No abstract

Molecular markers associated with gene coding regions are useful tools for bridging functional and structural genomics. Due to their high abundance in plant genomes, single nucleotide polymorphisms (SNPs) are present within virtually all genomic regions, including most coding sequences. The objective of this study was to develop a set of SNPs for the apple by taking advantage of the wealth of genomics resources available for the apple, including a large collection of expressed sequenced tags (ESTs). Using bioinformatics tools, a search for SNPs within an EST database of approximately 350,000 sequences developed from a variety of apple accessions was conducted. This resulted in the identification of a total of 71,482 putative SNPs. As the apple genome is reported to be an ancient polyploid, attempts were made to verify whether those SNPs detected in silico were attributable either to allelic polymorphisms or to gene duplication or paralogous or homeologous sequence variations. To this end, a set of 464 PCR primer pairs was designed, PCR was amplified using two subsets of plants, and the PCR products were sequenced. The SNPs retrieved from these sequences were then mapped onto apple genetic maps, including a newly constructed map of a Royal Gala x A689-24 cross and a Malling 9 x Robusta 5, map using a bin mapping strategy. The SNP genotyping was performed using the high-resolution melting (HRM) technique. A total of 93 new markers containing 210 coding SNPs were successfully mapped. This new set of SNP markers for the apple offers new opportunities for understanding the genetic control of important horticultural traits using quantitative trait loci (QTL) or linkage disequilibrium analysis. These also serve as useful markers for aligning physical and genetic maps, and as potential transferable markers across the Rosaceae family.

The aim of this paper is to show how micromorphology is able to furnish information with the degree of precision necessary for analysing site formation processes and traces of activities in a variety of settings. Use of large resin-impregnated thin sections allows contextual analysis of taphonomy and depositional relationships between sediments and artefact and bioarchaeological remains. We illustrate this by reference to results from a three-year NERC project which examined depositional sequences in core domestic and ritual contexts in three early urban sites in the Near East in different sociocultural and environmental contexts. We discuss how micromorphology is able to trace different pre-depositional, depositional and post-depositional histories of components, before considering its contribution to detecting spatial and temporal variation in uses of space; enabling identification of single depositional episodes within secondary contexts. Together these capacities are providing richly networked data on human activities and behaviour.

No abstract

No abstract