The gene encoding fibroin light chain protein (FibL) is specifically expressed in the posterior silk gland of silkworm and repressed in other tissues. The binding sites of several transcription factors involved in the silk gland transcription specificity of fibl promoter have been recognized, including SGFB, PSGF and BMFA. Here we report the leak expression of the enhanced green fluorescent protein (EGFP) reporter gene in tissues other than the posterior silk gland in vivo when under the control of a shortened fibl promoter with deletion of the 5' terminal 41 bp sequence, which is located at -650 nt to -610 nt upstream of the fibl transcription starting site. Assay of silk gland specificity of the promoters was performed by observation of green fluorescence in tissues of silkworm larvae following inter-haemocoelic injection of recombinant Autographa californica multiple nuclear polyhedrosis virus carrying the EGFP reporter gene controlled by different lengths of fibl promoters. Our results indicated that availability of the binding sites of several known factors, including SGFB, PSGF and BMFA, is not sufficient for intact silk gland transcription specificity of fibl promoter, and there are possible inhibitor binding sites in the 41 bp sequence (-650 nt to -610 nt) upstream of the transcription starting site which may be required to repress the activity of fibl promoter in other tissues.
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http://dx.doi.org/10.1111/j.1745-7270.2005.00117.x | DOI Listing |
Int J Biol Macromol
December 2024
State Key Laboratory of Resource Insects, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400715, China; Yibin Academy of Southwest University, Southwest University, Chongqing 400715, China. Electronic address:
Endoreplication is particularly important in the context of silk protein synthesis within the silk gland cells of silkworms. Our previous research indicated that the BmE2F1 enhances the silk yield of silkworm cocoons, but the underlying molecular mechanism remains elusive. In this study, we employed RNA-sequencing to dissect the transcriptional profiles of silk glands in the wild-type Dazao silkworm strain and the overexpression (OE) silkworm strain with specific overexpression of the BmE2F1 gene in silk glands.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing 400715, China.
Spider silk is part of a special class of natural protein fibers that have high strength and toughness: these materials have excellent comprehensive properties that are not found in other natural fibers (including silk) or most synthetic fibers. Spider egg case filaments have good hardness, can resist water, can protect spider eggs from external threats, have a significantly high initial modulus and high moisture absorption rate, and are expected to be used as a new generation of environmentally friendly natural polymer fibers and biomaterials. However, spiders are predatory and difficult to rear in large numbers, and it is also difficult to obtain spider egg case filaments in large quantities.
View Article and Find Full Text PDFAdv Mater
December 2024
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, 400715, China.
Long historical evolution and domestication endow silkworms with the super ability to synthesize and secrete massive silk proteins using silk glands. The major component of this secretion consists of silk fibroin, considered a promising biomaterial for tissue repairs and engineering. To further expand the utility of this unique protein, there is a continuing need for silk fibroin functionalization.
View Article and Find Full Text PDFBiomaterials
December 2024
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, 400716, China. Electronic address:
Cleft palate is one of the most prevalent congenital craniofacial birth defects in human congenital facial anomaly. Severe cleft palate is usually accompanied by alveolar bone defects (ABDs). Growth factors (GFs) are considered as desirable opportunity to promote the craniofacial healing post the surgery.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Life Sciences, Jiangsu University, Zhenjiang 212013, China. Electronic address:
This study investigates the impact of β-fructofuranosidase (Bmsuc1) on the development of the silk gland in silkworms (Bombyx mori). Previous research shows that Bmsuc1 is highly expressed in the silk glands and may be involved in silk gland development and protein synthesis. However, the precise mechanism by which Bmsuc1 regulates silk gland development remains unclear.
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