Project description:Harsh environments enforce the expression of behavioural, morphological, physiological, and reproductive rejoinders, including torpor. Here we study the morphological, cellular, and molecular alterations in torpor architype in the colonial urochordate Botrylloides aff. leachii by employing whole organism Transmission electron (TEM) and light microscope observations, RNA sequencing, real-time polymerase chain reaction (qPCR) quantification of selected genes, and immunoloc- alization of WNT, SMAD and SOX2 gene expressions. On the morphological level, torpor starts with gradual regression of all zooids and buds which leaves the colony surviving as condensed vasculature remnants that may be ‘aroused’ to regenerate fully functional colonies upon changes in the environment. Simultaneously, we observed altered distributions of hemolymph cell types. Phagocytes doubled in number, while the number of morula cells declined by half. In addition, two new circulating cell types were observed, multi-nucleated and bacteria-bearing cells. RNA sequencing technology revealed marked differences in gene expression between different organism compartments and states: active zooids and ampullae, and between mid-torpor and naive colonies, or naive and torpid colonies. Gene Ontology term enrichment analyses further showed disparate biological processes. In torpid colonies, we observed overall 233 up regulated genes. These genes included NR4A2, EGR1, MUC5AC, HMCN2 and. Also, 27 transcription factors were upregulated in torpid colonies including ELK1, HDAC3, RBMX, MAZ, STAT1, STAT4 and STAT6. Interestingly, genes involved in developmental processes such as SPIRE1, RHOA, SOX11, WNT5A and SNX18 were also upregulated in torpid colonies. We further validated the dysregulation of 22 genes during torpor by utilizing qPCR. Immunohistochemistry of representative genes from three signaling pathways revealed high expression of these genes in circulated cells along torpor. WNT agonist administration resulted in early arousal from torpor in 80% of the torpid colonies while in active colonies WNT agonist triggered the torpor state. Abovementioned results thus connote unique transcriptome landscapes associated with Botrylloides leachii torpor.
Project description:Canonical RNA processing in mammalian mitochondria necessitates that tRNAs are recognised by nucleases to release flanking transcripts. However, not all mitochondrial transcripts are punctuated by tRNAs, and the mechanism and factors involved in their processing has remained unsolved. Here, we demonstrate that phosphatase activity of the carbon catabolite repressor 4 domain containing family member ANGEL2 is required for the hydrolysis of 3′ phosphates, resulting from non-canonical processing. Interaction studies in Drosophila further identify that members of the FAST kinase domain containing protein family are involved in the formation of these 3′ phosphates. Our results therefore resolve the mechanism of RNA processing in metazoan mitochondria, by defining the outstanding non-canonical processing mechanism.
Project description:This study in rats was designed to investigate whether whole rhye (WR) can influence the metabolism of n-3 and n-6 long-chain fatty acids (LCFA) and gut microbiota composition. For 12 weeks, rats were fed a diet containing either 50% WR or 50% refined rye (RR). Total bacterial DNA was extracted from fecal and cecal samples (n=5 per group). 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray. A 15 chip study was realized, each corresponding to hybridization with 250ng of labelled 16S rRNA gene amplicons from either mice fecal and cecal samples. Each probe (4441) was synthetized in three replicates.
Project description:A three-stage continuous fermentative system was developed to simulate and control physicochemical factors of the gut biology. Inoculation was of each reactor was performed from a human fecal sample which was initially amplified with a batch procedure. Samples from the initial feces, the batch and from the bioreactors media were collected to extract bacterial DNA. 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray. A 5 chip study was realized, each corresponding to hybridization with 250ng of labelled 16S rRNA gene amplicons from either the initial stool, the batch inoculum or fermentative medium different compartments of the simulated colon (Proximal, Transversal and Distal). Each probe (4441) was synthetized in three replicates.
Project description:A three-stage continuous fermentative system was developed to simulate and control physicochemical factors of the gut biology. Inoculation was of each reactor was performed from a human fecal sample which was initially amplified with a batch procedure. Samples from the initial feces, the batch and from the bioreactors media were collected to extract bacterial DNA. 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray.