Search

The standard evolutionary theory of aging predicts a negative relationship (trade-off) between fecundity and longevity. However, in principle, the fecundity–longevity relationship can become positive in populations in which individuals have unequal resources. Positive fecundity–longevity relationships also occur in queens of eusocial insects such as ants and bees. Developmental diet is likely to be central to determining trade-offs as it affects key fitness traits, but its exact role remains uncertain. For example, in Drosophila melanogaster , changes in adult diet can affect fecundity, longevity, and gene expression throughout life, but it is unknown how changes in developmental (larval) diet affect fecundity–longevity relationships and gene expression in adults. Using D. melanogaster , we tested the hypothesis that varying developmental diets alters the directionality of fecundity–longevity relationships in adults, and characterized associated gene expression changes. We reared larvae on low (20%), medium (100%), and high (120%) yeast diets, and transferred adult females to a common diet. We measured fecundity and longevity of individual adult females and profiled gene expression changes with age. Adult females raised on different larval diets exhibited fecundity–longevity relationships that varied from significantly positive to significantly negative, despite minimal differences in mean lifetime fertility or longevity. Treatments also differed in age-related gene expression, including for aging-related genes. Hence, the sign of fecundity–longevity relationships in adult insects can be altered and even reversed by changes in larval diet quality. By extension, larval diet differences may represent a key mechanistic factor underpinning positive fecundity–longevity relationships observed in species such as eusocial insects. [ABSTRACT FROM AUTHOR]

Only two hydromedusan species, Turritopsis dohrnii and T. sp. have exhibited experimental multiple-repeat life cycle reversion in the laboratory, which can be artificially induced by various means such as incubation with CsCl, heat shock, and mechanical damage with needles. In the present study, we constructed a genome assembly of T. dohrnii using Pacific Biosciences long-reads and Illumina short-reads, for which the genome DNA was extracted from 1,500 young medusae originated from a single clone. The total length of the draft genome sequence of T. dohrnii was 435.9 Mb (N50 length 747.2 kb). We identified 23,314 high-confidence genes and found the characteristics of RNA expression amongst developmental stages. Our genome assembly and transcriptome data provide a key model system resource that will be useful for understanding cyclical rejuvenation. [ABSTRACT FROM AUTHOR]

Intellectual disability is closely related to impaired GABA neurotransmission. Brpf1 was specifically expressed in medial ganglionic eminence (MGE), a developmental niche of GABAergic interneurons, and patients with BRPF1 mutations showed intellectual disability. To test its role in the development and function of MGE-derived GABAergic interneurons, we performed immunofluorescence staining, whole-cell patch-clamp, MGE transplantation, and mRNA-Seq to understand its effect on neuronal differentiation, dendritic morphology, electrophysiology, migration, and gene regulation, using mouseMGE-derived GABAergic interneurons infected with AAV-shBrpf1. The results showed that Brpf1 knockdown had a decreasing trend, although not significant, on the differentiation of GABAergic interneurons into parvalbumin+ interneurons. Moreover, increased firing threshold, decreased number of evoked action potentials, and a reduced amplitude of miniature inhibitory postsynaptic currents were observed before any significant change of MAP2+ dendritic morphology and in vivo migration ability appeared. Finally, mRNA-Seq analysis revealed that genes related to neurodevelopment and synaptic transmission such as Map2k7 were dysregulated. Our results demonstrated a key role of Brpf1 in inhibitory neurotransmission and related gene expression of GABAergic interneurons. [ABSTRACT FROM AUTHOR]

The shapes of plant organs reflect the evolution of each lineage and have been diversified according to lineage-specific adaptations to environment. Research on the molecular pathways responsible for organ shapes has traditionally been focused mainly on leaves or flowers. Thus, little is known about the pathways controlling fruit shapes, despite their diversity in some plant species. In this study, we analyzed oriental persimmon (Diospyros kaki), which exhibits considerable diversity in fruit shapes among cultivars, to elucidate the underlying molecular mechanism using transcriptomic data and quantitative evaluation. First, to filter the candidate genes associated with persimmon fruit shapes, the whole gene expression patterns obtained using mRNA-Seq analysis from 100 individuals, including a segregated population and various cultivars, were assessed to detect correlations with principal component scores for fruit shapes characterized with elliptic Fourier descriptors. Next, a gene co-expression network analysis with weighted gene co-expression network analysis (WGCNA) package revealed that class 1 KNOX family genes and SEEDSTICK function as integrators along with some phytohormone-related genes, to regulate the fruit shape diversity. On the other hand, the OVATE family genes also contribute to fruit shape diversity, of which pathway would be potentially shared with other plant species. Evolutionary aspects suggest that acquisition of a high lineage-specific and variable expression of class 1 KNOX gene, knotted-like homeobox of Arabidopsis thaliana 1 (KNAT1), in young fruit is important for establishing the persimmon-specific mechanism that determines fruit shape diversity. [ABSTRACT FROM AUTHOR]

