Desiccation does not drastically increase the accessibility of exogenous DNA to nuclear genomes: Evidence from the frequency of endosymbiotic DNA transfer
| Autor: | Cheng Fang, Deng-Ke Niu, Jun-Peng Zhao, Zhihua Ni, Xiao-Yu Zhou, Xi-Xi Li |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Adineta ricciae Nuclear gene Gene Transfer Horizontal lcsh:QH426-470 lcsh:Biotechnology Rotifera Selaginella tamariscina Biology Non-homologous end joining (NHEJ) 01 natural sciences Genome DNA Mitochondrial Horizontal gene transfer (HGT) 03 medical and health sciences Bdelloid rotifers lcsh:TP248.13-248.65 Genetics Tardigrada Animals Nuclear plastid DNA (NUPT) Plastids Double-strand breaks (DSBs) Desiccation 030304 developmental biology Cell Nucleus 0303 health sciences Plants Nuclear mitochondrial DNA (NUMT) biology.organism_classification lcsh:Genetics Horizontal gene transfer Exogenous DNA Numt 010606 plant biology & botany Biotechnology Research Article |
| Zdroj: | BMC Genomics, Vol 21, Iss 1, Pp 1-12 (2020) BMC Genomics |
| DOI: | 10.21203/rs.3.rs-20529/v2 |
| Popis: | Background Although horizontal gene transfer (HGT) is a widely accepted force in the evolution of prokaryotic genomes, its role in the evolution of eukaryotic genomes remains hotly debated. Some bdelloid rotifers that are resistant to extreme desiccation and radiation undergo a very high level of HGT, whereas in another desiccation-resistant invertebrate, the tardigrade, the pattern does not exist. Overall, the DNA double-strand breaks (DSBs) induced by prolonged desiccation have been postulated to open a gateway to the nuclear genome for exogenous DNA integration and thus to facilitate the HGT process, thereby enhancing the rate of endosymbiotic DNA transfer (EDT). Results We first surveyed the abundance of nuclear mitochondrial DNAs (NUMTs) and nuclear plastid DNAs (NUPTs) in five eukaryotes that are highly resistant to desiccation: the bdelloid rotifers Adineta vaga and Adineta ricciae, the tardigrade Ramazzottius varieornatus, and the resurrection plants Dorcoceras hygrometricum and Selaginella tamariscina. Excessive NUMTs or NUPTs were not detected. Furthermore, we compared 24 groups of desiccation-tolerant organisms with their relatively less desiccation-tolerant relatives but did not find a significant difference in NUMT/NUPT contents. Conclusions Desiccation may induce DSBs, but it is unlikely to dramatically increase the frequency of exogenous sequence integration in most eukaryotes. The capture of exogenous DNA sequences is possible only when DSBs are repaired through a subtype of non-homologous end joining, named alternative end joining (alt-EJ). Due to the deleterious effects of the resulting insertion mutations, alt-EJ is less frequently initiated than other mechanisms. |
| Databáze: | OpenAIRE |
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