Differentiation within the gonads of Drosophila revealed by immunofluorescence

Development ◽  
1981 ◽  
Vol 63 (1) ◽  
pp. 233-242
Author(s):  
Danny L. Brower ◽  
R. J. Smith ◽  
Michael Wilcox
Keyword(s):  
Epithelial Cells ◽  
Hybrid Cell ◽  
Proximal Part ◽  
Follicular Epithelium ◽  
Follicle Development ◽  
Nurse Cells ◽  
Border Cells ◽  
Anterior Pole ◽  
Posterior Pair ◽  
Adult Ovary

The antibody produced by the hybrid cell line DA.1B6 binds to the diploid epithelial cells of Drosophila. In this paper, we describe the immunofluorescence-binding pattern of the antibody to the gonads. A bright sheath of fluorescence extends from the seminal vesicle onto the most proximal part of the adult testis. The only other significant binding to the organ is to the apical cells of the germinal proliferation centre, which fluoresce brightly in testes from adults and from third instar larvae. In the adult ovary, there is strong binding to the cells of the follicular epithelium, although this binding is reduced in the latter stages of follicle development. Soon after the formation of a follicle, a pair of epithelial cells at each pole of the follicle can be seen to fluoresce much more brightly than the other cells. This early differentiation is reflected in the morphogenetic behaviour of these polar cells as the follicle develops. The anterior pair are among the ‘border cells’ which migrate between the nurse cells to the anterior pole of the developing oocyte; and, when the follicular epithelium around the oocyte becomes columnar, the posterior pair of cells do not elongate as much as the surrounding cells.

Oogenesis in Dacus tryoni (Frogg.) (Diptera: Trypetidae)

1965 ◽  
Vol 13 (3) ◽  
pp. 423 ◽  
Author(s):  
DT Anderson ◽  
GC Lyford
Keyword(s):  
Lipid Droplets ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Vitelline Membrane ◽  
Nurse Cells ◽  
Border Cells ◽  
Positive Material ◽  
Polytene Nuclei

Oogenesis in D. tryoni is typical of cyclorrhaphous Diptera. The ovariolar germarium produces a linear succession of 16-cell cysts enclosed by follicle cells. The cells of a cyst are interconnected by cytoplasmic canals and differentiate as 15 nurse cells and a posterior oocyte. Previtellogenesis occupies 3 days, vitellogenesis 1 day. The oocyte grows slowly during previtellogenesis, with little differentiation, rapidly during vitellogenesis, when protein and fatty yolk deposition, axial differentiation, and nuclear breakdown to first maturation metaphase, take place. The nurse cells grow rapidly during previtellogenesis and early vitellogenesis, developing large polytene nuclei and RNA-rich cytoplasm, and pour an RNA-rich nutrient stream into the oocyte during early vitellogenesis. The stream also contains P.A.S.-positive material, lipid droplets, possibly protein precursors, and nucleotides. Later, the nurse cells degenerate. Both growth and degeneration of the nurse cells are polarized, the posterior cells leading the more anterior cells. The follicular epithelium, cuboidal during previtellogenesis, differentiates as columnar around the oocyte, squamous outside the nurse cells, and anteriorly as border cells which migrate between the nurse cells to the anterior end of the oocyte. Late in vitellogenesis, the follicular epithelium secretes the chorion and vitelline membrane. It is not yet possible to discern in oogenesis the establishment in the oocyte of the prepattern essential for normal epigenesis.

