Project description:Tunicates are the sister group of vertebrates and thus occupy a key position for investigations into vertebrate innovations as well as into the consequences of the vertebrate-specific genome duplications. Nevertheless, tunicate genomes have not been studied extensively in the past, and comparative studies of tunicate genomes have remained scarce. The carpet sea squirt Didemnum vexillum, commonly known as "sea vomit", is a colonial tunicate considered an invasive species with substantial ecological and economical risk. We report the assembly of the D. vexillum genome using a hybrid approach that combines 28.5 Gb Illumina and 12.35 Gb of PacBio data. The new hybrid scaffolded assembly has a total size of 517.55 Mb that increases contig length about eightfold compared to previous, Illumina-only assembly. As a consequence of an unusually high genetic diversity of the colonies and the moderate length of the PacBio reads, presumably caused by the unusually acidic milieu of the tunic, the assembly is highly fragmented (L50 = 25,284, N50 = 6539). It is sufficient, however, for comprehensive annotations of both protein-coding genes and non-coding RNAs. Despite its shortcomings, the draft assembly of the "sea vomit" genome provides a valuable resource for comparative tunicate genomics and for the study of the specific properties of colonial ascidians.
Project description:This data series contains the sequences and read counts of Piwi-interacting RNAs and other small RNAs from mouse and rat testes extracts. In a search for different classes of small RNAs that might be involved in transcriptional gene silencing, we encountered a novel class of small RNAs within mammalian testes. This study reports the identification of small RNAs and their relative abundance levels to each other based on the deep coverage of the cDNA library. Keywords: High-throughput pyrosequencing by the 454 Life Sciences Genome Sequencer 20™ System
2006-07-03 | GSE5026 | GEO
Project description:Low coverage 454 genome sequencing of North American fireflies
Project description:Characterization of gene expression levels with RNA-seq was performed on self-renewing (SR) and senescent (SEN) human adult adipose derived mesenchymal stem cells (hADSCs) using the Roche 454 pyrosequencing platform.