Project description:The naked mole-rat (NMR; Heterocephalus glaber) has recently gained considerable attention in the scientific community for its unique potential to unveil novel insights in the fields of medicine, biochemistry, and evolution. NMRs exhibit unique adaptations that include protracted fertility, cancer resistance, eusociality, and anoxia. This suite of adaptations is not found in other rodent species, suggesting that interrogating conserved and accelerated regions in the NMR genome will find regions of the NMR genome fundamental to their unique adaptations. However, the current NMR genome assembly has limits that make studying structural variations, heterozygosity, and non-coding adaptations challenging. We present a complete diploid naked-mole rat genome assembly by integrating long-read and 10X-linked read genome sequencing of a male NMR and its parents, and Hi-C sequencing in the NMR hypothalamus (N=2). Reads were identified as maternal, paternal or ambiguous (TrioCanu). We then polished genomes with Flye, Racon and Medaka. Assemblies were then scaffolded using the following tools in order: Scaff10X, Salsa2, 3d-DNA, Minimap2-alignment between assemblies, and the Juicebox Assembly Tools. We then subjected the assemblies to another round of polishing, including short-read polishing with Freebayes. We assembled the NMR mitochondrial genome with mitoVGP. Y chromosome contigs were identified by aligning male and female 10X linked reads to the paternal genome and finding male-biased contigs not present in the maternal genome. Contigs were assembled with publicly available male NMR Fibroblast Hi-C-seq data (SRR820318). Both assemblies have their sex chromosome haplotypes merged so that both assemblies have a high-quality X and Y chromosome. Finally, assemblies were evaluated with Quast, BUSCO, and Merqury, which all reported the base-pair quality and contiguity of both assemblies as high-quality. The assembly will next be annotated by Ensembl using public RNA-seq data from multiple tissues (SRP061363). Together, this assembly will provide a high-quality resource to the NMR and comparative genomics communities.

Project description:The domestic goat, Capra hircus (2n=60), is one of the most important domestic livestock species in the world. Here we report its high quality reference genome generated by combining Illumina short reads sequencing and a new automated and high throughput whole genome mapping system based on the optical mapping technology which was used to generate extremely long super-scaffolds. The N50 size of contigs, scaffolds, and super-scaffolds for the sequence assembly reported herein are 18.7 kb, 3.06 Mb, and 18.2 Mb, respectively. Almost 95% of the supper-scaffolds are anchored on chromosomes based on conserved syntenic information with cattle. The assembly is strongly supported by the RH map of goat chromosome 1. We annotated 22,175 protein-coding genes, most of which are recovered by RNA-seq data of ten tissues. Rapidly evolving genes and gene families are enriched in metabolism and immune systems, consistent with the fact that the goat is one of the most adaptable and geographically widespread livestock species. Comparative transcriptomic analysis of the primary and secondary follicles of a cashmere goat revealed 51 genes that were significantly differentially expressed between the two types of hair follicles. This study not only provides a high quality reference genome for an important livestock species, but also shows that the new automated optical mapping technology can be used in a de novo assembly of large genomes. Corresponding whole genome sequencing is available in NCBI BioProject PRJNA158393. We have sequenced a 3-year-old female Yunnan black goat and constructed a reference sequence for this breed. In order to improve quality of gene models, RNA samples of ten tissues (Bladder, Brain, Heart, Kidney, Liver, Lung, Lymph, Muscle, Ovarian, Spleen) were extracted from the same goat which was sequenced. To investigate the genic basis underlying the development of cashmere fibers using the goat reference genome assembly and annotated genes, we extracted RNA samples of primary hair follicle and secondary hair follicle from three Inner Mongolia cashmere goats and conducted transcriptome sequencing and DGE analysis. This submission represents RNA-Seq component of study.

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