Germ cell cluster in the panoistic ovary of Thysanoptera (Insecta)

Pritsch, Michael; Büning, Jürgen

doi:10.1007/bf00312163

Cited by 39 publications

(16 citation statements)

References 18 publications

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“…Neopanoistic ovaries have also been demonstrated in representatives of other insect orders, e.g. Thysanoptera (Pritsch and Büning 1989), Siphonaptera (Büning 1994; Simiczyjew et al . 1998b), and Megaloptera (Szymańska et al.…”

Section: Discussionmentioning

confidence: 97%

“…There, proliferating germ cells initially form clusters by incomplete cytokineses. Later during differentiation, however, these clusters are split into single cells and eventually panoistic ovarioles are formed (Pritsch and Büning 1989). If this is also the case in the ovarioles of Boreus the mode of the germ cell differentiation needs elucidation.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Structure of the ovary in Nannochorista neotropica Navás (Insecta: Mecoptera: Nannochoristidae) with remarks on mecopteran phylogeny

Simiczyjew

2002

Acta Zoologica

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Preliminary histological analysis showed that the ovaries in Nannochorista neotropica are composed of numerous ovarioles of panoistic type. In the ovaries of adult females each ovariole consists of a terminal filament, vitellarium and pedicle while a germarium is absent. Morphological observations supported by simple histochemical tests revealed the presence of multiple nucleoli in the oocyte nucleus. The appearance of multiple nucleoli suggests that the extrachromosomal amplification of ribosomal DNA may take place in the oocytes of Nannochorista. The results show that in the structure of the ovariole and the course of oogenesis nannochoristids share noteworthy derived features with boreids, but differ significantly from all other mecopterans. These findings indicate the possible monophyly of an assemblage comprising the Nannomecoptera, Neomecoptera and Siphonaptera.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Structure of the ovary in Nannochorista neotropica Navás (Insecta: Mecoptera: Nannochoristidae) with remarks on mecopteran phylogeny

Simiczyjew

2002

Acta Zoologica

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“…1j). Such an organization of the nucleoli has been observed in panoistic ovaries of several hemimetabolous insects (e.g., Pritsch and Buning 1989; Rosciszewska and Soldan 1999). It is usually believed that it reflects high transcriptional activity of ribosomal genes (rDNA).…”

Section: Resultsmentioning

confidence: 56%

Meiosis, Balbiani body and early asymmetry of Thermobia oocyte

et al. 2016

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The meiotic division guarantees maintenance of a genetic diversity; it consists of several stages, with prophase I being the longest and the most complex. We decided to follow the course of initial stages of meiotic division in ovaries of Thermobia domestica using modified techniques of squash preparations, semithin sections, and electron microscopy. We show that germaria contain numerous germline cells that can be classified into three categories: cystoblasts, meiotic oocytes, and growing previtellogenic oocytes. The cystoblasts are located most apically. The meiotic oocytes occupy the middle part of the germarium, and the previtellogenic oocytes can be found in the most basal part, near the vitellarium. Analyses of the semithin sections and squash preparations show that post leptotene meiotic chromosomes gather in one region of the nucleoplasm where they form the so-called bouquet. The telomeres of the bouquet chromosomes are attached to a relatively small area (segment) of the nuclear envelope. Next to this envelope segment, the nucleolar organizers are also located. We show that in concert to sequential changes inside the oocyte nuclei, rearrangement of organelles within the ooplasm (oocyte cytoplasm) takes place. This leads to the formation of the Balbiani body and consequent asymmetry of the ooplasm. These early nuclear and cytoplasmic asymmetries, however, are transient. During diplotene, the chromosome bouquet disappears, while the Balbiani body gradually disperses throughout the ooplasm. Finally, our observations indicate the presence of lampbrush chromosomes in the nuclei of previtellogenic oocytes. In the close vicinity to lampbrush chromosomes, characteristic spherical nuclear bodies are present.

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“…This implies that oocyte development does not always require intercellular bridges to aid cytoplasmic transport from nurse cells. Yet curiously, in several species with panoistic ovaries, mitotic germ cells are interconnected with cytoplasmic bridges, followed by separation of individual germ cells, each of which become an oocyte [53–56]. …”

Section: Evolution Of Germ Cell Connectivity: Nursing Mechanism Does mentioning

confidence: 99%

Stay Connected: A Germ Cell Strategy

Jensen

Lei

et al. 2017

Trends in Genetics

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Germ cells develop as a cyst of interconnected sibling cells in a broad range of organisms in both sexes. A well-established function of intercellular connectivity is to transport cytoplasmic materials from ‘nurse’ cells to oocytes, a critical process for developing functional oocytes in ovaries of many species. However, there are situations where connectivity exists without a nursing mechanism, and the biological meaning of such connectivity remains obscure. In this review, we summarize the current knowledge on the formation of intercellular connectivity, and discuss its meaning by visiting multiple examples of germ cell connectivity observed in evolutionarily distant species.

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Germ cell cluster in the panoistic ovary of Thysanoptera (Insecta)

Cited by 39 publications

References 18 publications

Structure of the ovary in Nannochorista neotropica Navás (Insecta: Mecoptera: Nannochoristidae) with remarks on mecopteran phylogeny

Structure of the ovary in Nannochorista neotropica Navás (Insecta: Mecoptera: Nannochoristidae) with remarks on mecopteran phylogeny

Meiosis, Balbiani body and early asymmetry of Thermobia oocyte

Stay Connected: A Germ Cell Strategy

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