Related Experiment Video
Updated: Jul 26, 2026

Zinc-finger Nuclease Enhanced Gene Targeting in Human Embryonic Stem Cells
Published on: August 23, 2014
Resurrecting the ancestral steroid receptor: ancient origin of estrogen signaling
Joseph W Thornton1, Eleanor Need, David Crews
1Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, OR 97403, USA. joet@uoregon.edu
Abstract:
Receptors for sex and adrenal steroid hormones are absent from fully sequenced invertebrate genomes and have not been recovered from other invertebrates. Here we report the isolation of an estrogen receptor ortholog from the mollusk Aplysia californica and the reconstruction, synthesis, and experimental characterization of functional domains of the ancestral protein from which all extant steroid receptors (SRs) evolved. Our findings indicate that SRs are extremely ancient and widespread, having diversified from a primordial gene before the origin of bilaterally symmetric animals, and that this ancient receptor had estrogen receptor-like functionality. This gene was lost in the lineage leading to arthropods and nematodes and became independent of hormone regulation in the Aplysia lineage.
Related Concept Videos
Embryonic Stem Cells
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Reporter Genes
Commonly used reporter...
Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
Methods of Nuclear Reprogramming

