The possible evolutionary significance of repeat elements near and within an early chorion gene in the late chorion locus ofBombyx mori
✍ Scribed by George C. Rodakis; Rena Lecanidou
- Publisher
- Springer
- Year
- 1992
- Tongue
- English
- Weight
- 811 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0022-2844
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✦ Synopsis
Three/3-type early chorion gene copies (6F6.1, 6F6.2, and 6F6.3) are dispersed in the late region of chorion locus Ch 1-2. Detailed analysis of the 5'-flanking region and the intron of 6F6.1 shows that they contain sequences that are homologous to Bombyx mori Bml repeat elements. Interestingly, the Bml-type segment of the intron is interrupted by the insertion of a sequence that shows significant similarities with part of an intron of B. mori and Bombyx mandarina fibroin genes, and with part of the 3'-flanking region ofB. mori prothoracicotropic hormone and tRNA-Glu genes; this sequence may represent a new repetitive, possibly transposable, element ofB. mori. Following the Bm 1-homologous sequence of the 6F6.1 5'-flanking region and preceding the gene promoter region, a short DNA segment shows sequence motifs that are also present in the ErA. 1 promoter region. The occurrence of these sequences near one end or within the Bml repeat element is suggestive of complex sequence transfer events. Comparative analysis of known B. mori chorion a-gene promoters and of Bm 1 repeat elements suggests, with marginal statistical significance, that these two sets of sequences contain common elements.