The differentiation and proliferation of follicle cells during oocyte growth in Lacerta sicula

Development ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 5-15
Author(s):  
S. Filosa ◽  
C. Taddei ◽  
P. Andreuccetti
Keyword(s):  
Small Cells ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Oocyte Growth ◽  
Large Follicle ◽  
Differentiation And Proliferation ◽  
Pyriform Cells

The follicular epithelium of the lizard oocytes undergoes structural and morphological modifications throughout oocyte growth. During this process the number of follicle cells increases and the epithelium acquires a multilayered and polymorphic organization which is characterized by the appearance of large follicle cells (intermediate and pyriform cells). The number of large cells also increases during oocyte growth and this increase parallels that of small cells. However, only the small cells become labelled one hour after [3H-]thymidine administration. Large cells have been found labelled after a longer period of time, i.e. 4–5 months after isotope injection. All these results together indicate that large follicle cells arise from the differentiation of small cells.

Intercellular bridges between follicle cells and oocyte during the differentiation of follicular epithelium in Lacerta sicula Raf

1978 ◽  
Vol 33 (1) ◽  
pp. 341-350
Author(s):  
P. Andreuccetti ◽  
C. Taddei ◽  
S. Filosa
Keyword(s):  
Follicle Cells ◽  
Follicular Epithelium ◽  
Intercellular Bridges ◽  
Cytoplasmic Material ◽  
Function Transfer ◽  
Pyriform Cells

Intercellular bridges first appear during lizard oogenesis when follicles are rather small (150 microgram in diameter); at this stage they form connecting links between the oocyte and follicle cells, which have not yet differentiated into pyriform cells. Later on, when the follicles have become larger (1 mm) and the follicular epithelium appears constituted by 3 types of cells (small, intermediate and pyriform cells) they form connecting links between the oocyte and both intermediate and pyriform cells. The establishment of intercellular bridges between pyriform cells and the oocyte precedes the complete differentiation of the former, which excludes the possibility that the fusion between pyriform cells and oocyte occurs only after these cells are completely differentiated. In still larger follicles (up to 2 mm in diameter), during the degeneration of the pyriform cells, the occurrence, inside the bridges, of mitochondria and other cytoplasmic material suggests that these cells at the end of their function transfer their contents into the oocyte.

Two actions of juvenile hormone on the follicle cells of Rhodnius prolixus Stål

1975 ◽  
Vol 53 (8) ◽  
pp. 1187-1188 ◽  
Author(s):  
Randa Abu-Hakima ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Developmental Stages ◽  
Normal Animal ◽  
Rhodnius Prolixus ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Intercellular Spaces

The follicular epithelium of vitellogenic oocytes from allatectomized females of Rhodnius fails to develop large intercellular spaces when exposed to juvenile hormone (JH) in vitro. This suggests that in the normal animal, the follicle cells require JH at two developmental stages. Differentiation of the cells in the presence of JH represents one requirement, and only those cells which have undergone this initial priming are fully competent to exhibit the second response, the development of intercellular spaces.

Memoirs: The Structure of the Ovary and the Formation of the Corpus Luteum in Hoplodactylus Maculatus, Gray

1940 ◽  
Vol s2-82 (326) ◽  
pp. 337-374
Author(s):  
MARY M. M. BOYD
Keyword(s):  
Corpus Luteum ◽  
Zona Pellucida ◽  
Single Layer ◽  
Small Cells ◽  
Follicular Epithelium ◽  
Male And Female ◽  
Physiological Importance ◽  
Egg Membrane ◽  
Theca Externa ◽  
Theca Interna

The structure of the ovary, including stages in the ripening of the oocytes, is described. A prolonged diplotene stage with ‘lamp-brush’ chromosomes is shown to occur in reptiles, as in other classes of vertebrates with large yolky eggs. The striated layer of the egg membrane is shown to be composed of the same cuticular substance as the zona pellucida. A follicular epithelium composed of three types of cells, later reduced to a single layer of small cells, agreeing with Loyez's observations, is described. A discontinuous theca interna, comparable with that of mammalia, is noted outside the membrana propria of the nearly ripe oocyte. A thin, soft, fibrous shell membrane is formed round the uterine egg and polyspermy occurs. The latebra, and the male and female pronuclei in apposition, are described. The corpus luteum is shown to consist of luteal cells invested by fibroblasts from the theca externa. Septa of fibroblasts are also present, but no blood-vessels. The theca is rich in capillaries. The theca interna plays no part in the development of the corpus luteum. A lipoid secretion, which may be of physiological importance, is formed in it. It is compared with that in Monotremes and Marsupials.

