BOMBYXIN F1 GENE - STRUCTURE AND EXPRESSION OF A NEW BOMBYXIN FAMILY GENE THAT FORMS A PAIR WITH BOMBYXIN B10 GENE

Bombyxin F1 gene, a new bombyxin family gene, has been identified. The F1 gene forms a pair with bombyxin B10 gene with an opposite transcri ptional orientation and the gene pair F1/B10 is located between bombyx in gene pairs B9/C1 and A7/B7 in a bombyxin gene cluster. The nucleoti de sequence of the F1. gene and its deduced amino acid sequence deviat e moderately from those characterized previously for the family-A, fam ily-B, family-C, family-D, and family-E bombyxin genes; the bombyxin F 1 gene and preprobombyxin F1 share no more than 62% and 53% sequence i dentities with other bombyxin members, respectively. Harr-plot analysi s indicated that the spacer of the F1/B10 gene pair has low sequence s imilarity with that of other bombyxin gene pairs characterized. The bo mbyxin F1 mRNA in Bombyx mori brain was shown to locate in four pairs of medial neurosecretory cells, which also produce other bombyxin fami ly mRNAs. Genomic Southern hybridization indicated that the Bombyx hap loid genome contains a single copy of the family-F bombyxin gene.