Alternative 3-terminal exons, which use intronic polyadenylation sites, are generally unconserved and lowly expressed, while the main gene products end in the last exon of genes. In this study, we discover a class of human genes, where the last exon appeared recently during evolution, and the major gene product uses an alternative 3-terminal exon corresponding to the ancestral last exon of the gene. This novel class of alternative 3-terminal exons are down-regulated on a large scale by doxorubicin, a cytostatic drug targeting topoisomerase II, and play a role in cell cycle regulation, including centromere-kinetochore assembly. The RNA-binding protein, HuR/ELAVL1 is a major regulator of this specific set of alternative 3-terminal exons. HuR binding to the alternative 3-terminal exon in the pre-messenger RNA promotes its splicing, and is reduced by topoisomerase inhibitors. These findings provide new insights into the evolution, function and molecular regulation of alternative 3-terminal exons.
A recently evolved class of alternative 3'-terminal exons involved in cell cycle regulation by topoisomerase inhibitors.
Cell line
View SamplesFor most multigenic disorders, clinical manifestation (penetrance) and presentation (expressivity) are likely to be an outcome of genetic interaction between multiple susceptibility genes. Here, using gene knockouts in mice we evaluated genetic interaction between loss of Ret and loss of Sema3d, two Hirschsprung disease (HSCR) susceptibility genes. We intercrossed Ret and Sema3d double null heterozygotes to generate mice with the nine possible genotypes and assessed survival by counting various genotypes, myenteric plexus development by acetylcholinesterase (AchE) staining and embryonic day 12.5 (E12.5) gut transcriptome by RNA-sequencing. Survival rates of Ret wildtype, null heterozygote and null homozygote mice at E12.5, birth and weaning were not influenced by the genotypes at Sema3d locus and vice-versa. Loss of myenteric plexus was observed only in all Ret null homozygotes, irrespective of the genotypes at Sema3d locus, and Sema3d null heterozygote and homozygote mice had normal gut innervation. As compared to wildtype mice gut gene expression, loss of Ret in null homozygotes led to differential expression of ~300 genes, whereas loss of Sema3d in null homozygotes had no major consequence and there was no evidence supporting major interaction between the two genes influencing gut transcriptome. Overall, given the null alleles and phenotypic assays used, we did not find evidence for genetic interaction between Ret and Sema3d affecting survival, myenteric plexus formation or gut transcriptome. Overall design: poly-A RNA-seq in embryonic day 12.5 mouse gut from 3 wildtype males, 3 wildtype females, 3 Ret null homozyogote males, 3 Ret null homozyogote females, 3 Sema3d null homozyogote males, 3 Sema3d null homozyogote females, 3 Ret-Sema3d double null homozyogote males, 3 Ret-Sema3d double null homozyogote females
Testing the Ret and Sema3d genetic interaction in mouse enteric nervous system development.
Sex, Specimen part, Cell line, Subject
View SamplesTo elucidate biological processes underlying the keratocyte, fibroblast, and myofibroblast phenotypes of corneal stromal cells, the gene expression patterns of these primary cultures from mouse cornea were compared with those of the adult and 10-day postnatal mouse cornea.
Microarray studies reveal macrophage-like function of stromal keratocytes in the cornea.
No sample metadata fields
View SamplesThe cornea continues to mature after birth to develop a fully functional, refractive and protective barrier tissue. Here we investigated the complex biological events underlying this process by profiling global genome-wide gene expression patterns of the immature postnatal day 10 and seven week-old adult mouse cornea. The lens and tendon were included in the study to increase the specificity of genes identified as up regulated in the corneal samples. Notable similarities in gene expression between the cornea and the tendon were in the mesenchymal extracellular matrix collagen (types I, III, V, VI) and proteoglycan (lumican, decorin and biglycan) genes. Expression similarities in the cornea and lens were limited to certain epithelial genes and the crystallins. Approximately 76 genes were over expressed in the cornea samples that showed basal expression levels in the lens and tendon. Thirty-two of these were novel with no known functions in the cornea. These include genes with a potential role in protection against oxidative stress (Dhcr24, Cdo1, Akr1b7, Prdx6), inflammation (Ltb4dh, Wdr1), ion-transport (Pdzk1ip1, Slc12a2, Slc25a17) and transcription (Zfp36l3, Pdzk1ip1). Direct comparison of the cornea of two ages showed selective up regulation of 50 and 12 genes in the P10 and adult cornea, respectively. Of the up regulated P10 genes several encode extracellular matrix collagens and proteoglycans that are stable components of the adult cornea and their high transcriptional activity at P10 indicate a period of active corneal growth and matrix deposition in the young cornea. Much less is known about the genes selectively over expressed in the adult cornea; some relate to immune response and innervations (Npy), and possibly to electron transport (Cyp24a1, Cyp2f2) and others of yet unknown functions in the cornea (Rgs10, Psmb8, Xlr4)). This study detected expression of genes with known functions in the cornea, providing additional validation of the microarray experiments. Importantly, it identified several novel genes whose functions have not been investigated in the cornea.
