Project description:Tree ring features are affected by environmental factors and therefore are the basis for dendrochronological studies to reconstruct past environmental conditions. Oak wood often provides the data for these studies because of the durability particularly of oak heartwood and, hence the availability of samples spanning long time periods of the distant past. Wood formation is regulated in part by epigenetic mechanisms such as DNA methylation. Studies in the methylation state of DNA preserved in oak heartwood thus could identify epigenetic tree ring features informing on past environmental conditions. We investigated the feasibility of such studies using heartwood samples core-drilled from the trunks of standing oak trees spanning the AD 1776-2014. Heartwood contains little DNA, and large amounts of phenolic compounds known to hinder the preparation of high-throughput sequencing libraries. We sequenced whole-genome and DNA methylome libraries for oak heartwood up to 100 and 50 years of age, respectively. However, only 56 genomic regions with sufficient coverage for quantitative methylation analysis were identified, suggesting that the high-throughput sequencing of DNA will be in principal feasible for wood formed <100 years ago is impeded by the reduction in library complexity caused by the bisulfite treatment used to generate the oak methylome.
Project description:Acute Oak Decline (AOD) is a decline-disease currently spreading in Britain, threatening oak trees. Here, we analyze and compare the proteomes of inner bark tissue sampled from oak stems of trees symptomatic with AOD and non-symptomatic trees.
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.