined into laboratory procedures, and preliminary results are shown. The traditional test problem for genetic algorithms called the MAX 1s problem is addressed. Preliminary experimental results indicate successful laboratory \separation by tness" of DNA(More)
DNA computing often requires oligonucleotides that do not produce erroneous cross-hybridizations. By using in vitro evolution, huge libraries of non-crosshybridizing oligonucleotides might be evolved in the test tube. As a first step, a fitness function that corresponds to noncrosshybridization has to be implemented in an experimental protocol. Therefore, a(More)