Project description:Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD) genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses.The 2b-RAD protocol was carried out in-house at a non-specialized laboratory using 20 R. ecuadoriensis adults collected from the central coast and southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analyzed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphism (SNP) discovery. Preliminary population genomic analyses (global AMOVA and Bayesian clustering) were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However, only BcgI and CspCI restriction enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses detected a signal of genetic structuring across the study area.Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at epidemiologically relevant scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialized molecular biological equipment.
Project description:Restriction site Associated DNA (RAD) tags are a genome-wide representation of every site of a particular restriction enzyme by short DNA tags. Most organisms segregate large numbers of DNA sequence polymorphisms that disrupt restriction sites, which allow RAD tags to serve as genetic markers spread at a high-density throughout the genome. Here, we demonstrate the applicability of RAD markers for both individual and bulk-segregant genotyping. First, we show that these markers can be identified and typed on pre-existing microarray formats. Second, we present a method that uses RAD marker DNA to rapidly produce a low-cost microarray genotyping resource that can be used to efficiently identify and type thousands of RAD markers. We demonstrate the utility of the former approach by using a tiling path array for the fruit fly to map a recombination breakpoint, and the latter approach by creating and utilizing an enriched RAD marker array for the threespine stickleback. The high number of RAD markers enabled localization of a previously identified region, as well as a second novel region also associated with the lateral plate phenotype. Taken together, our results demonstrate that RAD markers, and the method to develop a RAD marker microarray resource, allow high-throughput, high-resolution genotyping in both model and non-model systems. Keywords: microarray genotyping
Project description:To investiage the ability of positve inotropism from myocardial Rad reduction we induced Rad knockout after onset of pressure overload to reverse or compensate progression of heart failure
Project description:Background2b-RAD (type IIB endonucleases restriction-site associated DNA) approach was invented by Wang in 2012 and proven as a simple and flexible method for genome-wide genotyping. However, there is still plenty of room for improvement for the existent 2b-RAD approach. Firstly, it doesn't include the samples pooling in library preparation as other reduced representation libraries. Secondly, the information of 2b-RAD tags, such as tags numbers and distributions, in most of species are unknown. The purposes of the research are to improve a new 2b-RAD approach which possesses samples pooling, moreover to figure out the characteristic and application potentiality of 2b-RAD tags by bioinformatics analysis.ResultsTwelve adapter1 and an adapter2 were designed. A library approach comprising digestion, ligation, pooling, PCR and size selection were established. For saving costs, we used non-phosphorylated adapters and indexed PCR primers. A F2 population of rice (Oryza sativa .L) was genotyped to validate the new approach. On average, 2000332 high quality reads of each sample were obtained with high evenness. Totally 3598 markers containing 3804 SNPs were discovered and the missing rate was 18.9%. A genetic linkage map of 1385 markers was constructed and 92% of the markers' orders in the genetic map were in accordance with the orders in chromosomes. Meanwhile, the bioinformatics simulation in 20 species showed that the BsaXI had the most widespread recognition sites, indicating that 2b-RAD tags had a powerful application potentiality for high density genetic map. Using modified adapters with a fix base in 3'end, 2b-RAD was also fit for QTL studies with low costs.ConclusionsAn improved 2b-RAD genotyping approach was established in this research and named as I2b-RAD. The method was a simple, fast, cost-effective and multiplex sequencing library approach. It could be adjusted by selecting different enzymes and adapters to fit for alternative uses including chromosomes assembly, QTL fine mapping and even natural population analysis.
Project description:The goal of the microarray experiment was to do a head-to-head comparison of the U1 Adaptor technology with siRNA in terms of specificity at the genome-wide level. U1 Adaptors represent a novel gene silencing method that employs a mechanism of action distinct from antisense and RNA interference (RNAi). The U1 Adaptor is a bifunctional oligonucleotide having a “Target Domain” that is complementary to a site in the target gene's terminal exon and a “U1 Domain” that binds to the U1 small nuclear RNA (snRNA) component of the U1 small nuclear ribonucleoprotein (U1 snRNP) splicing factor. Tethering of U1 snRNP to the target pre-mRNA inhibits 3' end processing (i.e., polyA tail addition) leading to degradation of that RNA species within the nucleus thereby reducing mRNA levels. We demonstrate that U1 Adaptors can specifically inhibit both reporter and endogenous genes. Further, targeting the same gene either with multiple U1 Adaptors or with U1 Adaptors and small interfering RNAs (siRNAs), strongly enhances gene silencing, the latter as predicted from their distinct mechanisms of action. Such combinatorial targeting requires lower amounts of oligonucleotides to achieve potent silencing.
Project description:One of the most recognizable physiological phenomena is the adrenergic-induced fight-or-flight increase in heart rate and cardiac contraction. For the β-adenergic agonist-induced enhancement of calcium influx and transients, and contractility in the heart, we identify the dual requirement of a subpopulation of Rad-bound calcium channels under basal conditions and PKA phosphorylation of Rad. In mice expressing a non-phosphorylatable Rad mutant, basal cardiac contractility is reduced and adrenergic-augmentation of the calcium current and contractility are disabled. Expression of mutant calcium channel β-subunits that cannot bind the mutant Rad restored contractility, revealing a highly specific therapeutic approach to mimic the contractility imparted by adrenergic agonists. Our findings place Rad and its modulation of calcium channels at the nexus of adrenergic modulation of cardiac responses.
Project description:Fight-or-flight responses involve β-adrenergic-induced increases in heart rate and contractile force. Despite decades of investigations, predominantly focusing on ryanodine receptor and phospholamban phosphorylation, the molecular mechanisms underlying the sympathetic nervous system control of cardiac contractility remain controversial and incompletely elucidated. Here, we identify the calcium-channel inhibitor Rad as a critical component. In cardiomyocytes isolated from knock-in mice expressing Rad with alanine-substitutions of the four PKA-phosphorylated serine residues (4SA-Rad), calcium currents cannot be increased by adrenergic agonists or phosphatase inhibitor. In these mice, basal cardiac contractility, exercise capacity and heart rate are reduced, and the augmentation of contractile force by adrenergic agonists is severely blunted. Expression of mutant calcium-channel β-subunits that cannot bind Rad is sufficient to restore calcium influx and cardiac contractility in 4SA-Rad mice to levels induced by adrenergic agonists in wild-type mice, revealing a potential therapeutic approach to enhance cardiac contractility while bypassing stimulation of adrenergic receptors.