Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome
Endogenous retroviruses (ERVs) are integrated into host DNA as the result of ancient germ line infections, primarily by extinct exogenous retroviruses. Thus, vertebrates’ genomes contain thousands of ERV copies, providing a “fossil” record for ancestral retroviral diversity and its evolution within...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-08-01
|
| Series: | Viruses |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1999-4915/15/9/1856 |
| _version_ | 1797576447466930176 |
|---|---|
| author | Saili Chabukswar Nicole Grandi Liang-Tzung Lin Enzo Tramontano |
| author_facet | Saili Chabukswar Nicole Grandi Liang-Tzung Lin Enzo Tramontano |
| author_sort | Saili Chabukswar |
| collection | DOAJ |
| description | Endogenous retroviruses (ERVs) are integrated into host DNA as the result of ancient germ line infections, primarily by extinct exogenous retroviruses. Thus, vertebrates’ genomes contain thousands of ERV copies, providing a “fossil” record for ancestral retroviral diversity and its evolution within the host genome. Like other retroviruses, the ERV proviral sequence consists of <i>gag</i>, <i>pro</i>, <i>pol</i>, and <i>env</i> genes flanked by long terminal repeats (LTRs). Particularly, the <i>env</i> gene encodes for the envelope proteins that initiate the infection process by binding to the host cellular receptor(s), causing membrane fusion. For this reason, a major element in understanding ERVs’ evolutionary trajectory is the characterization of <i>env</i> changes over time. Most of the studies dedicated to ERVs’ <i>env</i> have been aimed at finding an “actual” physiological or pathological function, while few of them have focused on how these genes were once acquired and modified within the host. Once acquired into the organism, genome ERVs undergo common cellular events, including recombination. Indeed, genome recombination plays a role in ERV evolutionary dynamics. Retroviral recombination events that might have been involved in <i>env</i> divergence include the acquisition of <i>env</i> genes from distantly related retroviruses, <i>env</i> swapping facilitating multiple cross-species transmission over millions of years, ectopic recombination between the homologous sequences present in different positions in the chromosomes, and template switching during transcriptional events. The occurrence of these recombinational events might have aided in shaping retroviral diversification and evolution until the present day. Hence, this review describes and discusses in detail the reported recombination events involving ERV <i>env</i> to provide the basis for further studies in the field. |
| first_indexed | 2024-03-10T21:52:04Z |
| format | Article |
| id | doaj.art-fd439c27166c4ad48fa4a81d8e38c15d |
| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-03-10T21:52:04Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Viruses |
| spelling | doaj.art-fd439c27166c4ad48fa4a81d8e38c15d2023-11-19T13:22:40ZengMDPI AGViruses1999-49152023-08-01159185610.3390/v15091856Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host GenomeSaili Chabukswar0Nicole Grandi1Liang-Tzung Lin2Enzo Tramontano3Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, ItalyLaboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, ItalyDepartment of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, TaiwanLaboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, ItalyEndogenous retroviruses (ERVs) are integrated into host DNA as the result of ancient germ line infections, primarily by extinct exogenous retroviruses. Thus, vertebrates’ genomes contain thousands of ERV copies, providing a “fossil” record for ancestral retroviral diversity and its evolution within the host genome. Like other retroviruses, the ERV proviral sequence consists of <i>gag</i>, <i>pro</i>, <i>pol</i>, and <i>env</i> genes flanked by long terminal repeats (LTRs). Particularly, the <i>env</i> gene encodes for the envelope proteins that initiate the infection process by binding to the host cellular receptor(s), causing membrane fusion. For this reason, a major element in understanding ERVs’ evolutionary trajectory is the characterization of <i>env</i> changes over time. Most of the studies dedicated to ERVs’ <i>env</i> have been aimed at finding an “actual” physiological or pathological function, while few of them have focused on how these genes were once acquired and modified within the host. Once acquired into the organism, genome ERVs undergo common cellular events, including recombination. Indeed, genome recombination plays a role in ERV evolutionary dynamics. Retroviral recombination events that might have been involved in <i>env</i> divergence include the acquisition of <i>env</i> genes from distantly related retroviruses, <i>env</i> swapping facilitating multiple cross-species transmission over millions of years, ectopic recombination between the homologous sequences present in different positions in the chromosomes, and template switching during transcriptional events. The occurrence of these recombinational events might have aided in shaping retroviral diversification and evolution until the present day. Hence, this review describes and discusses in detail the reported recombination events involving ERV <i>env</i> to provide the basis for further studies in the field.https://www.mdpi.com/1999-4915/15/9/1856endogenous retrovirusesenvelope generecombination |
| spellingShingle | Saili Chabukswar Nicole Grandi Liang-Tzung Lin Enzo Tramontano Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome Viruses endogenous retroviruses envelope gene recombination |
| title | Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome |
| title_full | Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome |
| title_fullStr | Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome |
| title_full_unstemmed | Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome |
| title_short | Envelope Recombination: A Major Driver in Shaping Retroviral Diversification and Evolution within the Host Genome |
| title_sort | envelope recombination a major driver in shaping retroviral diversification and evolution within the host genome |
| topic | endogenous retroviruses envelope gene recombination |
| url | https://www.mdpi.com/1999-4915/15/9/1856 |
| work_keys_str_mv | AT sailichabukswar enveloperecombinationamajordriverinshapingretroviraldiversificationandevolutionwithinthehostgenome AT nicolegrandi enveloperecombinationamajordriverinshapingretroviraldiversificationandevolutionwithinthehostgenome AT liangtzunglin enveloperecombinationamajordriverinshapingretroviraldiversificationandevolutionwithinthehostgenome AT enzotramontano enveloperecombinationamajordriverinshapingretroviraldiversificationandevolutionwithinthehostgenome |