scholarly journals Apical, Lateral, and Basal Polarization Cues Contribute to the Development of the Follicular Epithelium during Drosophila Oogenesis

2000 ◽  
Vol 151 (4) ◽  
pp. 891-904 ◽  
Author(s):  
Guy Tanentzapf ◽  
Christian Smith ◽  
Jane McGlade ◽  
Ulrich Tepass
Keyword(s):  
Apical Membrane ◽  
Pdz Domain ◽  
Basal Membrane ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Epithelial Surface ◽  
Mosaic Analysis ◽  
Spectrin Cytoskeleton ◽  
Surface Domains ◽  
Mesenchymal Epithelial Transition

Analysis of the mechanisms that control epithelial polarization has revealed that cues for polarization are mediated by transmembrane proteins that operate at the apical, lateral, or basal surface of epithelial cells. Whereas for any given epithelial cell type only one or two polarization systems have been identified to date, we report here that the follicular epithelium in Drosophila ovaries uses three different polarization mechanisms, each operating at one of the three main epithelial surface domains. The follicular epithelium arises through a mesenchymal–epithelial transition. Contact with the basement membrane provides an initial polarization cue that leads to the formation of a basal membrane domain. Moreover, we use mosaic analysis to show that Crumbs (Crb) is required for the formation and maintenance of the follicular epithelium. Crb localizes to the apical membrane of follicle cells that is in contact with germline cells. Contact to the germline is required for the accumulation of Crb in follicle cells. Discs Lost (Dlt), a cytoplasmic PDZ domain protein that was shown to interact with the cytoplasmic tail of Crb, overlaps precisely in its distribution with Crb, as shown by immunoelectron microscopy. Crb localization depends on Dlt, whereas Dlt uses Crb-dependent and -independent mechanisms for apical targeting. Finally, we show that the cadherin–catenin complex is not required for the formation of the follicular epithelium, but only for its maintenance. Loss of cadherin-based adherens junctions caused by armadillo (β-catenin) mutations results in a disruption of the lateral spectrin and actin cytoskeleton. Also Crb and the apical spectrin cytoskeleton are lost from armadillo mutant follicle cells. Together with previous data showing that Crb is required for the formation of a zonula adherens, these findings indicate a mutual dependency of apical and lateral polarization mechanisms.

Juvenile hormone increases ouabain-binding capacity of microsomal preparations from vitellogenic follicle cells

1983 ◽  
Vol 61 (7) ◽  
pp. 826-831 ◽  
Author(s):  
T. T. Ilenchuk ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Binding Capacity ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Curvilinear Relationship ◽  
Scatchard Analysis ◽  
Ouabain Binding ◽  
Binding Characteristics ◽  
Brain Microsomes

A comparison has been made of the effects of juvenile hormone (JH) on the binding characteristics for ouabain of microsomes prepared from brain and from cells of the follicular epithelium surrounding previtellogenic or vitellogenic oocytes in Rhodnius. JH has no effect on the binding of ouabain to brain microsomes and decreases the Kd, but does not alter the Bmax for previtellogenic follicle cells. For vitellogenic follicle cells, Scatchard analysis reveals a curvilinear relationship, which is interpreted as indicating that a new population of JH-sensitive ouabain-binding sites develops as the follicle cell enters vitellogenesis. These results are related to earlier data obtained on the effect of JH on ATPase activity, volume changes in isolated follicle cells, and the development of spaces between the cells of the follicular epithelium.

