scholarly journals Visualization of Clathrin-Mediated Endocytosis in Live Drosophila Egg Chambers

2014 ◽  
pp. 349-360 ◽  
Author(s):  
Anupma Jha ◽  
Linton M. Traub
Keyword(s):  
Egg Chambers

Microscale MALDI Imaging of Outer-Layer Lipids in Intact Egg Chambers fromDrosophila melanogaster

2011 ◽  
Vol 83 (10) ◽  
pp. 3918-3925 ◽  
Author(s):  
Pawel L. Urban ◽  
Chia-Hsien Chang ◽  
June-Tai Wu ◽  
Yu-Chie Chen
Keyword(s):  
Outer Layer ◽  
Maldi Imaging ◽  
Egg Chambers

scholarly journals Germline Cell Death Is Inhibited byP-Element Insertions Disrupting thedcp-1/pitaNested Gene Pair in Drosophila

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 1881-1888 ◽  
Author(s):  
Bonni Laundrie ◽  
Jeanne S Peterson ◽  
Jason S Baum ◽  
Jeffrey C Chang ◽  
Dana Fileppo ◽  
...  
Keyword(s):  
Cell Death ◽  
Nurse Cell ◽  
Zinc Finger Protein ◽  
P Element ◽  
Germline Cell ◽  
Developmentally Regulated ◽  
Developmental Abnormalities ◽  
Egg Chambers ◽  
Caspase Gene ◽  
Active Caspase

AbstractGermline cell death in Drosophila oogenesis is controlled by distinct signals. The death of nurse cells in late oogenesis is developmentally regulated, whereas the death of egg chambers during mid-oogenesis is induced by environmental stress or developmental abnormalities. P-element insertions in the caspase gene dcp-1 disrupt both dcp-1 and the outlying gene, pita, leading to lethality and defective nurse cell death in late oogenesis. By isolating single mutations in the two genes, we have found that the loss of both genes contributes to this ovary phenotype. Mutants of pita, which encodes a C2H2 zinc-finger protein, are homozygous lethal and show dumpless egg chambers and premature nurse cell death in germline clones. Early nurse cell death is not observed in the dcp-1/pita double mutants, suggesting that dcp-1+ activity is required for the mid-oogenesis cell death seen in pita mutants. dcp-1 mutants are viable and nurse cell death in late oogenesis occurs normally. However, starvation-induced germline cell death during mid-oogenesis is blocked, leading to a reduction and inappropriate nuclear localization of the active caspase Drice. These findings suggest that the combinatorial loss of pita and dcp-1 leads to the increased survival of abnormal egg chambers in mutants bearing the P-element alleles and that dcp-1 is essential for cell death during mid-oogenesis.

logjam Encodes a Predicted EMP24/GP25 Protein That Is Required for Drosophila Oviposition Behavior

Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 173-186
Author(s):  
Ginger E Carney ◽  
Barbara J Taylor
Keyword(s):  
Intracellular Trafficking ◽  
Oviposition Behavior ◽  
Egg Laying ◽  
P Element ◽  
Female Reproduction ◽  
Multiple Functions ◽  
Cytoplasmic Vesicles ◽  
Egg Chambers ◽  
Low Levels ◽  
Overlapping Transcripts

Abstract A newly characterized Drosophila melanogaster gene, logjam (loj), functions in female reproduction by modulating oviposition behavior. The locus encodes at least six overlapping transcripts with unique 5′ ends. P-element mutants that express very low levels of loj transcripts are unable to oviposit mature eggs. This phenotype can be rescued by the introduction of a transgene expressing the most abundant loj transcript. As for many genes that specify behavioral outputs, loj is present in the adult central nervous system (CNS). Interestingly, it is also observed in vitellogenic egg chambers, suggesting that there may be multiple functions for this gene in egg-laying behavior. loj encodes a predicted protein with homology to the EMP24/GP25 transmembrane components of cytoplasmic vesicles and likely functions in intracellular trafficking.

