Targeted modification of the complete chicken lysozyme gene by poxvirus-mediated recombination.

We have developed a novel ex vivo system for the rapid one-step targeted modification of large eucaryotic DNA sequences. The highly recombinant environment resulting from infection of rabbit cornea cells with the Shope fibroma virus was exploited to mediate precise modifications of the complete chicken lysozyme gene domain (21.5 kb).

Analysis of an approach to oviduct-specific expression of modified chicken lysozyme genes.

The -2.7 kb enhancer (E) element of the chicken lysozyme gene domain appears to govern expression of the gene in macrophages but not in oviduct tubular gland cells, the only other site of lysozyme expression. The ultimate goal of our research was to determine whether lysozyme domain variants could be developed that would mainly be expressed in the oviduct so that transgenic birds could be produced that would deposit exogenous protein in the egg white.

Characteristics of a cluster of xylanase genes in Fibrobacter succinogenes S85.

Xylanase genes xyn10D, xyn10E, and xyn10B, located sequentially on the Fibrobacter succinogenes S85 chromosome, were separately cloned and their properties characterized. Analysis of the sequences documented that xylanases Xyn10D, Xyn10E, and Xyn10B each consist of an N-terminal catalytic domain (glycosyl hydrolase family 10) and a C-terminal carbohydrate-binding module (CBM, family 6) connected by proline-rich linker sequences. The amino acid sequences exhibited similarities of between 53 and 60%.

Measuring conservation of contiguous sets of autosomal markers on bovine and porcine genomes in relation to the map of the human genome.

Based on published information, we have identified 991 genes and gene-family clusters for cattle and 764 for pigs that have orthologues in the human genome. The relative linear locations of these genes on human sequence maps were used as "rulers" to annotate bovine and porcine genomes based on a CSAM (contiguous sets of autosomal markers) approach. A CSAM is an uninterrupted set of markers in one genome (primary genome; the human genome in this study) that is syntenic in the other genome (secondary genome; the bovine and porcine genomes in this study).

Comparative mapping of Homo sapiens chromosome 4 (HSA4) and Sus scrofa chromosome 8 (SSC8) using orthologous genes representing different cytogenetic bands as landmarks.

The recently published draft sequence of the human genome will provide a basic reference for the comparative mapping of genomes among mammals. In this study, we selected 214 genes with complete coding sequences on Homo sapiens chromosome 4 (HSA4) to search for orthologs and expressed sequence tag (EST) sequences in eight other mammalian species (cattle, pig, sheep, goat, horse, dog, cat, and rabbit). In particular, 46 of these genes were used as landmarks for comparative mapping of HSA4 and Sus scrofa chromosome 8 (SSC8); most of HSA4 is homologous to SSC8, which is of particular interest because of its association with genes affecting the reproductive performance of pigs.