The role of the follicular epithelium in growing eggs of a dipteran insect during late oogenesis and cleavage

1983 ◽  
Vol 178 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Pablo Junquera
Keyword(s):  
Follicular Epithelium ◽  
Dipteran Insect

scholarly journals Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis

2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Qi Li ◽  
Ling Shen ◽  
Tianchi Xin ◽  
Wenjuan Xiang ◽  
Wenlian Chen ◽  
...  
Keyword(s):  
Follicular Epithelium ◽  
Drosophila Oogenesis ◽  
Anterior Posterior

Identifying loci required for follicular patterning using directed mosaics

Development ◽  
1998 ◽  
Vol 125 (12) ◽  
pp. 2263-2271 ◽  
Author(s):  
J.B. Duffy ◽  
D.A. Harrison ◽  
N. Perrimon
Keyword(s):  
Cell Migration ◽  
Cell Shape ◽  
Egf Receptor ◽  
Essential Genes ◽  
Follicular Epithelium ◽  
Loss Of Function ◽  
Developmental Pathway ◽  
Adult Tissues ◽  
Phenotypic Screen

We have developed a ‘directed mosaic’ system in Drosophila by using the GAL4 system to control the expression of the yeast recombinase, FLP, in a spatial and temporal fashion. By directing FLP expression, we show that it is possible to efficiently and specifically target loss-of-function studies for vital loci to the developmental pathway of interest. A simple F1 adult phenotypic screen demonstrated that most adult tissues can be analyzed with this approach. Using GAL4 lines expressed during oogenesis, we have refined the system to examine the roles of vital loci in the development of the follicular epithelium. We have identified essential genes involved in egg chamber organization, cell migration and cell shape. Further, we have used this technique to gain insights into the role of the Drosophila EGF receptor pathway in establishing the egg axes. Finally, using different UAS-FLP, GAL4 and existing FRT lines, we have built stocks that permit the analysis of approximately 95% of the genome in follicular mosaics.

scholarly journals Role of EphA4 Receptor Signaling in Thyroid Development: Regulation of Folliculogenesis and Propagation of the C-Cell Lineage

Endocrinology ◽  
2011 ◽  
Vol 152 (3) ◽  
pp. 1154-1164 ◽  
Author(s):  
Louise Andersson ◽  
Jessica Westerlund ◽  
Shawn Liang ◽  
Therese Carlsson ◽  
Elena Amendola ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Cell Lineage ◽  
Follicular Epithelium ◽  
Tyrosine Kinase Receptor ◽  
C Cells ◽  
Knock Out ◽  
Reverse Signaling ◽  
Knock Out Mice ◽  
Green Fluorescent

Transcriptome analysis revealed that the tyrosine kinase receptor EphA4 is enriched in the thyroid bud in mouse embryos. We used heterozygous EphA4-EGFP knock-in mice in which enhanced green fluorescent protein (EGFP) replaced the intracellular receptor domain (EphA4+/EGFP) to localize EphA4 protein in thyroid primordial tissues. This showed that thyroid progenitors originating in the pharyngeal floor express EphA4 at all embryonic stages and when follicles are formed in late development. Also, the ultimobranchial bodies developed from the pharyngeal pouch endoderm express EphA4, but the ultimobranchial epithelium loses the EGFP signal before it merges with the median thyroid primordium. Embryonic C cells invading the thyroid are exclusively EphA4-negative. EphA4 expression continues in the adult thyroid. EphA4 knock-out mice and EphA4-EGFP homozygous mutants are euthyroid and have a normal thyroid anatomy but display subtle histological alterations regarding number, size, and shape of follicles. Of particular interest, the pattern of follicular abnormality differs between EphA4−/− and EphA4EGFP/EGFP thyroids. In addition, the number of C cells is reduced by >50% exclusively in animals lacking EphA4 forward signaling (EphA4EGFP/EGFP). Heterozygous EphA4 mutants have no apparent thyroid phenotype. We conclude that EphA4 is a novel regulator of thyroid morphogenesis that impacts on postnatal development of the two endocrine cell lineages of the differentiating gland. In this process both EphA4 forward signaling (in the follicular epithelium) and reverse signaling mediated by its cognate ligand(s) (A- and/or B-ephrins expressed in follicular cells and C cells, respectively) are probably functionally important.