Drosophila betaHeavy-spectrin is essential for development and contributes to specific cell fates in the eye

Development ◽  
1998 ◽  
Vol 125 (11) ◽  
pp. 2125-2134 ◽  
Author(s):  
G.H. Thomas ◽  
D.C. Zarnescu ◽  
A.E. Juedes ◽  
M.A. Bales ◽  
A. Londergan ◽  
...  
Keyword(s):  
Membrane Skeleton ◽  
Specific Cell ◽  
Cell Integrity ◽  
Cell Fates ◽  
Gene Encoding ◽  
Rhodamine Phalloidin ◽  
Morphological Defects ◽  
Egg Chambers ◽  
Alpha Spectrin ◽  
Cell Cell

The spectrin membrane skeleton is a ubiquitous cytoskeletal structure with several cellular roles, including the maintenance of cell integrity, determination of cell shape and as a contributor to cell polarity. We have isolated mutations in the gene encoding βHeavy-spectrin in Drosophila, and have named this essential locus karst. karst mutant individuals have a pleiotropic phenotype characterized by extensive larval lethality and, in adult escapers, rough eyes, bent wings, tracheal defects and infertility. Within karst mutant eyes, a significant number of ommatidia specifically lack photoreceptor R7 alongside more complex morphological defects. Immunolocalization of betaHeavy-spectrin in wild-type eye-antennal and wing imaginal discs reveals that betaHeavy-spectrin is present in a restricted subdomain of the membrane skeleton that colocalizes with DE-cadherin. We propose a model where normal levels of Sevenless signaling are dependent on tight cell-cell adhesion facilitated by the betaHeavy-spectrin membrane skeleton. Immunolocalization of betaHeavy-spectrin in the adult and larval midgut indicates that it is a terminal web protein, but we see no gross morphological defects in the adult apical brush border in karst mutant flies. Rhodamine phalloidin staining of karst mutant ovaries similarly reveals no conspicuous defect in the actin cytoskeleton or cellular morphology in egg chambers. This is in contrast to mutations in alpha-spectrin, the molecular partner of betaHeavy-spectrin, which affect cellular structure in both the larval gut and adult ovaries. Our results emphasize the fundamental contribution of the spectrin membrane skeleton to normal development and reveals a critical interplay between the integrity of a cell's membrane skeleton, the structure of cell-cell contacts and cell signaling.

Frazzled/Dcc acts independently of Netrin to promote germline survival during Drosophila oogenesis

Development ◽  
2021 ◽  
Vol 148 (24) ◽  
Author(s):  
Samantha A. Russell ◽  
Kaitlin M. Laws ◽  
Greg J. Bashaw
Keyword(s):  
Cell Death ◽  
Axon Guidance ◽  
Transcriptional Activation ◽  
Nutrient Sensing ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Egg Chambers ◽  
Death Effector ◽  
Female Germline

ABSTRACT The Netrin receptor Frazzled/Dcc (Fra in Drosophila) functions in diverse tissue contexts to regulate cell migration, axon guidance and cell survival. Fra signals in response to Netrin to regulate the cytoskeleton and also acts independently of Netrin to directly regulate transcription during axon guidance in Drosophila. In other contexts, Dcc acts as a tumor suppressor by directly promoting apoptosis. In this study, we report that Fra is required in the Drosophila female germline for the progression of egg chambers through mid-oogenesis. Loss of Fra in the germline, but not the somatic cells of the ovary, results in the degeneration of egg chambers. Although a failure in nutrient sensing and disruptions in egg chamber polarity can result in degeneration at mid-oogenesis, these factors do not appear to be affected in fra germline mutants. However, similar to the degeneration that occurs in those contexts, the cell death effector Dcp-1 is activated in fra germline mutants. The function of Fra in the female germline is independent of Netrin and requires the transcriptional activation domain of Fra. In contrast to the role of Dcc in promoting cell death, our observations reveal a role for Fra in regulating germline survival by inhibiting apoptosis.

