ISSN:
1617-4623
Keywords:
Wild silkworm
;
Fibroin gene
;
5′-end region
;
Sequence comparison
;
Domesticated silkworm
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The fibroin gene of the wild silkworm Bombyx mandarina was identified through hybridization with the fibroin DNA of the domesticated species, B. mori. Using their cross homology, we isolated the clone carrying the fibroin gene from a B. mandarina genomic library in λ Charon 30. A resultant recombinant phage contained the DNA fragment corresponding to the 5′-end region of the B. mori fibroin gene. After subcloning the DNA fragment into pUC12, its DNA sequence was partially determined. Comparison of the nucleotide sequence of the 5′-end region from the two species showed that the B. mandarina fibroin gene is highly homologous to that of B. mori but the extent of homology varies in different functional domains within this region. In particular, the promoters and enhancer-like element sequences are identical in the two species, indicating that these regions are essential for fibroin gene expression irrespective of species. In contrast, there is an appreciable amount of base change in the region far upstream from the enhancer-like element sequence and in the intron-region. These results support the view that the B. mandarina which exists in nature at present is a possible ancestor of the domesticated silkworm, B. mori.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00422057
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