scholarly journals Thyroid Swelling and Thyroiditis in the Setting of Recent hCG Injections and Fine Needle Aspiration

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Elizabeth M. Lamos ◽  
Kashif M. Munir
Keyword(s):  
Thyroid Nodule ◽  
Fine Needle Aspiration ◽  
Needle Aspiration ◽  
Neck Mass ◽  
Cross Reactivity ◽  
Follicular Epithelium ◽  
Fine Needle ◽  
Thyroid Fine Needle Aspiration ◽  
Thyroid Swelling

A 60-year-old woman presented with a neck mass and underwent fine needle aspiration of a left thyroid nodule. During this time, she had been injected with hCG for weight loss. Soon after, she developed rapid diffuse thyroid growth with pain. She was ultimately diagnosed with thyrotoxicosis due to postaspiration subacute thyroiditis and subsequently became hypothyroid. This condition is rare in the nonpregnant state in noncystic nodules with a smaller needle gauge approach. The incidence of thyroid nodule discovery and evaluation is increasing. As more procedures are undertaken, understanding of potential complications is important. This case highlights potential complications of thyroid fine needle aspiration including diffuse thyroid swelling and thyroiditis. The role of hCG injections is speculated to have potentially stimulated thyroid follicular epithelium via cross-reactivity with the TSH receptor and contributed to the acute inflammatory response after fine needle aspiration.

scholarly journals Gene-regulatory independent functions for insect DNA methylation

2018 ◽  
Author(s):  
Adam J. Bewick ◽  
Zachary Sanchez ◽  
Elizabeth C. Mckinney ◽  
Allen J. Moore ◽  
Patricia J. Moore ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Functional Role ◽  
Dna Methyltransferase ◽  
Ovarian Tissue ◽  
Experimental Manipulation ◽  
Oncopeltus Fasciatus ◽  
Follicular Epithelium ◽  
Independent Functions

AbstractThe function of cytosine (DNA) methylation in insects remains unknown. Here we provide evidence for the functional role of the maintenance DNA methyltransferase 1 (Dnmt1) in an insect using experimental manipulation. Through RNA interference (RNAi) we successfully post-transcriptionally knocked downDnmt1in ovarian tissue of the hemipteranOncopeltus fasciatus(the large milkweed bug). Individuals depleted forDnmt1, and subsequently DNA methylation, failed to reproduce. Eggs were inviable and declined in number, and nuclei structure of follicular epithelium was aberrant. Depletion of DNA methylation did not result in changes in gene or transposable element expression revealing an important function of DNA methylation seemingly not contingent on gene expression. Our work provides direct experimental evidence for a functional role ofDnmt1and DNA methylation independent of gene expression in insects.

scholarly journals The role of integrins in Drosophila egg chamber morphogenesis

2019 ◽  
Author(s):  
Holly E. Lovegrove ◽  
Dan T. Bergstralh ◽  
Daniel St Johnston
Keyword(s):  
Basement Membrane ◽  
Cell Polarity ◽  
Cell Shape ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Egg Chambers ◽  
Germline Cyst ◽  
Egg Chamber

AbstractA Drosophila egg chamber is comprised of a germline cyst surrounded by a tightly-organised epithelial monolayer, the follicular epithelium (FE). Loss of integrin function from the FE disrupts epithelial organisation at egg chamber termini, but the cause of this phenotype remains unclear. Here we show that the β-integrin Myospheroid (Mys) is only required during early oogenesis when the pre-follicle cells form the FE. mys mutants disrupt both the formation of a monolayered epithelium at egg chamber termini and the morphogenesis of the stalk between adjacent egg chambers, which develops through the intercalation of two rows of cells into a single-cell wide stalk. Secondary epithelia, like the FE, have been proposed to require adhesion to the basement membrane to polarise. However, Mys is not required for pre-follicle cell polarisation, as both follicle and stalk cells localise polarity factors correctly, despite being mispositioned. Instead, loss of integrins causes pre-follicle cells to basally constrict, detach from the basement membrane and become internalised. Thus, integrin function is dispensable for pre-follicle cell polarity but is required to maintain cellular organisation and cell shape during morphogenesis.

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