Project description:Diapause is a reversible developmental arrest faced by many organisms in harsh environments. Annual killifish present this mechanism in three possible stages of development. Killifish are freshwater teleosts from Africa and America that live in ephemeral ponds, which dry up in the dry season. The juvenile and adult populations die, and the embryos remain buried in the bottom mud until the next rainy season. Thus, species survival is entirely embryo-dependent, and they are perhaps the most remarkable extremophile organisms among vertebrates. The aim of the present study was to gather information about embryonic diapauses with the use of a “shotgun” proteomics approach in diapause III and prehatching Austrolebias charrua embryos. Our results provide insight into the molecular mechanisms of diapause III. We detected a diapause-dependent change in a large group of proteins involved in different functions, such as metabolic pathways and stress tolerance, as well as proteins related to DNA repair and epigenetic modifications. Furthermore, we observed a diapauseassociated switch in cytoskeletal proteins. This first glance into global protein expression differences between prehatching and diapause III could provide clues regarding the induction/maintenance of this developmental arrest in A. charrua embryos. There appears to be no single mechanism underlying diapause and the present data expand our knowledge of the molecular basis of diapause regulation. This information will be useful for future comparative approaches among different diapauses in annual killifish and/or other organisms that experience developmental arrest.
Project description:Embryos from 8 populations of killifish, four with evolved tolerances, were exposed to PCB-126. Approximately 5 replicate embryos per treatment/control were sequenced. Desensitization of aryl hydrocarbon receptor signaling to PCB-126 is found in all four populations with evolved pollution tolerance, and represents the strongest transcriptional difference between tolerant and sensitive populations.
Project description:The Atlantic killifish (Fundulus heteroclitus) is an ideal model species to study physiological and toxicological adaptations to stressors. Killifish inhabiting the PCB-contaminated Superfund site in New Bedford Harbor, MA (NBH) have evolved resistance to toxicity and activation of the aryl hydrocarbon receptor (AHR) signaling pathway after exposure to PCBs and other AHR agonists. Until recently, a lack of genomic information has limited efforts to understand the molecular mechanisms underlying environmental adaptation to stressors. The advent of high throughput sequencing has facilitated an unbiased assessment of coding as well as non-coding RNAs in any species of interest. Among non-coding RNAs, microRNAs (miRNAs) are important regulators of gene expression and play crucial roles in development and physiology. The objective of this study is to catalog the miRNAs in killifish and determine their expression patterns in the embryos from contaminated (NBH) and pristine (Scorton Creek, MA (SC)) sites. Embryos from NBH and SC were collected daily from 1 to 15 days post-fertilization and RNA from pooled samples from each site was sequenced using SOLiD sequencing. We obtained 7.5 and 11 million raw reads from pooled SC and NBH samples, respectively. Analysis of the sequencing data identified 216 conserved mature miRNA sequences that are expressed during development. Using the draft killifish genome, we retrieved the miRNA precursor sequences. Based on the capacity of these putative precursor sequences to form the characteristic hairpin loop (assessed using RNAfold), we identified 197 conserved miRNA sequences in the genome.
Project description:Very recently, a number of independent studies showed that serum levels of embryonic micro-RNA (miR) clusters 371-3 and 302abc/367 are predictive for the presence of testicular type II germ cell tumors. These miRs could be used to sensitively detect SE and EC components which are indeed known to express these miRs [1-7]. This study investigates ca 750 miRs in a high throughput approach to validate these previously identified markers and identify novel potential miR markers for testicular type II germ cell tumors. 1. Belge, G., et al., Serum levels of microRNAs miR-371-3: a novel class of serum biomarkers for testicular germ cell tumors? Eur Urol, 2012. 61(5): p. 1068-9. 2. Dieckmann, K.P., et al., MicroRNAs miR-371-3 in serum as diagnostic tools in the management of testicular germ cell tumours. Br J Cancer, 2012. 107(10): p. 1754-60. 3. Gillis, A.J., et al., Targeted serum miRNA (TSmiR) test for diagnosis and follow-up of (testicular) germ cell cancer patients: a proof of principle. Mol Oncol, 2013. 7(6): p. 1083-92. 4. Gillis, A.J., et al., High-throughput microRNAome analysis in human germ cell tumours. J Pathol, 2007. 213(3): p. 319-28. 5. Murray, M.J. and N. Coleman, Testicular cancer: a new generation of biomarkers for malignant germ cell tumours. Nat Rev Urol, 2012. 9(6): p. 298-300. 6. Murray, M.J., et al., Identification of microRNAs From the miR-371~373 and miR-302 clusters as potential serum biomarkers of malignant germ cell tumors. Am J Clin Pathol, 2011. 135(1): p. 119-25. 7. Voorhoeve, P.M., et al., A genetic screen implicates miRNA-372 and miRNA-373 as oncogenes in testicular germ cell tumors. Cell, 2006. 124(6): p. 1169-81.
Project description:The successful proliferation and differentiation of testicular cells are vital for the survival, continuity and preservation of species. However, a comprehensive molecular orchestration underlying the spermatogenic process in teleost testis development throughout the annual cycle remains elusive. In this study, the testicular cells derived from adult black rockfish at distinct stages—Regressed, Regenerating, and Differentiating were dissected via single cell transcriptome sequencing. A continuous developmental trajectory of spermatogenic cells, from spermatogonia to spermatids, was delineated, elucidating the molecular events involved in the spermatogonia development. Subsequently, the dynamic regulation of gene expressions associated with spermatogonia proliferation and differentiation was observed across spermatogonia subgroups and various developmental stages. A bioenergetic transition from glycolysis to mitochondrial respiration of spermatogonia during annual developmental cycle was demonstrated, and a deeper level of heterogeneity and molecular characteristics was revealed by re-clustering analysis. The developmental trajectory of Sertoli cells in annual reproductive cycle was examined, and the divergence of Leydig cells and macrophage were explored. Additionally, the interaction network between testicular micro-environment somatic cells and spermatogenic cell were established. Overall, our study provides detailed information on both germ and somatic cells within teleost testis during annual reproductive cycle, along with insights into the molecular regulation of spermatogonia dynamics, which lay the foundation for spermatogenesis regulation and germplasm preservation of endangered species.
Project description:The World Health Organization has recognized testicular function with temperature dependence. Testicular heat exposure caused by occupational factors, lifestyle and clinical disease, etc., can lead to different degrees of reproductive obstacles. The aim of this study is to reveal the transcriptional regulatory network and their potential crucial roles in testicular heat exposure. After passing quality control, the high throughput sequencing data of mouse testicular tissue for scrotum heat exposure and control group were carried out various analyses including differentially expressed transcriptome exploration, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and network regulation. Differential transcriptome expression analysis revealed that 279 miRNAs (138 upregulation and 141 downregulation) were identified as significant differential expression in the mouse testicular tissue of heat exposure compared with control group using the cut-off of log2fold change >= 0.585, p value <= 0.05 and q value <= 1.00. This research provides high throughput sequencing data of transcriptome in testicular heat exposure model and lays the foundation for further study on the miRNA in male reproductive diseases related to elevated testicular temperature.