Acquired drug resistance is the major reason why patients fail to respond to cancer therapies. It is a challenging task to determine the tipping point of endocrine resistance and detect the associated molecules. Derived from new systems biology theory, the dynamic network biomarker (DNB) method is designed to quantitatively identify the tipping point of a drastic system transition and can theoretically identify DNB genes that play key roles in acquiring drug resistance. We analyzed time-course mRNA sequence data generated from the tamoxifen-treated estrogen receptor (ER)-positive MCF-7 cell line, and identified the tipping point of endocrine resistance with its leading molecules. The results show that there is interplay between gene mutations and DNB genes, in which the accumulated mutations eventually affect the DNB genes that subsequently cause the change of transcriptional landscape, enabling full-blown drug resistance. Survival analyses based on clinical datasets validated that the DNB genes were associated with the poor survival of breast cancer patients. The results provided the detection for the pre-resistance state or early signs of endocrine resistance. Our predictive method may greatly benefit the scheduling of treatments for complex diseases in which patients are exposed to considerably different drugs and may become drug resistant. [ABSTRACT FROM AUTHOR]

Here we present TENOR (Transcriptome ENcyclopedia Of Rice, http://tenor.dna.affrc.go.jp), a database that encompasses large-scale mRNA sequencing (mRNA-Seq) data obtained from rice under a wide variety of conditions. Since the elucidation of the ability of plants to adapt to various growing conditions is a key issue in plant sciences, it is of great interest to understand the regulatory networks of genes responsible for environmental changes. We used mRNA-Seq and performed a time-course transcriptome analysis of rice, Oryza sativa L. (cv. Nipponbare), under 10 abiotic stress conditions (high salinity; high and low phosphate; high, low and extremely low cadmium; drought; osmotic; cold; and flood) and two plant hormone treatment conditions (ABA and jasmonic acid). A large number of genes that were responsive to abiotic stresses and plant hormones were detected by differential expression analysis. Furthermore, several responsive genes were found to encode transcription factors that could control the transcriptional network of stress responses, but the timing of the induction of these genes was not uniform across conditions. A significant number of cis-regulatory elements were enriched in the promoter regions of the responsive genes and were shared among conditions. These data suggest that some key components of gene regulation networks are shared between different stress signaling pathways. All the resources (novel genes identified from mRNA-Seq data, expression profiles, co-expressed genes and cis-regulatory elements) can be searched for and are available in TENOR. [ABSTRACT FROM AUTHOR]

Background: Common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are the species most closely related to humans. For this reason, it is especially important to have complete and accurate chimpanzee nucleotide and protein sequences to understand how humans evolved their unique capabilities. We provide transcriptome data from four untransformed cell types derived from the reference Pan troglodytes, "Clint", to better annotate the chimpanzee genome and provide empirical validation for proposed gene models of this important species. Findings: RNA was extracted from primary cells cultured from four tissues: skin, adipose stroma, vascular smooth muscle and skeletal muscle. These four RNA samples were sequenced on the Illumina HiSeq 2000 platform. Sequences were deposited in the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA). Transcripts were assembled, annotated and deposited in the NCBI Transcriptome Shotgun Assembly (TSA) database. Conclusions: We have provided a high quality annotation of 44,275 transcripts with full-length coding sequence (CDS). This set represented a total of 10,110 unique genes, thus providing empirical support for their existence. This dataset can be used to improve the annotation of the Pan troglodytes genome. [ABSTRACT FROM AUTHOR]

In light of ongoing climate changes in wine-growing regions, the selection of drought-tolerant rootstocks is becoming a crucial factor for developing a sustainable viticulture. In this study, M, a new rootstock genotype that shows tolerance to drought, was compared from a genomic and transcriptomic point of view with the less drought-tolerant genotype 101.14. The root and leaf transcriptome of both 101.14 and the M4 rootstock genotype was analysed, following exposure to progressive drought conditions. Multifactorial analyses indicated that stress treatment represents the main factor driving differential gene expression in roots, whereas in leaves the genotype is the prominent factor. Upon stress, M4 roots and leaves showed a higher induction of resveratrol and flavonoid biosynthetic genes, respectively. The higher expression of VvSTS genes in M, confirmed by the accumulation of higher levels of resveratrol in M4 roots compared with 101.1, was coupled to an up-regulation of several VvWRKY transcription factors. Interestingly, VvSTS promoter analyses performed on both the resequenced genomes highlighted a significantly higher number of W-BOX elements in the tolerant genotype. It is proposed that the elevated synthesis of resveratrol in M4 roots upon water stress could enhance the plant's ability to cope with the oxidative stress usually associated with water deficit. [ABSTRACT FROM AUTHOR]

