Identification of regulatory regions in the DNA puff BhC4‐1 promoter

Abstract

The mechanisms that control DNA puff BhC4-1 expression in the salivary gland of sciarid late larvae have been shown to be conserved in Drosophila. By analysing Drosophila transformed with constructs carrying progressive deletions of the BhC4-1 promoter fragment (-3314/+40) fused to the lacZ reporter gene we show that the elements required for the correct BhC4-1-lacZ developmental regulation in prepupal salivary glands are contained in a 226 bp fragment (-186/+40). Also, interestingly, this study identified a 67 bp fragment (-253/-187) that activates BhC4-1-lacZ expression specifically in the ring gland.

Functional and bioinformatics analyses reveal conservation of cis‐regulatory elements between sciaridae and drosophilidae

“…The (2158/2114) region is contained in the 129 bp salivary gland enhancer and overlaps with the (2159/2140) sequence, which was previously identified as showing similarity both to a 20 bp conserved sequence that is present in the promoter regions of all DNA puff genes and to an adenine-rich consensus sequence found in steroid responsive insect genes (Monesi et al, 2003). The (2158/ 2114) also contains a consensus binding site for the BR-C Z3 isoform and a consensus binding site for the BR-C Z1 isoform, both of which regulate BhC4-1-lacZ expression in the salivary gland (Basso et al, 2006).…”

“…BhC4-1 Proximal Promoter in the D. melanogaster Genome Functional assays suggested that the BhC4-1 proximal promoter contains two enhancers: a 67 bp (2253/ 2187) ring gland enhancer and a 129 bp (2186/258) salivary gland enhancer (Monesi et al, 2003). The Drosophila genomic sequence (Release 4.2.1) was screened for nucleotide sequences that are similar to these enhancers using the BLAST algorithm (Altschul et al, 1990), in which the seeding step of the program used a word size of seven with the inactivation of the default filter that masks off query sequence segments that have low compositional complexity (DUST).…”

“…Primers were designed that introduced Eco RI sites at positions (2253) and (2186) of the BhC4-1 promoter and a reverse primer which introduced a Bam HI site at position (258). A (2370/140) BhC4-1 promoter fragment (Monesi et al, 2003) was used as a template in the PCR reactions, and the amplified fragments were gel purified, digested with Eco RI and Bam HI and the 196 bp (2253/258) and 129 bp (2186/258) fragments were ligated into the pBluescript II KS1 vector (Stratagene). To obtain the (2253/258) and (2186/258) constructs, the 196 bp and 129 bp fragments were subcloned into the pBP vector.…”

“…Previous studies have suggested the existence of both a salivary gland enhancer and a ring gland enhancer within the BhC4-1 proximal promoter (Monesi et al, 2003). Here we employ a combination of bioinformatics and functional approaches to extend the characterization of these sciarid enhancers.…”

Genome size of three Brazilian flies from the Sciaridae family

“…The invertebrates constitute the major form of multicellular life but the genome size of only about 1,300 invertebrate species is available in Gregory's Animal Genome Size Database (Gregory 2001). For Diptera, the genome size has been described for only 12 families, mainly Drosophilidae and Cullicidae, but no data is available for other dipteran families such as the Sciaridae although insects of this family have been widely used in molecular and cell biology research (Fiorini et al, 2001;Basso Jr. et al, 2002;Monesi et al, 2003;Soares et al, 2003) and the description of their genome size is not only important in these research areas but it could also help in the solution of evolutionary questions relating to the Diptera. The aim of the study presented in this paper was to contribute to the data on insect genome size by determining the DNA content and the genome size of the Brazilian sciarids Bradysia hygida, Rhynchosciara americana and Trichosia pubescens using absorbance measurements of Feulgen-stained neuroblast nuclei from larvae of these species.…”