Dataset Information

Identification of testis-relevant genes from testes ESTs and cDNA microarray in the black tiger shrimp

ABSTRACT: Identification of testis-relevant genes using in silico analysis from testes ESTs and cDNA microarray in the black tiger shrimp (Penaeus monodon) A total of 4,803 ESTs from the testis library were unidirectionally sequenced and analyzed in silico using a customizable data analysis package, ESTplus. A total of 2,702 unique sequences from 424 contigs and 2,278 singletons were identified. Approximately, 1,134 sequences from the total of 2,702 unique sequences (contigs and singletons) are homologous to genes with known functions. Some of which (mago nashi, insulin-degrading enzyme, actin-depolymerizing factor) are related to testicular development in studies of other organisms. Moreover, the sequences were further characterized according to the gene ontology categories (41% biological process, 24% molecular function, 35% cellular component). By comparing with the EST libraries of other tissues, a total of 1,579 possible testis-specific ESTs were identified. Some of these testis-specific ESTs, such as Phospholipase A2 and Matrix Metalloproteinases, have functions relevant to testicular development. In addition, novel ESTs (621 ESTs) that have never been identified in any ESTs from the Penaeidae family were found in this study. Through cDNA microarray analysis, some of testis-specific ESTs were preferentially expressed in testes to ovary; one of which was a saposin homolog. Therefore, saposin was further characterized by real-time PCR and its full-length sequence was obtained by RACE-PCR.

ORGANISM(S): Penaeus monodon

PROVIDER: GSE19037 | GEO | 2010/11/04

SECONDARY ACCESSION(S): PRJNA120643

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Alfalfa, [Medicago sativa (L.) sativa], a widely-grown perennial forage has potential for development as a cellulosic ethanol feedstock. The application of genomic approaches would advance development of alfalfa as a cellulosic feedstock. However, the genomics of alfalfa, a non-model species, is still in its infancy. The recent advent of RNA-Seq, a massively parallel sequencing method for transcriptome analysis, provides an opportunity to expand the identification of alfalfa genes and polymorphisms, and conduct in-depth transcript profiling. Cell walls in stems of alfalfa genotype 708 have higher cellulose and lower lignin concentrations compared to cell walls in stems of genotype 773. Using the Illumina GA-II platform, a total of 198,861,304 expression sequence tags (ESTs, 76 bp in length) were generated from cDNA libraries derived from elongating stem (ES) and post-elongation stem (PES) internodes of 708 and 773. These ESTs were de novo assembled into 132,153 unique sequences. By combining the de novo assembled ESTs (132,153 sequences) with our previously identified EST sequences (341,984 sequences, unpublished data), and the ESTs available from GenBank (12,371 sequences), we built the first Alfalfa Gene Index (MSGI 1.0). MSGI 1.0 contains 124,025 unique sequences including 22,729 tentative consensus sequences (TCs), 22,315 singletons and 78,981 pseudo-singletons. We identified a total of 1, 294 simple sequence repeats (SSR) among the sequences in MSGI 1.0. In addition, a total of 10,826 single nucleotide polymorphisms (SNPs) were predicted between the two genotypes. Transcript profiling of stem internodes of genotypes 708 and 773 was conducted by quantifying the number of Illumina EST reads that were mapped to sequences in MSGI 1.0. We identified numerous candidate genes that may play a role in stem development as well as candidate genes that may contribute to the differences in cell wall composition in stems of the two genotypes. Our results demonstrate that RNA-Seq can be successfully used for gene identification, polymorphism detection and transcript profiling in alfalfa, a non-model, allogamous, autotetraploid species. The alfalfa gene index (MSGI 1.0) assembled in this study, and the SNPs, SSRs and candidate genes identified can be used to improve alfalfa as a cellulosic feedstock.

Project description:The soil worm Enchytraeus crypticus (oligochaete) is an ecotoxicology model species although without genome or transcriptome sequence information. The present research aimed at studying, via high-throughput pyrosequencing, the transcriptome of Enchytraeus crypticus, sampled from multiple test conditions, and the construction of a high-density microarray for functional genomic studies. A pyrosequencing run retrieved approximately 1.5 million reads representing 645 million bases. After assembly, 27,296 contigs and 87,686 singletons were obtained. from which 44% and 25% were annotated as protein-coding genes. We show that the high amount of orphan genes is not due to poor sequence or assemble quality: 84% of the contig sequences contains an open reading frame with a start codon and E. crypticus homologs were identified for 92% of the core eukaryotic genes. Moreover, 65 and 77% of the unknown singletons and contigs, respectively, showed transcriptional activity. An Agilent 180K microarray platform was designed and validated by hybridizing cDNA from 3 day zinc- exposed E. crypticus to the concentration corresponding to 50% reduction in reproduction (EC50). Overall, 70% of all probes exerted a hybridization signal above background level. More specifically, the probes derived from contigs showed a wider range of average intensities when compared to probes derived from singletons. In total, 522 significantly regulated transcripts were identifying upon zinc exposure. Several significantly regulated genes exerted predicted functions (e.g. zinc efflux, zinc transport) associated with zinc stress. Unexpectedly, the microarray data suggest that zinc exposure alters retrotransposon activity in the E. crypticus genome. In conclusion, characterization of the presented E. crypticus transcriptome and associated microarray platform is a valuable and high quality resource that permits further functional genomics experiments examining gene expression patterns underlying distinct environmental stress conditions. We show that unknown sequences are not the result of technical errors but mostly represent functional genes that are actively transcribed.

Dataset Information

Identification of testis-relevant genes from testes ESTs and cDNA microarray in the black tiger shrimp

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure