ABSTRACT
Germ cell-specific ATP-dependent RNA helicase, the product of the mouse vasa homolog (Mvh), has been shown to play an essential role in the development of the male germ cell. In male Mvh knockout mice, premeiotic germ cells arrest at the zygotene stage. To investigate the role of MVH protein in the progression of meiosis, we searched for genes encoding partners that interact with MVH in testicular germ cells. Using the yeast two-hybrid system, we found that MVH interacts with mouse RanBPM, a Ran-GTP binding protein involved in microtubule nucleation. RanBPM is predominantly expressed in the testis, especially in maturating spermatocytes. Within the cell, RanBPM and MVH are closely associated with perinuclear RNA-protein complexes and chromatoid bodies. The interaction of MVH with RanBPM points to a functional relationship between translational regulation and the microtubule nucleation during meiosis. Mol. Reprod. Dev. 66: 1-7, 2004.
Subject(s)
Germ Cells/enzymology , Meiosis/physiology , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , RNA Helicases/genetics , RNA Helicases/metabolism , ran GTP-Binding Protein/genetics , ran GTP-Binding Protein/metabolism , Adaptor Proteins, Signal Transducing , Amino Acid Sequence , Animals , Cytoskeletal Proteins , DEAD-box RNA Helicases , Humans , In Situ Hybridization , Male , Mice , Mice, Knockout , Microtubules/metabolism , Molecular Sequence Data , Nuclear Proteins/chemistry , Spermatogenesis/physiology , Testis/cytology , Testis/metabolism , Tissue Distribution , Two-Hybrid System Techniques , ran GTP-Binding Protein/chemistryABSTRACT
Knock-in embryonic stem (ES) cells, in which GFP or lacZ was expressed from the endogenous mouse vasa homolog (Mvh), which is specifically expressed in differentiating germ cells, were used to visualize germ cell production during in vitro differentiation. The appearance of MVH-positive germ cells depended on embryoid body formation and was greatly enhanced by the inductive effects of bone morphogenic protein 4-producing cells. The ES-derived MVH-positive cells could participate in spermatogenesis when transplanted into reconstituted testicular tubules, demonstrating that ES cells can produce functional germ cells in vitro. In vitro germ cell differentiation provides a paradigm for studying the molecular basis of germ line establishment, as well as for developing new approaches to reproductive engineering.
