The seventh iteration of the reference genome assembly for Rattus norvegicus-mRatBN7.2-corrects numerous misplaced segments and reduces base-level errors by approximately 9-fold and increases contiguity by 290-fold compared with its predecessor. Gene annotations are now more complete, improving the mapping precision of genomic, transcriptomic, and proteomics datasets. We jointly analyzed 163 short-read whole-genome sequencing datasets representing 120 laboratory rat strains and substrains using mRatBN7.2. We defined ∼20.0 million sequence variations, of which 18,700 are predicted to potentially impact the function of 6,677 genes. We also generated a new rat genetic map from 1,893 heterogeneous stock rats and annotated transcription start sites and alternative polyadenylation sites. The mRatBN7.2 assembly, along with the extensive analysis of genomic variations among rat strains, enhances our understanding of the rat genome, providing researchers with an expanded resource for studies involving rats.

• Keywords
• Rnor_6.0, genetic map, heterogeneous stock, hybrid rat diversity panel, inbred strains, mRatBN7.2, phylogenetic tree, rat, recombinant inbred, reference genome,
• MeSH
• Molecular Sequence Annotation MeSH
• Genetic Variation genetics   MeSH
• Genome * genetics   MeSH
• Genomics * MeSH
• Rats MeSH
• Whole Genome Sequencing MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The seventh iteration of the reference genome assembly for Rattus norvegicus-mRatBN7.2-corrects numerous misplaced segments and reduces base-level errors by approximately 9-fold and increases contiguity by 290-fold compared to its predecessor. Gene annotations are now more complete, significantly improving the mapping precision of genomic, transcriptomic, and proteomics data sets. We jointly analyzed 163 short-read whole genome sequencing datasets representing 120 laboratory rat strains and substrains using mRatBN7.2. We defined ~20.0 million sequence variations, of which 18.7 thousand are predicted to potentially impact the function of 6,677 genes. We also generated a new rat genetic map from 1,893 heterogeneous stock rats and annotated transcription start sites and alternative polyadenylation sites. The mRatBN7.2 assembly, along with the extensive analysis of genomic variations among rat strains, enhances our understanding of the rat genome, providing researchers with an expanded resource for studies involving rats.

• Keywords
• Genetic Map, Heterogeneous Stock, Hybrid Rat Diversity Panel, Inbred Strains, Phylogenetic Tree, Rat, Recombinant Inbred, Reference Genome, Rnor_6.0, mRatBN7.2,
• Publication type
• Journal Article MeSH
• Preprint MeSH

The role of alternative promoter usage in tissue-specific gene expression has been well established; however, its role in complex diseases is poorly understood. We performed cap analysis of gene expression (CAGE) sequencing from the left ventricle of a rat model of hypertension, the spontaneously hypertensive rat (SHR), and a normotensive strain, Brown Norway to understand the role of alternative promoter usage in complex disease. We identified 26,560 CAGE-defined transcription start sites in the rat left ventricle, including 1,970 novel cardiac transcription start sites. We identified 28 genes with alternative promoter usage between SHR and Brown Norway, which could lead to protein isoforms differing at the amino terminus between two strains and 475 promoter switching events altering the length of the 5' UTR. We found that the shift in Insr promoter usage was significantly associated with insulin levels and blood pressure within a panel of HXB/BXH recombinant inbred rat strains, suggesting that hyperinsulinemia due to insulin resistance might lead to hypertension in SHR. Our study provides a preliminary evidence of alternative promoter usage in complex diseases.

• MeSH
• Transcription, Genetic genetics   MeSH
• Hypertension * genetics   metabolism   MeSH
• Rats MeSH
• Rats, Inbred SHR MeSH
• Promoter Regions, Genetic genetics   MeSH
• Sequence Analysis, RNA methods   MeSH
• Gene Expression Profiling methods   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Little is known about the impact of trans-acting genetic variation on the rates with which proteins are synthesized by ribosomes. Here, we investigate the influence of such distant genetic loci on the efficiency of mRNA translation and define their contribution to the development of complex disease phenotypes within a panel of rat recombinant inbred lines. RESULTS: We identify several tissue-specific master regulatory hotspots that each control the translation rates of multiple proteins. One of these loci is restricted to hypertrophic hearts, where it drives a translatome-wide and protein length-dependent change in translational efficiency, altering the stoichiometric translation rates of sarcomere proteins. Mechanistic dissection of this locus across multiple congenic lines points to a translation machinery defect, characterized by marked differences in polysome profiles and misregulation of the small nucleolar RNA SNORA48. Strikingly, from yeast to humans, we observe reproducible protein length-dependent shifts in translational efficiency as a conserved hallmark of translation machinery mutants, including those that cause ribosomopathies. Depending on the factor mutated, a pre-existing negative correlation between protein length and translation rates could either be enhanced or reduced, which we propose to result from mRNA-specific imbalances in canonical translation initiation and reinitiation rates. CONCLUSIONS: We show that distant genetic control of mRNA translation is abundant in mammalian tissues, exemplified by a single genomic locus that triggers a translation-driven molecular mechanism. Our work illustrates the complexity through which genetic variation can drive phenotypic variability between individuals and thereby contribute to complex disease.

• Keywords
• Cardiac hypertrophy, Complex disease, Genetic variation, HXB/BXH rat recombinant inbred panel, Ribosome biogenesis, Ribosome profiling, Ribosomopathy, Spontaneously hypertensive rats (SHR), Translational efficiency, trans QTL mapping,
• MeSH
• Organelle Biogenesis MeSH
• Genetic Variation MeSH
• Peptide Chain Initiation, Translational * MeSH
• Cardiomegaly genetics   metabolism   pathology   MeSH
• Rats MeSH
• Quantitative Trait Loci * MeSH
• RNA, Small Nucleolar genetics   metabolism   MeSH
• RNA, Messenger genetics   metabolism   MeSH
• Myocardium metabolism   pathology   MeSH
• Mice, Inbred C57BL MeSH
• Mice, Knockout MeSH
• Mice MeSH
• Rats, Inbred SHR MeSH
• Rats, Transgenic MeSH
• Gene Expression Regulation MeSH
• Ribosomal Proteins genetics   metabolism   MeSH
• Ribosomes genetics   metabolism   pathology   MeSH
• Saccharomyces cerevisiae genetics   metabolism   MeSH
• Sarcomeres metabolism   pathology   MeSH
• Gene Expression Profiling MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• RNA, Small Nucleolar MeSH
• RNA, Messenger MeSH
• Ribosomal Proteins MeSH