Biomedical subjects

Glyn Jenkins

Publications and source records attributed to Glyn Jenkins.

7 recordsLinked to original sources

PubMed2006

Multi-substrate chromosome preparations for high throughput comparative FISH.

BACKGROUND: A modification of a standard method of fluorescence in situ hybridisation (FISH) is described, by which a combination of several substrates and probes on single microscope slides enables more accurate comparisons of the distribution and abundance of chromosomal sequences and improves the relatively low throughput of standard FISH methods. RESULTS: The utility and application of multi-colour, multi-substrate FISH is illustrated by the simultaneous physical mapping of retrotransposon sequences to three species of Avena, and single locus BAC (bacterial artificial chromosome) clones and rDNA probes to three species of Brachypodium, demonstrating how this would enable better understanding of complex phylogenetic relationships among some of the species belonging to these two genera. CONCLUSION: The results show that use of multi-substrate chromosome preparations significantly increases the utility of FISH in comparative analyses of the distribution and abundance of chromosomal sequences in closely related plant species.

Avena↗

PubMed2006

Alignment of the genomes of Brachypodium distachyon and temperate cereals and grasses using bacterial artificial chromosome landing with fluorescence in situ hybridization.

As part of an initiative to develop Brachypodium distachyon as a genomic "bridge" species between rice and the temperate cereals and grasses, a BAC library has been constructed for the two diploid (2n = 2x = 10) genotypes, ABR1 and ABR5. The library consists of 9100 clones, with an approximate average insert size of 88 kb, representing 2.22 genome equivalents. To validate the usefulness of this species for comparative genomics and gene discovery in its larger genome relatives, the library was screened by PCR using primers designed on previously mapped rice and Poaceae sequences. Screening indicated a degree of synteny between these species and B. distachyon, which was confirmed by fluorescent in situ hybridization of the marker-selected BACs (BAC landing) to the 10 chromosome arms of the karyotype, with most of the BACs hybridizing as single loci on known chromosomes. Contiguous BACs colocalized on individual chromosomes, thereby confirming the conservation of genome synteny and proving that B. distachyon has utility as a temperate grass model species alternative to rice.

Chromosomes, Artificial, Bacterial↗

PubMed2004

Laying the cytotaxonomic foundations of a new model grass, Brachypodium distachyon (L.) Beauv.

Brachypodium distachyon is a ubiquitous, temperate grass species which is being developed and exploited as an alternative model to rice, in order to gain access to important syntenic regions of the genomes of less tractable relatives such as wheat. As part of this initiative, this paper describes for the first time the cytotaxonomy of members of the polyploid series of this species, and challenges the assumption that the series evolved simply by chromosome doubling. In situ hybridization using genomic DNA probes and rDNA markers uncovers a hybrid origin of several of the polyploid ecotypes, and sheds light upon the complex evolution of this species and its close relatives.

Chromosome Painting↗

PubMed2003

A high-copy-number CACTA family transposon in temperate grasses and cereals.

A lineage of CACTA family transposons has been identified in temperate grasses and cereals, and a full-length representative of the subfamily from Lolium perenne has been sequenced. Both the size and internal organization of the L. perenne element are typical of other CACTA family elements but its high copy number and strong conservation are unexpected. Comparison with homologs in other species suggests that this lineage has adopted a distinct and novel evolutionary strategy, which has allowed it to maintain its presence in genomes over long periods of time.

Amino Acid Sequence↗

PubMed2003

Unfolding large-scale maps.

This is an account of the development and use of genetic maps, from humble beginnings at the hands of Thomas Hunt Morgan, to the sophistication of genome sequencing. The review charters the emergence of molecular marker maps exploiting DNA polymorphism, the renaissance of cytogenetics through the use of fluorescence in situ hybridisation, and the discovery and isolation of genes by map-based cloning. The historical significance of sequencing of DNA prefaces a section describing the sequencing of genomes, the ascendancy of particular model organisms, and the utility and limitations of comparative genomic and functional genomic approaches to further our understanding of the control of biological processes. Emphasis is given throughout the treatise as to how the structure and biological behaviour of the DNA molecule underpin the technological development and biological applications of maps.

Arabidopsis↗

PubMed2002

The nature and destiny of translocated B-chromosome-specific satellite DNA of rye.

Translocations of A chromosome-specific and B chromosome-specific satellite DNA were tracked by fluorescence in situ hybridisation from an irradiated M1 generation of an experimental population of rye (Secale cereale L.) to its M2 progeny. Although high frequencies of large structural rearrangements were detected in root-tip meristems of M1 plants, none was present at meiosis or in somatic cells of their progeny. These results are interpreted in terms of efficient "filtering" of translocations during vegetative development, and not in the more usual terms of meiosis presenting a physical barrier to structural variants. These observations highlight the fact that B-A translocations are not tolerated, and may explain why this form of chromosome mutation is largely absent from natural populations.

Chromosome Mapping↗

PubMed2002

Combinatorial labelling of DNA probes enables multicolour fluorescence in situ hybridisation in plants.

This paper demonstrates a simple but effective use of combinatorial probes to label plant chromosomes by multicolour fluorescence in situ hybridisation (FISH). Three different DNA probes were labelled with only two different fluorophores, hybridised to somatic metaphase chromosomes of Secale cereale and Triticum aestivum, simultaneously visualised, and unequivocally distinguished in a single FISH experiment. Combinatorial labelling can augment karyotypical investigations, physical mapping of chromosomes and other analyses in plants based upon FISH.

Chromosomes↗