In mammalian female reproduction, primordial follicles serve as stores to sustain the ovulation cycle. Regulations of primordial follicle development, activation, and dormancy in mice are summarized in a review by Nagamatsu (pp. 189–195). The importance of mechanical stress, especially extracellular matrix (ECM)-mediated pressure, for the maintenance of primordial follicle dormancy was recently demonstrated. Primordial follicles treated with collagenase, trypsin, and knockout serum replacement (KSR) (this mixture called CTK) to digest ECM were examined by immunohistochemistry. Ovaries treated solely with phosphate-buffered saline displayed primordial follicles composed of flat granulosa cells and complex stress fibers, as revealed by phalloidin. In contrast, CTK treatment resulted in fewer stress fibers and cuboidal-shaped granulosa cells, suggesting oocyte activation.
Recent studies suggested that a small sub-population of embryonic stem (ES) cells exhibit 2-cell stage embryo-like (2-cell-like) features, including the reactivation of murine endogenous retrovirus with leucin transfer RNA primer, high histone mobility, and dispersed chromocenters. Furuta et al. investigated the organelle morphology of 2-cell-like cells using electron microscopy (Furuta et al. Lipid droplets are formed in 2-cell-like cells. pp. 79–81). They demonstrated the formation of a lipid droplet during the transition from ES cells to 2-cell-like cells, and proposed that these cells utilize a unique energy storage and production pathway.
Previous reports suggested the involvement of alpha-tubulin N-acetyltransferase 1 (ATAT1) in flagella formation in spermatozoa; however, whether ATAT1 is expressed in flagella and involved in spermatozoa maturation and capacitation remains to be elucidated. Yanai et al. evaluated the expression of ATAT1 in the male reproductive system in mice using immunostaining and western blotting (Yanai et al. Expression and localization of alpha-tubulin N-acetyltransferase 1 in the reproductive system of male mice. pp. 59–66). The localization of ATAT1 protein in the male germline was detected during spermiogenesis as well as spermatozoa maturation. Therefore, these results suggest that ATAT1 might be involved not only in flagella formation, but also in the acetylation process during spermatozoa maturation and capacitation.
Green Fluorescent Protein as a Novel Vital Marker in Transgenic Mouse
Released: October 20, 2010 | Volume 43 Issue 6 Pages j19-j25
Masaru OKABE, Masahito IKAWA, Shuichi YAMADA, Tomoko NAKANISHI, Tadashi BABA
Mitochondrial reactive oxygen species regulate mitochondrial biogenesis in porcine embryos
Released: April 21, 2021 | Volume 67 Issue 2 Pages 141-147
Mio KAGEYAMA, Jun ITO, Koumei SHIRASUNA, Takehito KUWAYAMA, Hisataka IWATA
Adaptations for Brood Parasitism in Cuculus Cuckoos
Released: October 20, 2010 | Volume 41 Issue 6 Pages j127-j133
Follicular Growth and Atresia in Mammalian Ovaries: Regulation by Survival and Death of Granulosa Cells
Released: March 22, 2012 | Volume 58 Issue 1 Pages 44-50
Fuko MATSUDA, Naoko INOUE, Noboru MANABE, Satoshi OHKURA