Research into the kinds of tolerances needed for critical systems involves a large amount of interdisciplinary work. The more complex the system, the more carefully all possible interactions have to be considered and prepared for. Considering the importance of high-value systems in transport, public utilities and the military, the field of topics that touch on research is very wide: it can include such obvious subjects as software modeling and reliability, or hardware design, to arcane elements such as stochastic models, graph theory, formal or exclusionary logic, parallel processing, remote data transmission, and more.[19]
The level of salt tolerance provided by known transporter genes in the modern rice cultivars is insufficient and hence new genes or novel allelic variants of these transporters are needed for enhanced salinity tolerance. Crop domestication has selected only a few agronomically desirable alleles and left behind vast pool of genetic diversity in the wild progenitor species due to domestication bottleneck (Tanksley and McCouch 1997). Potential implication of germplasm and crop wild relatives under extreme environment conditions has been reviewed (Mickelbart et al. 2015). Allelic variant of members of HKT transporters such TmHKT1;5-A (Munns et al. 2012), TaKHT1;5-D (Yang et al. 2014) has been introgressed from wild relatives that led to increase in yield of the plant. Allele mining identifies superior alleles from related genotypes that may have been the effect of mutations in the process of evolution. The superior alleles can be used to develop allele specific markers and use them in marker assisted selection and also in tracing the evolution of alleles. Sequencing based allele mining and association analysis is an effective strategy to unravel the hidden potential of wild rice germplasm. Allele mining has been used across the crop species and novel alleles have been identified for abiotic stress tolerance genes in rice (Latha et al. 2004; Negrão et al. 2013; Platten et al. 2013; Singh et al. 2015a), maize (Yu et al. 2010) and barley (Cseri et al. 2011). However, a collection of untapped germplasm is required to mine novel desirable alleles and identify nucleotide sequence variations associated with these alleles (Kumar et al. 2010). India has a wealth of untapped wild rice germplasm that requires hasty expeditions to collect and exploit this fast depleting genetic resource (Singh et al. 2013). The genes already exploited from Indian wild rice include grassy stunt virus resistance from Oryza nivara (Khush and Ling 1974), Bph 19(t) from Oryza rufipogon (Li et al. 2010), Xa38 from Oryza nivara (Bhasin et al. 2012), salinity tolerance genes, inositol methyl transferase (Sengupta et al. 2008) and L-myo-inositol 1-phosphate synthase from wild rice Porteresia coarctata (Das-Chatterjee et al. 2006). The male sterility (MS) gene from O. rufipogon was introduced into the cultivated rice, leading to development of high yielding hybrid rice (Yuan et al. 1993). The beneficial alleles derived from wild relatives of rice have been transferred into elite genetic backgrounds leading to enhanced trait performance in rice (McCouch et al. 2007; Xiao et al. 1996; Xiao et al. 1998).
Tolerance Data 2013 Torrent
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Wild rice is expected to play important role in rice improvement in the coming years. In this study we explored untapped diversity of Indian wild rice to identify natural alleles of the HKT transporter family genes. Analysis of nucleotide sequence variations for eight HKT family genes in wild rice showed higher nucleotide and haplotypic diversity as compared to the cultivated rice varieties (Table 1, Fig. 2). This supports the notion that wild relatives are genetically much more diverse than their cultivated counterparts (Hoisington et al. 1999). However, nucleotide variations of a gene is also associated with respect to position in the gene (McNally et al. 2006). Platten et al. (2013) observed comparatively lower nucleotide diversity and haplotypic diversity in cultivated rice and identified relationship between different haplotypes and salt tolerance for HKT1;5 gene. Our results indicate that nucleotide diversity was quite different from haplotype diversity as only effective SNPs participated in haplotypic group determination (Goodall-Copestake et al. 2012). Differences between nucleotide and haplotype diversity has been measured across different genes such as Sucrose Synthase 3 in rice (Lestari et al. 2011) and OsDREB1F in wild and cultivated rice (Singh et al. 2015a).
