The homeodomain transcription factor Orthopedia is involved in development of the Drosophila hindgut
- PDF / 6,688,444 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 64 Downloads / 176 Views
RESEARCH
Open Access
The homeodomain transcription factor Orthopedia is involved in development of the Drosophila hindgut Kirsten Hildebrandt†, Nicole Bach†, Dieter Kolb and Uwe Walldorf*
Abstract Background: The Drosophila hindgut is commonly used model for studying various aspects of organogenesis like primordium establishment, further specification, patterning, and morphogenesis. During embryonic development of Drosophila, many transcriptional activators are involved in the formation of the hindgut. The transcription factor Orthopedia (Otp), a member of the 57B homeobox gene cluster, is expressed in the hindgut and nervous system of developing Drosophila embryos, but due to the lack of mutants no functional analysis has been conducted yet. Results: We show that two different otp transcripts, a hindgut-specific and a nervous system-specific form, are present in the Drosophila embryo. Using an Otp antibody, a detailed expression analysis during hindgut development was carried out. Otp was not only expressed in the embryonic hindgut, but also in the larval and adult hindgut. To analyse the function of otp, we generated the mutant otp allele otpGT by ends-out gene targeting. In addition, we isolated two EMS-induced otp alleles in a genetic screen for mutants of the 57B region. All three otp alleles showed embryonic lethality with a severe hindgut phenotype. Anal pads were reduced and the large intestine was completely missing. This phenotype is due to apoptosis in the hindgut primordium and the developing hindgut. Conclusion: Our data suggest that Otp is another important factor for hindgut development of Drosophila. As a downstream factor of byn Otp is most likely present only in differentiated hindgut cells during all stages of development rather than in stem cells. Keywords: Drosophila hindgut, Orthopedia, Transcription factor, Homeobox, otp mutants
Background The Drosophila embryonic hindgut is a single-layered ectodermally derived epithelium surrounded by visceral musculature [1–3]. It arises from a group of cells at the posterior part of the blastoderm stage embryo referred to as the hindgut primordium [1]. The hindgut primordium is a ring of about 200 blastoderm cells that is internalised during gastrulation to form a short, wide sac. In a relatively short time this epithelium sac is * Correspondence: [email protected] † Kirsten Hildebrandt and Nicole Bach contributed equally to this work. Developmental Biology, Saarland University, Building 61, 66421 Homburg/ Saar, Saarland, Germany
transformed into a long tube containing approximately 700 cells [1, 4, 5]. The growth of the hindgut starting at stage 12 is not due to cell divisions, but a twofold endoreplication [6] that leads to an increase in cell size, and as a consequence total length of the hindgut [7, 8]. During this process, the developing hindgut becomes subdivided along the anterior posterior (AP) axis and the dorsoventral (DV) axis. Along the AP axis, the hindgut forms three morphologically distinct regions: the small intestine, large intesti
Data Loading...
