A PCR/restriction digestion assay for the detection of the transcript variants 1 and 2 of POU5F1.
POU5F1 has two alternatively spliced transcripts: a long (variant 1, NM_002701) and a short (variant 2, NM_203289) transcript. Only variant 1 is a key regulator of pluripotency. Hence, it is important to be able to distinguish this transcript from variant 2 and from the many pseudogenes present in the genome. Previous studies on the expression of POU5F1 were, however, usually carried out without considering the existence of the two transcripts and the pseudogenes which could be the source of false positive RT-PCR amplification. Here, we establish an RT-PCR/restriction digestion analysis to distinguish variant 1 of POU5F1 from variant 2 and all its currently known pseudogenes. Variant 1 has ApaI and Tsp45I restriction sites, which are not present in the pseudogenes or in variant 2. Thus, ApaI- and Tsp45I- digestions of POU5F1 PCR fragment, amplified with primers flanking these sites, are sufficient to identify the true variant 1 of POU5F1. To study the expression of variant 2 of POU5F1, two forward primers in the 5'-region that are not present in variant 1 were combined with reverse primers located in exon 3 of POU5F1 common to both transcripts. The assay was applied on 10 samples from peripheral blood leukocytes and commercially available ready-cDNAs from leukocytes and testis. We found that only variant 2 was expressed in leukocytes and testis and that the extracted RNA was not completely DNA free, despite DNAse treatment. This trace amount of DNA is a source of false positive RT-PCR amplifications. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.
Panagopoulos
Ioannis
I
Department of Clinical Genetics, Lund University Hospital, SE-221 85 Lund, Sweden. ioannis.panagopoulos@med.lu.se
Möller
Emely
E
Isaksson
Margareth
M
Mertens
Fredrik
F
D000293:Adolescent; D000328:Adult; D017398:Alternative Splicing; D016477:Artifacts; D001483:Base Sequence; D004247:DNA / Q000032:analysis; D004407:Dysgerminoma / Q000378:metabolism; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D050814:Octamer Transcription Factor-3 / Q000032:analysis* / Q000235:genetics; D010051:Ovarian Neoplasms / Q000378:metabolism; D012150:Polymorphism, Restriction Fragment Length; D020033:Protein Isoforms / Q000032:analysis* / Q000235:genetics; D011544:Pseudogenes; D012333:RNA, Messenger / Q000235:genetics* / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013737:Testis / Q000378:metabolism
D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D020033:Protein Isoforms; D012333:RNA, Messenger; D004247:DNA