Chorion Genes: A Landscape of Their Evolution, Structure, and Regulation

2015 ◽  
Vol 60 (1) ◽  
pp. 177-194 ◽  
Author(s):  
Argyris Papantonis ◽  
Luc Swevers ◽  
Kostas Iatrou
Keyword(s):  
Chorion Genes

scholarly journals Visualization of Drosophila melanogaster chorion genes undergoing amplification.

1988 ◽  
Vol 8 (7) ◽  
pp. 2811-2821 ◽  
Author(s):  
Y N Osheim ◽  
O L Miller ◽  
A L Beyer
Keyword(s):  
Time Frame ◽  
Maximum Activity ◽  
Follicle Cells ◽  
Control Element ◽  
Active Gene ◽  
Chorion Genes ◽  
Temporal Specificity ◽  
Preferential Amplification ◽  
Essential Region ◽  
Large Clusters

We visualized by electron microscopy the preferential amplification of Drosophila chorion genes in late-stage follicle cells. Chromatin spreads revealed large clusters of actively transcribed genes of the appropriate size, spacing, and orientation for chorion genes that were expressed with the correct temporal specificity. Occasionally the active genes were observed within or contiguous with intact replicons and replication forks. In every case, our micrographs are consistent with the hypothesis that the central region of each chorion domain contains a replication origin(s) used during the amplification event. In one case, a small replication bubble was observed precisely at the site of the essential region of the X chromosome amplification control element. The micrographs also suggest that forks at either end of a replicon frequently progress very different distances, presumably due to different times in initiation or different rates of movement. It appears that all chorion genes (even those coding for minor proteins) are transcribed in a "fully on" condition, albeit for varied durations, and that if replication fork passage does inactivate a promoter, it does so very transiently. Furthermore, a DNA segment containing one active gene is likely to have an additional active gene(s). Surprisingly, during the time frame of expected maximum activity, approximately half of the chorion sequences appear transcriptionally inactive.

scholarly journals Linkage and evolutionary diversification of developmentally regulated multigene families: tandem arrays of the 401/18 chorion gene pair in silkmoths.

1981 ◽  
Vol 1 (9) ◽  
pp. 814-828 ◽  
Author(s):  
C W Jones ◽  
F C Kafatos
Keyword(s):  
Gene Pair ◽  
Single Individual ◽  
Developmentally Regulated ◽  
Evolutionary Diversification ◽  
Repeat Units ◽  
Chorion Genes ◽  
Restriction Sites ◽  
Multiple Copies ◽  
Flanking Sequences ◽  
Silkmoth Chorion

The coordinately expressed silkmoth chorion genes, 401 and 18, are closely linked as a pair, in divergent orientation. Analysis of overlapping clones (chromosomal "walk") demonstrated that each of the multiple copies of this gene pair is embedded within a larger deoxyribonucleic acid unit, which is tandemly repeated in a few arrays or possibly a single array. Southern analysis and examination of clones from a single individual moth demonstrated that the repeat units are extensively polymorphic in restriction sites, length, and possibly number, no differential amplification was evident during choriogenesis. Intron and 5'-flanking sequences were shown to be specific for the 401/18 gene pair and not to be present elsewhere in the genome. The spatial distribution of variations in the genes and their flanking sequences were examined.

scholarly journals Evolution of a multigene family of chorion proteins in silkmoths.

1982 ◽  
Vol 2 (5) ◽  
pp. 554-563 ◽  
Author(s):  
G C Rodakis ◽  
N K Moschonas ◽  
F C Kafatos
Keyword(s):  
Protein Structure ◽  
Bombyx Mori ◽  
Dna Sequences ◽  
Multigene Family ◽  
Antheraea Polyphemus ◽  
Antheraea Pernyi ◽  
Chorion Genes ◽  
Base Substitutions ◽  
New Protein

The evolution of the A family of chorion genes was examined by comparing new protein and DNA sequences from the silkmoths Antheraea pernyi and Bombyx mori with previously known sequences from Antheraea polyphemus. The comparisons indicated that the A family and its major subfamilies are ancient and revealed how parts of the genes corresponding to distinct regions of the protein structure have evolved, both by base substitutions and by segmental reduplications and deletions.

Drosophila chorion genes: Cracking the eggshell's secrets

BioEssays ◽  
1991 ◽  
Vol 13 (3) ◽  
pp. 97-105 ◽  
Author(s):  
Terry L. Orr-Weaver
Keyword(s):  
Chorion Genes

scholarly journals Synergistic interactions of silkmoth chorion promoter-binding factors.

1991 ◽  
Vol 11 (4) ◽  
pp. 1954-1964 ◽  
Author(s):  
Y A Skeiky ◽  
K Iatrou
Keyword(s):  
Cell Line ◽  
Transcriptional Activation ◽  
Transcriptional Repression ◽  
Specific Binding ◽  
Ovarian Tissue ◽  
Mobility Shift ◽  
Minimum Requirement ◽  
Synergistic Interactions ◽  
Chorion Genes ◽  
Silkmoth Chorion

Two DNA-binding proteins, BCFI and BCFII, that interact with defined promoter sequences of silkmoth chorion genes of late developmental specificity appear in the nuclei of follicular cells at a time that coincides with the transcriptional activation of the corresponding genes. BCFI prebinding is shown to be indispensable for stable binding of BCFII to its cognate sequence. BCFI and BCFII synergism requires a relatively stringent stereospecific alignment and is a prerequisite for the assembly of higher-order protein-promoter DNA complexes containing additional factors, which are neither gene (stage) nor class (chorion) specific. Binding of BCFI to its site correlates with the induction of DNA structural perturbations that may facilitate assembly of additional factors on the promoter. The BCFI-binding domain contains a core hexanucleotide sequence, AGATAA, which represents the major binding determinant of the erythroid-specific transcription factor GATA-1 of higher vertebrates. This sequence is shown to be necessary and sufficient for binding of BCFI, as it is for a factor that is present in induced K562 human erythroleukemic cells, presumably GATA-1. Comparative analyses of mobility shift patterns obtained with partially proteolyzed preparations of these two unrelated factors were used to confirm that a BCFI-like chorion promoter-binding protein, which is present in the nuclei of an established silkmoth cell line derived from ovarian tissue, is in fact BCFI. The transcriptional repression of endogenous chorion genes in this cell line coupled with the documented absence of factor BCFII suggests that the synergistic interactions between these two factors constitute a minimum requirement for late chorion gene expression.

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