The road to maturation: somatic cell interaction and self-organization of the mammalian oocyte

Abstract

Mammalian oocytes go through a long and complex developmental process while acquiring the competencies that are required for fertilization and embryogenesis. Recent advances in molecular genetics and quantitative live imaging reveal new insights into the molecular basis of the communication between the oocyte and ovarian somatic cells as well as the dynamic cytoskeleton-based events that drive each step along the pathway to maturity. Whereas self-organization of microtubules and motor proteins direct meiotic spindle assembly for achieving genome reduction, actin filaments are instrumental for spindle positioning and the establishment of oocyte polarity needed for extrusion of polar bodies. Meiotic chromatin provides key instructive signals while being 'chauffeured' by both cytoskeletal systems.

Role of gap junction-mediated communications in regulating large-scale chromatin configuration remodeling and embryonic developmental competence acquisition in fully grown bovine oocyte

“…Interestingly, the removal of cumulus cells altered the process of chromatin remodeling with different dynamics compared to 1-heptanol induced breakdown of communication. Since paracrine factors secreted by oocytes and somatic cells regulate many important aspects of early ovarian follicle development and oocyte growth [10,[25][26][27][28], we hypothesize that both paracrine and junctional mechanisms are involved in modulating large-scale chromatin configuration changes.…”

Characterization of multi-locus imprinting disturbances and underlying genetic defects in patients with chromosome 11p15.5 related imprinting disorders

“…Despite the identification of MLID causative mutations in members of the NLRP and zinc-finger protein families in few BWS/SRS patients [10,21,22], the role of these proteins in the imprinting process and the pattern of inheritance remain to be fully elucidated. A role for NLRP mutations in MLID was suggested based on the observation of shared hypomethylated loci between MLID and hydatiform mole [23]. In particular, NLRP7 mutations have been associated with the most severe form of MLID, the biparental hydatiform mole [24].…”

Sirt2‐BubR1 acetylation pathway mediates the effects of advanced maternal age on oocyte quality

“…Before acquiring the capabilities that are required for fertilization and embryogenesis, oocytes must go through a prolonged and complicated developmental process (Li & Albertini, 2013). Upon completion of early prophase I in which S‐phase and recombination are taking place in the fetal ovary, oocytes remain arrested in dictyotene stage with largely decondensed chromatin within the nucleus, termed “germinal vesicle” (germinal vesicle stage, GV) within primordial follicles up to decades in the human.…”