Given that a single mutation in your genome can cause a serious genetic disorder, it is challenging to accept the following scenario: Imagine something inserting a large segment of its DNA into your genome. One might expect such an insertion to disrupt the genome, potentially leading to severe systemic issues, such as cancer or even death. Yet, in the Darwinian fantasy world, this is not the case. In this extraordinary scenario, when a retrovirus inserts its DNA into a species’ genome, this chunk of viral DNA later aids a process as critical as species’ reproduction—rather than harming the species. This is difficult to accept, as reproduction is a vital process for any species and must function almost flawlessly. If it fails, there is no reproduction—and thus, no evolution. Even more astonishing is the claim by evolutionists that these events occurred independently many times across various species. It would be remarkable if this worked even once, let alone multiple times.
Endogenous retroviruses are ubiquitous in the vertebrate genomes. On occasion, hosts recruited retroviral genes to mediate their own biological functions, a process formally known as co-option or exaptation. Much remains unknown about the extent of retroviral gene co-option in vertebrates, although more than ten retroviral gene co-option events have been documented. Here, we use a phylogenomic approach to analyze more than 700 vertebrate genomes to uncover retroviral gene co-option taking place during the evolution of vertebrates. We identify a total of 177 independent retroviral gene co-option events in vertebrates, a majority of which have not been reported previously. Among these retroviral gene co-option events, 93 and 84 involve gag and env genes, respectively. More than 78.0% (138 out of 177) of retroviral gene co-option occurred within mammals. The gag and env co-option events share a generally similar temporal pattern with less frequent retroviral gene co-option identified in the deep branches, suggesting that retroviral gene co-option might have not been maintained for very long time periods. Moreover, we find co-opted retroviral genes are subject to different selection pressure, implying potentially diverse cellular functionality. Our study provides a comprehensive picture of co-opted retroviral genes during the evolution of vertebrates and has implications in understanding the ancient evolution of vertebrate–retrovirus interaction.
Source:
Frequent Retroviral Gene Co-option during the Evolution of Vertebrates | Molecular Biology and Evolution | Oxford Academic (oup.com)