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1

Diversification of follicular cells in the ovaries of the horse fly Haematopota italica (Diptera: Tabanidae). similarities and differences with the Drosophila Model System

100%
Jaglarz M. K., Jablonska A., Kisiel E., Bilinski S. M.
Folia Biologica
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2009
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vol. 57
|
issue 1-2
1-12
EN
In insect ovaries, germ line cells are surrounded by somatic cells that initially form a uniform follicular epithelium. The subsequent diversification of the follicular cells into several subpopulations enables specification of distinct structures in different regions of complex eggshells. It also influences the patterning of the future embryo. These processes have been extensively studied at both the cellular and molecular levels using the Drosophila ovary as a model system. It is not clear however, to what extent the Drosophila model of the follicular epithelium patterning is universal for the entire Diptera group. Here, we analyze the diversification of the follicular cells in a distant Drosophila relative, the horse fly, Haematopota italica. We found that in this species, there are 6 recognizably different follicular cell subpopulations within the previtellogenic ovarian follicles. Ultrastructural analysis of the follicular epithelium revealed two morphologically distinct clusters of follicular cells residing at the anterior and posterior poles of the follicles. Each cluster consists of 2-3 polar cells located centrally and surrounded by several outer cells called border cells (at the anterior pole) or border-like cells (at the posterior pole). During previtellogenesis, the clusters lose the initial symmetry as their cells differentiate and develop conspicuous cytoplasmic projections comprising cytoskeletal elements. Ultimately, the follicular cells of the anterior and posterior clusters become morphologically different and, as we suggest, participate in different processes during oogenesis and formation of the and, eggshell in H. italica.
2

Distribution of accessory nuclei in the oocytes of the sawfly, Athalia rosae (Hymenoptera: Tenthredinidae)

100%
Zawadzka M.
Folia Biologica
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1996
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vol. 44
61-66
EN
In the oocytes of Athalia rosae accessory nuclei (AN) arise in late previtellogenesis. Three categories of AN: large (LAN), medium (MAN), and small (SAN) can be distinguished. Distribution of AN along the anteroposterior and dorsoventral axes of the oocyte is uneven. In the previtellogenic and vitellogenic oocytes dorsoventral polarity is marked by an abundance of AN in the ventral ooplasm. Distribution of AN along anteroposterior axis depends on the stage of oogenesis. In this paper the possible mechanism responsible for the uneven distribution of AN is proposed and discussed.
3

Structure of the ovary and the differentiation of follicular epithelium in the pig louse, Haematopinus suis (Insecta: Phthiraptera)

100%
Zelazowska M.
|
EN
The female reproductive system of the pig louse, Haematopinus suis (Insecta: Phthiraptera) is composed of paired ovaries, lateral oviducts, and a common oviduct that leads into a vagina. Clusters of mycetocytes (= cells filled with symbiotic organisms) are associated with lateral oviducts. Each ovary is composed of five loosely arranged ovarioles of the polytrophic-meroistic type. An individual ovariole is covered by a basal lamina and is composed of a terminal filament, germarium, and vitellarium. The terminal filament is composed of large, disc-shaped cells that are orientated perpendicularly to the long axis of the ovariole. The basal part of the terminal filament is separated from the germarium by a well-developed transverse septum. The germarium is short and filled with clusters of oogonial cells. In each cluster the cells are joined by intercellular bridges, filled with fusomal material. Within the cluster, only one cell, the future oocyte, enters the prophase of the first meiotic division; the other cells differentiate into nurse cells. The basal part of the germarium is filled with the somatic prefollicular cells. The boundary between the germarium and the vitellarium is not distinct. The vitellarium contains linearly arranged ovarian follicles in subsequent stages of oogenesis (previtellogenesis, vitellogenesis and choriogenesis). Each follicle consists of an oocyte and 7 nurse cells and is surrounded by follicular cells. During oogenesis the follicular cells diversify, so that ultimately, five morphologically distinct subpopulations of these cells can be distinguished: (1) cells in contact with the nurse cells, (2) anterior cells, (3) mainbody cells, (4) posterior cells, and (5) interfollicular cells. Interestingly, the follicular cells associated with the anterior part of the oocyte, i.e. located in space at the oocyte/nurse cell border (fold cells) are mitotically active throughout previtellogenesis. It might be suggested, in this context, that the separation of the oocyte from the nurse cell compartment is brought about by mitotic divisions, consequent multiplication and centripetal migration of these cells.
4

Identification of synaptonemal complexes in postnatal oocytes from one-day-old puppies of domestic dog (Canis familiaris)

100%
Lechniak D., Sosnowski J., Witonski M.
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|
vol. 38
|
issue 4
477-479
EN
The present paper describes a synaptonemal complexes analysis carried out on oocytes collected from the ovaries of one-day-old puppies of domestic dog (Canis familiaris). Ovaries have been collected from 20 individuals altogether. Synaptonemal complexes were identified in oocytes originating from two puppies. It is concluded that the onset of canine female meiosis may occur earlier than previously reported.
5

Structure of ovaries and oogenesis in dermapterans. II. The nurse cells, nuage aggregates and sponge bodies

