Intercellular bridges coordinate the transition from pluripotency to meiosis in mouse fetal oocytes

“…Although recently developed imaging and tissue clearing methods have advanced the study of meiotic initiation in mice (Soygur et al, 2021), our understanding of early development of female germ cells in humans is largely based on cytological (Baker, 1963; Manotaya & Potter, 1963), histological (Bendsen, Byskov, Andersen, & Westergaard, 2006; Kurilo, 1981), and electron microscopy techniques (Gondos, Bhiraleus, & Hobel, 1971; Gondos, Westergaard, & Byskov, 1986). Chromosomal and light microscopic analyses revealed the presence of preleptotene stage germ cells that are characterized by dense chromosome masses in human ovaries from as early as 9-10 weeks of fetal development (fetal age; FA) (Bendsen et al, 2006; Gondos et al, 1986).…”