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Current Topics in Developmental Biology 2019The fate of future generations depends on a high-quality germ line. For a female to successfully produce offspring, her oocytes must be successfully specified and their... (Review)
Review
The fate of future generations depends on a high-quality germ line. For a female to successfully produce offspring, her oocytes must be successfully specified and their contents meticulously organized. Germ cells are specified by two general mechanisms: inductive and inherited. In the inductive mechanism, the primordial germ cells (PGCs) are induced by signals from the surrounding cells. In the inherited mechanism, PGCs are specified by passing localized germ plasm material from the oocyte to the future germ cells. The Balbiani body, a conserved oocyte aggregate, facilitates the organization of the oocyte into a polarized cell with discrete cytoplasmic domains, including localizing the germ plasm. In the mouse, the Balbiani body is implicated in oocyte survival, while in frogs and zebrafish the Balbiani body carries specific mRNAs to the vegetal pole. These asymmetric mRNAs form the foundation of the functionally polarized oocyte and play important roles in axial patterning and germ plasm formation of the embryo.
Topics: Animals; Cell Polarity; Chromosomal Puffs; Humans; Inheritance Patterns; Oocytes; RNA, Messenger; Vertebrates
PubMed: 31155356
DOI: 10.1016/bs.ctdb.2019.04.003 -
Arthropod Structure & Development Jul 2014In many animal species, germ cells are specified by maternally provided, often asymmetrically localized germ cell determinant, termed the germ plasm. It has been shown... (Review)
Review
In many animal species, germ cells are specified by maternally provided, often asymmetrically localized germ cell determinant, termed the germ plasm. It has been shown that in model organisms such as Xenopus laevis, Danio rerio and Drosophila melanogaster germ plasm components (various proteins, mRNAs and mitochondria) are delivered to the proper position within the egg cell by germline specific organelles, i.e. Balbiani bodies, nuage accumulations and/or sponge bodies. In the present article, we review the current knowledge on morphology, molecular composition and functioning of these organelles in main lineages of arthropods and different ovary types on the backdrop of data derived from the studies of the model vertebrate species.
Topics: Animals; Arthropods; Female; Germ Cells; Ovary
PubMed: 24398038
DOI: 10.1016/j.asd.2013.12.003 -
Cell Cycle (Georgetown, Tex.) Jan 2017
Topics: Amyloid; Animals; Chromosomal Puffs; Mitochondria; Models, Biological; Oocytes; Oogenesis; Xenopus; Xenopus Proteins
PubMed: 27736303
DOI: 10.1080/15384101.2016.1241605 -
Journal of Assisted Reproduction and... Nov 2017Early oocytes of nearly all animal species contain a transient organelle assemblage termed the Balbiani body. Structure and composition of this assemblage may vary even... (Review)
Review
Early oocytes of nearly all animal species contain a transient organelle assemblage termed the Balbiani body. Structure and composition of this assemblage may vary even between closely related species. Despite this variability, the Balbiani body always comprises of numerous tightly clustered mitochondria and accumulations of nuage material. It has been suggested that the Balbiani body is an evolutionarily ancestral structure, which plays a role in various processes such as the localization of organelles and macromolecules to the germ plasm, lipidogenesis, as well as the selection/elimination of dysfunctional mitochondria from female germline cells. We suggest that the selection/elimination of mitochondria is a primary and evolutionarily ancestral function of Balbiani body, and that the other functions are secondary, evolutionarily derived additions. We propose a simple model explaining the role of the Balbiani body in the selection of mitochondria, i.e., in the mitochondrial DNA (mtDNA) bottleneck phenomenon.
Topics: Animals; Cytoplasm; DNA, Mitochondrial; Female; Germ Cells; Humans; Mitochondria; Oocytes; Oogenesis
PubMed: 28755153
DOI: 10.1007/s10815-017-1006-3 -
Methods in Molecular Biology (Clifton,... 2019Approaches to visualize the Balbiani body of zebrafish primary oocytes using protein, RNA, and mitochondrial markers are described. The method involves isolation,...
Approaches to visualize the Balbiani body of zebrafish primary oocytes using protein, RNA, and mitochondrial markers are described. The method involves isolation, histology, staining, and microscopic examination of early zebrafish oocytes. These techniques can be applied to visualize gene products that are localized to the Balbiani body, and when applied to mutants can be used to decipher molecular and genetic pathways acting in Balbiani body development in early oocytes.
Topics: Animals; Biomarkers; Endoplasmic Reticulum; Female; Fluorescent Antibody Technique; Immunohistochemistry; In Situ Hybridization; Mitochondria; Molecular Imaging; Oocytes; Oogenesis; RNA; Zebrafish
PubMed: 30737697
DOI: 10.1007/978-1-4939-9009-2_16 -
Journal of Fish Biology May 2022The Balbiani body (Bb) was examined in primary growth phase oocytes for the first time in two clupeoid fish species, the Mediterranean sardine, Sardina pilchardus, and...
