Evolution of the autosomal chorion cluster inDrosophila. II. Chorion gene expression and sequence comparisons of thes16 ands19 genes in evolutionarily distant species

Abstract

We present a total of 13 kb of DNA sequences, encompassing autosomal chorion genes and their flanking DNA in four species of the genusDrosophila. Against a background of extensive divergence in introns and even in parts of the coding regions, islands of strong conservation are evident in the proximal 5′ flanking and 5′ untranslated sequences. An extragenic region of strong conservation is seen downstream of the last chorion gene in the autosomal cluster. The conserved DNA elements may be related to the conserved regulatory features of this cluster, including gene amplification and tissue- and temporally regulated transcription.