Such a simple question but I got really confused. There are several papers out there talking about H2A.Z1 and H2A.Z2 (although I have seen some papers mentioning in introduction that H2A.Z is encoded by a single gene in mammals) but when I go to the ncbi gene database or to the UCSC genome browser, I can only find one gene. I would be very grateful if somebody has some insights about it.
It is possible that one gene codes for two different isoforms. You have to check for alternative splicing/polyadenylation and translation products of the single gene from genome browser.
Thanks for your reply! That's what I originally thought - that mentioned isoforms of H2A.Z might just come from alternative transcription/translation starts. But now I might have actually found the second H2A.Z gene, which is H2Afv (really confusing). It encodes a protein that is only few amino acids different from H2A.Z. And its sequence is referenced in a couple of H2A.Z papers. I am not 100% sure yet, though.
Actually, there is single gene and three protein coding transcripts in mice.
Check the link below:
http://www.ensembl.org/Mus_musculus/Gene/Summary?db=core;g=ENSMUSG00000037894;r=3:137864487-137866922
Thanks a lot for the link! have never really used the ensembl site before, it seems to summarise the gene info quite nicely.
there h2afv is listed as a paralogue, btw