ChickRH6: a chicken whole-genome radiation hybrid panel

Abstract

-As a first step towards the development of radiation hybrid maps, we have produced a radiation hybrid panel in the chicken by fusing female embryonic diploid fibroblasts irradiated at 6 000 rads with HPRT-deficient hamster Wg3hCl 2 cells. Due to the low retention frequency of the chicken fragments, a high number of clones was produced from which the best ones were selected. Thus, 452 fusion clones were tested for retention frequencies with a panel of 46 markers. Based on these results, 103 clones with a mean marker retention of 23.8% were selected for large scale culture to produce DNA in sufficient quantities for the genotyping of numerous markers. Retention frequency was tested again with the same 46 markers and the 90 best clones, with a final mean retention frequency of 21.9%, were selected for the final panel. This panel will be a valuable resource for fine mapping of markers and genes in the chicken, and will also help in building BAC contigs. chicken / radiation hybrid / mapping

A gene-based radiation hybrid map of chicken microchromosome 14: Comparison to human and alignment to the assembled chicken sequence

“…The average retention rate for the markers was 23.7%, in accordance with the first estimates for the panel [24]. The retention frequency along the chromosome, as estimated by plotting the retention of the markers from the framework map against their positions, demonstrates that the higher retention rates were [15].…”

“…This can explain the higher retention rate observed for microchromosome markers when constructing the panel [24], since they have a higher chance than macrochromosome markers of being close to the centromere. …”

“…1). The marker MCW0123, which was used for selecting the clones while constructing the panel [24] did not show a particularly high level of retention, when compared to the surrounding markers.…”

“…The production of the RH panel has already been described [24]. Briefly, normal diploid female chicken fibroblasts irradiated at 6000 rads by gamma rays from a Cesium-137 source were fused to the hypoxanthine guanine phosphoribosyl transferase (HPRT)-deficient hamster cell line, Wg3hCl2 [13].…”

“…RH mapping is a powerful tool for locating genes since it uses the simple polymerase chain reaction (PCR): contrariwise to genetic markers, RH markers do not require the development of polymorphism. The whole genome radiation hybrid (WGRH) panel we produced [24] has already been used to build radiation maps for chicken microchromosome 15 [20], macrochromosome 4 and 7 [25,28], and maps of other chromosomes are under construction.…”