Mouse LTKcells were transfected with a pair of defective Herpes simplex virus thymidine kinase ( t k ) genes. One tk gene had an 8-bp insertion mutation while the second gene had a 100-bp inversion. Extrachromosomal homologous recombination leading to the reconstruction of a functional tk gene was monitored by selecting for tk positive cells using medium supplemented with hypoxanthine/ aminopte...

The ProDom database is a comprehensive set of protein domain families automatically generated from the SWISS-PROT and TrEMBL sequence databases. An associated database, ProDom-CG, has been derived as a restriction of ProDom to completely sequenced genomes. The ProDom construction method is based on iterative PSI-BLAST searches and multiple alignments are generated for each domain family. The Pr...

The biochemistry of eukaryotic homologous recombination caught fire with the discovery that Rad51 is the eukaryotic homolog of the bacterial RecA and T4 UvsX proteins; and this field is still hot. The core reaction of homologous recombination, homology search and DNA strand invasion, along with the proteins catalyzing it, are conserved throughout evolution in principle. However, the increased c...

Non-homologous end joining (NHEJ) is an important DNA repair pathway for DNA double-strand breaks. Several proteins, including Ku, DNA-PKcs, Artemis, XRCC4/Ligase IV and XLF, are involved in the NHEJ for the DNA damage detection, DNA free end processing and ligation. The classical model of NHEJ is a sequential model in which DNA-PKcs is first recruited by the Ku bound DNA prior to any other rep...

Homologous recombination was investigated in Escherichia coli with two plasmids, each carrying the homologous region (two defective neo genes, one with an amino-end deletion and the other with a carboxyl-end deletion) in either direct or inverted orientation. Recombination efficiency was measured in recBC sbcBC and recBC sbcA strains in three ways. First, we measured the frequency of cells carr...

Bread wheat is a hexaploid (AABBDD, 2n=6x=42) containing three related ancestral genomes, each having 7 chromosomes, giving 42 chromosomes in diploid cells. During meiosis true homologues are correctly associated in wild-type wheat, but a degree of association of related chromosomes (homoeologues) occurs in a mutant (ph1b). We show that the centromeres are associated in non-homologous pairs in ...

Promoters are upstream gene regulatory sequences recognized by transcription factors (TFs) involved in controlling initiation and progression. For modern crop improvement, the design of efficient constructs relies on promoter efficiency, tissue specificity, other characteristics that allow introgression agronomically relevant traits to overcome biotic abiotic stresses. Several constitutive vira...

DNA damage is part and parcel of the life a cell an organism. Cells respond to by initiating response (DDR) pathways that allow for removal damaged subsequent repair. At least five major repair operate in humans – base excision (BER), nucleotide (NER), mismatch (MMR) double-strand break (DSB), which involves homologous recombination (HR) non-homologous end-joining (NHEJ). This talk will focus o...

In this paper, we apply two different parallel programming model, the message passing model using Message Passing Interface (MPI) and the multithreaded model using Pthreads, to protein sequence homologous search. The protein sequence homologous search uses Hirschberg algorithm for the pair-wise sequence alignment. The performance of the homologous search using the MPI-Pthread is compared to the...

Homologous DNA recombination is a general genetic phenomenon in which corresponding genetic information on a DNA is exchanged with or copied from its homologous or sister chromosomal DNA. Homologous recombination consists of a series of biochemical reactions of a pair of DNAs, and a key step in this process is the formation of heteroduplex joints by pairing of a single-stranded tail derived fro...