Morphogenesis of silkmoth chorion: Initial framework formation and its relation to synthesis of specific proteins

Regier, Jerome C.; Mazur, Grace Dane; Kafatos, Fotis C.; Paul, Miles

doi:10.1016/0012-1606(82)90160-9

Cited by 55 publications

(35 citation statements)

References 16 publications

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“…Early proteins form an initial scaffold, into which middle proteins intercalate to add mass and density, while late (high-cysteine) proteins percolate throughout the previously deposited lamellae to crosslink the whole chorion and, in addition, form the outer lamellate crust Regier et al, 1982Regier et al, , 1995.…”

Section: P9005mentioning

confidence: 99%

“…The formation of the helicoidal lamellar chorion is proposed to occur in four temporally discrete steps, framework formation (small number of lamellae are deposited), expansion (thickening of existing lamellae), densification (thickening of fibers within lamellae), and surface sculpturing (deposition of additional lamellae that can be sculpted into surface structures, e.g., the aeropyle crowns of A. polyphemus eggs; Regier et al, 1982;Mazur et al, 1989;Leclerc and Regier, 1993).…”

Section: Chorion Genes and Regulation Of Chorion Gene Expression P0935mentioning

confidence: 99%

See 1 more Smart Citation

Vitellogenesis and Post-Vitellogenic Maturation of the Insect Ovarian Follicle

Swevers

2005

Comprehensive Molecular Insect Science

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Section: P9005mentioning

confidence: 99%

Section: Chorion Genes and Regulation Of Chorion Gene Expression P0935mentioning

confidence: 99%

Vitellogenesis and Post-Vitellogenic Maturation of the Insect Ovarian Follicle

Swevers

2005

Comprehensive Molecular Insect Science

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“…Furthermore, the CA and CB families are developmentally early (12,13) and probably construct the initial framework of the chorion (10) when during evolution these events occurred. Multiple chorion proteins of the A, B, and C size classes are evident in Lepidoptera outside the superfamily Bombycoidea, suggesting that at least some families and subfamilies are ancient.…”

Section: )mentioning

confidence: 99%

“…10% of the chorion mass. It appears to play an important morphogenetic role: it constitutes the bulk of the early proteins that are responsible for formation of the initial chorion framework (10) and that are required for organization of the quantitatively dominant components, which are secreted later (11). Only one C component has been sequenced to date, in A. polyphemus, and has proved to be related to the B family (12).…”

mentioning

confidence: 99%

Evolution of the silk moth chorion gene superfamily: gene families CA and CB.

Lecanidou¹,

Rodakis²,

Eickbush³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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The nucleotide sequences of two developmentally early chorion cDNA clones from Bombyx mori define two distinct proline-rich chorion protein families, which we name CA and CB to indicate their homologies to the previously defined chorion protein families A and B, as well as the developmentally late and cysteine-rich HcA and HcB chorion families. Thus, the chorion gene superfamily has two symmetrical branches, each consisting of three families: the a branch (A, CA, HcA families) and the , ( branch (B, CB, HcB families).The evolution of the superfamily is discussed.The chorion or eggshell of silk moths is a complex extracellular structure: in the wild moth Antheraea polyphemus, as many as 186 polypeptides have been resolved by twodimensional gel electrophoresis (1); partial protein sequence analysis as well as extensive characterization of genomic and cDNA clones indicate that many of these components are encoded by distinct genes (reviewed in refs. 2 and 3).Despite this present-day complexity, there is an underlying evolutionary simplicity: a high proportion of the chorion genes are related by descent, constituting homologous gene families. This was first shown for the two predominant families known as A and B (2). Superficially distinct chorion proteins with very high cysteine content (Hc proteins) were shown by DNA sequencing to correspond to offshoots of the A and B families and were correspondingly named HcA and HcB (4-6). In each of these four families, the central part of the sequence (central domain) is most highly conserved, apparently for reasons of protein secondary structure (7). Extensive homologies are evident between A and HcA or B and HcB central domains. Furthermore, A and B central domains show distant similarities, suggesting that the chorion genes constitute a superfamily derived from a single ancestral gene (8, 9). The amino-and carboxyl-terminal sequences (left and right arms) are considerably more variable, but even they show similarities both within and among the chorion gene families.Little is known about the class of chorion proteins named C. That class is quite complex (42 of 186 electrophoretically resolved components in A. polyphemus; ref. 1), although it accounts for only ca. 10% of the chorion mass. It appears to play an important morphogenetic role: it constitutes the bulk of the early proteins that are responsible for formation of the initial chorion framework (10) and that are required for organization of the quantitatively dominant components, which are secreted later (11). Only one C component has been sequenced to date, in A. polyphemus, and has proved to be related to the B family (12).In the course of characterizing a complex set of genes expressed in early choriogenesis of Bombyx mori, we have sequenced two C-like cDNA clones. These clones show that the C class in fact includes two distinct families, related to the A and B families and accordingly named CA and CB. We discuss those two new families in the context of the evolutionary history of the entire superfamily. M...

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“…At the supramolecular level, the chorion is a highly ordered and complex structure that undergoes discrete modes of morphogenesis, resulting in a continuous reordering of an early framework (3,4). At the protein level, >100 components, some with distinct functions, are synthesized in varying amounts in a time-dependent and cell-specific manner (5)(6)(7).…”

mentioning

confidence: 99%

Evolutionary changes in the developmental expression of silkmoth chorion genes and their morphological consequences.

Hatzopoulos¹,

Regier²

1987

Proc. Natl. Acad. Sci. U.S.A.

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Discrete changes in silkmoth choriogenesis have occurred during evolution, as exemplified in the present report in Antheraea polyphemus and Hyalophora cecropia. At the level of morphology, the chorion of A. polyphemus has surface structures, called aeropyle crowns, that are absent from H. cecropia. Aeropyle crowns form during the very late period of choriogenesis and consist of two substructures lamellae and filer. Filler is present in H. cecropia in greatly reduced amounts. At the level of protein synthesis, overall similarities in the two species are maintained until the very late period of choriogenesis, when synthesis of aeropyle crown components is maximal. In H. cecropia, very late periodspecific proteins are reduced in number and abundance. Several of these minor proteins are candidates for El and E2, the components of filler. El and E2 RNAs are about 35 times more abundant in A. polyphemus, despite very similar gene copy numbers and times of expression in the two species. These results support the hypothesis that evolutionary changes in chorion morphology have resulted from regulatory changes in the expression of chorion genes, either at the level of transcription or mRNA decay. The hypothesis that evolutionary changes in chorion morphology are based on terminal addition onto a preexisting developmental program is discussed.

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Morphogenesis of silkmoth chorion: Initial framework formation and its relation to synthesis of specific proteins

Cited by 55 publications

References 16 publications

Vitellogenesis and Post-Vitellogenic Maturation of the Insect Ovarian Follicle

Vitellogenesis and Post-Vitellogenic Maturation of the Insect Ovarian Follicle

Evolution of the silk moth chorion gene superfamily: gene families CA and CB.

Evolutionary changes in the developmental expression of silkmoth chorion genes and their morphological consequences.

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