scholarly journals Fibroin Secretion in the Posterior Silk Gland Cells of a Flimsy Cocoon Mutant of Bombyx mori

1980 ◽  
Vol 5 (1) ◽  
pp. 105-108 ◽  
Author(s):  
Noriko Adachi-Yamashita ◽  
Bungo Sakaguchi ◽  
Haruo Chikushi
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Gland Cells ◽  
Posterior Silk Gland

scholarly journals EXTRUSION OF NUCLEAR MATERIALS INTO CYTOPLASM IN THE POSTERIOR SILK GLAND CELLS OF SILKWORM, BOMBYX MORI

1968 ◽  
Vol 36 (3) ◽  
pp. C5-10 ◽  
Author(s):  
Yutaka Tashiro ◽  
Shiro Matsuura ◽  
Takashi Morimoto ◽  
Sunao Nagata
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Nuclear Materials ◽  
Gland Cells ◽  
Silkworm Bombyx Mori ◽  
Posterior Silk Gland

scholarly journals Lysosomes and Related Structures in the Posterior Silk Gland Cells of Bombyx mori. II. In Prepupal and Early Pupal Stadium

1976 ◽  
Vol 1 (3) ◽  
pp. 223-235 ◽  
Author(s):  
Shiro Matsuura ◽  
Takeo Shimadzu ◽  
Yutaka Tashiro
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Gland Cells ◽  
Posterior Silk Gland

scholarly journals Enhanced Myc Expression in Silkworm Silk Gland Promotes DNA Replication and Silk Production

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 361
Author(s):  
Wenliang Qian ◽  
Yan Yang ◽  
Zheng Li ◽  
Yuting Wu ◽  
Xuechuan He ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cell Growth ◽  
Silk Gland ◽  
Biological Functions ◽  
Gland Cells ◽  
Silk Production ◽  
Myc Gene ◽  
Cell Growth And Proliferation ◽  
Silkworm Silk ◽  
Posterior Silk Gland

Silkworm is an economically important insect that synthetizes silk proteins for silk production in silk gland, and silk gland cells undergo endoreplication during larval period. Transcription factor Myc is essential for cell growth and proliferation. Although silkworm Myc gene has been identified previously, its biological functions in silkworm silk gland are still largely unknown. In this study, we examined whether enhanced Myc expression in silk gland could facilitate cell growth and silk production. Based on a transgenic approach, Myc was driven by the promoter of the fibroin heavy chain (FibH) gene to be successfully overexpressed in posterior silk gland. Enhanced Myc expression in the PSG elevated FibH expression by about 20% compared to the control, and also increased the weight and shell rate of the cocoon shell. Further investigation confirmed that Myc overexpression increased nucleus size and DNA content of the PSG cells by promoting the transcription of the genes involved in DNA replication. Therefore, we conclude that enhanced Myc expression promotes DNA replication and silk protein expression in endoreplicating silk gland cells, which subsequently raises silk yield.

scholarly journals CRISPR-Mediated Endogenous Activation of Fibroin Heavy Chain Gene Triggers Cellular Stress Responses in Bombyx mori Embryonic Cells

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 552
Author(s):  
Wenbo Hu ◽  
Xiaogang Wang ◽  
Sanyuan Ma ◽  
Zhangchuan Peng ◽  
Yang Cao ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Heavy Chain ◽  
Stress Responses ◽  
Cellular Stress ◽  
Silk Gland ◽  
Cellular Stress Response ◽  
Molar Ratio ◽  
Chain Gene ◽  
Gland Cells ◽  
Cellular Stress Responses

The silkworm Bombyx mori is an economically important insect, as it is the main producer of silk. Fibroin heavy chain (FibH) gene, encoding the core component of silk protein, is specifically and highly expressed in silk gland cells but not in the other cells. Although the silkworm FibH gene has been well studied in transcriptional regulation, its biological functions in the development of silk gland cells remain elusive. In this study, we constructed a CRISPRa system to activate the endogenous transcription of FibH in Bombyx mori embryonic (BmE) cells, and the mRNA expression of FibH was successfully activated. In addition, we found that FibH expression was increased to a maximum at 60 h after transient transfection of sgRNA/dCas9-VPR at a molar ratio of 9:1. The qRT-PCR analysis showed that the expression levels of cellular stress response-related genes were significantly up-regulated along with activated FibH gene. Moreover, the lyso-tracker red and monodansylcadaverine (MDC) staining assays revealed an apparent appearance of autophagy in FibH-activated BmE cells. Therefore, we conclude that the activation of FibH gene leads to up-regulation of cellular stress responses-related genes in BmE cells, which is essential for understanding silk gland development and the fibroin secretion process in B. mori.

P25 gene regulation in Bombyx mori silk gland: two promoter-binding factors have distinct tissue and developmental specificities

1992 ◽  
Vol 12 (12) ◽  
pp. 5768-5777
Author(s):  
B Durand ◽  
J Drevet ◽  
P Couble
Keyword(s):  
Bombyx Mori ◽  
Head Capsule ◽  
Regulatory Elements ◽  
Silk Gland ◽  
Related Factor ◽  
Developmental Studies ◽  
Hormonal Change ◽  
Specific Expression ◽  
Gland Cells ◽  
Gene Status

The gene encoding the silk protein P25 is expressed in the posterior silk gland of Bombyx mori with strict territorial and developmental specificities. The cis-acting regulatory elements previously located within the 441-bp 5' proximal sequence of the gene were examined for protein-binding capacities. We identified two factors, BMFA and SGFB, that lead to prominent band shifts and the target sites for which are included in a region homologous to the fibroin gene enhancer sequence. Analysis of the tissue-specific incidence of both factors showed that BMFA is ubiquitous, whereas SGFB is restricted to the silk gland cells. However, SGFB was found in both posterior and middle silk gland cells and therefore likely directs organ-specific, but not territory-specific, expression. Developmental studies throughout the fourth larval molt, at which the P25 gene status changes from derepressed to repressed, revealed that BMFA is reversibly modified at the transition from intermolt to molt. Indeed, the preexisting BMFA is replaced by a structurally related factor, BMFA', during the 2 h following head capsule apolysis. The exact temporal coincidence of this conversion with the onset of gene repression suggests that BMFA' is involved in transcription inactivation and likely results from a transduction process initiated by the hormonal change at molting.

Localization of the genes for silk fibroin in silk gland cells of Bombyx mori

1976 ◽  
Vol 49 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Christian Thomas ◽  
Donald D. Brown
Keyword(s):  
Bombyx Mori ◽  
Silk Fibroin ◽  
Silk Gland ◽  
Gland Cells

The Ultrastructure and Functions of the Silk Gland Cells of Bombyx mori

1984 ◽  
pp. 323-364 ◽  
Author(s):  
Hiromu Akai
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Gland Cells
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