Analysis of the spatial organization of the XL chromosome attachment site in nurse cell nuclei of the malaria mosquito Anopheles atroparvus

Abstract Anopheles funestus Giles is one of the major malaria vectors in Africa, but little is known about its genetics. Lack of a cytogenetic map characterized by regions has hindered the progress of genetic research with this important species. This study developed a cytogenetic map of An. funestus using ovarian nurse cell polytene chromosomes. We demonstrate an important application with the cytogenetic map for characterizing various chromosomal inversions for specimens collected from coastal Kenya. The linear and spatial organization of An. funestus polytene chromosomes was compared with the best-studied malaria mosquito, An. gambiae Giles. Comparisons of chromosome morphology between the two species have revealed that the most extensive chromosomal rearrangement occurs in pericentromeric heterochromatin of autosomes. Differences in pericentromeric heterochromatin types correlate with nuclear organization differences between An. funestus and An. gambiae. Attachments of chromosomes to the nuclear envelope strongly depend on the presence of diffusive β-heterochromatin. Thus, An. funestus and An. gambiae exhibit species-specific characteristics in chromosome-linear and -spatial organizations.

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Oogenesis in Lucilia Cuprina (Wied.) (Diptera: Calliphoridae). Ii. The Effect of Aziridinyl Chemosterilants on Oogenesis.

Australian Journal of Zoology ◽

10.1071/zo9790349 ◽

1979 ◽

Vol 27 (3) ◽

pp. 349 ◽

Cited By ~ 3

Author(s):

GAC Beattie

Keyword(s):

Direct Effect ◽

Nurse Cell ◽

Ovarian Development ◽

Fat Body ◽

Endocrine System ◽

Lucilia Cuprina ◽

Follicle Cells ◽

Cell Nuclei

Inhibition of ovarian development in L. cuprina by two aziridinyl chemosterilants, N,N'-hexamethylenebis(1-aziridinecarboxamide) and N. N'bisaziridinyl-N"-cyclohexylphosphine sulphide, was due to the direct effect of the sterilants on the ovary. The sterilants caused infecundity by interfering with mitosis in the follicle cells. Contrary to the accepted view, no evidence was obtained to suggest that infecundity resulted from inhibition of endomitosis in the nurse cell nuclei. Neither sterilant prevented the digestion of protein by the midgut, nor did they prevent the endocrine system and fat body from functioning.

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Basement membrane and interstitial matrix components form separate matrices in heterokaryons of PYS-2 cells and fibroblasts

Journal of Cell Science ◽

10.1242/jcs.104.1.59 ◽

1993 ◽

Vol 104 (1) ◽

pp. 59-68

Author(s):

P. Laurila ◽

I. Leivo

Keyword(s):

Basement Membrane ◽

Matrix Protein ◽

Spatial Organization ◽

Gene Dosage ◽

Parental Cell ◽

Cell Nuclei ◽

Fibronectin Matrix ◽

Basement Membrane Protein ◽

The Matrix

In order to gain further understanding of the spatial organization of interstitial and basement membrane matrices, we studied the expression of the interstitial matrix protein, fibronectin, and the basement membrane protein, laminin, in heterokaryons formed by the fusion of normal fibroblasts and teratocarcinoma-derived epithelial PYS-2 cells. These heterokaryons showed various distributions of the matrix proteins depending on the proportions of the different parental cell nuclei within the cytoplasm of the cell. Heterokaryons containing equal numbers of fibroblast and PYS-2 cell nuclei showed an abundant laminin matrix subcellularly and only minor amounts of fibronectin matrix at the periphery of the cells. Similar results were obtained in heterokaryons containing an excess of epithelial cell nuclei. In heterokaryons containing an excess of fibroblast nuclei, on the other hand, laminin matrix was reduced and a fibrillar fibronectin matrix was seen also on top of the cell body. The results suggest a gene dosage-type of effect on the expression of these proteins. Furthermore, extracellular laminin and fibronectin matrices did not codistribute around the heterokaryons but the two proteins were assembled into separate structures. The lack of codistribution of fibronectin and laminin matrices in heterokaryons suggests that the molecular interactions, which determine the assembly of basement membrane and interstitial matrices in these cells are highly type-specific. Similar mechanisms may also operate in the assembly of extracellular matrices in vivo.