88%
Tworzydlo W., Kisiel E.
Folia Biologica
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2010
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vol. 58
|
issue 1-2
67-72
EN
In three studied dermapteran species, Doru lineare, Opisthocosmia silvestris and Forficula auricularia, ovarian follicles are composed of two cells only, the oocyte and a single nurse cell. The nuclei of the nurse cells are large, ameboid and contain highly active nucleoli. RER elements, ribosomes, mitochondria and electron-dense aggregations of nuage material are present in the cytoplasm. Immunolocalization analysis revealed that in earwigs the nuage does not contain snRNAs. In one of the studied species, Doru lineare, apart from .canonical. nuage aggregations, characteristic RER/nuage complexes were found. These structures are morphologically similar to the sponge bodies present in the cytoplasm of the Drosophila germline cells. We suggest that RER/nuage complexes in Doru, as sponge bodies in Drosophila, are implicated in mRNA translocation.
6

Oogenesis in Vimba vimba (L. 1758) from Drawienski National Park (NW Poland)

88%
Hliwa P., Femska-Zakes K., Martyniak A., Krol J.
Folia Biologica
|
2003
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vol. 51
|
issue 3-4
165-170
EN
The objective of the studies was to analyse the process of oogenesis in vimba from a non-migratory population living in the waters of Drawienski National Park in north-west Poland. The character of spawning of this species is an obstacle in determining the right moment to catch spawners or developing artificial spawning biotechniques. Previtellogenesis of vimba begins about six months after hatching and lasts three years. The trophoplasmatic growth of oocytes (October ? March/April) begins when carbohydrate vesicles appear near the nuclei oocytes of sexually mature females (aged 4+). Just before spawning, granulated, lipoprotein-like substances are cumulated. The resorption of pre-ovulation corpora lutea (non-ejected oocytes) and post-ovulation corpora lutea (ruptured theca folds and follicles) begins in the ovary of vimba in the middle of June. These were observed in histological cross sections for about two to three months. Describing the process of oogenesis can provide a foundation for developing practical applications in aquaculture aimed at preserving the biodiversity of the park?s waters and this critically endangered species of the Polish ichthyofauna.
7

The ovary of Neotituria kongosana (Hemiptera, Cicadomorpha: Ledridae). Ultrastructure of the tropharium and terminal filamen

88%
Lupa B., Kim J.-K., Bilinski S. M.
Folia Biologica
|
1999
|
vol. 47
|
issue 3-4
123-130
EN
Each of the 2 ovaries of Neotituria kongosana consists of 7 telotrophic ovarioles. Within the ovariole, the terminal filament, germarium, vitellarium, and pedicel can be distinguished. The terminal filaments are composed of disc-shaped basal cells and elongated apical cells, oriented parallel to the long ovariole axis. The apical and lateral aspects of the tropharium are encompassed by a single layer of somatic cells termed inner sheath cells. These cells are diversified into larger apical inner sheath cells (AISC) and much smaller lateral inner sheath cells (LISC). The tropharium is filled with numerous individual trophocytes (= nurse cells). All the trophocytes are surrounded by complete plasma membranes and are joined to a centrally located trophic core by means of narrow cytoplasmic extensions, termed trophic processes. The terminal filament is separated from the rest of the ovariole by a relatively solid transverse septum. It is suggested that the material constituting the septum is synthesized by 2 types of cell, namely the AISC and the basal cells of the terminal filament. Anagenesis of hemipteran ovarioles is discussed in relation to the findings presented.
8

Structure of ovaries and oogenesis in Corydalidae and Chauliodidae (Insecta, Megaloptera). I. Architecture of adult ovarioles and previtellogenesis

88%
Szymanska B., Kubrakiewicz J., Jankowska W., Bilinski S. M.
Folia Biologica
|
2001
|
vol. 49
|
issue 1-2
91-97
EN
The results of histological and EM studies on the ovaries of three representatives of Megaloptera: Chauliodes pectinicornis, Nigronia fasciata (Chauliodidae), and Corydalus peruvianus Corydalidae) are presented. It is shown that the ovaries of all 3 investigated species are panoistic (secondary panoistic, = neopanoistic) and consist of numerous (more than a hundred) ovarioles that are differentiated into 3 well-defined regions: the terminal filament, the germarium, and the vitellarium. The germaria of adult females are apparently non-functional and contain germ and somatic cells in various stages of degeneration. The vitellaria are composed of 12 ? 15 developing ovarian follicles (= oocytes surrounded by follicular cells) in a linear arrangement. In adult females these follicles can be classified into early previtellogenic, late previtellogenic, vitellogenic, and choriogenic. During early previtellogenesis oocyte nuclei (= germinal vesicles) contain single nucleolar masses. Histochemical analyses indicate that within the masses DNA as well as AgNOR proteins are present. During subsequent stages of the previtellogenic growth nucleolar masses gradually break down into smaller aggregations of coarse granular material, i.e. multiple nucleoli. In chauliodids the nucleoli are distributed evenly throughout the nucleoplasm while in the corydalid, C. peruvianus, they form a characteristic ring. The presented results are discussed in a phylogenetic context.
9

