Biology subjects

Teng, S.

Publications and source records attributed to Teng, S..

4 recordsLinked to original sources

bioRxiv2017

Rice TSV3 Encoding Obg-like GTPase Protein is Essential for Chloroplast Development during the Early Leaf Stage under Cold Stress

The Spo0B-associated GTP-binding (Obg) proteins occupy a wide variety of roles in the viability of nearly all bacteria. Its detailed roles in higher plants have not yet been elucidated. A novel rice thermo-sensitive virescent mutant tsv3 was identified in this study that displayed albino phenotype at 20{degrees}C before the 3-leaf stage while being normal green at 32{degrees}C or even at 20{degrees}C after the 4-leaf stage. The mutant phenotype was aligned with altered chlorophyll (Chl) content and chloroplast development. Map-based cloning and complementation test showed that TSV3 encoded a kind of small GTP binding protein. Subcellular localization revealed that TSV3 was in chloroplast. TSV3 transcripts were highly expressed in leaves and weak or undetectable in other tissues, suggesting the tissue-specific expression. In tsv3 mutant, the transcriptional levels of certain genes associated with biogenesis of chloroplast ribosomes 50S subunit were severely decreased at the 3-leaf-stage under cold stress, but could be recovered to normal levels at a higher temperature (32{degrees}C). The observations from this study indicated that the rice nuclear-encoded TSV3 plays important roles in chloroplast development at early leaf stage under cold stress.

plant biology↗

bioRxiv2017

Distributed Rhythm Generators Underlie Caenorhabditis elegans Forward Locomotion

Coordinated rhythmic movements are ubiquitous in animal behavior. In many organisms, chains of neural oscillators underlie the generation of these rhythms. In C. elegans, locomotor wave generation has been poorly understood; in particular, it is unclear where in the circuit rhythms are generated, and whether there exists more than one such generator. We used optogenetic and ablation experiments to probe the nature of rhythm generation in the locomotor circuit. We found that multiple sections of forward locomotor circuitry are capable of independently generating rhythms. By perturbing different components of the motor circuit, we localize the source of secondary rhythms to cholinergic motor neurons in the midbody. Using rhythmic optogenetic perturbation we demonstrate bidirectional entrainment of oscillations between different body regions. These results show that, as in many other vertebrates and invertebrates, the C. elegans motor circuit contains multiple oscillators that coordinate activity to generate behavior.

neuroscience↗

bioRxiv2017

Epigenetic Reprogramming of Tissue-Specific Transcription Promotes Metastasis

Tumor metastasis is the cause of death for 90% of cancer patients, and no currently-available therapies target this multi-step process in which cancer cells spread from the local tissue of a primary tumor to distant organs where they establish secondary tumors1. Although epithelial-to-mesenchymal transition2, tumor-secreted exosomes3, epigenetic regulators as well as other genes4-8 have been implicated in metastasis, little is known about how cells adapt to and colonize new tissue environments. Here, we show that the epigenetics-mediated reprogramming of tissue-specific gene transcription in cancer cells promotes metastasis. Using colorectal cancer (CRC) as a model, we found in both clinical and cell line studies that metastatic CRC cells lose their colon-specific gene transcription program and gain a liver-specific gene transcription program as they metastasize in the liver. Further, we found this transcription reprogramming is driven by a reshaped epigenetic landscape of both typical and super-enhancers. Chemical inhibition of enhancer activity disrupts the ability of cells to execute altered transcription programs and consequently inhibits metastasis. Binding motif analysis of the enhancers in liver metastatic CRC cells identified the liver-specific transcription factor FOXA2 as a key regulator, and knocking down of FOXA2 expression prevents the colonization of metastatic CRC cells in the liver of a mice xenograft model. These results, together with additional observations of similar reprogramming in several cohorts of clinical CRC tumor samples and in multiple other forms of metastatic cancers, indicate that this reprogramming may be a common feature of metastasis in multiple cancers and suggest the targeted disruption of this epigenetic reprogramming as a strategy for the development of therapies to treat metastasis, the leading cause of cancer-related mortality.

cancer biology↗

bioRxiv2016

Rare disruptive variants in the DISC1 Interactome and Regulome: association with cognitive ability and schizophrenia

Schizophrenia (SCZ), bipolar disorder (BD) and recurrent major depressive disorder (rMDD) are common psychiatric illnesses. All have been associated with lower cognitive ability, and show evidence of genetic overlap and substantial evidence of pleiotropy with cognitive function and neuroticism. Disrupted in schizophrenia 1 (DISC1) protein directly interacts with a large set of proteins (DISC1 Interactome) that are involved in brain development and signaling. Modulation of DISC1 expression alters the expression of a circumscribed set of genes (DISC1 Regulome) that are also implicated in brain biology and disorder. Here, we report targeted sequencing of 59 DISC1 Interactome genes and 154 Regulome genes in 654 psychiatric patients and 889 cognitively-phenotyped control subjects, on whom we previously reported evidence for trait association from complete sequencing of the DISC1 locus. Burden analyses of rare and singleton variants predicted to be damaging were performed for psychiatric disorders, cognitive variables and personality traits. The DISC1 Interactome and Regulome showed differential association across the phenotypes tested. After family-wise error correction across all traits (FWERacross), an increased burden of singleton disruptive variants in the Regulome was associated with SCZ (FWERacross P=0.0339). The burden of singleton disruptive variants in the DISC1 Interactome was associated with low cognitive ability at age 11 (FWERacross P=0.0043). These results suggest that variants in the DISC1 Interactome effect the risk of psychiatric illness through altered expression of schizophrenia-associated genes. The biological impact of rare variants highlighted here merit further study.

genetics↗