ABSTRACT: A ddRAD-based genetic map and its integration with the genome assembly of Japanese eel (Anguilla japonica) provides insights into genome evolution after the teleost-specifc genome duplication
Project description:A ddRAD-based genetic map and its integration with the genome assembly of Japanese eel (Anguilla japonica) provides insights into genome evolution after the teleost-specifc genome duplication
Project description:Background: The Japanese eel (Anguilla japonica) holds significant economic value in East Asia, but limitations in understanding its reproductive biology have hindered advancements in artificial breeding techniques. Previous research has primarily focused on conserved sex differentiation genes, offering limited insights into the broader molecular mechanisms driving gonadal development and sexual dimorphism. To address these limitations, this study aims to investigate key genes and pathways involved in gonadal development through a comprehensive transcriptomic analysis of male and female eel gonads. Results: PacBio Iso-Seq and Illumina RNA-Seq technologies were combined to conduct a full-length transcriptome analysis of male and female Japanese eel gonads at a post-differentiation, pre-maturation stage. A total of 24661 unigenes were identified in ovaries and 15023 in testes, along with genomic regulatory elements such as transcription factors, simple sequence repeats, and long non-coding RNAs. Additionally, 1,210 differentially expressed genes were detected. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed significant pathways involved in cell cycle regulation, metabolic processes, apoptosis, and hormone activity. Notably, several reproductive-related genes, including bambi, ccnb1, cdc20, gdf9, prlh, ccdc39, chrebp, tspo, syce3, and ngb, demonstrated significant dimorphic expression in eel gonads. Conclusions: This study provides valuable insights into the molecular mechanisms of gonadal differentiation and sexual dimorphism in Japanese eels. The findings expand the genetic resources available for the eel breeding industry and could facilitate the development of improved artificial breeding techniques focused on reproductive development.
Project description:We investigated salinity adaptation during the migration from freshwater to seawater of European eel (Anguilla anguilla) by examining the hypothesis that: The brain is the central organ for the co-ordination of environmental cues (day length, photoperiod, temperature and environmental salinity) with the anatomical and physiological adaptations which accompany pre-migrational morphogenesis and the osmoregulatory plasticity seen in post-migrational, salinity-adapted fish. We have characertised the mRNA expression profiles for the brains of fresh water and sea water adapted silver eel using a highly representative brain cDNA microarray. The array comprises 5760 cDNA clones from A.anguilla ranging from 0.5 -10 kb and an estimated redundancy of > 5 %.
Project description:We investigated the transition from juvenile yellow to the adult sexually maturing, migrating silver eel (Anguilla anguilla) by examining the hypothesis that: The brain is the central organ for the co-ordination of environmental cues (day length, photoperiod, temperature and environmental salinity) with the anatomical and physiological adaptations which accompany pre-migrational morphogenesis and the osmoregulatory plasticity seen in post-migrational, salinity-adapted fish. We have characertised the mRNA expression profiles for the brains of fresh water, yellow and silver eel using a highly representative brain cDNA microarray. The array comprises 5760 cDNA clones from A.anguilla ranging from 0.5 -10 kb and an estimated redundancy of > 5 %.
Project description:An European eel-specific microarray platform was developed to identify genes involved in response to pollutants A comparative analysis of gene expression was conducted between European eel Anguilla anguilla individuals from high (Tiber river, Italy) and low pollution (Bolsena lake, Italy) environments. Gene expression profiling was performed using an European eel-specific oligo-DNA microarray of 14,913 probes based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA (barcode on the left, DNA on the back surface, scanned through the glass) at a resolution of 5 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. Feature Extraction (FE) 9.5 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal.
