Project description:The cephalochordates amphioxus or lancelets are benthic marine animals representing the earliest divergent evolutionary lineage within chordates. Although amphioxus are present in most of the world's tropical and temperate oceans, only about thirty different species grouped into three different genera, Branchiostoma, Epigonichthys and Asymmetron have been described. In the genus Asymmetron, only two species have been characterized, although for one of them, A. lucayanum, several cryptic lineages exist. In this work we have sequenced and analyzed the mitogenome of an A. lucayanum population previously described in the Red Sea. The phylogenetic study using this complete mitogenome as well as the analysis of COI gene sequences of several individuals of this Red Sea population show that the Red Sea population is a new cryptic species. We propose to call this new species Asymmetron rubrum.
Project description:Cephalochordates, the sister group of tunicates plus vertebrates, have been called "living fossils" due to their resemblance to fossil chordates from Cambrian strata. The genome of the cephalochordate Branchiostoma floridae shares remarkable synteny with vertebrates and is free from whole-genome duplication. We performed RNA sequencing from larvae and adults of Asymmetron lucayanum, a cephalochordate distantly related to B. floridae. Comparisons of about 430 orthologous gene groups among both cephalochordates and 10 vertebrates using an echinoderm, a hemichordate, and a mollusk as outgroups showed that cephalochordates are evolving more slowly than the slowest evolving vertebrate known (the elephant shark), with A. lucayanum evolving even more slowly than B. floridae. Against this background of slow evolution, some genes, notably several involved in innate immunity, stand out as evolving relatively quickly. This may be due to the lack of an adaptive immune system and the relatively high levels of bacteria in the inshore waters cephalochordates inhabit. Molecular dating analysis including several time constraints revealed a divergence time of ∼120 Ma for A. lucayanum and B. floridae. The divisions between cephalochordates and vertebrates, and that between chordates and the hemichordate plus echinoderm clade likely occurred before the Cambrian.
Project description:Purpose: The goal of this study is to compare endothelial small RNA transcriptome to identify the target of OASL under basal or stimulated conditions by utilizing miRNA-seq. Methods: Endothelial miRNA profilies of siCTL or siOASL transfected HUVECs were generated by illumina sequencing method, in duplicate. After sequencing, the raw sequence reads are filtered based on quality. The adapter sequences are also trimmed off the raw sequence reads. rRNA removed reads are sequentially aligned to reference genome (GRCh38) and miRNA prediction is performed by miRDeep2. Results: We identified known miRNA in species (miRDeep2) in the HUVECs transfected with siCTL or siOASL. The expression profile of mature miRNA is used to analyze differentially expressed miRNA(DE miRNA). Conclusions: Our study represents the first analysis of endothelial miRNA profiles affected by OASL knockdown with biologic replicates.
Project description:A cDNA library was constructed by Novogene (CA, USA) using a Small RNA Sample Pre Kit, and Illumina sequencing was conducted according to company workflow, using 20 million reads. Raw data were filtered for quality as determined by reads with a quality score > 5, reads containing N < 10%, no 5' primer contaminants, and reads with a 3' primer and insert tag. The 3' primer sequence was trimmed and reads with a poly A/T/G/C were removed