Differentiation of follicular epithelium in polytrophic ovaries of Pieris napi (Lepidoptera: Pieridae)—how far to Drosophila model

Abstract

Lepidoptera together with its sister group Trichoptera belongs to the superorder Amphiesmenoptera, which is closely related to the Antliophora, comprising Diptera, Siphonaptera, and Mecoptera. In the lepidopteran Pieris napi , a representative of the family Pieridae, the ovaries typical of butterflies are polytrophic and consist of structural ovarian units termed ovarioles. Each ovariole is composed of a terminal filament, germarium, vitellarium, and ovariole stalk. The germarium houses developing germ cell clusters and somatic prefollicular and follicular cells. The significantly elongated vitellarium contains linearly arranged ovarian follicles in successive stages of oogenesis (previtellogenesis, vitellogenesis, and choriogenesis). Each follicle consists of an oocyte and seven nurse cells surrounded by follicular epithelium. During oogenesis, follicular cells diversify into five morphologically and functionally distinct subpopulations: (1) main body follicular cells (mbFC), (2) stretched cells (stFC), (3) posterior terminal cells (pFC), (4) centripetal cells (cpFC), and (5) interfollicular stalk cells (IFS). Centripetal cells are migratorily active and finally form the micropyle. Interfollicular stalk cells derive from mbFC as a result of mbFC intercalation. Differentiation and diversification of follicular cells in Pieris significantly differ from those described in Drosophila in the number of subpopulations and their origin and function during oogenesis.

Small body size of pseudoscorpions and a distinct architecture of the ovary: A step to miniaturization?

“…There is a clear tendency to reduce the number of gonads and/or the ducts and other organs of the reproductive sys tems. For instance, in insects, which commonly have paired ovaries and oviducts (Biliński, 1998;Büning, 1994;Garbiec & Kubrakiewicz, 2012;Mazurkiewicz Kania et al, 2019;Simiczyjew et al, 1998), un paired ovaries and oviducts have been reported in minute collem bolan species (Panina et al, 2019). In small or tiny chelicerates such as pseudoscorpions and some mites, the number of ovarian tubules is also significantly reduced, usually to one, compared to numerous and branched ovarian tubules in giant horseshoe crabs and large scorpions (reviewed in Dunlop, 2019).…”

Morphogenesis of the ovarian follicular epithelium during initial stages of embryogenesis of the viviparous earwig, Hemimerus talpoides

“…This intriguing, genetically regulated process leads to the formation of eight morphologically and functionally distinct subpopulations of cells that, after termination of yolk accumulation, participate in the formation of regionally specialized egg coverings (internal vitelline envelope and external chorion) termed collectively the eggshell. Diversification of the follicular cells has been also described in several other holometabolous and hemimetabolous insects, including non‐ Drosophila dipterans (gnats, snipe flies, and horse flies), lepidopterans (butterflies), neuropterans (lacewings), hymenopterans (parasitic wasps and wasps), mecopterans (scorpionflies), hemipterans (true bugs), mallophagans (bird‐lice), and plecopterans (stoneflies), for example, Tworzydlo, Jablonska, Kisiel, and Bilinski (), Jaglarz, Krzeminski, and Bilinski (), Jaglarz, Kubrakiewicz, and Bilinski (), Mazurkiewicz and Kubrakiewicz (), Garbiec and Kubrakiewicz (), and Mazurkiewicz‐Kania, Simiczyjew, and Jedrzejowska (). As a rule, the complexity of the eggshell of a given species depends on the number of the subpopulations of the follicular cells.…”

Quantitative models for building and growing fated small cell networks

“…Simple examples of four cell cysts (n = 2) are found in two types of clam shrimp, Cyzicus tetracerus and Lynceus brachyurus of different orders (Spinicaudata and Laevicaudata, respectively) [91], the scorpion fly Panorpa communis [92], and the bark lice Peripsocus phaeopterus and Stenopsocus stigmaticus [93]. Extending one round of division further are the whirligig beetles Gyrinus natator [94] and Dineutus nigrior [95], sheep ked Melophagus ovinus [96], and the majority of moths and butterflies in the order Lepidoptera [97][98][99][100][101][102]. A large portion of characterized cell cyst shapes in this class are those that contain 16 cells, as in Drosophila (figures 1b and 2d).…”