The environment has profound effects on the expression of many traits and reaction norms describe the expression dynamics of a trait across a broad range of environmental conditions. Here, we analyze gene expression in Drosophila melanogaster across four different developmental temperatures (13-29 °C). Gene expression is highly plastic with 83.3% of the genes being differentially expressed. We distinguished three components of plasticity: 1) Dynamics of gene expression intensity (sum of change), 2) direction of change, and 3) curvature of the reaction norm (linear vs. quadratic). Studying their regulatory architecture we found that all three plasticity components were most strongly affected by the number of different transcription factors (TFs) binding to the target gene. More TFs were found in genes with less expression changes across temperatures. Although the effect of microRNAs was weaker, we consistently noted a trend in the opposite direction. The most plastic genes were regulated by fewer TFs and more microRNAs than less plastic genes. Different patterns of plasticity were also reflected by their functional characterization based on gene ontology. Our results suggest that reaction norms provide an important key to understand the functional requirements of natural populations exposed to variable environmental conditions. [ABSTRACT FROM AUTHOR]

Background: Nonhuman primates are important for both biomedical studies and understanding human evolution. Although research in these areas has mostly focused on Old World primates, such as the rhesus macaque, the common marmoset (Callithrix jacchus), a New World primate, offers important advantages in comparison to other primates, such as an accelerated lifespan. To conduct Next Generation expression studies or to study primate evolution, a high quality annotation of the marmoset genome is required. The availability of marmoset transcriptome data from five tissues, including both raw sequences and assembled transcripts, will aid in the annotation of the newly released marmoset assembly. Findings: RNA was extracted from five tissues: skeletal muscle, bladder and hippocampus from a male common marmoset, and cerebral cortex and cerebellum from a female common marmoset. All five RNA samples were sequenced on the Illumina HiSeq 2000 platform. Sequences were deposited in the NCBI Sequence Read Archive. Transcripts were assembled, annotated and deposited in the NCBI Transcriptome Shotgun Assembly database. Conclusions: We have provided a high quality annotation of 51,163 transcripts with full-length coding sequence. This set represented a total of 10,833 unique genes. In addition to providing empirical support for the existence of these 10,833 genes, we also provide sequence information for 2,422 genes that were not previously identified in the Ensembl annotation of the marmoset genome. [ABSTRACT FROM AUTHOR]

To sense numerous odorants and chemicals, animals have evolved a large number of olfactory receptor genes (Olfrs) in their genome. In particular, the house mouse has ∼1,100 genes in the Olfr gene family. This makes the mouse a good model organism to study Olfr genes and olfaction-related genes. To date, whether male and female mice possess the same ability in detecting environmental odorants is still unknown. Using the next generation sequencing technology (paired-end mRNA-seq), we detected 1,088 expressed Olfr genes in both male and female olfactory epithelium. We found that not only Olfr genes but also odorant-binding protein (Obp) genes have evolved rapidly in the mouse lineage. Interestingly, Olfr genes tend to express at a higher level in males than in females, whereas the Obp genes clustered on the X chromosome show the opposite trend. These observations may imply a more efficient odorant-transporting system in females, whereas a more active Olfr gene expressing system in males. In addition, we detected the expression of two genes encoding major urinary proteins, which have been proposed to bind and transport pheromones or act as pheromones in mouse urine. This observation suggests a role of main olfactory system (MOS) in pheromone detection, contrary to the view that only accessory olfactory system (AOS) is involved in pheromone detection. This study suggests the sexual differences in detecting environmental odorants in MOS and demonstrates that mRNA-seq provides a powerful tool for detecting genes with low expression levels and with high sequence similarities. [ABSTRACT FROM AUTHOR]

Despite the major physiological dissimilarities between mature root regions and their tips, differences in their gene expression profiles remain largely unexplored. In this research, the transcriptome of rice (Oryza sativa L. subsp. japonica) mature root tissue and root tips was monitored using mRNA-Seq at two time points. Almost 50 million 76 bp reads were mapped onto the rice genome sequence, expression patterns for different tissues and time points were investigated, and at least 1106 novel transcriptionally active regions (nTARs) expressed in rice root tissue were detected. More than 30 000 genes were found to be expressed in rice roots, among which were 1761 root-enriched and 306 tip-enriched transcripts. Mature root tissue appears to respond more strongly to external stimuli than tips, showing a higher expression of, for instance, auxin-responsive and abscisic acid-responsive genes, as well as the phenylpropanoid pathway and photosynthesis upon light. The root tip-enriched transcripts are mainly involved in mitochondrial electron transport, organelle development, secondary metabolism, DNA replication and metabolism, translation, and cellular component organization. During root maturation, genes involved in cell wall biosynthesis and modification, response to oxidative stress, and secondary metabolism were activated. For some nTARs, a potential role in root development can be put forward based on homology to genes involved in CLAVATA signalling, cell cycle regulators, and hormone signalling. A subset of differentially expressed genes and novel transcripts was confirmed using (quantitative) reverse transcription-PCR. These results uncover previously unrecognized tissue-specific expression profiles and provide an interesting starting point to study the different regulation of transcribed regions of these tissues. [ABSTRACT FROM PUBLISHER]