Today, researchers came again one step closer to using gene-drives for population control of pest species. In this case, Kyrou et al. targeted the highly conserved sexual differentiator, doublesex, using CRISPR/Cas9. They show that by disrupting the intron-exon boundary of the female-specific splice variant they could create intersexes that are sterile instead of healthy females. As they only targeted the female-splice variant, males were unaffected. However, it did require a homozygous mutation as one functional allele was still enough for normal female development. By creating a gene-drive targeting this specific site, they could spread this mutation quickly through the population, crashing it within a few generations.
What is even more important, usually gene-drives are quickly rendered ineffective because of random mutations destroying the homing site, thereby creating resistance to it. This build up of resistance has been shown in another recent paper by KaramiNejadRanjbar et al. where a gene-drive targeting transformer was created. Transformer is directly upstream of doublesex in the sex determination cascades of most insects, and acts as a splicing factor for doublesex female-specific splicing (Verhulst et al. 2010). Targeting transformer also results in genetic females developing into intersexes or even complete males, while leaving genetic males unaffected. As as discussed by Kyrou et al. resistant alleles emerged quickly in the transformer homing site and the gene-drive was compromized. However, this build up of mutations was not observed in the doublesex gene-drive, possibly because heterozyous females are still fully fertile while in the case of a transformer gene-drive I suspect that a heterozygous null-mutation is enough for female to male conversion. In addition, in general transformer has a higher mutation rate compared to doublesex (Eirín-López and Sánchez, 2015).
Gene regulatory evolution in insect sexual dimorphism
Within my lab I'm looking for a highly motivated and skilled postdoc candidate, interested in curiosity-driven research who can work in a multidisciplinary team in a collaborative spirit. Your main task will be to identify the binding sites and target genes of the sexual differentiator, doublesex.
For more background on the position, go to Available positions.
To apply for this position please go here. The deadline is September 23.
I'm super happy to announce that I have been awarded a NWO-Vidi grant of 800.000 EUR for five years to continue and further develop my research on the evolution of male-female phenotypic differences. To be more specific, I will look at the molecular basis of three sex-specific characteristics that have recently arisen in insects.
For those of you interested in my proposal, you can download it here.
Within approximately two months I will be advertising two PhD projects and one Post-doc position. If you are highly motivated, conceptually strong with a background in molecular biology, biotechnology or related and interested in joining my team, keep an eye on the site or contact me.
Vidi is aimed at experienced researchers who have carried out successful research for a number of years after obtaining their PhDs. Together with Veni and Vici, Vidi is part of the NWO Talent Scheme. Researchers in the NWO Talent Scheme are free to submit their own subject for funding. NWO thus encourages curiosity-driven and innovative research. NWO selects researchers based on the quality of the researcher, the innovative character of the research, the expected scientific impact of the research proposal and the possibilities for knowledge use.
See NWO website for more information.
Are you interesting in working on the fore-front of biological control in a multidisciplinary project? Do you enjoy combining field work in greenhouses with experiments in the laboratory?
On the 12th of February it is International Darwin Day. A great day to remember what Charles Darwin did for Science in general and Biology in particular. Thanks to his research and dedication we have a much better understanding of why life is shaped as it is throughout history of time.
And what better way to celebrate this with a parody done by the brilliant artist A Capella Science in which he explains in the most awesome way the field of Evolutionary Developmental Biology.
By the way, check out the other videos he's made on for example Gravitational Waves or the history of Exoplanets.
Just before Christmas I received news that my ZonMW Enabling Technologies Hotel proposal called RENEW: Resequencing Nasonia to Enhance its Workability is getting subsidized!
Very soon the Netherlands Society for Evolutionary Biology will be a fact and we will celebrate this initiative with our first ever meeting on the 11th of April 2018 in Akousticum in Ede.
Does climate change spell doom for sea turtles only because of the way they determine their sex?
Recently, scientists discovered by accident that a small strip of Whatman no. 1 paper can capture nucleic acids rapidly from a crude mixture containing ground up tissue in a lysis buffer. The paper strip can then be quickly washed without releasing the nucleic acid. After these steps, the paper strip retains enough nucleic acids to be dipped into a PCR reaction mixture and be used for amplification (Zou et al. 2017).
A new genome tool has just become a bit easier to use in the lab with the publication of a knock-in CRISPR/Cas9 mouse. This tool allows researchers to easily edit the genome in specific locations so they can study the effect of a gene knockdown or alteration. Already, researchers were able to use this technique in vitro but now, a mouse strain has been made that can take this CRISPR/Cas9 system to the next level.