The Balbiani body (Bb) was examined in primary growth phase oocytes for the first time in two clupeoid fish species, the Mediterranean sardine, Sardina pilchardus, and the European anchovy, Engraulis encrasicolus, which belong to different families, Clupeidae and Engraulidae, respectively. Cytoplasmic morphological changes of early secondary growth oocytes were also investigated using confocal laser scanning microscopy, light and transmission electron microscopy. The ultrastructural observations showed that the two species develop a distinct spherical Bb. However, differences in the cytoplasm, mainly in the perinuclear area, were observed. Briefly, in sardine the Bb coexists with a thick perinuclear ring containing mitochondria, nuage, endoplasmic reticulum and small vesicles, while in anchovy this perinuclear ring is thinner, consisting of complexes of nuage and mitochondria. After the disassembly of the Bb, a prominent cytoplasmic zonation develops in the secondary growth oocytes of sardine and anchovy, although with different organelle distribution between the two species. Sardine oocytes exhibit a thick zone of endoplasmic reticulum around the nucleus, whereas in those of anchovy, a thick mitochondria-rich ring surrounding the nucleus was observed. The cytoplasmic characteristics, such as the perinuclear ring in primary oocytes in sardine and the mitochondria-rich ring of early secondary oocytes in anchovy, are also discernible in histological sections by standard procedures and could thus be used as indicators of maturity or imminent spawning period in routine light microscopy observations, providing a valuable tool for applied fisheries biology.
Topics: Animals; Cell Nucleus; Cytoplasm; Fishes; Oocytes; Oogenesis
PubMed: 35244939
DOI: 10.1111/jfb.15032 -
MicroPublication Biology 2023Dormant human oocytes contain a perinuclear super-organelle, called the Balbiani Body, which is not present in mature oocytes. Here, we use confocal imaging to visualize...
Dormant human oocytes contain a perinuclear super-organelle, called the Balbiani Body, which is not present in mature oocytes. Here, we use confocal imaging to visualize two Balbiani Body markers-mitochondria and the DEAD-box helicase DDX4-in preantral follicles isolated from a 20-year-old female patient. In primordial follicles, mitochondria were concentrated in a ring near the oocyte nucleus, while DDX4 formed adjacent micron-scale spherical condensates. In primary and secondary follicles, the mitochondria were dispersed throughout the oocyte cytoplasm, and large DDX4 condensates were not visible. Our data suggest that the Balbiani Body breaks down during the primordial to primary follicle transition, thus releasing mitochondria and soluble DDX4 protein into the oocyte cytoplasm.
PubMed: 37920272
DOI: 10.17912/micropub.biology.000989 -
Current Topics in Developmental Biology 2004
Review
Topics: Animals; Biological Evolution; Cytoplasm; Cytoplasmic Structures; Germ Cells; Mitochondria; Oocytes; Oogenesis; RNA
PubMed: 14975245
DOI: 10.1016/S0070-2153(04)59001-4 -
Cell Jul 2022Mouse germline cysts, on average, develop into six oocytes supported by 24 nurse cells that transfer cytoplasm and organelles to generate a Balbiani body. We showed that...
Mouse germline cysts, on average, develop into six oocytes supported by 24 nurse cells that transfer cytoplasm and organelles to generate a Balbiani body. We showed that between E14.5 and P5, cysts periodically activate some nurse cells to begin cytoplasmic transfer, which causes them to shrink and turnover within 2 days. Nurse cells die by a programmed cell death (PCD) pathway involving acidification, similar to Drosophila nurse cells, and only infrequently by apoptosis. Prior to initiating transfer, nurse cells co-cluster by scRNA-seq with their pro-oocyte sisters, but during their final 2 days, they cluster separately. The genes promoting oocyte development and nurse cell PCD are upregulated, whereas the genes that repress transfer, such as Tex14, and oocyte factors, such as Nobox and Lhx8, are under-expressed. The transferred nurse cell centrosomes build a cytocentrum that establishes a large microtubule aster in the primordial oocyte that organizes the Balbiani body, defining the earliest oocyte polarity.
Topics: Animals; Apoptosis; Cell Enlargement; Cell Lineage; Cysts; Cytoplasm; Drosophila melanogaster; Female; Gene Expression Regulation, Developmental; Mice; Oocytes; Ovary
PubMed: 35623357
DOI: 10.1016/j.cell.2022.05.001 -
Genes Jan 2020The most important role of mitochondria is to supply cells with metabolic energy in the form of adenosine triphosphate (ATP). As synthesis of ATP molecules is... (Review)
Review
The most important role of mitochondria is to supply cells with metabolic energy in the form of adenosine triphosphate (ATP). As synthesis of ATP molecules is accompanied by the generation of reactive oxygen species (ROS), mitochondrial DNA (mtDNA) is highly vulnerable to impairment and, consequently, accumulation of deleterious mutations. In most animals, mitochondria are transmitted to the next generation maternally, i.e., exclusively from female germline cells (oocytes and eggs). It has been suggested, in this context, that a specialized mechanism must operate in the developing oocytes enabling escape from the impairment and subsequent transmission of accurate (devoid of mutations) mtDNA from one generation to the next. Literature survey suggest that two distinct and irreplaceable pathways of mitochondria transmission may be operational in various animal lineages. In some taxa, the mitochondria are apparently selected: functional mitochondria with high inner membrane potential are transferred to the cells of the embryo, whereas those with low membrane potential (overloaded with mutations in mtDNA) are eliminated by mitophagy. In other species, the respiratory activity of germline mitochondria is suppressed and ROS production alleviated leading to the same final effect, i.e., transmission of undamaged mitochondria to offspring, via an entirely different route.
Topics: Animals; DNA, Mitochondrial; Female; Mitochondria; Mitophagy; Mutation; Oocytes; Oogenesis
PubMed: 31963356
DOI: 10.3390/genes11010104