Patterning of the follicle cell epithelium along the anterior-posterior axis during Drosophila oogenesis

Development ◽  
1998 ◽  
Vol 125 (15) ◽  
pp. 2837-2846 ◽  
Author(s):  
A. Gonzalez-Reyes ◽  
D. St Johnston
Keyword(s):  
Follicle Cell ◽  
Cell Types ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Axis Formation ◽  
Main Body ◽  
Drosophila Oogenesis ◽  
Egfr Mutant ◽  
Anterior Posterior ◽  
Anterior Posterior Axis

Gurken signals from the oocyte to the adjacent follicle cells twice during Drosophila oogenesis; first to induce posterior fate, thereby polarising the anterior-posterior axis of the future embryo and then to induce dorsal fate and polarise the dorsal-ventral axis. Here we show that Gurken induces two different follicle cell fates because the follicle cells at the termini of the egg chamber differ in their competence to respond to Gurken from the main-body follicle cells in between. By removing the putative Gurken receptor, Egfr, in clones of cells, we show that Gurken signals directly to induce posterior fate in about 200 cells, defining a terminal competence domain that extends 10–11 cell diameters from the pole. Furthermore, small clones of Egfr mutant cells at the posterior interpret their position with respect to the pole and differentiate as the appropriate anterior cell type. Thus, the two terminal follicle cell populations contain a symmetric prepattern that is independent of Gurken signalling. These results suggest a three-step model for the anterior-posterior patterning of the follicular epithelium that subdivides this axis into at least five distinct cell types. Finally, we show that Notch plays a role in both the specification and patterning of the terminal follicle cells, providing a possible explanation for the defect in anterior-posterior axis formation caused by Notch and Delta mutants.

scholarly journals The ETS-transcription factor Pointed is sufficient to regulate the posterior fate of the follicular epithelium

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev189787
Author(s):  
Cody A. Stevens ◽  
Nicole T. Revaitis ◽  
Rumkan Caur ◽  
Nir Yakoby
Keyword(s):  
Transcription Factor ◽  
Growth Factor Receptor ◽  
Bmp Signaling ◽  
Janus Kinase ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
T Box ◽  
Border Cell ◽  
Morphogenetic Protein ◽  
Ets Transcription Factor

ABSTRACTThe Janus-kinase/signal transducer and activator of transcription (JAK/STAT) pathway regulates the anterior posterior axis of the Drosophila follicle cells. In the anterior, it activates the bone morphogenetic protein (BMP) signaling pathway through expression of the BMP ligand decapentaplegic (dpp). In the posterior, JAK/STAT works with the epidermal growth factor receptor (EGFR) pathway to express the T-box transcription factor midline (mid). Although MID is necessary for establishing the posterior fate of the egg chamber, we show that it is not sufficient to determine a posterior fate. The ETS-transcription factor pointed (pnt) is expressed in an overlapping domain to mid in the follicle cells. This study shows that pnt is upstream of mid and that it is sufficient to induce a posterior fate in the anterior end, which is characterized by the induction of mid, the prevention of the stretched cells formation and the abrogation of border cell migration. We demonstrate that the anterior BMP signaling is abolished by PNT through dpp repression. However, ectopic DPP cannot rescue the anterior fate formation, suggesting additional targets of PNT participate in the posterior fate determination.

Homozygous mutation of foxh1 arrests oogenesis causing infertility in female Nile tilapia†

2019 ◽  
Vol 102 (3) ◽  
pp. 758-769
Author(s):  
Wenjing Tao ◽  
Hongjuan Shi ◽  
Jing Yang ◽  
Hamidou Diakite ◽  
Thomas D Kocher ◽  
...  
Keyword(s):  
Phase Iii ◽  
Follicle Cells ◽  
Homozygous Mutation ◽  
Serum Estradiol ◽  
Oocyte Growth ◽  
Expression Of Genes ◽  
Estrogen Production ◽  
Estrogen Synthesis ◽  
Smad Protein ◽  
Estradiol 17Β

