Project description:The Antarctic icefish, a family (Channichthyidae) of teleosts within the perciform suborder Notothenioidei, are the only known vertebrates without oxygen-transporting hemoglobins and that are largely devoid of circulating erythrocytes. To elucidate the evo-devo mechanisms underpinning the suppressed erythropoiesis in the icefish, we conducted comparative studies on the transcriptomes and microRNAomes of the primary hematopoietic tissues between an icefish (Chionodraco hamatus) and two red-blooded notothenioids (Trematomus bernacchii and Gymnodraco acuticeps). We identified substantial remodeling of the hematopoietic programs in the icefish through which erythropoiesis is selectively suppressed. Experimental verification showed that erythropoietic suppression in the icefish may be attributable to the upregulation of TGF-β signaling, which coincides with reductions in multiple transcription factors essential for erythropoiesis and the upregulation of hundreds of microRNAs, the majority (> 80%) of which potentially target erythropoiesis regulating factors.
Project description:<p><strong>BACKGROUND:</strong> Manchurian walnut (Juglans mandshurica Maxim.) is a tree with multiple industrial uses and medicinal properties in the Juglandaceae family (walnuts and hickories). J. mandshurica produces juglone, which is a toxic allelopathic agent and has potential utilization value. Furthermore, the seed of J. mandshurica is rich in various unsaturated fatty acids and has high nutritive value.</p><p><strong>FINDINGS:</strong> Here, we present a high-quality chromosome-scale reference genome assembly and annotation for J. mandshurica (n = 16) with a contig N50 of 21.4 Mb by combining PacBio high-fidelity reads with high-throughput chromosome conformation capture data. The assembled genome has an estimated sequence size of 548.7 Mb and consists of 657 contigs, 623 scaffolds and 40,453 protein-coding genes. In total, 60.99% of the assembled genome consists of repetitive sequences. Sixteen super-scaffolds corresponding to the 16 chromosomes were assembled, with a scaffold N50 length of 33.7 Mb and a BUSCO complete gene percentage of 98.3%. J. mandshurica displays a close sequence relationship with Juglans cathayensis, with a divergence time of 13.8 million years ago. Combining the high-quality genome, transcriptome and metabolomics data, we constructed a gene-to-metabolite network and identified 566 core and conserved differentially expressed genes, which may be involved in juglone biosynthesis. Five CYP450 genes were found that may contribute to juglone accumulation. NAC, bZip, NF-YA and NF-YC are positively correlated with the juglone content. Some candidate regulators (e.g., FUS3, ABI3, LEC2 and WRI1 transcription factors) involved in the regulation of lipid biosynthesis were also identified.</p><p><strong>CONCLUSIONS:</strong> Our genomic data provide new insights into the evolution of the walnut genome and create a new platform for accelerating molecular breeding and improving the comprehensive utilization of these economically important tree species.</p>
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.