We previously demonstrated that an Sp1-dependent reporter gene is preferentially expressed in G2 of the 1-cell mouse embryo following microinjection of the male pronucleus when compared to microinjection of the female pronucleus (P.T. Ram and R.M. Schultz, 1993, Dev. Biol. 156, 552-556). We also noted that expression of the reporter gene is not observed following microinjection of the germinal ...

Cytoskeletal organization is central to establishing cell polarity in various cellular contexts, including during messenger ribonucleic acid sorting in Drosophila melanogaster oocytes by microtubule (MT)-dependent molecular motors. However, MT organization and dynamics remain controversial in the oocyte. In this paper, we use rapid multichannel live-cell imaging with novel image analysis, track...

Drosophila bicoid mRNA is synthesized in the nurse cells and transported to the oocyte where microtubules and Exuperantia protein mediate localization to the anterior pole. Fluorescent bicoid mRNA injected into the oocyte displays nonpolar microtubule-dependent transport to the closest cortical surface, and the oocyte microtubule cytoskeleton lacks clear axial asymmetry. Nonetheless, bicoid mRN...

The occurrence of a negative energy balance (NEB) and concurrent metabolic changes may be responsible for impaired reproductive performance. A characteristic metabolic feature of NEB is the mobilization of body fat, reflected in an increased plasma non-esterified fatty acids (NEFA) concentration. High plasma concentration of NEFA is reflected in elevated NEFA follicular concentrations. The aim ...

Transcription factors in the germline play important roles in ovary formation and folliculogenesis, and control both oocyte development and somatic cell function. Factor in the germline (Figla) and newborn ovary homeobox gene (Nobox) represent a growing number of oocyte-specific transcription factors that regulate genes unique to oocytes. Studies on oocyte-specific transcription factors are imp...

Vertebrate eggs arrest at metaphase of the second meiotic division before fertilization under the effect of a cytostatic factor (CSF). This arrest is established during oocyte maturation by the MAPK kinase module, comprised of Mos, MEK, MAPKs and p90. Maintenance of CSF arrest at metaphase requires inhibitors of the anaphase-promoting complex (APC) like Emi1, which sequesters the APC activator ...

In most species, the meiotic cell cycle is arrested at the transition between prophase and metaphase through unclear somatic signals. Activation of the Cdc2-kinase component of maturation promoting factor (MPF) triggers germinal vesicle breakdown after the luteinizing hormone (LH) surge and reentry into the meiotic cell cycle. Although high levels of cAMP and activation of protein kinase A (PKA...

Establishment of anterior-posterior and dorsal-ventral polarity within the Drosophila egg chamber requires signaling between the germline and the somatic cells of the ovary. The gene gurken (grk) encodes a TGFalpha-like protein that is localized within the developing oocyte and is thought to locally activate torpedo/Egfr (top/Egfr), the Drosophila homolog of the EGF receptor, which is expressed...