Kishimoto N.,Japan National Institute of Agrobiological Science |
Nagai J.-I.,Kagoshima Prefectural Institute for Agricultural Development KIAD |
Kinoshita T.,Saga Prefectural Agriculture Research Center |
Ueno K.,Kumage Branch |
And 2 more authors.
PLoS ONE | Year: 2013
Transcriptional gene silencing (TGS)-a phenomenon observed in endogenous genes/transgenes in eukaryotes-is a huge hindrance to transgenic technology and occurs mainly when the genes involved share sequence homology in their promoter regions. TGS depends on chromosomal position, suggesting the existence of genomic elements that suppress TGS. However, no systematic approach to identify such DNA elements has yet been reported. Here, we developed a successful novel screening strategy to identify such elements (anti-silencing regions-ASRs), based on their ability to protect a flanked transgene from TGS. A silenced transgenic tobacco plant in which a subsequently introduced transgene undergoes obligatory promoter-homology dependent TGS in trans allowed the ability of DNA elements to prevent TGS to be used as the screening criterion. We also identified ASRs in a genomic library from a different plant species (Lotus japonicus: a perennial legume); the ASRs include portions of Ty1/copia retrotransposon-like and pararetrovirus-like sequences; the retrotransposon-like sequences also showed interspecies anti-TGS activity in a TGS-induction system in Arabidopsis. Anti-TGS elements could provide effective tools to reduce TGS and ensure proper regulation of transgene expression. Furthermore, the screening strategy described here will also facilitate the efficient identification of new classes of anti-TGS elements. © 2013 Kishimoto et al. Source
Maw A.A.,Kagoshima University |
Shimogiri T.,Kagoshima University |
Yamamoto K.,Kagoshima University |
Kawabe K.,Kagoshima University |
And 3 more authors.
Journal of Poultry Science | Year: 2013
This is the first study in which genetic diversity of eight chicken populations including Satsumadori, Satsuma-jidori and three populations each of improved and commercial chicken by using 102 indels markers. Both of Satsumadori and Satsuma-jidori were referred to as Satsuma's chickens in this study. The proportion of polymorphic loci, average observed and expected heterozygosities were ranged from 0.500 to 0.814, from 0.147 to 0.257 and from 0.175 to 0.247, respectively. Monomorphic indels loci being specific to a particular population were detected in some populations. The coefficients of genetic differentiation (Gst) of the Satsuma's chickens and six populations of improved and commercial chickens were 0.124 and 0.287, respectively. The Gst for all populations was 0.329. The (Ds) genetic distance matrixes for all possible pairs (28 pairs) of populations were estimated from allele frequency to construct UPGMA tree. The UPGMA tree clearly divided Satsuma's chickens and the other populations. The 2-D scatter plots of PCA analysis assembled the individuals into their respective populations. © 2013, Japan Poultry Science Association. Source