Biomedical subjects

P Dowding

Publications and source records attributed to P Dowding.

4 recordsLinked to original sources

PubMed2006

Plastid genome characterisation in Brassica and Brassicaceae using a new set of nine SSRs.

We report a new set of nine primer pairs specifically developed for amplification of Brassica plastid SSR markers. The wide utility of these markers is demonstrated for haplotype identification and detection of polymorphism in B. napus, B. nigra, B. oleracea, B. rapa and in related genera Arabidopsis, Camelina, Raphanus and Sinapis. Eleven gene regions (ndhB-rps7 spacer, rbcL-accD spacer, rpl16 intron, rps16 intron, atpB-rbcL spacer, trnE-trnT spacer, trnL intron, trnL-trnF spacer, trnM-atpE spacer, trnR-rpoC2 spacer, ycf3-psaA spacer) were sequenced from a range of Brassica and related genera for SSR detection and primer design. Other sequences were obtained from GenBank/EMBL. Eight out of nine selected SSR loci showed polymorphism when amplified using the new primers and a combined analysis detected variation within and between Brassica species, with the number of alleles detected per locus ranging from 5 (loci MF-6, MF-1) to 11 (locus MF-7). The combined SSR data were used in a neighbour-joining analysis (SMM, D (DM) distances) to group the samples based on the presence and absence of alleles. The analysis was generally able to separate plastid types into taxon-specific groups. Multi-allelic haplotypes were plotted onto the neighbour joining tree. A total number of 28 haplotypes were detected and these differentiated 22 of the 41 accessions screened from all other accessions. None of these haplotypes was shared by more than one species and some were not characteristic of their predicted type. We interpret our results with respect to taxon differentiation, hybridisation and introgression patterns relating to the 'Triangle of U'.

Base Sequence↗

PubMed1994

Fungal spores in faeces as evidence of fungus ingestion by sheep.

In Ireland, upland areas are becoming extensively planted with coniferous forest to which sheep are allowed access. Such forest produces many more fruiting bodies of basidiomycetes than the blanket bog on which it was planted. Faecal samples taken from hill and adjacent forest (Picea abies) grazing areas showed an autumnal increase in radiocaesium in the forest samples compared with the hill samples, and there was an indication of higher in vivo radiocaesium activity in the autumn, particularly in individual animals which are known to graze the forest. The peak faecal and in vivo radiocaesium levels coincided with the fungal growing season. A new method is presented using fungal spores, which proves the ingestion of fungi by sheep and permits the identification and quantification of the fungi consumed.

Animal Feed↗

PubMed1990

Forecasting spore concentrations: a time series approach.

Fungal basidiospores and Cladosporium spores are the two most numerous spore types in the air of Dublin and its surroundings. They are known to have allergenic components, and the aim of the study described here is to develop a predictive model for these spores. A very simple model, which combines an estimated diurnal rhythm with a simple, one-parameter time series model, provided good short-term forecasts. The one-step prediction error variance was reduced by 88% for Cladosporium spores and by 98% for basidiospores.

Air Microbiology↗

PubMed1990

Leafyeasts as indicators of air quality in Europe.

Leafyeast populations were surveyed in 1987 and 1988 with the help of schoolchildren at 23 centres throughout Europe located at Brussels, Rochfort-Marche, Flobecq-Renaix and Tournai (Belgium); Aberdeen and Halifax (Britain); Lyon, Rouen and Toulouse (France); Hamburg, Koblenz and Stuttgart (Federal Republic of Germany); Banbridge, Belfast, Dublin and Enniskillen (Ireland); Hollenfels and Ettenbruck (Luxembourg); Apeldoorn, Deventer, Harlem, Leiderdorp and Zutphen (Netherlands). From one to one hundred schools were involved at each centre. The results demonstrate the suitability of leafyeasts for assessing air quality in both urban and rural areas of the non-Mediterranean countries of Europe. Low counts are associated with known pollution sources. As leafyeast populations change quite quickly, the effect of weather systems on the impact of pollution clouds from urban/industrial areas can be followed. Leafyeasts thus give information complementary to that from traditional biological monitors like lichens which provide an integrated picture of the pattern of air pollution over the months or years prior to study.

Journal Article↗