Apoptosis in late stage Drosophila nurse cells does not require genes within the H99 deficiency

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 1075-1082 ◽  
Author(s):  
K. Foley ◽  
L. Cooley
Keyword(s):  
Dna Fragmentation ◽  
Late Stage ◽  
Expression Patterns ◽  
Nuclear Material ◽  
Nurse Cells ◽  
Wild Type ◽  
Negative Regulators ◽  
Egg Chambers ◽  
Positive Regulators ◽  
Egg Chamber

We have determined that nurse cells are cleared from the Drosophila egg chamber by apoptosis. DNA fragmentation begins in nurse cells at stage 12, following the completion of cytoplasm transfer from the nurse cells to the oocyte. During stage 13, nurse cells increasingly contain highly fragmented DNA and disappear from the egg chamber concomitantly with the formation of apoptotic vesicles containing highly fragmented nuclear material. In dumpless mutant egg chambers that fail to complete cytoplasm transport from the nurse cells, DNA fragmentation is markedly delayed and begins during stage 13, when the majority of cytoplasm is lost from the nurse cells. These data suggest the presence of cytoplasmic factors in nurse cells that inhibit the initiation of DNA fragmentation. In addition, we have examined the ovarian expression patterns of regulatory genes implicated in Drosophila apoptosis. The positive regulators, reaper (rpr), head involution defective (hid) and grim, as well as the negative regulators, DIAP1 and DIAP2, are transcribed during oogenesis. However, germline clones homozygous for the deficiency Df(3)H99, which deletes rpr, hid and grim, undergo oogenesis in a manner morphologically indistinguishable from wild type, indicating that genes within this region are not necessary for apoptosis in nurse cells.

scholarly journals MicroRNA regulation of CTP synthase and cytoophidium in Drosophila melanogaster

2018 ◽  
Author(s):  
Najat Dzaki ◽  
Woo Wai Kan ◽  
Ghows Azzam
Keyword(s):  
De Novo ◽  
Mirna Gene ◽  
Target Prediction ◽  
Metabolic Enzyme ◽  
Gene Count ◽  
Micro Rnas ◽  
Egg Chambers ◽  
Regulatory Effects ◽  
Qpcr Quantification

AbstractCTPsyn is a crucial metabolic enzyme which synthesizes CTP molecules through the de novo or salvage pathway. It has the extraordinary ability to compartmentalize into filaments termed cytoophidia. Although this property is retained amongst orthologues, and cytoophidia are therefore found across kingdoms, the mechanisms behind their formation remain unknown. Micro-RNAs (miRNAs) are single-stranded RNA with length of 20 – 22 nucleotides, capable of exerting mRNA silencing and degradation as a form of regulation. D. melanogaster itself has a high total gene count to miRNA gene number ratio, alluding to the possibility that CTPsyn may too come under the regulatory effects of these small RNAs. A thorough miRNA overexpression involving 123 UAS-miRNA lines, followed by staining of ovarian cytoophidia dme-egg chambers, revealed a small group of candidates which confer either a lengthening or truncating effect on the structure. Prime candidates are identified on the basis of consistency. MiR-975 and miR-1014 are both cytoophidia-elongating, whereas miR-190 and miR-932 are cytoophidia-shortening. Though target prediction shows that miR-975 and miR-932 do indeed have binding sites on CTPsyn mRNA, in vitro assays instead revealed that none of the four candidates may actually do so. This suggests that the effects asserted by overexpressed miRNAs indirectly reach CTPsyn and its cytoophidia through the actions of middling elements. In silico target prediction and qPCR quantification indicated that, at least for miR-932 and miR-1014, these undetermined elements may be players in fat metabolism. This is the first study to thoroughly investigate miRNAs in connection to CTPsyn expression and activity in any species. The findings presented could serve as a basis for further queries into not only the fundamental aspects of the enzyme’s regulation, but may uncover new facets of closely related pathways as well.