The extracellular electrical current pattern and its variability in vitellogenic Drosophila follicles

1986 ◽  
Vol 81 (1) ◽  
pp. 189-206 ◽  
Author(s):  
J. Bohrmann ◽  
A. Dorn ◽  
K. Sander ◽  
H. Gutzeit
Keyword(s):  
Juvenile Hormone ◽  
Current Density ◽  
Developmental Stages ◽  
Electrical Current ◽  
Posterior Pole ◽  
The Other ◽  
Follicular Epithelium ◽  
Nurse Cells ◽  
Vibrating Probe ◽  
Current Pattern

We determined the extracellular electrical current pattern around Drosophila follicles at different developmental stages (7–14) with a vibrating probe. At most stages a characteristic pattern can be recognized: current leaves near the oocyte end of the follicle and enters at the nurse cells. Only at late vitellogenic stages was an inward-directed current located at the posterior pole of many follicles. Most striking was the observed heterogeneity both in current pattern and in current density between follicles of the same stage. Different media (changed osmolarity or pH, addition of cytoskeletal inhibitors or juvenile hormone) were tested for their effects on extrafollicular currents. The current density was consistently influenced by the osmolarity of the medium but not by the other parameters tested. Denuded nurse cells (follicular epithelium locally stripped off) show current influx, while an accidentally denuded oocyte produced no current. Our results show that individual follicles may be electrophysiologically different, though their uniform differentiation during vitellogenesis does not reflect such heterogeneity.

Effects of hempa on the gonads of Locusta Migratoria (L.) (Orthoptera, Acrididae)

1976 ◽  
Vol 66 (2) ◽  
pp. 313-315 ◽  
Author(s):  
Vishwa Nath ◽  
P. K. Mittal ◽  
Chander Sheikher
Keyword(s):  
Epithelial Cells ◽  
Locusta Migratoria ◽  
Germinal Vesicle ◽  
Empty Space ◽  
Follicular Epithelium ◽  
Cell Nuclei ◽  
Yolk Formation ◽  
Multinucleated Cells ◽  
Follicular Epithelial Cell ◽  
Follicular Epithelial

AbstractOnly a very strong dose of 0·5 mg of hempa caused necrosis in testes of Locusta migratoria (L.). The apical cells, spermatogonia and primary spermatocytes became pycnotic and the germ cells were disorganised. Multinucleated cells also developed, due to failure of spindle formation, and a few hypertrophied spermatids occurred. In ovaries the chromatin of the follicular epithelial cell nuclei was abnormally fragmented; nuclei of the follicular epithelial cells became pycnotic; germinal vesicle was badly damaged; cytoplasm of the follicular epithelial cells was drawn into the peripheral empty space formed by the contraction of the ooplasm; the follicular epithelium degenerated later; and yolk formation was inhibited. With increased doses and post-treatment periods necrosis became more marked. Hempa was more effective in the ovary than in the testes of L. migratoria.

scholarly journals Domain-specific functions of Stardust in Drosophila embryonic development

2016 ◽  
Vol 3 (11) ◽  
pp. 160776 ◽  
Author(s):  
Leonie Koch ◽  
Sabine Feicht ◽  
Rui Sun ◽  
Arnab Sen ◽  
Michael P. Krahn
Keyword(s):  
Epithelial Cells ◽  
Compound Eye ◽  
Function Analysis ◽  
Pdz Domain ◽  
Adherens Junction ◽  
Adaptor Protein ◽  
Follicular Epithelium ◽  
Cell Contact ◽  
Subapical Region

