Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1

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

100%
Tworzydlo W., Kisiel E.
Folia Biologica
|
2010
|
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.
2

Development of terminal filaments and ovariole envelopes in Thermobia domestica (Insecta, Zygentoma) larvae

100%
Kisiel E., Klag J.
Folia Biologica
|
2001
|
vol. 49
|
issue 3-4
199-204
EN
The 3rd instar female larvae of Thermobia domestica have five pairs of gonad primordia, each enclosed within a basal lamina (tunica propria). At the end of the 3rd instar some somatic cells scattered on the outer surface of the lamina are seen. During the 4th larval instar the gonad primordia start to form the ovarioles. Each ovariole is elongated and polarized, having anterior and posterior ends. The anterior group of outer somatic cells proliferate to form the terminal filament. At the 6th larval stage the ovarioles are already formed. The terminal filament is separated from the germarium by a thick basal lamina (transverse septum). There are three types of cell building the terminal filament. 1/ Basal cells with numerous finger ? like projections; 2/ Cells with electron lucent cytoplasm and large nuclei, and 3/ Cells with darker cytoplasm containing bundles of fibers and more compact nuclei. The outer surface of the filament is covered by a thick, fibrous basal lamina. The somatic cells that in the previous stages were scattered on the tunica propria as distinct cells, in the 6th larval stage form a cellular envelope (tunica externa). This envelope is formed by a layer of flat cells, and contains numerous tracheae.
3

Karyomere formation in cleaving eggs of Tetradontophora bielanensis (Collembola)

81%
Klag J., Jura C., Krzysztofowicz A., Kisiel E.
Folia Biologica
|
1995
|
vol. 43
|
issue 1-2
61-67
EN
The term "karyomere"designates a p[articular kind oforganization of the telophase nucleus, in which each individual chromosome is surrounded by a typical nuclear envelope, thus representing a small nuclear structure.In T.bielenensis they are formed during firts prophase and subsequently change into chromosomes making a metaphase plate.Each metaphase chromosome is completly enclosed by a double envelope, similar to a nuclear one but devoid of nuclear pores.The only place on the chromosome where the envelope is not complete is the region of the kinetochore.Anaphase starts with the division of the chromosome into chromatids and subsequent decondensation of the latter.During anaphase, te process of decondensation of the chromatids starts at the leading ends of each chromatid and hence, they acquire a tennis racket-like appearance.As a result, on the spindle poles two groups of the chromosome vesicles or karyomeres are gethered.Each karyomere has the appearance of a typical nucleus enclosed by a double envelope pierced by nucleus pores filed with nucleoplasm containing patches ofchromatin.It is suggested that karyomeres are formed only in species with a large amount of chromatin in their nuclei.
4

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

81%
Jaglarz M. K., Jablonska A., Kisiel E., Bilinski S. M.
Folia Biologica
|
2009
|
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.
5

Predetermination of cytokinesis and transition from holoblastic to partial superficial cleavage in early embryonic development of Tetrodontophora bielanensis (Collembola)

81%
Klag J., Krzysztofowicz A., Jura C., Kisiel E.
Folia Biologica
|
2000
|
vol. 48
|
issue 3-4
137-142
EN
In the T. bielanensis embryo, only karyokinesis occurs during the first cleavage division, and a two-nuclear syncytial embryo forms. Then, two cytoplasmic concentrations in the form of elongated rolls perpendicular to each other develop below the periplasm at the animal pole of the egg. The second cleavage division is also associated with karyokineses only. After the embryo reaches the four-nuclear stage, cytokineses occur at its animal pole, and two cleavage furrows perpendicular to each other develop in the periplasm above the cytoplasmic concentrations. The cell membranes forming within the furrows do not invade the cytoplasmic concentrations, but their growing tips push them into the egg interior, where they merge and form the central cytoplasmic concentration. The developing cell membranes do not invade the central cytoplasm; they band and grow above its surface. Four pyramidal blastomeres form as a result of this. The eight-blastomere embryo forms through both karyokinesis and cytokinesis, but the growing cell membranes now band below the previous ones and cut off anucleate parts of the mother blastomeres, which fuse with the central cytoplasm. Thus, during this phase of development the transition from holoblastic to partial superficial cleavage is initiated. Morphological analysis suggests that the formation of the first two cytokineses is predetermined by and depends on factors connected with the animal pole periplasm. It also suggests that the central cytoplasm constitutes the morphological field, inducing the transition from holoblastic to partial superficial cleavage.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.