Effect of gap junction uncoupling in full-grown <i>Bufo arenarum</i> ovarian follicles: participation of cAMP in meiotic arrest

Villecco, Evelina I.; Aybar, Manuel J.; Genta, Susana B.; Sánchez, Sara S.; Riera, Alicia N. Sánchez

doi:10.1017/s0967199400000952

Cited by 13 publications

(17 citation statements)

References 25 publications

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“…Their closure appeared to inhibit the supply of MIS from the granulosa cells to the oocytes, and consequently induced the resumption of meiosis. A similar phenomenon was reported in the South American toad (Bufo arenarum), in which the oocytematuration process was triggered when the GJs were blocked (Villecco et al, 2000). Moreover, the disruption of GJs between oocytes and follicle cells is necessary for the LH-dependent resumption of oocyte meiosis in the ovarian follicles of mammals (for a review, see Dekel, 2005).…”

Section: Introductionsupporting

confidence: 60%

Differential expression and localization of four connexins in the ovary of the ayu (Plecoglossus Altivelis)

Yamamoto

Yoshizaki

Takeuchi

et al. 2007

Molecular Reproduction Devel

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The post-vitellogenic oocytes of teleost fish are generally unresponsive to maturation-inducing hormone (MIH) until a luteinizing hormone (LH) surge stimulates sensitivity via the acquisition of oocyte-maturational competence (OMC). Heterologous gap junctions (GJs) between granulosa cells and the oocyte have been previously implicated in the regulation of oocyte maturation in various vertebrate species. Although heterologous GJ are present in ovarian follicles of ayu (Plecoglossus altivelis), their role in maturation remains unclear. In the present study, we cloned and characterized complementary DNAs for GJ protein connexin (Cx), and examined the expression pattern of Cx messenger RNAs in the ayu ovary. Four Cx cDNAs with predicted molecular masses of 32.1 (Cx32.1), 34.9 (Cx34.9), 44.1 (Cx44.1), and 44.2 (Cx44.2) kDa, respectively, were cloned. Northern blot analysis revealed that the levels of Cx44.1 and Cx44.2 transcripts were similar during the vitellogenic and ovulatory stages. Cx32.1 transcripts were more abundant during the vitellogenic stage, but their levels declined thereafter. Cx34.9 transcript levels increased during the vitellogenic stage and remained high during the acquisition of OMC. In situ hybridization revealed that Cx44.1 and Cx44.2 signals were restricted to the oocyte, whereas the Cx32.1 and Cx34.9 signals were detected in both cellular fractions. Furthermore, a dye-transfer assay revealed the presence of functional GJs between the oocytes and follicle cells. These results suggest that Cx34.9 contributes to the formation of heterologous GJs between oocytes and granulosa cells. Moreover, GJs formed by Cx34.9 may function during the LH-dependent acquisition of OMC and the MIH-dependent resumption of meiosis in ayu.

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Section: Introductionsupporting

confidence: 60%

Differential expression and localization of four connexins in the ovary of the ayu (Plecoglossus Altivelis)

Yamamoto

Yoshizaki

Takeuchi

et al. 2007

Molecular Reproduction Devel

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“…Several investigators have proposed cAMP to be one of the molecules involved in meiotic arrest (Eppig & Downs, 1984; Tsafriri et al ., 1996; Chen et al ., 2009). In the anuran Bufo arenarum oocytes we demonstrated that cAMP exerts an inhibitory effect on the maturation induced by the uncoupling of gap junctions when oocytes are pretreated with octanol (Villecco et al ., 2000). However, there is no detailed information concerning cAMP participation during X. laevis vitellogenesis.…”

Section: Introductionmentioning

confidence: 99%

Involvement of cAMP and calmodulin in endocytic yolk uptake duringXenopus laevisoogenesis