In Drosophila , the adaptor protein Stardust is essential for the stabilization of the polarity determinant Crumbs in various epithelial tissues, including the embryonic epidermis, the follicular epithelium and photoreceptor cells of the compound eye. In turn, Stardust recruits another adaptor protein, PATJ, to the subapical region to support adherens junction formation and morphogenetic events. Moreover, Stardust binds to Lin-7, which is dispensable in epithelial cells but functions in postsynaptic vesicle fusion. Finally, Stardust has been reported to bind directly to PAR-6, thereby linking the Crumbs–Stardust–PATJ complex to the PAR-6/aPKC complex. PAR-6 and aPKC are also capable of directly binding Bazooka (the Drosophila homologue of PAR-3) to form the PAR/aPKC complex, which is essential for apical–basal polarity and cell–cell contact formation in most epithelia. However, little is known about the physiological relevance of these interactions in the embryonic epidermis of Drosophila in vivo . Thus, we performed a structure–function analysis of the annotated domains with GFP-tagged Stardust and evaluated the localization and function of the mutant proteins in epithelial cells of the embryonic epidermis. The data presented here confirm a crucial role of the PDZ domain in binding Crumbs and recruiting the protein to the subapical region. However, the isolated PDZ domain is not capable of being recruited to the cortex, and the SH3 domain is essential to support the binding to Crumbs. Notably, the conserved N-terminal regions (ECR1 and ECR2) are not crucial for epithelial polarity. Finally, the GUK domain plays an important role for the protein's function, which is not directly linked to Crumbs stabilization, and the L27N domain is essential for epithelial polarization independently of recruiting PATJ.

scholarly journals Memoirs: The Development of the Ovary and Ovarian Egg of a Mosquito, Anopheles maculipennis, Meig

1921 ◽  
Vol s2-65 (259) ◽  
pp. 395-448
Author(s):  
A. J. NICHOLSON
Keyword(s):  
Mitotic Division ◽  
Follicular Epithelium ◽  
Oocyte Nucleus ◽  
Nurse Cells ◽  
Anterior Portion ◽  
Tracheal System ◽  
Short Period ◽  
Entrapped Air ◽  
The Individual ◽  
Second Period

1. The period at which the ovaries of A. maeulipennis commence to develop depends on the season and locality. Normally this is from about the middle of March to the beginning of April. 2. A meal of blood appears to be necessary for the production of eggs. 3. One meal of blood is sufficient to cause eggs to be produced. After the lapse of a day the large blood-mass in the stomach shows two zones: a posterior partially-digested portion and an anterior portion of apparently fresh blood. This appearance has sometimes been taken as evidence that more than one meal of blood has been consumed. 4. The eggs are fully developed six days after the insect has fed on blood. 5. In the case of two insects which were observed at the time of oviposition the eggs were laid immediately after dark. 6. The muscle-bands of the ovarian sheaths are striped; not unstriped as is usual in insects. 7. A large number of vacuolated cells are found in the ovary. The nature of these is not clear, but they appear to have some relation to the tracheal system. 8. The chorion of the egg is highly specialized to retain air round the egg, and the buoyancy of the egg is entirely due to the entrapped air. 9. The floats are-produced by a very specialized form of folding of the follicular epithelium. 10. The micropyle apparatus is produced by specialized cells of the epithelium, the ‘rosette-cells’. 11. Immediately below the micropyle is a specialized portion of the inner wall, the ‘stopper’. 12. The inner and outer walls of the egg, though formed of entirely different substances, are both secreted by the follicular epithelium. 13. The inner wall is first gelatinous in nature and transparent; but, after the egg is laid, becomes brittle and dark in colour, causing the egg to appear black. This change in character only takes place when the eggs are laid on water. 14. The mature egg contains two distinct kinds of yolk, one of large granules which are proteid in nature, and the other of small granules the nature of which I have been unable to determine. 15. There are two distinct periods of growth of the eggfollicles, the first culminating in the ‘resting stage’ and the second only commencing after the mosquito has bad a meal of blood. 16. Each egg-follicle consists of a follicular epithelium surrounding seven nurse-cells and an oocyte. These appear to be the product of a single oogoniuni. 17. The cells of the follicular epithelium multiply by mitotic division during the whole of the first period of growth. In the second period, though the follicular epithelium increases greatly in area, this is due purely to the increase in size of the individual cells. 18. From the earliest stages separate vegetative and germinal portions can be distinguished in the oocyte nucleus. 19. During the second period of growth the oocyte nucleus branches throughout the entire oocyte. 20. The branching nucleus, in conjunction with the nursecells, takes an active part in the nutrition of the oocyte. 21. The branching of the nucleus may be regarded as a mechanism for the purpose of increasing the surface. 22. I have observed a similar method of branching of the oocyte nucleus in Theobaldia annulata, and it probably also exists in Necrophorus vespillo and Si1pha sp. 23. The branching nucleus is almost entirely the product of the nucleolus. 24. The branching nucleus is morphologically and physiologically comparable to the Corpuscles of Balbiani of other animals. 25. The germinal portion of the nucleus, the ‘chromatin residue’, is the product of the condensation of the spirerae threads. 26. The ‘chromatin residue’ becomes invisible for a short period and reappears after oviposition as the segmentation nucleus. 27. The chromatin of the active nurse-cells consists of minute bars situated on a much convoluted band of linin. 28. Degeneration of a certain number of egg-follicles is normal during the development of the ovary. 29. Sporozoa are frequently found in the eggs, often completely replacing the whole of the yolk.

