Mettl22-flox Mouse

Mettl22, or Methyltransferase-like 22, is a member of the methyltransferase-like (METTL) family. It functions as a non-histone lysine methyltransferase, methylating the DNA/RNA-binding protein Kin17 on lysine 135, which affects Kin17's association with chromatin [1]. Mettl22 is also involved in hematopoietic stem cell development [2].

In a functional genome-wide RNAi screen, Mettl22 was identified as a gene required for the differentiation of embryonic stem cells into hematopoietic stem/progenitor cells in vitro. In vivo validation in zebrafish confirmed it to be essential for hematopoietic stem/progenitor cell (HSPC) development and for maintenance of human HSCs [2]. Also, in the European sea bass, early exposure to elevated temperature led to an increase in the expression of Mettl22 in early differentiating female gonads, suggesting its role in epigenetic regulatory mechanisms related to sex differentiation [3].

In conclusion, Mettl22 plays crucial roles in hematopoietic stem cell development and potentially in epigenetic regulation during sex differentiation in fish. The discovery of its essentiality in HSPC development through in vitro and in vivo models like zebrafish provides valuable insights into stem cell-related biological processes and may have implications for regenerative medicine.