If they are so sure they are different, why don't they put out a press release or at least post something on their website? Putting it as a note on Facebook just seems odd and it is not very well written. I just don't get it. Even if some of their findings are inconsistent with DeFreitas et. al.'s findings it seems to early to say with such conviction that they are different. Presumably technology was very different 20 years ago and maybe DeFreitas was wrong about certain assertions made about the virus size, etc.
It was probably written by Andrea Whittemore whos been sick a long time -- she doesnt have a scientific background in any case, I believe.
Be kind of odd to make a press release about it, because it would be natural to scientists to see it isnt the same. DeFreitas' PCR and DNA probes both depend on pretty specific DNA-DNA binding. I am almost sure XMRV's DNA is too different to cross react with HTLV-2 DNA in this way, nor should it cross react serologically. HTLV is not a gammaretrovirus, it is a pretty different varmint.
Heres a BLAST alignment showing that one of DeFreitas' sequences is very different from XMRV. I hope I did this correctly.
This first one is a perfect match to HTLV-II, because DeFreitas took her sequence from known HTLV-II sequences. This match has a one in one billion chance of occurring in a random DNA sequence equally long as HTLV-II's genome. The letters at the bottom show the nucleotides from the query vs the nucleotides of the HTLV-II genome. The little bars are supposed to signify the match of each position, but they are out of alignment because of a change of fonts.
>gb|AF326584.1| Human T-cell lymphotropic virus type 2 strain k96, complete proviral
genome
Length=8955
Score = 52.0 bits (26), Expect = 1e-09
Identities = 26/26 (100%), Gaps = 0/26 (0%)
Strand=Plus/Plus
Query 1 GTCTCCCCTAGCGCCCCCGCCGCCCC 26
||||||||||||||||||||||||||
Sbjct 1084 GTCTCCCCTAGCGCCCCCGCCGCCCC 1109
And heres the top match for XMRV, not so great at all. An eleven-nucleotide match this "good" or better has a 0.51 or 51% chance of occurring by chance in *any* random sequence 8200 nucleotides long (the length of XMRV's genome):
>gb|EU981609.1| Homo sapiens isolate day3_459_1 Xenotropic MuLV-related virus
integration site
Length=184
Score = 22.3 bits (11), Expect = 0.51
Identities = 11/11 (100%), Gaps = 0/11 (0%)
Strand=Plus/Plus
Query 5 CCCCTAGCGCC 15
|||||||||||
Sbjct 141 CCCCTAGCGCC 151