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Signal Sequences Associated with Fibroin Gene Expression are Identical in Fibroin‐Producer and ‐Nonproducer Tissues
Author(s) -
SUZUKI YOSHIAKI,
ADACHI SATOKO
Publication year - 1984
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1984.00139.x
Subject(s) - fibroin , biology , gene , transcription (linguistics) , microbiology and biotechnology , exon , intron , bombyx mori , dna , gene expression , bombyx , genetics , silk , linguistics , philosophy , computer science , operating system
DNA sequencing has been carried out for the region of nucleotide position −649 to +1261 of the fibroin DNA originally cloned from Bombyx mori pupae in which the fibroin gene is not expressed (nonproducer tissues). This sequence was compared with that from the posterior silk gland cells, where the gene is expressed (producer tissue), of a different strain. Both sequences are indentical in the regions of −297 to +333 and +746 to +1261, leaving some base changes in the remaining regions. The regions of the identical sequences contain important signals for the fibroin gene expression; −29 to +6 for promoter function, −238 to −116 and −73 to −53 for signals for transcription enhancement, and around +66 and +1037 for the exon/intron boundaries. Template activities of the fibroin DNAs from the producer and the nonproducer were indistinguishable when assayed in a cell‐free transcription system prepared from the silk glands. The result suggests that the base changes found in the regions of −649 to −298 and +334 to +745 of the fibroin DNAs from two strains are neutral mutations that do not affect the transcription activities of the genes. Thus, DNA rearrangements or somatic mutations are not likely to contribute to the tissue‐specific expression of the fibroin gene.