Project description:Affymetrix single nucleotide polymorphism (SNP) array data were collected to study genome-wide patterns of genomic variation across a broad geographical range of Island Southeast Asian populations. This region has experienced an extremely complex admixture history. Initially settled ~50,000 years ago, Island Southeast Asia has since been the recipient of multiple waves of population movements, most recently by Austronesian-speaking groups ultimately from Neolithic mainland Asia and later arrivals during the historic era from India and the Middle East. We have genotyped SNPs in ~500 individuals from 30 populations spanning this entire geographical region, from communities close to mainland Asia through to New Guinea. Particular attention has been paid to genomic data that are informative for population history, including the role of recent arrivals during the historic era and admixture with archaic hominins.
Project description:Real- time reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a technique that allows for the quantification of mRNA transcripts present within a tissue of interest. To ensure that quantified amounts of mRNA determined by RT qPCR is due to biological differences rather than a product of variation in testing protocol, results need to be normalized. Normalization has historically relied on the use of reference genes, or genes whose transcript expression does not differ in the tissue of interest independent of the experimental condition. In the field of equine reproductive studies, ACTB and GAPDH have been the most widely used reference genes for normalization of RT-qPCR results. However, recent studies have demonstrated that these genes may have drastically varied expression levels in different tissues and in different physiological states. Our study was aimed at examining different putative reference genes (historic reference genes as well as genes identified by RNA-seq to be stable across different sample types) in equine corpus luteum samples at day 11 and day 13 in pregnant and non-pregnant animals. Stability of genetic expression was evaluated via three stability software analyses (GeNorm, NormFinder and BestKeeper). We hypothesized that the most commonly used historic reference genes (ACTB, GAPDH and B2M) would be the most stably expressed genes in equine corpus luteum samples. COX4I1 and SRP14 were both found to be within the top three most stable genes of all samples for all methods. When assessing the least stably expressed genes, the historic reference genes were frequently identified across the three softwares. Exploration of putative reference genes should be considered when investigating dynamic endocrine organs such as those used in reproductive studies. RT-qPCR studies evaluated with historic genes should be interpreted cautiously.
Project description:Amelogenin, a protein involved in the formation of enamel occurs as two isoforms, AMEL X and AMEL Y, which are encoded on the X and Y chromosome respectively. Isoform-specific peptides can be used for the determination of the chromosomal sex in ancient teeth. This strategy was used to determine the chromosomal sex of individuals from tooth material of historic New Zealand cemetery samples by mass spectrometry-based amelogenin peptide analysis. We show what can happen when osteobiographies are constructed for individuals for whom osteological sex estimation was inaccurate. We also highlight the uses of peptide analysis in identifying individuals, particularly non-adults for whom osteological sex estimation is not possible. Peptide analysis of historic New Zealand cemetery samples has helped to change our interpretations and added to our understanding of these populations.
Project description:Purpose: To determine how divergent strains of C. difficile respond to environmental changes, the transcriptomes of two historic and two recently isolated hypervirulent strains were analyzed following nutrient shift and osmotic shock. Methods: Following nutrient shift and osmotic shock, mRNA profile were determined using sequing of transcriptome in biological duplicates, using Illumina Hi-seq 2000. Results: After applying the quality control steps, for each sample, sequence reads were 90 nucleotides in length and the total number of reads per sample was ~ 26.6 million on average. Expression of more than 90% CDS was detected under the three experimental conditions combined. About 20% of these genes were indentified to be differentially expressed at 1.5 fold or more. Conclusions: Our results reveal that although C. difficile strains contain a large number of shared and strain specific genes, the majority of the differentially expressed genes were core genes. We also detected a number of transcriptionally active regions that were not part of the primary genome annotation. Some of these are likely to be small regulatory RNAs. Differential stress transcriptomes of two historic (strain 630 and 196) and two recently emerged hypervirulent strains (stain R20291 and 32g58) of C. difficile was determined by deep sequencing, in duplicate, using Illumina Hi-Seq 2000.
Project description:Teeth are a well-known source of information for paleoanthropologists. Here, we established the ancient dental metaproteomes in several samples from historic sites. The shotgun metaproteomics analysis relies on a iterative search strategy for the identification of the proteins and their origins.
Project description:Teeth are a well-known source of information for paleoanthropologists. Here, we established the ancient dental metaproteomes in several samples from historic sites. The shotgun metaproteomics analysis relies on a iterative search strategy for the identification of the proteins and their origins.
Project description:This study aimed to investigate the transcriptional differences to metal exposure in two populations of Brown trout. These trout were taken from two separate locations, one population with historic exposure to metals and evidence of metal tolerance, and a second population from a clean environment. These fish were then exposed to metals within a laboratory environment and the transcriptional response before and after exposure was assessed in both liver and gill tissues. Six biological replicates were taken from each condition/population/tissue combination.