Expression of dorsal-ventral genes during early development of Rhynchosciara americana embryos

Abstract

The establishment of dorsal-ventral polarity in Drosophila is a complex process which involves the action of maternal and zygotically expressed genes. Interspecific differences in the expression pattern of some of these genes have been described in other species. Here we present the expression of dorsal-ventral genes during early embryogenesis in the lower dipteran Rhynchosciara americana. The expression of four genes, the ventralizing genes snail (sna) and twist (twi) and the dorsalizing genes decapentaplegic (dpp) and zerknüllt (zen), was investigated by whole-mount in situ hybridization. Sense and antisense mRNA were transcribed in vitro using UTP-digoxigenin and hybridized at 55°C with dechorionated fixed embryos. Staining was obtained with anti-digoxigenin alkaline phosphatase-conjugated antibody revealed with NBT-BCIP solution. The results showed that, in general, the spatial-temporal expression of R. americana dorsalventral genes is similar to that observed in Drosophila, where twi and sna are restricted to the ventral region, while dpp and zen are expressed in the dorsal side. The differences encountered were subtle and probably represent a particular aspect of dorsal-ventral axis determination in R. americana. In this lower dipteran sna is expressed slightly later than twi and dpp expression is expanded over the lateral ectoderm during cellular blastoderm stage. These data suggest that the establishment of dorsal-ventral polarity in R. americana embryos follows a program similar to that observed in Drosophila melanogaster.

Identification of 3′UTR sequence elements and a teloplasm localization motif sufficient for the localization of Hro‐twist mRNA to the zygotic animal and vegetal poles

“…), the Brazilian fly (Carvalho et al . ), the beetle (Handel et al . ), and the purple sea urchin (Wu et al .…”

“…A few of the Twist orthologues are expressed before the mesodermal layer is specified. These include orthologues in the fruit fly (Thisse et al 1987), the Brazilian fly (Carvalho et al 2005), the beetle (Handel et al 2005), and the purple sea urchin (Wu et al 2008). However, there is functional evidence for Twist's role in gastrulation only for Dm-Twist (fruit fly).…”

Bradysia hygida (Diptera, Sciaridae) presents two eukaryotic Elongation Factor 1A gene homologues: partial characterization of the eukaryotic Elongation Factor 1A-F1 gene

“…In addition to gene amplification and transcription, several other processes have been investigated using the Sciaridae family as a model, including mechanisms of telomere maintenance (11,12), programmed cell death (13), establishment of dorsoventral polarity (14), and the immune response (15). These studies contributed to the understanding of these processes and further strengthened the view that the study of non-model organisms can contribute to the understanding of processes of general occurrence in metazoans.…”