Two haplotypes (H1 and H10) of the OsHKT2;3 were associated with salt tolerance SES score. In addition, total 4 SNPs were associated with the analysed salt tolerance traits, one synonymous, one intronic and two non-synonymous SNPs, S761 and S1001, both leading to Iso to Thr substitution at amino acid positions 77 and 157, respectively (Table 2). The isoleucine to threonine substitution is known to impact post translation modifications such as phosphorylation. An increase in the phosphorylation level has been observed with increase in Thr in a protein sequence (Vlad et al. 2008). The non-synonymous mutations outside functional domain of genes may alter structure of the protein and consequently its function (Negrão et al. 2013). Both synonymous and non-synonymous SNPs showed significant association with salt tolerance traits, perhaps affecting the RNA splicing, mRNA stability, and post-translational modification of protein function (Negrão et al. 2013). Some of this could be due to close linkage of a non-functional SNP with the functional SNP. A large number of rare alleles and haplotypes were observed for different HKT genes, whose association with trait could not be studied due to low minor allele frequency. Rare alleles contributing to the gain or enhancement of the trait value may be useful for future adaptability of the rice crop, these may involve novel mechanisms of salt tolerance. Introgression of rare alleles through marker-assisted backcross breeding (MABB) techniques may help develop new genetic resources for breeding of rice for tolerance to extreme salt stress. To find out effective rare alleles, bi-parental mapping populations involving these lines will be needed to validate the function of rare alleles and also to understand their genetic control mechanisms (Semagn et al. 2010).
A total of 299 wild rice accessions including 244 new accessions collected from different geographical regions of India along with their passport data and 58 accessions from NBPGR gene bank, New Delhi, India were analysed. In addition, 6 cultivated O. sativa (salt tolerant FL478, CSR27, CSR11 with different tolerance mechanisms, MI48 as a moderate check while VSR156 and Pusa 44 as sensitive checks) were used. The collection sites and other detailed information on each wild rice accession is available in a database at (Additional file 1: Table S1).
Theoretically, there is no hard limit. However, an etcd cluster probably should have no more than seven nodes. Google Chubby lock service, similar to etcd and widely deployed within Google for many years, suggests running five nodes. A 5-member etcd cluster can tolerate two member failures, which is enough in most cases. Although larger clusters provide better fault tolerance, the write performance suffers because data must be replicated across more machines.
To construct a genetic linkage map efficiently, we need a genome-wide marker set and an efficient genotyping system. The Ion AmpliSeq Targeted Sequencing technology (Thermo Fisher Scientific, Waltham, MA, USA) can quickly detect polymorphisms by amplicon-based multiplex targeted NGS [15, 16]. Here, we developed genetic maps with AmpliSeq and sought QTLs for PHS tolerance in buckwheat by NGS-BSA. We developed genome-wide markers for QTL analysis and detected several QTLs related to PHS tolerance. In addition, we developed linked markers and investigated the effect of selection with the markers. Furthermore, we demonstrated the effectiveness of NGS-BSA by developing linkage maps from AmpliSeq data of markers linked to the SC allele. Our findings and marker development system will be useful for advancing genetic research for buckwheat breeding.
Together, these data show that an experimental breach of immunological tolerance in wild-type mice promotes the production of antibodies able to neutralize tier 2 strains of HIV-1. Importantly, these mice retain the ability to mount Env-specific antibody responses that further increase the percentage of mice neutralizing tier 2 HIV-1 variants and the effectiveness of these antibodies. However, continued Env immunization ultimately focuses the antibody response on gp120-neutralizing epitopes restricted to tier 1 HIV-1 strains.
Previous studies have evaluated the role of tolerance in the regulation of B cells that express autoreactive HIV-1 bnAb specificities (i.e., 2F5, 4E10) by generating Ig knock-in mice. Specifically, the rearranged Ig genes encoding these specificities have been introduced into the Ig loci, such that all developing B cells express the autoreactive HIV-1 bnAb as a surface antigen receptor (Verkoczy et al., 2010, 2011a, 2013; Doyle-Cooper et al., 2013; Zhang et al., 2016). Results from these studies have shown that B cells with these HIV-1 bnAb autoreactive specificities are predominantly censored by central tolerance in the bone marrow that ultimately precludes their further development. Recently, a small number of germline 2F5-expressing splenic B cells displaying an anergic phenotype have been reported to mount a gp41-specific antibody response, although whether these antibodies were able to neutralize HIV-1 was not shown (Zhang et al., 2016). Together, these studies have documented that central tolerance prevents the development of B cells expressing an autoreactive broadly neutralizing HIV-1 specificity. However, autoreactive B cells that have escaped central B cell tolerance also exist in the peripheral B cell pool of both humans and mice where they have been characterized to be functionally anergic (Pugh-Bernard et al., 2001; Wardemann et al., 2003; Merrell et al., 2006; Koelsch et al., 2007). Whether peripheral tolerance normally limits the ability of these cells from mounting a protective HIV-1 antibody response has not yet been established. 2ff7e9595c
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