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Maternal use of e-cigarette (e-cig) aerosols poses significant risks to fetal brain development, potentially increasing susceptibility to neurodevelopmental disorders in later life. However, the underlying mechanisms remain incompletely understood. This study aimed to understand the effects of fetal e-cig exposure on DNA methylome and transcriptomic changes in the neonatal brain. Pregnant rats were exposed to e-cig aerosols, and neonatal brains (5 males and 5 females/group) from both control and e-cig-exposed groups were used for experimental analysis. Results indicated that prenatal e-cig exposure altered site-specific DNA methylation patterns at both CpG and CH (non-CpG) sites, predominantly in intergenic and intronic regions, with sex dimorphism in methylation and gene expression changes. Gene ontology analysis revealed that e-cig exposure not only affected neuron projection development and axonogenesis but also altered pathways related to neurodegeneration and long-term depression. These findings provide novel insights into the dynamic changes of CpG and CH methylation induced by e-cig exposure, underscoring the susceptibility of the developing brain to maternal e-cig exposure and its potential implications for developmental disorders and neurodegenerative diseases later in life., (© 2024. The Author(s).)

The molecular mechanism of antenatal hypoxia impacting on fetal heart development and elevated risk of heart disease of adult offspring is poorly understood. We present a dataset integrating DNA methylome and transcriptome analyses of antenatal hypoxia affecting rat fetal and adult offspring hearts to understand hypoxia-mediated epigenomic reprogramming of the heart development. We showed that antenatal hypoxia not only induced DNA methylomic and transcriptomic changes in the fetal hearts, but also had a delayed and lasting effect on the adult offspring hearts. Of interest, antenatal hypoxia induced opposite changes in DNA methylation patterns in fetal and adult hearts, with a hypermethylation in the fetus and a hypomethylation in the adult. An extensive preprocessing, quality assessment, and downstream data analyses were performed on the genomic dataset so that the research community may take advantage of the public resource. These dataset could be exploited as a comprehensive resource for understanding fetal hypoxia-mediated epigenetic reprogramming in the heart development and further developmental programming of heart vulnerability to disease later in life.Figshare doi: https://doi.org/10.6084/m9.figshare.9948572.

Aims: Antenatal hypoxia negatively impacts foetal heart development, and increases the risk of heart disease later in life. The molecular mechanisms remain largely elusive. Here, we conducted a genome-wide analysis to study the impact of antenatal hypoxia on DNA methylome and transcriptome profiling in foetal and adult offspring hearts., Methods and Results: Pregnant rats were treated with normoxia or hypoxia (10.5% O2) from Day 15 to Day 21 of gestation. Hearts were isolated from near-term foetuses and 5-month-old male and female offsprings, and DNA methylome and RNA-seq were performed. Methylome data shows a sharp dip in CpG methylation centred at the transcription start site (TSS). CpG islands (CGIs) and CpG island shores (CGSs) within 10 kb upstream of the TSS are hypomethylated, compared with CGIs and CGSs within gene bodies. Combining transcriptome, data indicate an inverse relation between gene expression and CpG methylation around the TSS. Of interest, antenatal hypoxia induces opposite changes in methylation patterns in foetal and adult hearts, with hypermethylation in the foetus and hypomethylation in the adult. Also, there is significant sex dimorphism of changes in gene expression patterns in the adult offspring heart. Notably, pathway analysis indicates that enrichment of inflammation-related pathways are significantly greater in the adult male heart than those in the female heart., Conclusion: Our study provides an initial framework and new insights into foetal hypoxia-mediated epigenetic programming of pro-inflammatory phenotype in the heart development, linking antenatal stress, and developmental programming of heart vulnerability to disease later in life., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Malaria is one of the most debilitating mosquito-borne diseases with high global health burdens. While much of the research on malaria and mosquito-borne diseases is focused on Africa, Southeast Asia accounts for a sizable portion of the global burden of malaria. Moreover, about 50% of the Asian malaria incidence and deaths have been from India. A promising development in this context is that the completion of genome sequence of Anopheles stephensi, a major malaria vector in Asia, offers new opportunities for global health innovation, including the progress in deciphering the vectorial ability of this mosquito species at a molecular level. Moving forward, tissue-based expression profiling would be the next obvious step in understanding gene functions of An. stephensi. We report in this article, to the best of our knowledge, the first in-depth study on tissue-based transcriptomic profile of four important organs (midgut, Malpighian tubules, fat body, and ovary) of adult female An. stephensi mosquitoes. In all, we identified over 20,000 transcripts corresponding to more than 12,000 gene loci from these four tissues. We present and discuss the tissue-based expression profiles of majority of annotated transcripts in An. stephensi genome, and the dynamics of their alternative splicing in these tissues, in this study. The domain-based Gene Ontology analysis of the differentially expressed transcripts in each of the mosquito tissue indicated enrichment of transcripts with proteolytic activity in midgut; transporter activity in Malpighian tubules; cell cycle, DNA replication, and repair activities in ovaries; and oxidoreductase activities in fat body. Tissue-based study of transcript expression and gene functions markedly enhances our understanding of this important malaria vector, and in turn, offers rationales for further studies on vectorial ability and identification of novel molecular targets to intercept malaria transmission.

