Project description:The little skate, a cartilaginous fish evolutionarily distal from tetrapods, displays walking-like behavior and has conserved genetic programs and neuronal substrates for land-walking. Studies on little skate have been limited due to lack of high-quality genome assembly. Here, we generated an improved genome assembly of little skate reflecting precise gene annotation and structures and performed integrated analysis of gene expression and chromatin accessibility to investigate molecular mechanisms of fin motor neuron development. Through interspecies comparison of RNA expression, common and species-specific genes expressed in fin/limb/wing level motor neurons were identified. Moreover, by performing chromatin accessibility analysis with a pure fin motor neuron population the potential regulators controlling the gene expression in fin motor neurons were identified. Interspecies comparison of genomic data, gene expression, and chromatin accessibility assay suggest that the little skate has highly conserved gene regulatory mechanisms controlling tetrapod locomotion, which was not previously expected.
Project description:Sea urchins are emblematic marine animals with a rich fossil record and represent instrumental models for developmental biology. As echinoderms, sea urchins display several characteristics that set them apart from other deuterostomes such as their highly regulative embryonic development and their unique pentaradial adult body plan. To determine whether these characteristics are linked to particular genomic rearrangement or gene regulatory rewiring, we introduce a chromosome-scale genome assembly for sea urchin Paracentrotus lividus as well as extensive transcriptomic and epigenetic profiling during its embryonic development. We found that sea urchins show opposite modalities of genome evolution as compared to those of vertebrates: they retained ancestral chromosomal linkages that otherwise underwent mixing in vertebrates, while their intrachromosomal gene order has evolved much faster between sea urchin species that split 60 Myr ago than it did in vertebrates. We further assessed the conservation of the cis-regulatory program between sea urchins and chordates and identified conserved modules despite the developmental and body plan differences. We documented regulatory events underlying processes like zygotic genome activation and transition to larval stage in sea urchins. We also identified a burst of gene duplication in the echinoid lineage and showed that some of these expanded genes are involved in organismal novelties, such as Aristotle's lantern, tube feet, or in the specification of lineages through for instance the pmar1 and pop genes. Altogether, our results suggest that gene regulatory networks controlling development can be conserved despite extensive gene order rearrangement.
Project description:YerA41 is a myoviridae bacteriophage that was originally isolated due its ability to infect Yersinia ruckeri bacteria, the causative agent of enteric redmouth disease of salmonid fish. Several attempts to determine its genomic DNA sequence using traditional and next generation sequencing technologies failed, indicating that the phage genome is modified such way that it is an unsuitable template for PCR amplification and sequencing. To determine the YerA41 genome sequence we isolated RNA from phage-infected Y. ruckeri cells at different time points post-infection, and sequenced it. The host-genome specific reads were substracted and de novo assembly was performed on the unaligned reads.
Project description:Seafood fraud has become a global emerging issue, threatening food security and safety. Adulteration, substitution, dilution, and incorrect labeling of seafood products are fraudulent practices that violate consumer safety. In this context, developing sensitive, robust, and high-throughput molecular tools for food and feed authentication is becoming crucial for regulatory purposes. Analytical approaches such as proteomics mass spectrometry have shown promise in detecting incorrectly labeled products. For the application of these tools, genome information is crucial, but currently, for marine species of commercial importance, such information is unavailable. However, when combining proteomic analysis with spectra library matching, commercially important fish species were successfully identified, differentiated, and quantified in pure muscle samples and mixtures, even when genome information was scarce. This study further tested the previously developed proteomic-based spectra library-based approach was further tested to differentiate 29 fish species from the North Sea in individual samples, laboratory-prepared mixtures, and commercial samples. For authenticating libraries generated from 29 fish species, fresh muscle samples from the fish samples were matched against the reference libraries. Species of the fresh fish samples were correctly authenticated using the spectra libraries generated from the 29 fish species. Furthermore, processed commercial products containing mixtures of two or three fish species were matched against these spectra libraries to test the accuracy and robustness of this method for authentication of fish species. The results indicated that the method is suitable for the authentication of fish species from highly processed samples such as fish cakes and burgers. Spectra libraries built from 29 fish species in the North Sea can efficiently tackle current and future challenges in feed and food authentication analyses when prospecting new resources in the Arctic.
Project description:The little skate, a cartilaginous fish evolutionarily distal from tetrapods, displays walking-like behavior and has conserved genetic programs and neuronal substrates for land-walking. Studies on little skate have been limited due to lack of high-quality genome assembly. Here, we generated an improved genome assembly of little skate reflecting precise gene annotation and structures and performed integrated analysis of gene expression and chromatin accessibility to investigate molecular mechanisms of fin motor neuron development. Through interspecies comparison of RNA expression, common and species-specific genes expressed in fin/limb/wing level motor neurons were identified. Moreover, by performing chromatin accessibility analysis with a pure fin motor neuron population the potential regulators controlling the gene expression in fin motor neurons were identified. Interspecies comparison of genomic data, gene expression, and chromatin accessibility assay suggest that the little skate has highly conserved gene regulatory mechanisms controlling tetrapod locomotion, which was not previously expected.
2022-10-24 | GSE180336 | GEO
Project description:Genome assembly of Pearlspot fish