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Tissue-specific features of the X chromosome and nucleolus spatial dynamics in a malaria mosquito, Anopheles atroparvus

PLoS ONE ◽

10.1371/journal.pone.0171290 ◽

2017 ◽

Vol 12 (2) ◽

pp. e0171290 ◽

Cited By ~ 3

Author(s):

Semen M. Bondarenko ◽

Gleb N. Artemov ◽

Igor V. Sharakhov ◽

Vladimir N. Stegniy

Keyword(s):

X Chromosome ◽

Spatial Dynamics ◽

Malaria Mosquito ◽

Tissue Specific ◽

Anopheles Atroparvus

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Computational staining of pathology images to study tumor microenvironment in lung cancer

10.1101/630749 ◽

2019 ◽

Author(s):

Shidan Wang ◽

Ruichen Rong ◽

Donghan M. Yang ◽

Ling Cai ◽

Lin Yang ◽

...

Keyword(s):

Gene Expression ◽

Tumor Microenvironment ◽

Spatial Organization ◽

Risk Group ◽

Biological Pathways ◽

The Cancer Genome Atlas ◽

Analysis Tool ◽

Cell Nuclei ◽

Tumor Tissues ◽

Different Types

ABSTRACTThe spatial organization of different types of cells in tumor tissues reveals important information about the tumor microenvironment (TME). In order to facilitate the study of cellular spatial organization and interactions, we developed a comprehensive nuclei segmentation and classification tool to characterize the TME from standard Hematoxylin and Eosin (H&E)-stained pathology images. This tool can computationally “stain” different types of cell nuclei in H&E pathology images to facilitate pathologists in analyzing the TME.A Mask Regional-Convolutional Neural Network (Mask-RCNN) model was developed to segment the nuclei of tumor, stromal, lymphocyte, macrophage, karyorrhexis and red blood cells in lung adenocarcinoma (ADC). Using this tool, we identified and classified cell nuclei and extracted 48 cell spatial organization-related features that characterize the TME. Using these features, we developed a prognostic model from the National Lung Screening Trial dataset, and independently validated the model in The Cancer Genome Atlas (TCGA) lung ADC dataset, in which the predicted high-risk group showed significantly worse survival than the low-risk group (pv= 0.001), with a hazard ratio of 2.23 [1.37-3.65] after adjusting for clinical variables. Furthermore, the image-derived TME features were significantly correlated with the gene expression of biological pathways. For example, transcription activation of both the T-cell receptor (TCR) and Programmed cell death protein 1 (PD1) pathways was positively correlated with the density of detected lymphocytes in tumor tissues, while expression of the extracellular matrix organization pathway was positively correlated with the density of stromal cells.This study developed a deep learning-based analysis tool to dissect the TME from tumor tissue images. Using this tool, we demonstrated that the spatial organization of different cell types is predictive of patient survival and associated with the gene expression of biological pathways. Although developed from the pathology images of lung ADC, this model can be adapted into other types of cancers.

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BOTH NUCLEOLAR ORGANIZERS ARE REPLICATED IN DIPTERAN POLYPLOID TISSUES: A STUDY AT THE LEVEL OF INDIVIDUAL NUCLEI

Genetics ◽

10.1093/genetics/111.2.325 ◽

1985 ◽

Vol 111 (2) ◽

pp. 325-336

Author(s):

Esther J Belikoff ◽

Kathy Beckingham

Keyword(s):

Salivary Gland ◽

Nurse Cell ◽

Nuclear Dna ◽

Organizer Region ◽

Nucleolar Organizer Region ◽

Nucleolar Organizer ◽

Single Pair ◽

Cell Nuclei ◽

Calliphora Erythrocephala ◽

Nontranscribed Spacer

ABSTRACT Working with the Dipteran Calliphora erythrocephala, we have tested the hypothesis that only one nucleolar organizer region (NO) is replicated during polyploidization. NO replication was examined in two very different highly polyploid nuclear types: salivary gland nuclei and nurse cell nuclei. Two strains of the organism containing NO regions with highly diagnostic nontranscribed spacer (NTS) polymorphisms were prepared and reciprocal single pair-matings between members of the strains were performed. The representation of the two distinguishable NOs in diploid and polyploid DNAs of individual F1 progeny from each cross was then examined. DNA from a total polyploid nuclear DNA preparation and from individual polyploid nuclei of both tissue types was analyzed. Our results show conclusively that both genomic NOs are replicated in individual polyploid nuclei of both types. Further, evidence for variation in the relative replication of cistrons from the two NOs by individual nuclei was obtained. The cistron types present in the NOs of both strains showed differential replication upon polyploidization. In general, the patterns of differential cistron replication seen in salivary gland and nurse cell nuclei were similar.