scholarly journals Fascin regulates nuclear actin during Drosophila oogenesis

2016 ◽  
Vol 27 (19) ◽  
pp. 2965-2979 ◽  
Author(s):  
Daniel J. Kelpsch ◽  
Christopher M. Groen ◽  
Tiffany N. Fagan ◽  
Sweta Sudhir ◽  
Tina L. Tootle
Keyword(s):  
Nuclear Import ◽  
Follicle Development ◽  
Nuclear Actin ◽  
Nurse Cells ◽  
Nuclear Level ◽  
Drosophila Oogenesis ◽  
Developmental System ◽  
Import And Export

Drosophila oogenesis provides a developmental system with which to study nuclear actin. During Stages 5–9, nuclear actin levels are high in the oocyte and exhibit variation within the nurse cells. Cofilin and Profilin, which regulate the nuclear import and export of actin, also localize to the nuclei. Expression of GFP-tagged Actin results in nuclear actin rod formation. These findings indicate that nuclear actin must be tightly regulated during oogenesis. One factor mediating this regulation is Fascin. Overexpression of Fascin enhances nuclear GFP-Actin rod formation, and Fascin colocalizes with the rods. Loss of Fascin reduces, whereas overexpression of Fascin increases, the frequency of nurse cells with high levels of nuclear actin, but neither alters the overall nuclear level of actin within the ovary. These data suggest that Fascin regulates the ability of specific cells to accumulate nuclear actin. Evidence indicates that Fascin positively regulates nuclear actin through Cofilin. Loss of Fascin results in decreased nuclear Cofilin. In addition, Fascin and Cofilin genetically interact, as double heterozygotes exhibit a reduction in the number of nurse cells with high nuclear actin levels. These findings are likely applicable beyond Drosophila follicle development, as the localization and functions of Fascin and the mechanisms regulating nuclear actin are widely conserved.

Observations on changes in the female reproductive system of the wheat bulb fly Leptohylemyia coarctata (Fall.)

1971 ◽  
Vol 61 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Margaret G. Jones
Keyword(s):  
Winter Wheat ◽  
Reproductive System ◽  
Follicular Epithelium ◽  
Cereal Aphids ◽  
Nurse Cells ◽  
Female Reproductive System ◽  
Egg Development ◽  
Sugar Water ◽  
The Third ◽  
Water Traps

In Leptohylemyia coarctata (Fall.) the germarium cuts off oocytes which develop through the stages 00 and 0 and I-V, recognised in other Cyclorraphous flies, in 4–5 weeks. All eggs of one batch of the gonadotrophic cycle ripen at the same time. After oviposition, the split intima, the remains of the follicular epithelium, and the nurse cells slowly contract to form the follicular relic. Flies swept from winter wheat during June and July and caught in water traps in July and August showed all stages of egg development. In 1970, 24·7% of the females swept from the crop had completed the first, 4–7% the second and 0–4% the third gonadotrophic cycle. All the eggs were not laid at the same time. During later gonadotrophic cycles, some ovarioles were non-functional. Flies laid one or two batches of eggs, rarely three. In 1970, many flies were attacked and killed by E. muscae. Only one out of 115 newly emerged female wheat bulb flies presented with foods usually found in the crop or citrated blood contained mature eggs after 24–27 days in small cages. Those fed only on 0·1 M glucose survived but did not deposit yolk in the ovum; those provided only with yeast paste died. Honey dew from cereal aphids was the main source of sugar. Water in droplet form and space to move seem necessary for the maturation of the eggs.