Complementing genome sequence with deep transcriptome and proteome data could enable more accurate assembly and annotation of newly sequenced genomes. Here, we provide a proof-of-concept of an integrated approach for analysis of the genome and proteome of Anopheles stephensi, which is one of the most important vectors of the malaria parasite. To achieve broad coverage of genes, we carried out transcriptome sequencing and deep proteome profiling of multiple anatomically distinct sites. Based on transcriptomic data alone, we identified and corrected 535 events of incomplete genome assembly involving 1196 scaffolds and 868 protein-coding gene models. This proteogenomic approach enabled us to add 365 genes that were missed during genome annotation and identify 917 gene correction events through discovery of 151 novel exons, 297 protein extensions, 231 exon extensions, 192 novel protein start sites, 19 novel translational frames, 28 events of joining of exons, and 76 events of joining of adjacent genes as a single gene. Incorporation of proteomic evidence allowed us to change the designation of more than 87 predicted "noncoding RNAs" to conventional mRNAs coded by protein-coding genes. Importantly, extension of the newly corrected genome assemblies and gene models to 15 other newly assembled Anopheline genomes led to the discovery of a large number of apparent discrepancies in assembly and annotation of these genomes. Our data provide a framework for how future genome sequencing efforts should incorporate transcriptomic and proteomic analysis in combination with simultaneous manual curation to achieve near complete assembly and accurate annotation of genomes., (© 2017 Prasad et al.; Published by Cold Spring Harbor Laboratory Press.)

Accurate annotation of protein-coding genes is one of the primary tasks upon the completion of whole genome sequencing of any organism. In this study, we used an integrated transcriptomic and proteomic strategy to validate and improve the existing zebrafish genome annotation. We undertook high-resolution mass-spectrometry-based proteomic profiling of 10 adult organs, whole adult fish body, and two developmental stages of zebrafish (SAT line), in addition to transcriptomic profiling of six organs. More than 7,000 proteins were identified from proteomic analyses, and ∼ 69,000 high-confidence transcripts were assembled from the RNA sequencing data. Approximately 15% of the transcripts mapped to intergenic regions, the majority of which are likely long non-coding RNAs. These high-quality transcriptomic and proteomic data were used to manually reannotate the zebrafish genome. We report the identification of 157 novel protein-coding genes. In addition, our data led to modification of existing gene structures including novel exons, changes in exon coordinates, changes in frame of translation, translation in annotated UTRs, and joining of genes. Finally, we discovered four instances of genome assembly errors that were supported by both proteomic and transcriptomic data. Our study shows how an integrative analysis of the transcriptome and the proteome can extend our understanding of even well-annotated genomes., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)

RNA-Seq provides the capability to characterize the entire transcriptome in multiple levels including gene expression, allele specific expression, alternative splicing, fusion gene detection, and etc. The US FDA-led SEQC (i.e., MAQC-III) project conducted a comprehensive study focused on the transcriptome profiling of rat liver samples treated with 27 chemicals to evaluate the utility of RNA-Seq in safety assessment and toxicity mechanism elucidation. The chemicals represented multiple chemogenomic modes of action (MOA) and exhibited varying degrees of transcriptional response. The paired-end 100 bp sequencing data were generated using Illumina HiScanSQ and/or HiSeq 2000. In addition to the core study, six animals (i.e., three aflatoxin B1 treated rats and three vehicle control rats) were sequenced three times, with two separate library preparations on two sequencing machines. This large toxicogenomics dataset can serve as a resource to characterize various aspects of transcriptomic changes (e.g., alternative splicing) that are byproduct of chemical perturbation.

The rat is used extensively by the pharmaceutical, regulatory, and academic communities for safety assessment of drugs and chemicals and for studying human diseases; however, its transcriptome has not been well studied. As part of the SEQC (i.e., MAQC-III) consortium efforts, a comprehensive RNA-Seq data set was constructed using 320 RNA samples isolated from 10 organs (adrenal gland, brain, heart, kidney, liver, lung, muscle, spleen, thymus, and testes or uterus) from both sexes of Fischer 344 rats across four ages (2-, 6-, 21-, and 104-week-old) with four biological replicates for each of the 80 sample groups (organ-sex-age). With the Ribo-Zero rRNA removal and Illumina RNA-Seq protocols, 41 million 50 bp single-end reads were generated per sample, yielding a total of 13.4 billion reads. This data set could be used to identify and validate new rat genes and transcripts, develop a more comprehensive rat transcriptome annotation system, identify novel gene regulatory networks related to tissue specific gene expression and development, and discover genes responsible for disease and drug toxicity and efficacy.

