Dataset Information

Identification of genome wide targets of the hox protein Ultrabithorax (Ubx) in larval wing buds of Bombyx mori (Daizo)

ABSTRACT: Amongst the various different insect groups, there is remarkable diversity in the number and size of wings. However the development of the basic body plan in insects is similar to a large extent. The genes of the hox complex regulate various pathways to bring about the development or modification of different organs. Ubx, a gene of the bithorax hox complex is expressed in the third thoracic segment of insects and is known to specify the fate of wing appendage in that segment.To understand the role of Ubx and how its regulatory mechanism has evolved through the course of evolution we have compared its genome wide targets in different insect orders. The identification of regulatory pathways and the key players Ubx regulates is crucial to understand how it has controlled wing development across insect orders. Our lab has previously identified direct targets of Ubx in Drosophila using ChIP-chip (Agrawal et al, 2011). To further our knowledge on the role of regulation in development and modification of hind wing appendage we have studied the targets in the hind wings of other insects (silk moth; Lepidoptera and honeybee; Hymenoptera) and performed a comparative analysis. We have employed ChIP followed by illumina sequencing to identify the targets of Ubx in developing hind and fore wing buds of Bombyx larvae. This is a first next generation sequencing study in Lepidoptera in an attempt to understand wing development.

ORGANISM(S): Bombyx mori

PROVIDER: GSE71990 | GEO | 2016/07/27

SECONDARY ACCESSION(S): PRJNA292691

REPOSITORIES: GEO

ACCESS DATA

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

Project description:Amongst the various different insect groups, there is remarkable diversity in the number and size of wings. However the development of the basic body plan in insects is similar to a large extent. The genes of the hox complex regulate various pathways to bring about the development or modification of different organs. Ubx, a gene of the bithorax hox complex is expressed in the third thoracic segment of insects and is known to specify the fate of wing appendage in that segment.To understand the role of Ubx and how its regulatory mechanism has evolved through the course of evolution we have compared its genome wide targets in different insect orders. The identification of regulatory pathways and the key players Ubx regulates is crucial to understand how it has controlled wing development across insect orders. Our lab has previously identified direct targets of Ubx in Drosophila using ChIP-chip (Agrawal et al, 2011). To further our knowledge on the role of regulation in development and modification of hind wing appendage we have studied the targets in the hind wings of other insects (silk moth; Lepidoptera and honeybee; Hymenoptera) and performed a comparative analysis.To understand the differential development of wing appendages in insects we intend to compare the differential expression of fore and hind wing appendages in Diptera and Lepidoptera. We have employed RNA-seq using by illumina sequencing to identify the genes that are differentially expressed between fore and the hind wing bud of the Bombyx larvae. Only one replicate was performed as the intended study was to validate the differential targets in comparison to ChIP studies and other methods of select candidates. Total RNA was extarcted from wing buds of IV instar Bombyx larvae and sequenced on an illumina sequencer. Wing buds were collected directly in liquid nitrogen and 80 such buds each for fore and hind wing were collected from IV instar larvae. RNA was isolated from them and processed for Library preperation and illumina sequencing. One replicate was done as a supplement to ChIP studies.

Project description:Amongst the various different insect groups, there is remarkable diversity in the number and size of wings. However the development of the basic body plan in insects is similar to a large extent. The genes of the hox complex regulate various pathways to bring about the development or modification of different organs. Ubx, a gene of the bithorax hox complex is expressed in the third thoracic segment of insects and is known to specify the fate of wing appendage in that segment.To understand the role of Ubx and how its regulatory mechanism has evolved through the course of evolution we have compared its genome wide targets in different insect orders. The identification of regulatory pathways and the key players Ubx regulates is crucial to understand how it has controlled wing development across insect orders. Our lab has previously identified direct targets of Ubx in Drosophila using ChIP-chip (Agrawal et al, 2011). To further our knowledge on the role of regulation in development and modification of hind wing appendage we have studied the targets in the hind wings of other insects (silk moth; Lepidoptera and honeybee; Hymenoptera) and performed a comparative analysis. We have employed ChIP followed by illumina sequencing to identify the targets of Ubx in developing hind and fore wing buds of Bombyx larvae. This is a first next generation sequencing study in Lepidoptera in an attempt to understand wing development. Chromatin Immunoprecipitation (ChIP) was used to identify genome wide targets bound by Ubx in Bombyx larval wing buds. The experiment to enrich Ubx bound regions was carried out using a Bombyx N terminal-Ubx specific poylclonal antibody raised in Rabbit and purified against a Protein A column to obtain IgG fraction. An Immunoprecipitation (IP) with Normal Rabbit IgG was used as a negative control to eliminate the regions that pertained to non specific binding to an Immunogloubulin. The normalization of both ChIP and IgG was done against sequenced input chromatin. Two replicates of single end 36 bp reads were sequenced using Ilumina for all the three conditions and for both fore and hind wing tissue samples.The peaks common to both the replicates were considered after applying a FDR cutoff.The fore wing target set was used for comparison with the hind wing targets.

Project description:Hox genes regionalize the animal body axis by modifying complex morphogenetic and differentiation processes during development. The transformation of wings into halteres by the Hox gene Ultrabithorax (Ubx) in Drosophila melanogaster presents an excellent model system to study the transcriptional networks that control such complex developmental programmes. We have employed an inducible misexpression system to switch on Ubx in the wing epithelium at successive larval, prepupal and pupal stages, and have used microarray expression profiling to identify the primary transcriptional responses to Ubx. We find that Ubx regulates hundreds of downstream genes, mostly in a subtle manner. These targets are largely distinct at the different stages of appendage development and diversification. We have generated an experimental fly line combining the nabGal4NP3537-driver, a tub-GAL80ts transgene, and a UAS-UbxIa transgene (the control line was carrying a UAS-eGFP transgene instead). Our core microarray analysis has involved comparison of the transcriptional profile of experimental wings carrying the UAS-UbxIa transgene with that of control wings carrying the UAS-eGFP transgene. Pairwise comparisons have been carried out at three successive developmental stages, in particular at (i) the third instar larval wandering stage, about 4hrs before puparium formation at 29˚C, (ii) the prepupal stage, 6hrs after puparium formation (APF) at 29˚C, and (iii) the early pupal stage, 16hrs APF at 29˚C. Moreover, pairwise comparisons have been carried out with samples developed exclusively at 19˚C (UbxIa or eGFP expression OFF), as well as with samples collected at 16hrs after the temperature shift from 19 to 29˚C (UbxIa or eGFP expression ON). This has allowed us to distinguish the Ubx-dependent effects from the intrinsic expression differences between the fly lines used, and from the temperature-induced responses. We have carried out 4 biological replicates for each condition making a total of 48 hybridizations to Affymetrix Drosophila Genome 2.0 arrays.