Abstract Foxh1, a member of fox gene family, was first characterized as a transcriptional partner in the formation of the Smad protein complex. Recent studies have shown foxh1 is highly expressed in the cytoplasm of oocytes in both tilapia and mouse. However, its function in oogenesis remains unexplored. In the present study, foxh1−/− tilapia was created by CRISPR/Cas9. At 180 dah (days after hatching), the foxh1−/− XX fish showed oogenesis arrest and a significantly lower GSI. The transition of oocytes from phase II to phase III and follicle cells from one to two layers was blocked, resulting in infertility of the mutant. Transcriptomic analysis revealed that expression of genes involved in estrogen synthesis and oocyte growth were altered in the foxh1−/− ovaries. Loss of foxh1 resulted in significantly decreased Cyp19a1a and increased Cyp11b2 expression, consistent with significantly lower concentrations of serum estradiol-17β (E2) and higher concentrations of 11-ketotestosterone (11-KT). Moreover, administration of E2 rescued the phenotypes of foxh1−/− XX fish, as indicated by the appearance of phase III and IV oocytes and absence of Cyp11b2 expression. Taken together, these results suggest that foxh1 functions in the oocytes to regulate oogenesis by promoting cyp19a1a expression, and therefore estrogen production. Disruption of foxh1 may block the estrogen synthesis and oocyte growth, leading to the arrest of oogenesis and thus infertility in tilapia.

Brooding strategies in solitary ascidians: Corella species from north and south temperate waters

1995 ◽  
Vol 73 (9) ◽  
pp. 1666-1671 ◽  
Author(s):  
Charles C. Lambert ◽  
Ilsa M. Lambert ◽  
Gretchen Lambert
Keyword(s):  
New Zealand ◽  
North America ◽  
Pacific Coast ◽  
Follicle Cells ◽  
Northwest Pacific ◽  
Large Follicle ◽  
The Right ◽  
North And South ◽  
Vitelline Coat ◽  
Small Follicle

Corella inflata from the northwest Pacific coast of North America and Corella eumyota from southern New Zealand are both ovoviviparous solitary ascidians with very different methods of brood retention. Corella inflata eggs are covered with large follicle cells that are responsible for flotation. The floating eggs are trapped in the upwardly situated atrial chamber, where development ensues. Corella eumyota eggs have small follicle cells and do not float; the follicle cells produce a viscous glue that causes the eggs and embryos to stick to each other and to the right atrium. The follicle cells are not sticky when removed from the ovary but become so in about 15 min. In C. inflata, development to hatching requires 24–26 h at 13 °C and metamorphosis begins 17 h later. Corella eumyota tadpoles hatch at about 25 h at 15 °C and begin metamorphosis 11 h later. Both species retain the tadpoles well beyond hatching and release tadpoles fully competent to metamorphose. In C. inflata the tadpoles swim down and out of the atrium; C. eumyota tadpoles somehow break free of the glue-encrusted vitelline coat and swim out the atrial siphon. Tadpoles of both species swim vigorously when released and then rapidly metamorphose. Most tadpoles metamorphose in 15–20 min. Since both species spawn around dawn, tadpoles are released during the night.

scholarly journals Establishment of dorsal-ventral polarity of theDrosophilaegg requirescapicuaaction in ovarian follicle cells

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4553-4562 ◽  
Author(s):  
Deborah J. Goff ◽  
Laura A. Nilson ◽  
Donald Morisato
Keyword(s):  
Target Genes ◽  
Nuclear Translocation ◽  
Ovarian Follicle ◽  
Growth Factor Receptor ◽  
Follicle Cell ◽  
Dorsal Side ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Egfr Signaling ◽  
Cell Nuclei

The dorsal-ventral pattern of the Drosophila egg is established during oogenesis. Epidermal growth factor receptor (Egfr) signaling within the follicular epithelium is spatially regulated by the dorsally restricted distribution of its presumptive ligand, Gurken. As a consequence, pipe is transcribed in a broad ventral domain to initiate the Toll signaling pathway in the embryo, resulting in a gradient of Dorsal nuclear translocation. We show that expression of pipe RNA requires the action of fettucine (fet) in ovarian follicle cells. Loss of maternal fet activity produces a dorsalized eggshell and embryo. Although similar mutant phenotypes are observed with regulators of Egfr signaling, genetic analysis suggests that fet acts downstream of this event. The fet mutant phenotype is rescued by a transgene of capicua (cic), which encodes an HMG-box transcription factor. We show that Cic protein is initially expressed uniformly in ovarian follicle cell nuclei, and is subsequently downregulated on the dorsal side. Earlier studies described a requirement for cic in repressing zygotic target genes of both the torso and Toll pathways in the embryo. Our experiments reveal that cic controls dorsal-ventral patterning by regulating pipe expression in ovarian follicle cells, before its previously described role in interpreting the Dorsal gradient.

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