Tight junctions between ovarian follicle cells in the teleost (Plecoglossus altivelis)

Toshimori, Kiyotaka; Yasuzumi, Fumioki

doi:10.1016/s0022-5320(79)80019-2

Cited by 17 publications

(9 citation statements)

References 28 publications

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“…A first monolayer of granulosa cells, directly attached to the zona radiata, is first surrounded by a thin basal lamina, and then by several more or less distinct theca cell layers. The zona radiata, which is the future egg shell or egg chorion, shows numerous tiny radial canals through which finger-like microvilli from the oocyte and from granulosa cells cross each other, linked by numerous "gap-junctions" [81,82]. Granulosa cells form a regular monolayer, but the morphology and functions of these cells may be somewhat different between the animal and vegetal poles [83].…”

Section: Ovary Ovarian Follicle and Oocytementioning

confidence: 99%

Particularities of reproduction and oogenesis in teleost fish compared to mammals

2005

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-Compared to mammals, teleost reproduction presents many original features. Reproductive strategies of species are diversified into numerous adaptations to a large variety of aquatic environments. This diversity may concern sexuality, spawning and parental behaviour, sensitivity to environmental factors, and specific features of gametogenesis such as the duration of vitellogenesis, and egg morphology. Sexuality presents a variety of natural modalities, from gonochorism to hermaphrodism. The absence of definitive arrest of body growth in the adult of most species gives a particular interest to the practical control of growth-reproduction interactions. Vitellogenesis, which represents an important metabolic effort for the maternal organism, involves the synthesis of vitellogenin, a specific glycolipo-phosphoprotein produced in the liver under estradiol stimulation, and its incorporation into oocytes by a receptor mediated process. Both estradiol synthesis in follicle cells and vtg uptake by vitellogenic follicles appear to be mainly controlled by FSH. Oocyte maturation is directly triggered by a progestin, or MIS (maturation inducing steroid) synthesised in follicle cells mainly under LH control, and acting through the non-genomic activation of a membrane receptor. Practical applications of some of these particularities result mainly from the external character of the fertilisation process and of embryonic development, which allows manipulating respectively egg chromosome stocks and sex differentiation. Moreover, the sensitivity of sex differentiation to exogenous factors favours the development of practical methods to control the sex of farmed populations. Finally, the sensitivity of reproductive mechanisms to xenobiotics has led to various kinds of bioassays for putative pollutants.reproductive strategies / sexuality / spawning / vitellogenesis / oocyte maturation / fertilisation

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Section: Ovary Ovarian Follicle and Oocytementioning

confidence: 99%

Particularities of reproduction and oogenesis in teleost fish compared to mammals

2005

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“…Particularly clear evidence for the existence of heterologous gap junctions between the oocyte and follicle cells has been provided by freeze-fracture replicas of the follicle in Plecoglossus altevelis (Toshimori and Yasuzumi, 1979) and B . rerio (Fig.…”

Section: Intercellular Junctionsmentioning

confidence: 99%

Ultrastructural aspects of oogenesis and oocyte growth in fish and amphibians

Wallace

Selman

1990

J. Elec. Microsc. Tech.

233

152

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Oogenesis, the early events of primary oocyte growth (meiotic arrest, synapsis, ribosomal gene duplication), and folliculogenesis can be seen to particular advantage in the germinal ridge of the syngnathan ovary. After budding off the germinal ridge (a compartment of the luminal epithelium), nascent follicles then enter into a linear array of developing follicles within which temporal and stage-specific events can be correlated with spatial distribution. Prominent features of the later phase of primary oocyte growth include intense transcriptional activity and the formation and subsequent dispersal of the Balbiani vitelline body (mitochondrial cloud) concomitant with an increase in cytoplasmic organelles and volume. Further oocyte growth is characterized by a period of cortical alveolus (in teleosts) or cortical granule (in anurans) formation, in which Golgi elements play a predominant role, and finally vitellogenesis. The latter process, which is responsible for the preponderance of oocyte growth, includes the hepatic synthesis and secretion of vitellogenin (VTG), the uptake of VTG from the bloodstream into the oocyte by receptor-mediated endocytosis, and the transport of VTG via endosomes and multivesicular bodies to forming yolk platelets. In the process, VTG is proteolytically cleaved into the yolk proteins, which assume either a monoclinic (in cyclostomes) or orthorhombic (in teleosts and amphibians) crystalline array. Other structures associated with the growing oocyte are also briefly discussed, including nuage, the vitelline envelope, intercellular junctions between the oocyte and overlying follicle cells, pigment, intramitochondrial crystals in ranidae, and annulate lamellae.