Structure of ovarioles in adult queens and workers of the common wasp, Vespula germanica (Hymenoptera: Vespidae)

88%
Jablonska A., Bilinski S. M.
Folia Biologica
|
2001
|
vol. 49
|
issue 3-4
191-198
EN
The ovaries of the common wasp, Vespula germanica are polytrophic-meroistic and consist of 2-3 (workers) or 7 (queens) ovarioles. The ovarioles are differentiated into three regions: a terminal filament, a germarium, and a vitellarium. The germaria of both castes consist of two zones: an anterior zone of germ-cell cluster formation and a posterior one of germ-cell cluster differentiation. The vitellaria comprise 4 ? 6 (workers) or 7 ? 10 (queens) ovarian follicles (egg chambers). Each chamber consists of an oocyte and about 60 isodiametric nurse cells (trophocytes). The egg chambers have been arbitrarily classified into four developmental categories: early and late previtellogenic, vitellogenic, and choriogenic. The process of oogenesis in workers proceeds only up to the onset of the late previtellogenesis. Neither vitellogenic nor choriogenic egg chambers were observed in this caste. During early and late previtellogenesis the envelope of the oocyte nucleus proliferates and becomes highly folded. This process leads to the formation of characteristic organelles, termed accessory nuclei (AN). Although AN arise in the oocytes of both queens and workers, their number in the latter caste is always considerably lower. At the onset of the late previtellogenesis AN start to migrate towards the periphery of the oocyte where they reside till the end of oogenesis. The physiological state of the worker ovaries is discussed in the light of the presented results.
10

Microsporidia infect the Liophloeus lentus (Insecta, Coleoptera) ovarioles, developing oocytes and eggs.

88%
Swiatek P., Gorkiewicz T.
Folia Biologica
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2006
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vol. 54
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issue 1-2
61-67
EN
In the ovarioles of Liophloeus lentus (Insecta, Coleoptera, Curculionidae) two types of bacteria and parasitic microorganisms belonging to Microsporidia have been found. This study shows that the different microsporidian life stages (meronts, sporonts, sporoblasts and spores) infect the outer ovariole sheath, trophic chambers, follicular cells, late previtellogenic and vitellogenic oocytes and eggs. In trophic chambers the parasites are very abundant and are distributed unevenly, i.e. their large mass occupies the syncytial cytoplasm between the nurse cell nuclei, whereas the neck region of the trophic chamber (which houses young oocytes, prefollicular cells and trophic cords) is almost free of parasites. The developing oocytes and eggs contain a lower number of parasites which are usually distributed in the cortical ooplasm. The gross morphology of the ovaries is similar in infected and non-infected specimens. Similarly, the presence of a parasite seems to not disturb the course of oogensis. The only difference was found in the ultrastructure of mitochondria in young previtellogenic oocytes. In the infected females they are unusual i.e. bigger and spherical with tubullar cristae, whereas in the non-infected insects they are elongated and have lamellar cristae. As oogenesis progresses the unusual mitochondria rapidly change their morphology and become similar to the mitochondria in non-infected females. Taking into account the distribution of parasites within the ovarioles, it is suggested that they infect growing oocytes via outer ovariole sheath and follicular epithelium rather than via trophic cords.
11

Structure of ovaries and formation of egg envelopes in the stonefly, Leuctra autumnalis Aubert, 1948 (Plecoptera: Leuctridae). Ultrastructural studies

88%
Poprawa I., Baran A., Rosciszewska E.
Folia Biologica
|
2002
|
vol. 50
|
issue 1-2
29-38
EN
The investigation of ovaries and the formation of egg envelopes of the stonefly Leuctra autumnalis was carried out with light and transmission electron microscopes. The ovary of the studied species is paired and consists of several dozen panoistic ovarioles opening individually to the oviduct. The process of egg capsule formation already begins in previtellogenesis. At this time the follicular cells secrete precursors of the vitelline envelope. Analysis of the presented data suggests that the oocyte itself also takes part in the formation of the vitelline envelope during late vitellogenesis. Simultaneously, the follicular cells produce precursors of further layers of the egg capsule, i.e. two-layered chorion and extrachorion, consisting of two gelatinous layers and a flocculent one. The completely developed capsule contains channels, probably micropylar ones.
12

Ultrastructural studies of the ovary of Palaeococcus fuscipennis (Burmeister) (Insecta, Hemiptera, Coccinea: Monophlebidae)

88%
Szklarzewicz T., Kedra K., Niznik S.
Folia Biologica
|
2005
|
vol. 53
|
issue 1-2
45-50
EN
Ovaries of Palaeocoocus fuscipennis are composed of about 100 telotrophic ovarioles that are devoid of terminal filaments. In the ovariole a tropharium (=trophic chamber) and vitellarium can be distinguished. The tropharium contains 7 trophocytes. A single oocyte develops in the vitellarium. The oocyte is surrounded by follicular cells that do not undergo diversification into subpopulations. The obtained results are discussed in a phylogenetic context.
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