Luque

Serrano

Mónaco

et al. 2011

Zygote

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The aim of the present study was to show the participation and physiological role of calmodulin (CaM) and cAMP during vitellogenin endocytic uptake in the amphibian Xenopus laevis. The results showed a differential distribution of CaM in the ovary follicles during oogenesis. The CaM intracellular localization was not affected by gap junction's downregulation and CaM inhibition did not completely abolished the endocytic activity of oocytes. We showed that cAMP was able to completely rescue the endocytic competence in follicles in which gap junctional communication had been disrupted by octanol. Moreover cAMP was capable of restoring oocyte endocytic capability in the presence of octanol and stelazine, a CaM inhibitor. We propose that, in Vtg uptake regulation, cAMP is upstream of CaM during the endocytic signalling pathway.

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“…This presumably represents the contribution from the oocyte to the vitelline envelope, as seen in the cytological manifestation of the accumulation of dense vesicles in its cytoplasm, as suggested to occur in Bufo arenarum by Cabada et al (1996). Participation of the follicular epithelium in the formation of vitelline envelope has been suggested by Wallace and Jared (1976) and Dumont and Brummett (1978) in X. laevis, by Cabada et al (1996) in B. arenarum, by Villecco et al (2000) in C. cranwelli and by Sretarugsa et al (2001) in R. tigrina.…”

Section: Discussionmentioning

confidence: 85%

“…These variations are attributable to the adaptational requirements of the species to the diverse environments in which they lay their eggs and thus secure their development (Guraya 1976(Guraya , 1979Del Pino et al 1986;Del Pino 1989;Villecco et al 1996Villecco et al , 1999Villecco et al , 2000Villecco et al , 2002Uribe 2001Uribe , 2003Sanchez and Villecco 2003;Exbrayat 2006). A definite number of primordial follicles are established in the embryo (Skinner 2005).…”

Section: Introductionmentioning

confidence: 99%

Stages in follicle cell/oocyte interface during vitellogenesis in caecilians Ichthyophis tricolor and Gegeneophis ramaswamii: a transmission electron-microscopic study

et al. 2007

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We describe the ultrastructural organization of the vitellogenic follicle stages in two caecilian species. Monthly samples of slices of ovary of Ichthyophis tricolor and Gegeneophis ramaswamii from the Western Ghats of India were subjected to transmission electron-microscopic analysis, with special attention to the follicle cell/oocyte interface. In order to maintain uniformity of the stages among the amphibians, all the stages in the caecilian follicles were assigned to stages I-VI, the vitellogenic and post-vitellogenic follicles being assigned to stages III-VI. Stage III commences with the appearance of precursors of vitelline envelope material in the perivitelline space. Stages IV and V have been assigned appropriate substages. During the transition of stage III to stage VI oocytes, a sequential change occurs in the manifestations of follicle cells, perivitelline space, vitelline envelope and oocyte cortex. The vitelline envelope becomes a tough coat through the tunnels of which the macrovilli pass to interdigitate between the microvilli. The oocyte surface forms pinocytic vesicles that develop into coated pits and, later, coated vesicles. Contributions of the oocyte cortex to the vitelline envelope and of the follicle cells to yolk material via synthesis within them are indicated. The follicle cell/oocyte interface of vitellogenic follicles of these two caecilians resembles that in anurans and urodeles, with certain features being unique to caecilians. Thus, this paper throws light on the possible relationships of caecilians to anurans and urodeles with special reference to ovarian follicles.

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Effect of gap junction uncoupling in full-grown Bufo arenarum ovarian follicles: participation of cAMP in meiotic arrest

Cited by 13 publications

References 25 publications

Differential expression and localization of four connexins in the ovary of the ayu (Plecoglossus Altivelis)

Differential expression and localization of four connexins in the ovary of the ayu (Plecoglossus Altivelis)

Involvement of cAMP and calmodulin in endocytic yolk uptake duringXenopus laevisoogenesis

Stages in follicle cell/oocyte interface during vitellogenesis in caecilians Ichthyophis tricolor and Gegeneophis ramaswamii: a transmission electron-microscopic study

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