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Autophagic degradation of dBruce controls DNA fragmentation in nurse cells during late Drosophila melanogaster oogenesis

The Journal of Cell Biology ◽

10.1083/jcb.201002035 ◽

2010 ◽

Vol 190 (4) ◽

pp. 523-531 ◽

Cited By ~ 153

Author(s):

Ioannis P. Nezis ◽

Bhupendra V. Shravage ◽

Antonia P. Sagona ◽

Trond Lamark ◽

Geir Bjørkøy ◽

...

Keyword(s):

Cell Death ◽

Drosophila Melanogaster ◽

Dna Fragmentation ◽

Nurse Cell ◽

Nurse Cells ◽

Cell Nuclei ◽

Cytoplasmic Material ◽

Fragmented Dna ◽

Egg Chambers ◽

Autophagic Degradation

Autophagy is an evolutionarily conserved pathway responsible for degradation of cytoplasmic material via the lysosome. Although autophagy has been reported to contribute to cell death, the underlying mechanisms remain largely unknown. In this study, we show that autophagy controls DNA fragmentation during late oogenesis in Drosophila melanogaster. Inhibition of autophagy by genetically removing the function of the autophagy genes atg1, atg13, and vps34 resulted in late stage egg chambers that contained persisting nurse cell nuclei without fragmented DNA and attenuation of caspase-3 cleavage. The Drosophila inhibitor of apoptosis (IAP) dBruce was found to colocalize with the autophagic marker GFP-Atg8a and accumulated in autophagy mutants. Nurse cells lacking Atg1 or Vps34 in addition to dBruce contained persisting nurse cell nuclei with fragmented DNA. This indicates that autophagic degradation of dBruce controls DNA fragmentation in nurse cells. Our results reveal autophagic degradation of an IAP as a novel mechanism of triggering cell death and thereby provide a mechanistic link between autophagy and cell death.

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Drosophila singed, a fascin homolog, is required for actin bundle formation during oogenesis and bristle extension.

The Journal of Cell Biology ◽

10.1083/jcb.125.2.369 ◽

1994 ◽

Vol 125 (2) ◽

pp. 369-380 ◽

Cited By ~ 155

Author(s):

K Cant ◽

B A Knowles ◽

M S Mooseker ◽

L Cooley

Keyword(s):

Sea Urchin ◽

Actin Filament ◽

Nurse Cell ◽

Structural Integrity ◽

Molar Ratio ◽

Cell Nuclei ◽

Cytoplasmic Actin ◽

Filament Bundles ◽

Filament Bundle

Drosophila singed mutants were named for their gnarled bristle phenotype but severe alleles are also female sterile. Recently, singed protein was shown to have 35% peptide identity with echinoderm fascin. Fascin is found in actin filament bundles in microvilli of sea urchin eggs and in filopodial extensions in coelomocytes. We show that Drosophila singed is required for actin filament bundle formation in the cytoplasm of nurse cells during oogenesis; in severe mutants, the absence of cytoplasmic actin filament bundles allows nurse cell nuclei to lodge in ring canals and block nurse cell cytoplasm transport. Singed is also required for organized actin filament bundle formation in the cellular extension that forms a bristle; in severe mutants, the small disorganized actin filament bundles lack structural integrity and allow bristles to bend and branch during extension. Singed protein is also expressed in migratory cells of the developing egg chamber and in the socket cell of the developing bristle, but no defect is observed in these cells in singed mutants. Purified, bacterially expressed singed protein bundles actin filaments in vitro with the same stoichiometry reported for purified sea urchin fascin. Singed-saturated actin bundles have a molar ratio of singed/actin of approximately 1:4.3 and a transverse cross-banding pattern of 12 nm seen using electron microscopy. Our results suggest that singed protein is required for actin filament bundle formation and is a Drosophila homolog of echinoderm fascin.

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