The female reproductive system and oogenesis in Thulinius ruffoi (Tardigrada, Eutardigrada, Isohypsibiidae). (May 2019)

• Record Type: Journal Article
• Authors: Janelt, Kamil; Jezierska, Marta; Poprawa, Izabela
• Is Part Of: Arthropod structure & development. Volume 50(2019)
• Page Start: 53
• Page End: 63
• Publication Date: 2019-05
• Subjects: Tardigrades -- Ovary -- Oogenesis -- Ultrastructure; Arthropoda -- Morphology -- Periodicals; Arthropoda -- Anatomy -- Periodicals; Arthropoda -- Cytology -- Periodicals; Arthropods -- growth & development -- Periodicals; 595
• DOI: 10.1016/j.asd.2019.04.003
• Languages: English
• ISSNs: 1467-8039

Abstract

Abstract: In this study, we describe the female reproductive system organization and oogenesis in the eutardigrade Thulinius ruffoi . Light, confocal and electron microscopy was used in this study. During oogenesis, three phases can be distinguished: previtellogenesis, vitellogenesis, and choriogenesis. Germ-line cells form cell clusters in which the cells are connected by intercellular (cytoplasmic) bridges. These structures are crucial for delivering the yolk materials, macromolecules, ribosomes, and organelles to the developing oocyte. Vitellogenesis is of a mixed type. Autosynthesis and heterosynthesis of the yolk material occur. Yolk precursors that have been synthesized outside the ovary are delivered to the oocyte via endocytosis. We also present data on cortical granules, and moreover, we describe the cortical reaction in tardigrades, possibly for the first time. Highlights: The ovary of the tardigrade Thulinius ruffoi is of the meroistic polytrophic type. The germ cell clusters are branched. One cell in each cluster is the oocyte. The vitellogenesis is of the mixed type.