Project description:MicroRNAs (miRNAs) are endogenous small noncoding RNAs (18–25 nt) that are involved in many physiological processes including development, cancer, immunity, apoptosis and host-microbe interactions through posttranscriptional regulation of gene expression. In this study, we measured the profile of small RNAs over the developmental transitions of Spodoptera frugiperda from egg to adult. We identified 741 miRNAs, including 493 known and 248 novel miRNAs. In addition, we identified the miRNAs differentially expressed over the developmental transitions via weighted gene co-expression network analysis (WGCNA). This study identified critical miRNAs involved in the transitions of this important pest insect S. frugiperda from egg to adult, thus providing a useful resource for exploring the regulatory role of miRNAs during insect post-embryonic development.
Project description:Coxiella burnetii undergoes a biphasic developmental cycle within its host cell that generates morphologically and physiologically distinct large cell variants (LCV) and small cell variants (SCV). During the lag phase of the C. burnetii growth cycle, non-replicating SCV differentiate into replicating LCV that in turn differentiate back into SCV during stationary phase. Nearly homogeneous SCV are observed in infected Vero cells after extended incubation (21 to 28 days). In the current study, we sought to establish whether C. burnetii developmental transitions in host cells are recapitulated during host cell-free (axenic) growth in first and second generation acidified citrate cysteine media (ACCM-1 and ACCM-2, respectively). We show that ACCM-2 supported developmental transitions and viability. Although ACCM-1 also supported SCV to LCV transition, LCV to SCV transition did not occur after extended incubation (21 days). Instead, C. burnetii exhibited a ghost-like appearance with bacteria containing condensed chromatin but otherwise devoid of cytoplasmic content. This phenotype correlated with a near total loss in viability between 14 and 21 days of cultivation. Transcriptional profiling of C. burnetii following 14 days of incubation revealed elevated expression of oxidative stress genes in ACCM-1 cultivated bacteria. ACCM-2 differs from ACCM-1 by the substitution of methyl-b-cyclodextrin (Mb-CD) for fetal bovine serum. Addition of Mb-CD to ACCM-1 at 7 days post-inoculation rescued C. burnetii viability and lowered expression of oxidative stress genes. Thus, Mb-CD appears to alleviate oxidative stress in ACCM-2 to result in C. burnetii developmental transitions and viability that mimic host cell-cultivated organisms. Axenic cultivation of C. burnetii in ACCM-2 and new methods Coxiella axenic media 1 vs 2
Project description:We have performed the first systematic identification and analysis of intermediate size ncRNAs (50-500 nt) in the silkworm genome. We identified 194 novel ncRNAs, the expression profiles of them during the transitions from the egg to the first instar larva and from the fifth instar larva to the pupa were anlyzed by dual-channel microarray. Results showed that 12 ncRNAs had significantly differential expression during the two developmental transitions.
Project description:To investigate the chromatin state into an adult stem cell lineage, we generate cell-type specific chromatin state maps in the adult Drosophila intestine and identify principal chromatin state transitions during lineage determination. we profiled the binding sites of five chromatin-associated proteins from which the previously described five major types of chromatin.
Project description:Coxiella burnetii undergoes a biphasic developmental cycle within its host cell that generates morphologically and physiologically distinct large cell variants (LCV) and small cell variants (SCV). During the lag phase of the C. burnetii growth cycle, non-replicating SCV differentiate into replicating LCV that in turn differentiate back into SCV during stationary phase. Nearly homogeneous SCV are observed in infected Vero cells after extended incubation (21 to 28 days). In the current study, we sought to establish whether C. burnetii developmental transitions in host cells are recapitulated during host cell-free (axenic) growth in first and second generation acidified citrate cysteine media (ACCM-1 and ACCM-2, respectively). We show that ACCM-2 supported developmental transitions and viability. Although ACCM-1 also supported SCV to LCV transition, LCV to SCV transition did not occur after extended incubation (21 days). Instead, C. burnetii exhibited a ghost-like appearance with bacteria containing condensed chromatin but otherwise devoid of cytoplasmic content. This phenotype correlated with a near total loss in viability between 14 and 21 days of cultivation. Transcriptional profiling of C. burnetii following 14 days of incubation revealed elevated expression of oxidative stress genes in ACCM-1 cultivated bacteria. ACCM-2 differs from ACCM-1 by the substitution of methyl-b-cyclodextrin (Mb-CD) for fetal bovine serum. Addition of Mb-CD to ACCM-1 at 7 days post-inoculation rescued C. burnetii viability and lowered expression of oxidative stress genes. Thus, Mb-CD appears to alleviate oxidative stress in ACCM-2 to result in C. burnetii developmental transitions and viability that mimic host cell-cultivated organisms. Axenic cultivation of C. burnetii in ACCM-2 and new methods
Project description:We have performed the first systematic identification and analysis of intermediate size ncRNAs (50-500 nt) in the silkworm genome. We identified 194 novel ncRNAs, the expression profiles of them during the transitions from the egg to the first instar larva and from the fifth instar larva to the pupa were anlyzed by dual-channel microarray. Results showed that 12 ncRNAs had significantly differential expression during the two developmental transitions. The first instar larva sample was used for comparison to the sample of embryo, the fifth instar larva sample was used for comparison to the sample of pupa, respectively.
Project description:The limited regenerative capacity of the human heart is responsible for the high morbidity and mortality world-wide. In contrast, zebrafish possess a robust regenerative capacity. Here, we have characterized the chromatin state transitions during zebrafish heart regeneration and interrogated how gene expression patterns are orchestrated. We found a massive gain of repressive chromatin marks one day after myocardial injury, followed by a large-scale acquisition of active chromatin characteristics on day 4 and a switch to a repressive state on day 14. The correlative analysis predicted known and less well-characterized transcription factors and transcription factor ensembles involved in these transitions and classified them into activators or repressors of specific gene expression programs. Detailed analysis revealed that rapid transcriptional responses involved in extracellular matrix reorganization and TOR signaling involve the engagement of super-enhancers, while H3K4me3 breadth highly correlates with transcriptional activity and the dynamic transcriptional changes at genes involved in proteolysis, cell cycle activity, and cell differentiation. Finally, we detected significant evolutionary conservation between the regulatory regions that drive zebrafish and neonatal mouse regeneration, suggesting that reactivation of transcriptional and epigenetic networks converging on these conserved elements might unlock the regenerative potential of adult human hearts
Project description:To investigate the chromatin state into an adult stem cell lineage, we generate cell-type specific chromatin state maps in the adult Drosophila intestine and identify principal chromatin state transitions during lineage determination. we profiled the binding sites of five chromatin-associated proteins from which the previously described five major types of chromatin.
Project description:Cells dynamically change their internal organization via continuous cell state transitions to mediate a plethora of physiological processes. Understanding such continuous processes is severely limited due to a lack of tools to measure the holistic physiological state of single cells undergoing a transition. We combined live-cell imaging and machine learning to quantitatively monitor skeletal muscle precursor cell (myoblast) differentiation during multinucleated muscle fiber formation. Our machine learning model predicted the continuous differentiation state of single primary murine myoblasts over time and revealed that inhibiting ERK1/2 leads to a gradual transition from an undifferentiated to a terminally differentiated state 7.5-14.5 hours post inhibition. Myoblast fusion occurred ~3 hours after predicted terminal differentiation. Moreover, we showed that our model could predict that cells have reached terminal differentiation under conditions where fusion was stalled, demonstrating potential applications in screening. This method can be adapted to other biological processes to reveal connections between the dynamic single-cell state and virtually any other functional readout.