Morphogenesis of Drosophila ovarian ring canals

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 2015-2025 ◽  
Author(s):  
D.N. Robinson ◽  
K. Cant ◽  
L. Cooley
Keyword(s):  
Protein Assembly ◽  
Wild Type ◽  
Filamentous Actin ◽  
Ring Canal ◽  
Ring Canals ◽  
Normal Ring ◽  
Egg Chambers ◽  
Cytoplasmic Bridges ◽  
Carboxy Terminal ◽  
Ordered Ring

We analyzed the structure of cytoplasmic bridges called ring canals in Drosophila egg chambers. Two mutations, hu-li tai shao (hts) and kelch, disrupt normal ring canal development. We raised antibodies against the carboxy-terminal tail of hts and found that they recognize a protein that localizes specifically to ring canals very early in ring canal assembly. Accumulation of filamentous actin on ring canals coincides with the appearance of the hts protein. kelch, which is localized to the ring canals hours after hts and actin, is necessary for maintaining a highly ordered ring canal rim since kelch mutant egg chambers have ring canals that are obstructed by disordered actin and hts. Anti-phosphotyrosine antibodies immunostain ring canals beginning early in the germarium before hts and actin and throughout egg chamber development. The use of antibody reagents to analyze the structure of wild-type and mutant ring canals has shown that ring canal development is a dynamic process of cytoskeletal protein assembly, possibly regulated by tyrosine phosphorylation of some ring canal components.

The tumor suppressor gene, lethal(2)giant larvae (1(2)g1), is required for cell shape change of epithelial cells during Drosophila development

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2283-2294 ◽  
Author(s):  
P. Manfruelli ◽  
N. Arquier ◽  
W.P. Hanratty ◽  
M. Semeriva
Keyword(s):  
Epithelial Cells ◽  
Cell Shape ◽  
Imaginal Disc ◽  
Biochemical Characterization ◽  
Shape Change ◽  
Follicle Cells ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Egg Chambers ◽  
Disc Cells

Inactivation of the lethal(2)giant larvae (l(2)gl) gene results in malignant transformation of imaginal disc cells and neuroblasts of the larval brain in Drosophila. Subcellular localization of the l(2)gl gene product, P127, and its biochemical characterization have indicated that it participates in the formation of the cytoskeletal network. In this paper, genetic and phenotypic analyses of a temperature-sensitive mutation (l(2)glts3) that behaves as a hypomorphic allele at restrictive temperature are presented. In experimentally overaged larvae obtained by using mutants in the production of ecdysone, the l(2)glts3 mutation displays a tumorous potential. This temperature-sensitive allele of the l(2)gl gene has been used to describe the primary function of the gene before tumor progression. A reduced contribution of both maternal and zygotic activities in l(2)glts3 homozygous mutant embryos blocks embryogenesis at the end of germ-band retraction. The mutant embryos are consequently affected in dorsal closure and head involution and show a hypertrophy of the midgut. These phenotypes are accompanied by an arrest of the cell shape changes normally occurring in lateral epidermis and in epithelial midgut cells. l(2)gl activity is also necessary for larval fife and the critical period falls within the third instar larval stage. Finally, l(2)gl activity is required during oogenesis and mutations in the gene disorganize egg chambers and cause abnormalities in the shape of follicle cells, which are eventually internalized within the egg chamber. These results together with the tumoral phenotype of epithelial imaginal disc cells strongly suggest that the l(2)gl product is required in vivo in different types of epithelial cells to control their shape during development.

Studies on the female-sterile phenotype of 1(1)su(f) ts76a, a temperature-sensitive allele of the suppressor of forked mutation in Drosophila melanogaster

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 247-256
Author(s):  
Thomas G. Wilson
Keyword(s):  
Cell Death ◽  
Drosophila Melanogaster ◽  
Follicle Cell ◽  
Lethal Mutation ◽  
Female Sterility ◽  
Temperature Sensitive ◽  
Egg Chambers ◽  
A Cell ◽  
Sensitive Allele

A new allele of the suppressor of forked [su(f)] mutation in Drosophila melanogaster has been found and designated 1(1)su(f)ts76a. It is temperature-sensitive for suppression of forked (f) and has additional temperature-sensitive phenotypes of lethality, female sterility, and abnormal bristle formation at 29 °C. It closely resembles two other conditional alleles of su(f), 1(1)su(f)ts67g and 1(1)ts726. Female sterility at 29 °C is characterized by both disorganized egg chambers in the ovarioles and also chorion-deficient oocytes. Both of these abnormalities may be the result of premature follicle cell death. The observations on 1(1)su(f)ts76a are consistent with the proposal that the similar allele, 1(1)ts726, is a cell-lethal mutation specifically affecting mitotically active cells.

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