Project description:40mer probes were designed to detect plant viroids infection at the genus level. This microarray platform is able to detect a wide spectrum of all the 8 reported viroid genera, including 37 known plant viroid species. Viroid samples were extracted from infected plant hosts and plasmids. Total RNA was extracted and hybridized to the microarray.
Project description:Grapevine yellow speckle viroid-2 (GYSVd-2) is a viroid found only in grapevines in China and Australia. Here, we report the molecular characterization of GYSVd-2 isolated from three grapevine varieties in China. A total of 90 cDNA clones were sequenced including 30 cDNA clones obtained from each of the Black Olympia, Zaoyu, and Thomson Seedless isolates. Sequencing analysis identified 20, 18, and 12 different sequence variants from the 3 isolates, respectively. Furthermore, each of the isolates included one predominant sequence variant. Compared to the Australian variant of GYSVd-2 (Accession number: NC_003612), the Black Olympia variant was identical and the Zaoyu variant contained one substitution. In contrast, the Thomson Seedless isolate significantly varied from the Australian variant with three substitutions, two insertions, and four deletions. In silico structure analysis predicted that the variations were clustered in the terminal left, the pathogenicity, and the variable region of the predicted secondary structure of GYSVd-2.
Project description:Grapevine yellow speckle viroid 1 (GYSVd1), which is a member of the genus Apscaviroid, causes yellow speckle disease in grapevines. Here, we report the complete de novo genome assembly of GYSVd1 from the grapevine transcriptome and identified 10 single nucleotide polymorphisms of GYSVd1 across the grapevine populations.
Project description:40mer probes were designed to detect plant viroids infection at the genus level. This microarray platform is able to detect a wide spectrum of all the 8 reported viroid genera, including 37 known plant viroid species.
Project description:Recent findings indicate that nuclear speckles, a distinct type of nuclear body, interact with certain chromatin regions in a ground state. Here, we report that the chromatin structural factors CTCF and cohesin are required for full ground-state association between DNA and nuclear speckles. We identified a putative speckle targeting motif (STM) within cohesin subunit RAD21 and demonstrated that the STM is required for chromatin-nuclear speckle association, disruption of which impaired induction of speckle-associated genes. Depletion of the cohesin-releasing factor WAPL, which stabilizes cohesin on chromatin and reinforces DNA–speckle contacts, results in enhanced inducibility of speckle-associated genes. Additionally, we observed disruption of chromatin–nuclear speckle association in patient-derived cells with Cornelia de Lange syndrome, a congenital neurodevelopmental disorder involving defective cohesin pathways. In summary, our findings reveal a mechanism for establishing the ground state of chromatin–speckle association and promoting gene inducibility, with relevance to human disease.
Project description:Here, we report complete genome sequences of grapevine yellow speckle viroid 1 (GYSVd1) and hop stunt viroid (HSVd), members of the family Pospiviroidae, assembled from the transcriptome data generated from Ixeridium dentatum plants. To our knowledge, this is the first report of GYSVd1 and HSVd in I. dentatum.
Project description:The interchromatin space in the cell nucleus contains various membrane-less nuclear bodies. Recent findings indicate that nuclear speckles, comprising a distinct nuclear body, exhibit interactions with certain chromatin regions in a ground state. Key questions are how this ground state of chromatin-nuclear speckle association is established and what are the gene regulatory roles of this layer of nuclear organization. We report here that chromatin structural factors CTCF and cohesin are required for full ground state association between DNA and nuclear speckles. Disruption of ground state DNA-speckle contacts via either CTCF depletion or cohesin depletion had minor effects on basal level expression of speckle-associated genes, however we show strong negative effects on stimulus-dependent induction of speckle-associated genes. We identified a putative speckle targeting motif (STM) within cohesin subunit RAD21 and demonstrated that the STM is required for chromatin-nuclear speckle association. In contrast to reduction of CTCF or RAD21, depletion of the cohesin releasing factor WAPL stabilized cohesin on chromatin and DNA-speckle contacts, resulting in enhanced inducibility of speckle-associated genes. In addition, we observed disruption of chromatin-nuclear speckle association in patient derived cells with Cornelia de Lange syndrome (CdLS), a congenital neurodevelopmental diagnosis involving defective cohesin pathways, thus revealing nuclear speckles as an avenue for therapeutic inquiry. In summary, our findings reveal a mechanism to establish the ground organizational state of chromatin-speckle association, to promote gene inducibility, and with relevance to human disease.
Project description:The interchromatin space in the cell nucleus contains various membrane-less nuclear bodies. Recent findings indicate that nuclear speckles, comprising a distinct nuclear body, exhibit interactions with certain chromatin regions in a ground state. Key questions are how this ground state of chromatin-nuclear speckle association is established and what are the gene regulatory roles of this layer of nuclear organization. We report here that chromatin structural factors CTCF and cohesin are required for full ground state association between DNA and nuclear speckles. Disruption of ground state DNA-speckle contacts via either CTCF depletion or cohesin depletion had minor effects on basal level expression of speckle-associated genes, however we show strong negative effects on stimulus-dependent induction of speckle-associated genes. We identified a putative speckle targeting motif (STM) within cohesin subunit RAD21 and demonstrated that the STM is required for chromatin-nuclear speckle association. In contrast to reduction of CTCF or RAD21, depletion of the cohesin releasing factor WAPL stabilized cohesin on chromatin and DNA-speckle contacts, resulting in enhanced inducibility of speckle-associated genes. In addition, we observed disruption of chromatin-nuclear speckle association in patient derived cells with Cornelia de Lange syndrome (CdLS), a congenital neurodevelopmental diagnosis involving defective cohesin pathways, thus revealing nuclear speckles as an avenue for therapeutic inquiry. In summary, our findings reveal a mechanism to establish the ground organizational state of chromatin-speckle association, to promote gene inducibility, and with relevance to human disease.
Project description:In order to analyze the production of small RNA (sRNA) by viroids upon infecting the plants, the tomato plants (Lycopersicum esculentum cv. Rutgers) were inoculated with the variants of Potato spindle tuber viroid (PSTVd). After 21-days of post inoculation, total RNA was extracted and subjected for deep-sequencing using Illumina platform. The primers were trimmed and only 21- to 24-nt long small RNAs were filtered after quality check of the raw data. The filtered 21- to 24-nt was mapped against the genomic and antigenomic strands of the respective PSTVd variants using standard pattern matching algorithm. The profiling of viroid derived sRNA (vd-sRNA) revealed that the viroids are susceptible to host RNA silencing mechanism. Evaluation of the vd-sRNA production in PSTVd infected tomato plants by high-throughput sequencing of small RNAs.