Dynamics of a combined medea-underdominant population transformation system

Abstract

BackgroundTransgenic constructs intended to be stably established at high frequencies in wild populations have been demonstrated to “drive” from low frequencies in experimental insect populations. Linking such population transformation constructs to genes which render them unable to transmit pathogens could eventually be used to stop the spread of vector-borne diseases like malaria and dengue.ResultsGenerally, population transformation constructs with only a single transgenic drive mechanism have been envisioned. Using a theoretical modelling approach we describe the predicted properties of a construct combining autosomal Medea and underdominant population transformation systems. We show that when combined they can exhibit synergistic properties which in broad circumstances surpass those of the single systems.ConclusionWith combined systems, intentional population transformation and its reversal can be achieved readily. Combined constructs also enhance the capacity to geographically restrict transgenic constructs to targeted populations. It is anticipated that these properties are likely to be of particular value in attracting regulatory approval and public acceptance of this novel technology.

Technology Characterisation

“…Medea organisms exhibit a high-frequency stable equilibrium when the transgenic construct is associated without any fitness cost (Gokhale et al 2014). The fitness costs of homozygote Medea Drosophila were estimated to be 27.3% and 17.4%, respectively, for two different targeted genes.…”

“…For the RpL14 construct, this threshold is estimated to be as high as 61% of the total population (Reeves et al 2014). Therefore, an intentional underdominant population transformation is inherently reversible where it is realistically possible to release sufficient wild type individuals to traverse the unstable equilibrium in the lower frequency direction (Gokhale et al 2014).…”

Peer Review #1 of "Gene drives as a new quality in GMO releases—a comparative technology characterization (v0.1)"

“…If Medea is located on the X chromosome in a X/Y male heterogametic species, Medea is predicted to spread to allele fixation, with wild type alleles being completely eliminated (Akbari et al, 2014). Medea organisms exhibit a high-frequency stable equilibrium when the transgenic construct is associated without any fitness cost (Gokhale, Reeves & Reed, 2014). The fitness costs of homozygote Medea Drosophila were estimated to be 27.3% and 17.4%, respectively, for two different targeted genes.…”

A Matter of Taste: Lineage-Specific Loss of Function of Taste Receptor Genes in Vertebrates

“…However, an increasing number of studies have shown how some pseudogenes have a function regulating gene expression (Pink et al, 2011 ), or being transcribed into RNA (Frankish and Harrow, 2014 ). Multiple studies also highlighted how pseudogenes have had a remarkable functional plasticity and a dynamic role in species' evolution (Bekpen et al, 2009 ; Korrodi-Gregório et al, 2013 ; Risso et al, 2014 ): chemosensory genes, in particular, have been characterized by a succession of birth-and-death processes in different lineages (Dong et al, 2009a , b ). The aim of this mini-review is to provide an integrative view of the evolutionary history of taste receptor genes, with a focus on the main gene losses that have occurred in different lineages, pinpointing the genetic and biological factors driving these episodes.…”