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 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 Bombyx mori Dihydroorotate Dehydrogenase: Knockdown Inhibits Cell Growth and Proliferation via Inducing Cell Cycle Arrest

2018 ◽  
Vol 19 (9) ◽  
pp. 2581 ◽  
Author(s):  
Erhu Zhao ◽  
Xiaolan Jiang ◽  
Hongjuan Cui
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Dna Replication ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Bombyx Mori ◽  
Dihydroorotate Dehydrogenase ◽  
Pyrimidine Synthesis ◽  
Cycle Arrest ◽  
Cell Growth And Proliferation

Dihydroorotate dehydrogenase (DHODH), in the de novo pyrimidine biosynthetic pathway, is the fourth enzyme of pyrimidine synthesis and is used to oxidize dihydroorotate and hence to orotat. We cloned and characterized here the dhod of silkworms, Bombyx mori. The full-length cDNA sequence of dhod is 1339 bp, including an open reading frame (ORF) of 1173 bp that encoded a 390 amino acid protein. And two domains were involved in the Dihydroorotate dehydrogenase amino acid sequence of silkworms, Bombyx mori (BmDHODH), namely a DHO_dh domain and a transmembrane domain in N-termina. The silkworm dhod is expressed throughout development and in nine tissues. Moreover, knockdown of the silkworm dhod gene reduced cell growth and proliferation through G2/M phase cell cycle arrest. Similarly, DHODH inhibitor (leflunomide) also reduced cell growth and proliferation, with a significant decrease of cyclin B and cdk2. DHODH is the fourth enzyme of pyrimidine synthesis, so we also found that leflunomide can inhibit, at least in part, the endomitotic DNA replication in silk glands cells. These findings demonstrate that downregulation of BmDHODH inhibits cell growth and proliferation in silkworm cells, and the endomitotic DNA replication in silk gland cells.

The programme of DNA replication: beyond genome duplication

2013 ◽  
Vol 41 (6) ◽  
pp. 1720-1725 ◽  
Author(s):  
Blanca Gómez-Escoda ◽  
Pei-Yun Jenny Wu
Keyword(s):  
Dna Replication ◽  
Cell Growth ◽  
Dna Synthesis ◽  
Genetic Information ◽  
Replication Origin ◽  
Genome Duplication ◽  
Replication Initiation ◽  
Origin Activation ◽  
Key Steps ◽  
Cell Growth And Proliferation

The accurate duplication and transmission of genetic information is critical for cell growth and proliferation, and this is ensured in part by the multi-layered regulation of DNA synthesis. One of the key steps in this process is the selection and activation of the sites of replication initiation, or origins, across the genome. Interestingly, origin usage changes during development and in different pathologies, suggesting an integral interplay between the establishment of replication initiation along the chromosomes and cellular function. The present review discusses how the spatiotemporal organization of replication origin activation may play crucial roles in the control of biological events.

scholarly journals Lysosomes and Related Structures in the Posterior Silk Gland Cells ofBombyx mori. I. In Late Larval Stadium

1976 ◽  
Vol 1 (3) ◽  
pp. 205-222 ◽  
Author(s):  
Yutaka Tashiro ◽  
Takeo Shimadzu ◽  
Shiro Matsuura
Keyword(s):  
Silk Gland ◽  
Gland Cells ◽  
Posterior Silk Gland

scholarly journals Reduced level of secretion and absence of subunit combination for the fibroin synthesized by a mutant silkworm, Nd(2).

1984 ◽  
Vol 99 (6) ◽  
pp. 2005-2010 ◽  
Author(s):  
F Takei ◽  
F Oyama ◽  
K Kimura ◽  
A Hyodo ◽  
S Mizuno ◽  
...  
Keyword(s):  
Electrophoretic Mobility ◽  
Hybrid System ◽  
Disulfide Bond ◽  
Silk Gland ◽  
Subunit Structure ◽  
Present Evidence ◽  
Gland Cells ◽  
Subunit Combination ◽  
Posterior Silk Gland

Fibroin is normally composed of one H chain (350 kd) and one L chain (25 kd) which are connected by disulfide bond(s). However, the small amount of fibroin secreted into the lumen of the posterior silk gland of the Nd(2) (naked pupa) mutant does not contain L chain, although L chain mRNA is present and L chain is synthesized in the posterior silk gland cells of the mutant. In a hybrid silkworm, Nd(2)/Tamanashikasuri, where Tamanashikasuri is a normal producer of fibroin, L chain from the two alleles are distinguishable electrophoretically. It is demonstrated using this system that the L chain from the Nd(2) allele can combine normally with the H chain from Tamanashikasuri and the H-L complex is secreted normally. In another hybrid system, Nd(2)/J-131, where J-131 is a normal producer of fibroin, fibroin derived from the two alleles are distinguishable due to the different electrophoretic mobility of H chain. The fibroin derived from the J-131 allele is composed of H chain and L chain, while the fibroin derived from the Nd(2) allele is devoid of L chain, and its secretion is greatly reduced. We present evidence suggesting that the H chain derived from the Nd(2) allele is structurally abnormal and discuss how the H-L subunit structure is advantageous in the secretion of fibroin.

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

Phosphoproteomic analysis of the posterior silk gland of Bombyx mori provides novel insight into phosphorylation regulating the silk production

2016 ◽  
Vol 148 ◽  
pp. 194-201 ◽  
Author(s):  
Jia Song ◽  
Jiaqian Che ◽  
Zhengying You ◽  
Lupeng Ye ◽  
Jisheng Li ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Silk Production ◽  
Insight Into ◽  
Posterior Silk Gland
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