Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
Collection

toTop

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

home > search >

Dissection of a Ciona regulatory element reveals complexity of cross-species enhancer activity

Journal:
Developmental Biology


Issue Date:
2014


Abstract(summary):

Vertebrate genomes share numerous conserved non-coding elements, many of which function as enhancer elements and are hypothesised to be under evolutionary constraint due to a need to be bound by combinations of sequence-specific transcription factors. In contrast, few such conserved elements can be detected between vertebrates and their closest invertebrate relatives. Despite this lack of sequence identity, cross-species transgenesis has identified some cases where non-coding DNA from invertebrates drives reporter gene expression in transgenic vertebrates in patterns reminiscent of the expression of vertebrate orthologues. Such instances are presumed to reflect the presence of conserved suites of binding sites in the regulatory regions of invertebrate and vertebrate orthologues, such that both regulatory elements can correctly interpret the transactivating environment. Shuffling of binding sites has been suggested to lie behind loss of sequence conservation; however this has not been experimentally tested. Here we examine the underlying basis of enhancer activity for the Ciona intestinalis beta gamma-crystallin gene, which drives expression in the lens of transgenic vertebrates despite the Ciona lineage predating the evolution of the lens. We construct an interactive gene regulatory network (GRN) for vertebrate lens development, allowing network interactions to be robustly catalogued and conserved network components and features to be identified. We show that a small number of binding motifs are necessary for Ciona beta gamma-crystallin expression, and narrow down the likely factors that bind to these motifs. Several of these overlap with the conserved core of the vertebrate lens GRN, implicating these sites in cross species function. However when we test these motifs in a transgenic vertebrate they prove to be dispensable for reporter expression in the lens. These results show that current models depicting cross species enhancer function as dependent on conserved binding sites can be overly simplistic, with sound evolutionary inference requiring detailed dissection of underlying mechanisms.. (C) 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.orgilicenses/by/3.0/).


Page:
261---272


Similar Literature

Submit Feedback

This function is a member function, members do not limit the number of downloads