Forkhead transcription factors: key players in development and metabolism

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WHAT IS THE CORTEX?

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The Egg Cortex

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The Scope of This Review

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STORING INFORMATION AND BUILDING THE CORTEX DURING OOGENESIS

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Localizing Maternal Determinants in the Cortex

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Structuring and Positioning Information in the Cortex

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Cortical Polarity and Storage of Information in Other Oocytes

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The Cortex during Vitellogenesis

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MATURATION PREPARES THE CORTEX FOR FERTILIZATION

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Restructuring Cortical Endoplasmic Reticulum and Organelles during Maturation

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Restructuring the Cytoskeleton during Maturation

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Relocalization of Cortical mRNAs and Domains during Maturation

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The Cortex as the Site of Attachment and Fusion of Sperm and Egg

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FERTILIZATION TRANSFORMS THE EGG CORTEX

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Sperm-Induced Calcium Waves and Membranes

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Waves of Exocytosis and Endocytosis at Fertilization

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Fertilization-Induced Microfilament Reorganizations

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The Fertilized Egg Cortex

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WHAT THE CORTEX IS

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The Cortex as a Repository for Spatiotemporal Information

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The Questions That Remain

     

Fibroblast growth factors: key players in epithelial morphogenesis, repair and cytoprotection

Fibroblast growth factors (FGFs) regulate early development and organogenesis. In particular, a subfamily of FGFs is essential for the formation and differentiation of epithelial tissues and organs. Recent studies revealed a crucial role for these FGFs in repair of the skin, intestine and liver. In addition, the cytoprotective potential of FGFs suggests their use for the protection of epithelial cells under conditions of stress in vivo. Indeed, the first successful clinical trials using FGFs for the treatment of radiation- and chemotherapy-induced mucosal epithelial damage have been announced.     

Uterine leukocytes: key players in pregnancy

In species with hemochorial placentation, which includes humans, mice and rats, antigen-specific T and B lymphocytes which are responsible for acquired immunity are virtually absent from the maternal-fetal interface. In contrast, non-antigen specific natural killer cells and macrophages which provide innate immunity are abundant and highly specialized. Autocrine/paracrine factors such as steroid and polypeptide hormones, prostaglandins and anti-inflammatory cytokines that are present in the uterine environment during pregnancy re-program their secretory profiles. Recent studies using transgenic mice and other approaches indicate that these environmentally modified leukocytes have major pregnancy-associated functions that include facilitation of implantation, modulation of the maternal uterine vasculature, supply of growth factors to the placenta, promotion of trophoblast differentiation and facilitation of parturition.     

Caspases: key players in programmed cell death

Research in apoptosis has established a central role for caspases. The recent determination of structures of caspase-1, caspase-3 and caspase-8, together with biochemical studies, has greatly enhanced our understanding of the structure, function and specificity of these enzymes. This provides a basis for the further elucidation of the biological role of caspases and a guide to the design of selective inhibitors to treat caspase-mediated diseases.     

Argonaute proteins: key players in RNA silencing

During the past decade, small non-coding RNAs have rapidly emerged as important contributors to gene regulation. To carry out their biological functions, these small RNAs require a unique class of proteins called Argonautes. The discovery and our comprehension of this highly conserved protein family is closely linked to the study of RNA-based gene silencing mechanisms. With their functional domains, Argonaute proteins can bind small non-coding RNAs and control protein synthesis, affect messenger RNA stability and even participate in the production of a new class of small RNAs, Piwi-interacting RNAs.