Dataset Information

Mother-to-embryo vitellogenin transport in a viviparous teleost Xenotoca eiseni.

ABSTRACT: Vitellogenin (Vtg), a yolk nutrient protein that is synthesized in the livers of female animals, and subsequently carried into the ovary, contributes to vitellogenesis in oviparous animals. Thus, Vtg levels are elevated during oogenesis. In contrast, Vtg proteins have been genetically lost in viviparous mammals, thus the yolk protein is not involved in their oogenesis and embryonic development. In this study, we identified Vtg protein in the livers of females during the gestation of the viviparous teleost, Xenotoca eiseni Although vitellogenesis is arrested during gestation, biochemical assays revealed that Vtg protein was present in ovarian tissues and lumen fluid. The Vtg protein was also detected in the trophotaeniae of the intraovarian embryo. Immunoelectron microscopy revealed that Vtg protein is absorbed into intracellular vesicles in the epithelial cells of the trophotaeniae. Furthermore, extraneous Vtg protein injected into the abdominal cavity of a pregnant female was subsequently detected in the trophotaeniae of the intraovarian embryo. Our data suggest that the yolk protein is one of the matrotrophic factors supplied from the mother to the intraovarian embryo during gestation in X. eiseni.

SUBMITTER: Iida A

PROVIDER: S-EPMC6825291 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

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Publications

Mother-to-embryo vitellogenin transport in a viviparous teleost <i>Xenotoca eiseni</i>.

Iida Atsuo A Arai Hiroyuki N HN Someya Yumiko Y Inokuchi Mayu M Onuma Takeshi A TA Yokoi Hayato H Suzuki Tohru T Hondo Eiichi E Sano Kaori K

Proceedings of the National Academy of Sciences of the United States of America 20191008 44

Vitellogenin (Vtg), a yolk nutrient protein that is synthesized in the livers of female animals, and subsequently carried into the ovary, contributes to vitellogenesis in oviparous animals. Thus, Vtg levels are elevated during oogenesis. In contrast, Vtg proteins have been genetically lost in viviparous mammals, thus the yolk protein is not involved in their oogenesis and embryonic development. In this study, we identified Vtg protein in the livers of females during the gestation of the viviparo ...[more]

PMID: 31594851

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Project description:When animals are previously exposed to two different visual stimuli simultaneously, their learning performance at discriminating those stimuli delays: such a phenomenon is known as "classifying-together" or "Bateson effect". However, the consistency of this phenomenon has not been wholly endorsed, especially considering the evidence collected in several vertebrates. The current study addressed whether a teleost fish, Xenotoca eiseni, was liable to the Bateson effect. Three experiments were designed, by handling the visual stimuli (i.e., a full red disk, an amputated red disk, a red cross) and the presence of an exposure phase, before performing a discriminative learning task (Exp. 1: full red disk vs. amputated red disk; Exp. 2: full red disk vs. red cross). In the exposure phase, three conditions per pairs of training stimuli were arranged: "congruence", where fish were exposed and trained to choose the same stimulus; "wide-incongruence", where fish were exposed to one stimulus and trained to choose the other one; "narrow-incongruence", where fish were exposed to both the stimuli and trained to choose one of them. In the absence of exposure (Exp. 3), the discrimination learning task was carried out to establish a baseline performance as regards the full red disk vs. amputated red disk, and the full red disk vs. red cross. Results showed that fish ran into retardation effects at learning when trained to choose a novel stimulus with respect to the one experienced during the exposure-phase (wide-incongruence condition), as well as after being simultaneously exposed to both stimuli (narrow-incongruence condition). Furthermore, there were no facilitation effects due to the congruence compared with the baseline: in such a case, familiar stimuli did not ease the performance at learning. The study provides the first evidence about the consistency of the classifying-together effect in a fish species, further highlighting the impact of visual similarities on discrimination processes.

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Dataset Information

Mother-to-embryo vitellogenin transport in a viviparous teleost Xenotoca eiseni.

Publications

Mother-to-embryo vitellogenin transport in a viviparous teleost <i>Xenotoca eiseni</i>.

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