Differential gene expression patterns of the developing and adult mouse cornea compared to the lens and tendon.
No sample metadata fields
View SamplesThe ability of high-risk neuroblastoma to survive unfavorable growth conditions and multimodal therapy is hypothesized to result from a phenomenon known as reversible adaptive plasticity (RAP). RAP is a novel phenomenon enabling neuroblastoma cells to transition between a proliferative anchorage dependent (AD) state and a slow growing anoikis-resistant anchorage independent (AI) state.
A mechanism linking Id2-TGFβ crosstalk to reversible adaptive plasticity in neuroblastoma.
Specimen part
View SamplesTotal mRNA seq was perfomed on widtype and Ret null mouse embryonic gut at 2 stages of devlopment- E11.5 and E12.5 Overall design: Total RNA from 3 replicates each of wildtype and Ret null emryonic gut was converted to cDNA and run on HiSeq 2000 (75 bp paired end)
Enhancer Variants Synergistically Drive Dysfunction of a Gene Regulatory Network In Hirschsprung Disease.
Cell line, Subject
View SamplesIt is becoming better understood that radiation resistance in glioblastomas (GBMs) may be secondary to a self-renewing subpopulation of cells in the bulk tumor that form neurospheres in culture. This population has been referred to as Glioma stem cells (GSCs). One of the limitations regarding the use of GSCs is that these studies require fresh tumor biopsy samples obtained from patients, and can be extremely difficult to culture, propagate, and perform treatment-response assays. This report describes the generation of a self-renewing population of GSCs derived from commercially available U87 cells using NOD-SCID mice as carrier. The tumors were dissociated to obtain GSCs that demonstrate stem-like properties and high degree of chemo and radiation resistance. Pathological analysis of tumors obtained using GSCs exhibit all the histological hallmarks of human GBMs which is quite uncommon in GBM rodent models and hence could serve as a better model for pre-clinical study. We have shown that MGH87GSCs have an enhanced tumorogenicity than parental U87 and about 500 cells are sufficient to form tumors. To understand the transcriptome and accompanied proteome better, we explored the gene expression profiles of MGH87GSC and U87. We have shown that these GSCs are plastic like stem cells and can be directed towards a particular progeny within neural lineage by providing suitable growth factor. Our objective was to understand the genetic and biochemical mechanisms that control the self-renewal phenotype, asymmetric subdivision, chemo and radiation resistance and the role of the GSC niche in regulating the biological properties of GSC. Through this model we anticipate to devise therapeutic strategies to target this sub population of GSCs within GBMs to eradicate treatment resistance and tumor recurrence.
Cells isolated from residual intracranial tumors after treatment express iPSC genes and possess neural lineage differentiation plasticity.
Specimen part, Cell line
View SamplesE12.5 AV cushion and E17.5 AV valve from wild-type FVB/N mice and in vitro cultured MC3T3 cells
Shared gene expression profiles in developing heart valves and osteoblast progenitor cells.
No sample metadata fields
View SamplesWomen are born with millions of primordial follicles which gradually decrease with increasing age and this irreversible supply of follicles completely exhausts at menopause. The fertility capacity of women diminishes in parallel with aging. The mechanisms for reproductive aging are not fully understood. In our recent work we observed a decline in BRCA1 mediated DNA repair in aging rat primordial follicles. To further understand the age-related molecular changes, we performed microarray gene expression analysis using total RNA extracted from immature (1820 days) and aged (400450 days) rat primordial follicles. The results of current microarray study revealed that there were 1011 (>1.5 fold, p<0.05) genes differentially expressed between two groups in which 422 genes were up-regulated and 589 genes were down-regulated in aged rat primordial follicles compared to immature. The gene ontology and pathway analysis of differentially expressed genes revealed a critical biological function such as cell cycle, oocyte meiosis, chromosomal stability, transcriptional activity, DNA replication and DNA repair were affected by age and this considerable difference in gene expression profiles may have adverse influence on oocyte quality. Our data provide information on the processes that may contribute to aging and age-related decline in fertility.
Age-related changes in gene expression patterns of immature and aged rat primordial follicles.
Specimen part
View SamplesIdentification of genes and pathways relevant to Cervical cancer pathogenesis. The study also aimed at identifying probable mechanistic differences in the low and high HOTAIR expressing cervical cancers patients .
Bridging Links between Long Noncoding RNA HOTAIR and HPV Oncoprotein E7 in Cervical Cancer Pathogenesis.
Age, Specimen part
View Samples