Glucose absorption activity and gene expression of sugar transporters in the trophotaenia of the viviparous teleost Xenotoca eiseni

Atsuo Iida; Natsuho Tsuda; Junki Yoshida; Jumpei Nomura; Adisorn Ratanayotha; Takafumi Kawai; Eiichi Hondo

doi:10.1016/j.bbagen.2023.130464

Glucose absorption activity and gene expression of sugar transporters in the trophotaenia of the viviparous teleost Xenotoca eiseni

Biochim Biophys Acta Gen Subj. 2023 Nov;1867(11):130464. doi: 10.1016/j.bbagen.2023.130464. Epub 2023 Sep 16.

Authors

Atsuo Iida¹, Natsuho Tsuda², Junki Yoshida³, Jumpei Nomura³, Adisorn Ratanayotha⁴, Takafumi Kawai⁵, Eiichi Hondo⁶

Affiliations

¹ Department of Animal Sciences Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan; Department of Bioresource Sciences, School of Agricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan. Electronic address: tol2.4682@gmail.com.
² Department of Bioresource Sciences, School of Agricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan.
³ Department of Animal Sciences Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan.
⁴ Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkoknoi, Bangkok 10700, Thailand.
⁵ Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
⁶ Department of Animal Sciences Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan; Department of Bioresource Sciences, School of Agricultural Sciences, Nagoya University, Nagoya, Aichi 464-8602, Japan.

PMID: 37717926
DOI: 10.1016/j.bbagen.2023.130464

Abstract

In viviparous reproductive systems, nutrient transfer from mother to embryo plays a critical role in the generation of offspring. Herein, we investigated the mother-to-embryo nutrient transfer machinery in the viviparous teleost Xenotoca eiseni, which belongs to the family Goodeidae. The intraovarian embryo absorbs maternal supplements via the hindgut-derived placental structure termed the trophotaenia. Tracer analysis indicated that the trophotaenia can take up glucose analogs in ex vivo cultured embryos. The candidate genes for absorption, sglt1, glut2, atp1a, and atp1b, were determined from published transcriptomes. These genes were expressed in the trophotaenia of X. eiseni embryos. Fluorescent immunohistochemistry of Na⁺/K⁺ ATPase indicated the polarity of epithelial cells in the trophotaenia. The presented evidence suggests that the epithelial cell layer transports monosaccharides from the apical membrane of epithelial cells in a basolateral direction. Taken together, this study provides insight into how maternal fish maintain their offspring during gestation and will aid in the development of strategies to improve offspring generation in these fish.

Keywords: Glucose; Goodeidae; Transporter; Trophotaenia; Viviparity.