In vivo analyses of cytoplasmic transport and cytoskeletal organization during Drosophila oogenesis: characterization of a multi-step anterior localization pathway

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3655-3666 ◽  
Author(s):  
W.E. Theurkauf ◽  
T.I. Hazelrigg
Keyword(s):  
Laser Scanning ◽  
Fluorescent Protein ◽  
Drosophila Embryo ◽  
Nurse Cells ◽  
Anterior Pole ◽  
Microtubule Organization ◽  
Microtubule Network ◽  
Cytoplasmic Transport ◽  
Anterior Patterning

Anterior patterning of the Drosophila embryo depends on localization of bicoid (bcd) mRNA to the anterior pole of the developing oocyte, and bcd mRNA localization requires both the exuperantia (exu) gene and an intact microtubule cytoskeleton. To gain insight into the mechanism of anterior patterning, we have used time lapse laser scanning confocal microscopy to analyze transport of particles containing a Green Fluorescent Protein-Exu fusion (GFP-Exu), and to directly image microtubule organization in vivo. Our observations indicate that microtubules are required for three forms of particle movement within the nurse cells, while transport through the ring canals linking the nurse cells and oocyte appears to be independent of both microtubules and actin filaments. As particles enter the oocyte, a final microtubule-dependent step directs movement to the oocyte cortex. However, our observations and previous studies suggest that the polarity of the oocyte microtubule network is not in itself sufficient to generate anterior asymmetry, and that additional factors are required to restrict morphogens to the anterior pole. Based on these observations, we propose a multi-step anterior localization pathway.

scholarly journals Dynamic myosin activation promotes collective morphology and migration by locally balancing oppositional forces from surrounding tissue

2016 ◽  
Vol 27 (12) ◽  
pp. 1898-1910 ◽  
Author(s):  
George Aranjuez ◽  
Ashley Burtscher ◽  
Ketki Sawant ◽  
Pralay Majumder ◽  
Jocelyn A. McDonald
Keyword(s):  
Genetic Model ◽  
Germ Line ◽  
Cell Cluster ◽  
Surrounding Tissue ◽  
Nurse Cells ◽  
Border Cells ◽  
Mechanical Pressure ◽  
Physical Constraints ◽  
Border Cell

Migrating cells need to overcome physical constraints from the local microenvironment to navigate their way through tissues. Cells that move collectively have the additional challenge of negotiating complex environments in vivo while maintaining cohesion of the group as a whole. The mechanisms by which collectives maintain a migratory morphology while resisting physical constraints from the surrounding tissue are poorly understood. Drosophila border cells represent a genetic model of collective migration within a cell-dense tissue. Border cells move as a cohesive group of 6−10 cells, traversing a network of large germ line–derived nurse cells within the ovary. Here we show that the border cell cluster is compact and round throughout their entire migration, a shape that is maintained despite the mechanical pressure imposed by the surrounding nurse cells. Nonmuscle myosin II (Myo-II) activity at the cluster periphery becomes elevated in response to increased constriction by nurse cells. Furthermore, the distinctive border cell collective morphology requires highly dynamic and localized enrichment of Myo-II. Thus, activated Myo-II promotes cortical tension at the outer edge of the migrating border cell cluster to resist compressive forces from nurse cells. We propose that dynamic actomyosin tension at the periphery of collectives facilitates their movement through restrictive tissues.

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