RESUMO
The essential functions of polycomb repressive complex 1 (PRC1) in development and gene silencing are thought to involve long non-coding RNAs (lncRNAs), but few specific lncRNAs that guide PRC1 activity are known. We screened for lncRNAs, which co-precipitate with PRC1 from chromatin and found candidates that impact polycomb group protein (PcG)-regulated gene expression in vivo A novel lncRNA from this screen, CAT7, regulates expression and polycomb group binding at the MNX1 locus during early neuronal differentiation. CAT7 contains a unique tandem repeat domain that shares high sequence similarity to a non-syntenic zebrafish analog, cat7l Defects caused by interference of cat7l RNA during zebrafish embryogenesis were rescued by human CAT7 RNA, enhanced by interference of a PRC1 component, and suppressed by interference of a known PRC1 target gene, demonstrating cat7l genetically interacts with a PRC1. We propose a model whereby PRC1 acts in concert with specific lncRNAs and that CAT7/cat7l represents convergent lncRNAs that independently evolved to tune PRC1 repression at individual loci.
Assuntos
Diferenciação Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Modelos Biológicos , Neurônios/metabolismo , Complexo Repressor Polycomb 1/metabolismo , RNA Longo não Codificante/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Animais , Células HeLa , Humanos , Camundongos , Complexo Repressor Polycomb 1/genética , RNA Longo não Codificante/genética , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genéticaRESUMO
There is limited data on the spectrum and prevalence of rotavirus genotypes in older children and adults in Asia. This pilot study conducted between November 2012 and April 2013 tested for rotavirus in older children (>12 years of age), and adults with gastroenteritis from southern India. Stool samples from patients who were hospitalized or attended out-patient units with diarrhea were screened for rotavirus using Premier™ Rotaclone(®). Confirmatory testing was by another antigen detection sandwich, in-house ELISA, based on capture by a polyclonal serum and VP6 PCR. Genotyping for VP7 and VP4 was done using hemi-nested PCRs for G- and P-types circulating in India. A total of 626 stool samples from older children and adults were screened and 52 (8.4%) were initially positive for rotavirus by antigen detection. A high proportion of samples (27/51) were found to be false positives on confirmatory testing. Of the 23 samples for which genotyping results were obtained, G1P[8] was the most common genotype. There was one each of G1P[6], G1P[4] and two strains of G9P[4] while one sample showed mixed genotypes of G2 and G9P[4]. This study shows that group A rotavirus is found in 3.8% of diarrheal specimens in older children and adults with gastroenteritis in southern India and that common genotypes circulate in children and adults.
