Previously it was shown that the Ets proteins, PU.1 and Spi-B, exhibit functional redundancy in B lymphocytes. To investigate the possibility that PU.1 or Spi-B or both share overlapping roles with Ets-1 or Elf-1, PU.1+/-Ets-1-/-, PU.1+/-Elf-1-/-, and Spi-B-/-ETS-1-/- animals were generated. No blood cell defects were observed in these animals except those previously reported for Ets-1-/- mice. Therefore, no genetic overlap was detected between PU.1 or Spi-B with Ets-1 or Elf-1. In contrast, the results confirmed functional redundancy for PU.1 and Spi-B in that PU.1+/-Spi-B-/- bone marrow progenitors yielded smaller colonies in methylcellulose cultures than did wild-type, PU.1+/- or Spi- B-/- progenitors. In addition, PU.1+/-Spi- B+/+, PU.1+/-Spi-B+/-, and PU.1+/- Spi-B-/- mice displayed extramedullary splenic hematopoiesis. In summary, PU.1 and Spi-B regulate common target genes required for proliferation of hematopoietic progenitors or their committed descendants, whereas Ets-1 or Elf-1 do not appear to regulate shared target genes with PU.1 or Spi-B.
ASJC Scopus subject areas
- Cell Biology