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G Corbett

Publications and source records attributed to G Corbett.

8 recordsLinked to original sources
PubMed1997

Chloroplast DNA variability in wild and cultivated rice (Oryza spp.) revealed by polymorphic chloroplast simple sequence repeats.

Short mononucleotide repeats analogous to nuclear microsatellites or simple sequence repeats (SSRs) have been identified in chloroplast genomes. Primers flanking mononucleotide repeats in the fully sequenced rice chloroplast genome have been used in conjunction with PCR to amplify genomic DNA from 42 wild rice accessions. The amplification products exhibited length polymorphism, which allowed the levels of chloroplast variability detected to be quantified. Seven primer pairs that amplified products from different regions of the rice chloroplast were used, five of which also amplified polymorphic products in cultivated rice (Oryza sativa). Diversity values ranged from 0.5224 +/- 0.0845 (SE) to 0.8298 +/- 0.0085 in the wild accessions, which was higher than that detected in the O. sativa accessions. Both intra- and inter-specific polymorphism was detected, and the extent of chloroplast genomic differentiation based on chloroplast simple sequence repeat (cpSSR) assays was quantified using the RST statistic. Primers designed to amplify cpSSRs in O. sativa can also be used to generate polymorphic chloroplast markers in related taxa. The potential of using cpSSR to trace the origin of rice polyploid species is discussed.

Chloroplasts↗
PubMed1996

DNA fingerprints of rice (Oryza sativa) obtained from hypervariable chloroplast simple sequence repeats.

The aim of this research was to develop a convenient polymerase chain reaction-based assay that would allow intraspecific chloroplast variability to be detected. Our approach is based on the detection of length polymorphism within chloroplast mononucleotide microsatellite loci. Information from the fully sequenced rice chloroplast genome was used to identify 12 regions with a minimum of ten uninterrupted mononucleotide repeats. Primers flanking these repeats were used in conjunction with polymerase chain reaction to examine levels of polymorphism in six wild and 14 cultivated rice accessions. A total of six of the primer pairs revealed length polymorphism with between two and five size variants being detected. Diversity indices varied between 0.07 and 0.72. The length variation detected at multiple, physically linked sites was used to identify 15 unique haplotypes with an overall diversity index of 0.90. This level of polymorphism is sufficiently high to allow chloroplast variability to be studied at the intraspecific level. An additional 47 Oryza sativa accessions were also assayed with 31 unique chloroplast haplotypes being detected. The distribution of these haplotypes is described in relation to isozyme groupings and subspecies differentiation. The relevance and implications of these results for plant population genetics and the management of germplasm collections is discussed.

Chloroplasts↗
PubMed1994

A developmental study of the acquisition of colour terms in Setswana.

We report a study of the acquisition of colour terms by speakers of Setswana, the language of Botswana in Southern Africa. This was carried out as a test of Berlin & Kay's theory of colour term universals, on a language with less than the maximum complement of eleven basic colour terms, and in order to document changes in Setswana under the impact of economic development. Seventy-seven five- to nine-year-olds were studied on two colour tasks: elicited lists and colour naming. In general the data were consistent with Berlin & Kay's theory: the rank order of frequency of correct use of colour terms was similar to the order of the Berlin & Kay hierarchy; and primary colour terms were offered more frequently and were more likely to be used correctly than secondary colour terms. The use of English colour terms was prevalent, especially amongst the younger groups, but they functioned as substitutes for Setswana terms, rather than as a means to fill the vacant basic colour term slots.

Age Factors↗
PubMed1987

Pyoderma gangrenosum and myelodysplasia.

Pyoderma gangrenosum has been recognized occurring in association with acute and chronic leukaemia. More recently it has been described in patients with myelodysplasia (Jacobs, Palmer & Gordon-Smith 1985). We report a case of pyoderma gangrenosum in a patient with a preceding history of myelodysplasia, illustrating the problem of controlling the skin disease in this condition and the eventual transformation of the myelodysplasia into acute leukaemia. Treatment of the leukaemia resulted in improvement of the skin lesions.

Humans↗
PubMed1986

Isolation of the eclosion gene cluster and the developmental expression of the Gld gene in Drosophila melanogaster.

During the development of Drosophila melanogaster the expression of glucose dehydrogenase (GLD) changes from non sex-limited to male limited. We have isolated the Gld gene and three other functionally related genes in the eclosion gene cluster by the method of chromosome walking. The Gld gene has been identified by two deletions and a translocation which genetically define the gene. A 2.8-kb RNA has been identified as the putative GLD mRNA. The temporal and spatial expression of this RNA is correlated with the expression of the GLD enzyme and levels of the steroid hormone ecdysterone. Using single-strand antisense probes we have detected three RNA species. However these three transcripts are not derived from the Gld locus. One of these RNAs is weakly detected by the multiple cloning site of the pSP65 vector. The level of detection of this latter RNA is greatly increased by the insertion of a specific Gld gene fragment in the pSP65 vector.

Animals↗