Transcriptome Profiles and Gene Expression of Min6 Cells Are Altered by Pancreatic Stellate Cells

Aim: To identify the influence of pancreatic stellate cell (PSCs) secretions on gene expression profiles of Min6 cells by whole transcriptome sequencing. Methods: Pancreatic stellate cells (PSCs) were isolated from C57BL6J mice and propagated in vitro to acquire the activated phenotype. Total RNA was isolated from monocultured (MC) and PSC cocultured (CC) Min6 cells to prepare cDNA libraries, which were subjected to whole transcriptome sequencing for identifying differential expression of β-cell transcription factors (Pdx-1, Rfx6 and NeuroD1) related to insulin gene transcription and GSIS related genes such as Glut2, Gck, Abcc8, Kcnj11 and L-type Ca2+ channels (Cacnb2, Cacna1c). qRT-PCR was used to validate the gene expression. GSIS of Min6 cells was examined by estimating insulin levels in response to high glucose challenge. Results: Transcriptome analysis of discovery set revealed that coculture of Min6 cells with PSCs caused increased expression of β-cell specific genes (Ins1, Rfx6 and NeuroD1) concomitant with decreased expression of Pdx-1, MafA and Nkx2-2. Expression of GSIS associated genes (Glut2, Gck, Abcc8, Kcnj11 and Cacnb2) was decreased in such conditions. Validation by qRT-PCR in Min6 cells cocultured with PSCs revealed increased significant expression of Ins1 (2.1 ± 0.22 folds;p ≤ 0.001), Rfx6 (1.68 ± 0.23 folds;p ≤ 0.002) and NeuroD1 (0.96 ± 0.11 folds;p ≤ 0.01), accompanied by downregulation of Cacnb2 (-0.93 ± 0.57 folds;p ≤ 0.05). PSC secretions did not restore the GSIS from glucose unresponsive higher passage Min6 cells (MC: 1.33 ± 0.42;CC: 1.55 ± 0.72 pmol/mg protein;p = ns) upon high glucose stimulation. However, glucose responsive higher passage Min6 cells cocultured with PSCs presented increased insulin secretion (MC: 7.025 ± 0.64;CC: 14.84 ± 1.01 pmol/mg protein;p ≤ 0.04) concomitant with marginal increase of insulin contents. Conclusion: PSC secretions increase Ins1, Rfx6 and NeuroD1 gene expression, GSIS from glucose responsive Min6 cells, but do not restore the GSIS from glucose unresponsive Min6 cells.

Co-infection of Wolbachia and Spiroplasma in spider mite Tetranychus truncatus increases male fitness

Wolbachia and Spiroplasma are intracellular bacteria that are of great interest to entomologists,because of their ability to alter insect host biology in multiple ways.In the spider mite Tetranychus truncatus,co-infection of Wolbachia and Spiroplasma can induce cytoplasmic incompatibility(CI)and fitness costs;however,lttle is known about the effect of co-infection at the genetic level and the molecular mechanisms underlying CI.In this study,we explored the influence of the two symbionts on male mite host fitness and used RNA sequencing to generate the transcriptomes of T truncatus with four different types of infection.In total,we found symbiont-infected lines had a higher hatch proportion than the uninfected line,and the development time of the uninfected line was longer than that of the other lines.Co-infection changed the expression of many genes related to digestion detoxification,reproduction,immunity and oxidation reduction.Our results indicate that co-infection of Wolbachia and Spiroplasma confers multiple effects on their hosts,and helps iluminate the complex interactions between endosymbionts and arthropods.

FAWMine:An integrated database and analysis platform for fall armyworm genomics

Fall armyworm(Spodoptera frugiperda),a native insect species in the Americas,is rapidly becoming a major agricultural pest worldwide and is causing great damage to corn,rice,soybeans,and other crops.To control this pest,scientists have accumulated a great deal of high-throughput data of fall armyworm,and nine versions of its genomes and transcriptomes have been published.However,easily accessing and performing integrated analysis of these omics data sets is challenging.Here,we developed the Fall Armyworm Genome Database(FAWMine,http://159.226.67.243:8080/fawmine/)to maintain genome sequences,structural and functional annotations,transcriptomes,co-expression,protein interactions,homologs,pathways,and single-nucleotide variations.FAWMine provides a powerful framework that helps users to perform flexible and customized searching,present integrated data sets using diverse visualization methods,output results tables in a range of file formats,analyze candidate gene lists using multiple widgets,and query data available in other InterMine systems.Additionally,stand-alone JBrowse and BLAST services are also established,allowing the users to visualize RNA-Seq data and search genome and annotated gene sequences.Altogether,FAWMine is a useful tool for querying,visualizing,and analyzing compiled data sets rapidly and efficiently.FAWMine will be continually updated to function as a community resource for fall armyworm genomics and pest control research.