The rat has been used extensively as a model for evaluating chemical toxicities and for understanding drug mechanisms. However, its transcriptome across multiple organs, or developmental stages, has not yet been reported. Here we show, as part of the SEQC consortium efforts, a comprehensive rat transcriptomic BodyMap created by performing RNA-Seq on 320 samples from 11 organs of both sexes of juvenile, adolescent, adult and aged Fischer 344 rats. We catalogue the expression profiles of 40,064 genes, 65,167 transcripts, 31,909 alternatively spliced transcript variants and 2,367 non-coding genes/non-coding RNAs (ncRNAs) annotated in AceView. We find that organ-enriched, differentially expressed genes reflect the known organ-specific biological activities. A large number of transcripts show organ-specific, age-dependent or sex-specific differential expression patterns. We create a web-based, open-access rat BodyMap database of expression profiles with crosslinks to other widely used databases, anticipating that it will serve as a primary resource for biomedical research using the rat model.

The current study utilized a combined pharmacokinetic and genomic approach to demonstrate the feasibility of a new quality control method by using a panel of special differentially expressed genes (DEGs) as unique fingerprint to serve as marker of in vivo bioactivity for a representative traditional Chinese medicine (TCM) formula, Si-Wu-Tang (SWT). The method involves firstly obtaining possible in vivo active components, i.e., the "absorbable" components from the permeate of the Caco-2 monolayer model to simulate oral administration of two specific SWT products (CU-SWT, J-SWT), their component single herbs (Angelicae, Chuanxiong, Paeoniae, and Rehmanniae), and a standard mixture of active compounds (ferulic acid, ligustilide, senkyunolide A). Then, these respective absorbable components were incubated with MCF-7 cells to determine the gene expression profile using microarray processing/analysis as well as real-time PCR. From the available DEGs identified following the incubation, the magnitude of change in DEGs by real-time PCR was found to be consistent with that by microarray. The designated DEGs from the CU-SWT permeate were found to be distinct from other 19 products. Furthermore, the changes in the DEGs resulting from MCF-7 cells treated by eight replicate extracts of CU-SWT on three separate days were consistent. These results demonstrated sufficient specificity and consistency of the DEG panel which could serve as a unique bioactive "fingerprint" for the designated SWT product. The present method for DEG determination may be applied to other TCM products and with further definitive study can potentially provide a unique method for quality control of TCM in the future.

Human gene annotation is crucial for conducting transcriptomic and genetic studies; however, the impacts of human gene annotations in diverse databases on related studies have been less evaluated. To enable full use of various human annotation resources and better understand the human transcriptome, here we systematically compare the human annotations present in RefSeq, Ensembl (GENCODE), and AceView on diverse transcriptomic and genetic analyses. We found that the human gene annotations in the three databases are far from complete. Although Ensembl and AceView annotated more genes than RefSeq, more than 15,800 genes from Ensembl (or AceView) are within the intergenic and intronic regions of AceView (or Ensembl) annotation. The human transcriptome annotations in RefSeq, Ensembl, and AceView had distinct effects on short-read mapping, gene and isoform expression profiling, and differential expression calling. Furthermore, our findings indicate that the integrated annotation of these databases can obtain a more complete gene set and significantly enhance those transcriptomic analyses. We also observed that many more known SNPs were located within genes annotated in Ensembl and AceView than in RefSeq. In particular, 1033 of 3041 trait/disease-associated SNPs involved in about 200 human traits/diseases that were previously reported to be in RefSeq intergenic regions could be relocated within Ensembl and AceView genes. Our findings illustrate that a more complete transcriptome generated by incorporating human gene annotations in diverse databases can strikingly improve the overall results of transcriptomic and genetic studies.

De novo transcriptome assembly is an important approach in RNA-Seq data analysis and it can help us to reconstruct the transcriptome and investigate gene expression profiles without reference genome sequences. We carried out transcriptome assemblies with two RNA-Seq datasets generated from human brain and cell line, respectively. We then determined an efficient way to yield an optimal overall assembly using three different strategies. We first assembled brain and cell line transcriptome using a single k-mer length. Next we tested a range of values of k-mer length and coverage cutoff in assembling. Lastly, we combined the assembled contigs from a range of k values to generate a final assembly. By comparing these assembly results, we found that using only one k-mer value for assembly is not enough to generate good assembly results, but combining the contigs from different k-mer values could yield longer contigs and greatly improve the overall assembly.

The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi‐species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re‐processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user‐friendly format that is expected to broadly influence pineal research. [ABSTRACT FROM AUTHOR]

Spaceflight poses many challenges for humans. Ground-based analogs typically focus on single parameters of spaceflight and their associated acute effects. This study assesses the long-term transcriptional effects following single and combination spaceflight analog conditions using the mouse model: simulated microgravity via hindlimb unloading (HLU) and/or low-dose γ-ray irradiation (LDR) for 21 days, followed by 4 months of readaptation. Changes in gene expression and epigenetic modifications in brain samples during readaptation were analyzed by whole transcriptome shotgun sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS). The results showed minimal gene expression and cytosine methylation alterations at 4 months readaptation within single treatment conditions of HLU or LDR. In contrast, following combined HLU+LDR, gene expression and promoter methylation analyses showed multiple altered pathways involved in neurogenesis and neuroplasticity, the regulation of neuropeptides, and cellular signaling. In brief, neurological readaptation following combined chronic LDR and HLU is a dynamic process that involves pathways that regulate neuronal function and structure and may lead to late onset neurological sequelae. [ABSTRACT FROM AUTHOR]