Translation of Mutant Repetitive Genomic Sequences in Hirsutella sinensis and Changes in the Secondary Structures and Functional Specifications of the Encoded Proteins.

Autor: Li XZ; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai Academy of Animal Science and Veterinary, Qinghai University, Xining 810016, China., Li YL; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai Academy of Animal Science and Veterinary, Qinghai University, Xining 810016, China., Wang YN; State Key Laboratory of Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China., Zhu JS; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai Academy of Animal Science and Veterinary, Qinghai University, Xining 810016, China.; Institute of Biopharmaceutical and Health Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Jazyk: angličtina
Zdroj: International journal of molecular sciences [Int J Mol Sci] 2024 Oct 17; Vol. 25 (20). Date of Electronic Publication: 2024 Oct 17.
DOI: 10.3390/ijms252011178
Abstrakt: Multiple repetitive sequences of authentic genes commonly exist in fungal genomes. AT-biased genotypes of Ophiocordyceps sinensis have been hypothesized as repetitive pseudogenes in the genome of Hirsutella sinensis (GC-biased Genotype #1 of O. sinensis ) and are generated through repeat-induced point mutation (RIP), which is charactered by cytosine-to-thymine and guanine-to-adenine transitions, concurrent epigenetic methylation, and dysfunctionality. This multilocus study examined repetitive sequences in the H. sinensis genome and transcriptome using a bioinformatic approach and revealed that 8.2% of the authentic genes had repetitive copies, including various allelic insertions/deletions, transversions, and transitions. The transcripts for the repetitive sequences, regardless of the decreases, increases, or bidirectional changes in the AT content, were identified in the H. sinensis transcriptome, resulting in changes in the secondary protein structure and functional specification. Multiple repetitive internal transcribed spacer (ITS) copies containing multiple insertion/deletion and transversion alleles in the genome of H. sinensis were GC-biased and were theoretically not generated through RIP mutagenesis. The repetitive ITS copies were genetically and phylogenetically distinct from the AT-biased O. sinensis genotypes that possess multiple transition alleles. The sequences of Genotypes #2-17 of O. sinensis , both GC- and AT-biased, were absent from the H. sinensis genome, belong to the interindividual fungi, and differentially occur in different compartments of the natural Cordyceps sinensis insect-fungi complex, which contains >90 fungal species from >37 genera. Metatranscriptomic analyses of natural C. sinensis revealed the transcriptional silencing of 5.8S genes in all C. sinensis -colonizing fungi in natural settings, including H. sinensis and other genotypes of O. sinensis . Thus, AT-biased genotypes of O. sinensis might have evolved through advanced evolutionary mechanisms, not through RIP mutagenesis, in parallel with GC-biased Genotype #1 of H. sinensis from a common genetic ancestor over the long course of evolution.
Databáze: MEDLINE
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