What is this nonsense?
How am I supposed to have a blog titled ‘ERV’, crowing on about how awesome and special endogenous retroviruses are, when scientists keep friggen unearthing endogenous NON-retroviruses.
First there were Borna disease viruses.
Then there were filoviruses.
Then there were hepadnaviruses.
And NOW, NOW there are endogenous parvoviruses:
Im sure almost all of you have heard the term ‘parvo’ or ‘parvo virus’. Its a disease that ravages pets worldwide (the puppy I had when I was little got parvo, and luckily lived through it to be my best friend for 13 years).
But as I frequently do on ERV, I have to point out that not all viruses in this family are ‘bad’. The adeno-associated viruses I have talked about several times before are in the ‘parvo’ family (evolution in gene therapy, evolution in gene therapy for neurodegenerative diseases, viruses giving blind kids the ability to see). One interesting feature of these adeno-associated viruses is that even though they are not retroviruses, the do predictably insert in the same location (a specific region on Chromosome 19) in human cells. Unlike retroviruses, whose insertion is random. And, all viruses in this family must replicate in the cell nucleus and have a double-stranded DNA stage in their life-cycle (unlike some of the other endogenous non-retroviruses).
So its not entirely surprising we have now found endogenous parvoviruses.
But its still cool ?
In this particular paper, they characterized an endogenous parvovirus in rats. Its in Chromosome 5. About 30 million years old. They couldnt find evidence that this virus was being transcribed in any rat tissue (JUUUUUUNK!!!).
They also combed through the gene database looking for parvoviruses in other organisms. Apparently, theyre everywhere: “rat, opossum, wallaby, guinea pig, hedgehog, armadillo, American pika, elephant, rabbit, horse, puffer fish and in some invertebrates including drosophila and pea aphid”.
I know you all are waiting for the punchline– how do these new endogenous parvoviruses bode for common descent?
Nucleotide alignment of the homologous chromosome in mouse, human, dog showed this region to be non-conserved among these species.
NOOO! THE TRUTH HAS COME OUT!!! EVILUTION IS A LIIIIIIIIIIE!!!!! AAAAAAAAAAARRRRRRGGG IM MELTING! MEEEEEEEELTINGGGGG!!!!!
Well, no. These are just ‘young’ insertions. Mice have one too, but its in a different location, and the endogenous virus looks nothing like the endogenous virus in rats:
Although mouse and rat are the most closely related species in which EnPVs were found, the mouse EnPV was genetically closest to members of Dependovirus genus, in contrast to the rat EnPV (genetically closest to members of Parvovirus genus).
If scientists keep this up, Im going to have to change the name of this blog to ‘ERV and friends’ or ‘ERV Starship’ *grumblegrumble*…