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Biomedical subjects

R L Bowden

Publications and source records attributed to R L Bowden.

4 recordsLinked to original sources
PubMed2002

A genetic map of Gibberella zeae (Fusarium graminearum).

We constructed a genetic linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate-nonutilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine linkage groups. The total map length is approximately 1300 cM with an average interval of 2.8 map units between loci. Three of the nine linkage groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two linkage groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on linkage groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.

Chromosome Mapping↗
PubMed1990

Mechanism of Photosynthesis Decrease by Verticillium dahliae in Potato.

Young, visually symptomless leaves from potato (Solanum tuberosum) plants infected with Verticillium dahliae exhibited reduced carbon assimilation rate, stomatal conductance, and intercellular CO(2), but no increase in dark respiration, no change in the relationship between carbon assimilation rate versus intercellular CO(2), and no change in light use efficiency when intercellular CO(2) was held constant. Therefore, the initial decrease in photosynthesis caused by V. dahliae was caused by stomatal closure. Errors in the intercellular CO(2) calculation caused by uneven distribution of carbon assimilation rate across the leaf were tested by (14)CO(2) autoradiography. Patchiness was found at a low frequency. Low stomatal conductance was correlated with low leaf water potentials. Infection did not affect leaf osmotic potentials.

Journal Article↗
PubMed1989

The origin and distribution of vasa vasorum at the bifurcation of the common carotid artery with atherosclerosis.

The purpose of our study was to determine the origin and relation of vasa vasorum to atherosclerotic plaque at the bifurcation of the common carotid artery. We randomly selected 12 unembalmed adult human cadavers, 40-96 years of age. We prepared luminal casts of the arteries from eight cadavers and cleared the arteries from the remaining four cadavers. A network of vasa vasorum surrounding atherosclerotic plaque was observed in five luminal casts and in two cleared specimens; the vasa vasorum originated from the superior thyroid and ascending pharyngeal arteries. Three of the five luminal casts also demonstrated vasa vasorum arising directly from the internal carotid artery distal to the plaque. An extensive network of vasa vasorum was not observed in specimens from the five cadavers relatively free of gross atherosclerotic plaque. Our findings demonstrate the importance of the external carotid artery in giving rise to the vasa vasorum that supply the areas of atherosclerotic plaque.

Adult↗