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“…In the Atlantic croaker (Micropogonias undulatus) [6,7] and the red sea bream (Pagrus major) [8], an increase in the number of GJs between granulosa cells and oocytes has been observed by electron microscopy during the acquisition of OMC. Additionally, in the ayu, the presence of gapjunction-like structures between granulosa cells and oocytes, and between granulosa cells themselves, has been confirmed by electron microscopy [9][10][11]. However, the detailed function of the GJs between granulosa cells and oocytes in the LH-induced acquisition of OMC has previously remained unclear.…”

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confidence: 90%

Heterologous Gap Junctions between Granulosa Cells and Oocytes in Ayu (Plecoglossus altivelis): Formation and Role during Luteinizing Hormone-dependent Acquisition of Oocyte Maturational Competence

Yamamoto

Yoshizaki

2008

J. Reprod. Dev.

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Abstract. Gap junctions (GJs) are intercellular channels. Molecules with a molecular weight of 1 kDa or less can pass back and forth between adjacent cells through GJs. Communication between oocytes and the somatic cells that surround them via GJs is known to play key roles to initiate oocyte maturation in many vertebrates. However, little is known of the detailed functions of ovarian GJs during oocyte maturation in fish. The oocyte maturation of fish is induced by a maturation-inducing steroid (MIS). The sensitivity of oocytes to the MIS is known as oocyte maturational competence (OMC) and is induced by luteinizing hormone (LH). However, LH receptors are found on the surface of granulosa cells rather than oocytes. We therefore proposed that the LH signals received by granulosa cells were passed to oocytes via GJs. This review describes current knowledge of the role of GJs between granulosa cells and oocytes during the LH-induced acquisition of OMC in fish. ammalian oocytes are surrounded by cumulus cells, and their maturation is induced by luteinizing hormone (LH) stimulation. By contrast, fish oocytes are surrounded by a layer of granulosa cells, a basement membrane, and a further layer of theca cells (Fig. 1). LH stimulates these two layers to produce a maturation-inducing steroid (MIS). Oocyte maturation is induced by direct stimulation from the MIS. In most fish, the MIS is thought to be either 17,20β, [1].Sensitivity of oocyte to MIS is known to be crucial for oocyte maturation in many teleost species including our model fish ayu (Plecoglossus altivelis). This sensitivity, which is known as oocyte maturational competence (OMC), is induced by LH [1,2] (Fig. 2). LH therefore has two important functions in oocyte maturation: inducing the acquisition of OMC by stimulating the oocytes, and inducing MIS synthesis by the follicle cells. LH-induced acquisition of OMC and the subsequent MIS-induced oocyte maturation are separate steps both physiologically and mechanistically [1,2]. We found that incubating ayu post-vitellogenic follicle-enclosed oocytes in a culture medium containing MIS did not induce oocyte maturation [3]. However, pre-treating the follicle-enclosed oocytes with a culture medium containing human chorionic gonadotropin (hCG), which is known to have an LH-like function, caused them to respond to MIS and induced oocyte maturation [3]. We therefore proposed that the ayu follicle-enclosed oocytes acquired OMC via LH stimulation. However, the LH receptors are localized on the surface of the follicle cells, and are not present on the oocytes themselves [4]. Therefore, the mechanism by which LH induces the acquisition of OMC in cells without receptors has previously remained unclear.Our research has focused on the channels known as gap junctions (GJs) that are formed between granulosa cells and oocytes. Ions and second-messenger molecules can pass freely through GJs by means of diffusion [5] (Fig. 1). In the Atlantic croaker (Micropogonias undulatus) [6,7] and the red sea bream (Pagrus major) [8], an in...

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Tight junctions between ovarian follicle cells in the teleost (Plecoglossus altivelis)

Cited by 17 publications

References 28 publications

Particularities of reproduction and oogenesis in teleost fish compared to mammals

Particularities of reproduction and oogenesis in teleost fish compared to mammals

Ultrastructural aspects of oogenesis and oocyte growth in fish and amphibians

Heterologous Gap Junctions between Granulosa Cells and Oocytes in Ayu (Plecoglossus altivelis): Formation and Role during Luteinizing Hormone-dependent Acquisition of Oocyte Maturational Competence

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