-245 bp of 5'-flanking region from the human platelet factor 4 gene is sufficient to drive megakaryocyte-specific expression in vivo.
Platelet factor 4 (PF4) serves as a lineage-specific marker of megakaryocyte development. We previously identified two positively acting sequences in the human platelet factor 4 (hPF4) gene promoter that synergized to drive high-level luciferase reporter gene expression in vitro. Using portions of the hPF4 5'-flanking region linked to the lacZ reporter gene, we observed in this investigation that constructs with -245 bp of 5'-flanking region were more active than constructs with -2 kb of 5'-flanking region in vitro. We created two independent transgenic mouse lines with a -245-bp hPF4/lacZ construct. Cells from these mice were tested for beta-galactosidase (beta-gal) expression at the mRNA level by Northern blot and semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and at the protein level by immunohistochemistry assay. Mice from one line showed beta-gal expression specifically in all megakaryocytes of all ploidy classes from bone marrow and in platelets. Expression level was comparable to that driven by the 1.1-kb rat PF4 promoter in other transgenic mouse lines. Those in the second line showed no beta-gal expression in megakaryocytes, platelets, or any of the eight organs tested. The -245-bp hPF4 promoter is capable of driving reporter gene expression in a megakaryocyte-specific manner in transgenic mice. The small size of this megakaryocyte-specific promoter is compatible with that required in some viral vectors and may provide a model for targeting gene expression to megakaryocytes.
Cui
Z
Z
Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Reilly
M P
MP
Surrey
S
S
Schwartz
E
E
McKenzie
S E
SE
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D010978:Platelet Factor 4 / Q000235:genetics*; D051381:Rats; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion
D010978:Platelet Factor 4