Lifeboat Foundation

For more than two decades, I have been working to improve several staple food crops in Africa, including bananas, plantains, cassavas and yams. As principal scientist and a plant biotechnologist at the International Institute for Tropical Agriculture in Nairobi, I aim to develop varieties that are resistant to pests and diseases such as bacterial wilt, Fusarium wilt (caused by the fungus F. oxysporum) and banana streak virus.

[Editor’s note: Abdullahi Tsanni is a freelance science journalist based in Abuja, Nigeria.]

In 2011, my team and I created a set of tools, the only one of its kind in Africa, for changing DNA sequences so that we could develop genetically modified and genome-edited products in sub-Saharan Africa. In 2018, we pioneered the first application of CRISPR gene-editing technology to deactivate banana streak virus in plantains. This technology overcame a major hurdle in banana breeding on the continent, and is the first reported successful use of genome editing to improve bananas.

The honeybee (Apis mellifera) is an important insect pollinator of wild flowers and crops, playing critical roles in the global ecosystem. Additionally, the honeybee serves as an ideal social insect model. Therefore, functional studies on honeybee genes are of great interest. However, until now, effective gene manipulation methods have not been available in honeybees. Here, we reported an improved CRISPR/Cas9 gene-editing method by microinjecting sgRNA and Cas9 protein into the region of zygote formation within 2 hr after queen oviposition, which allows one-step generation of biallelic knockout mutants in honeybee with high efficiency. We first targeted the Mrjp1 gene. Two batches of honeybee embryos were collected and injected with Mrjp1 sgRNA and Cas9 protein at the ventral cephalic side and the dorsal posterior side of the embryos, respectively. The gene-editing rate at the ventral cephalic side was 93.3%, which was much higher than that (11.8%) of the dorsal-posterior-side injection. To validate the high efficiency of our honeybee gene-editing system, we targeted another gene, Pax6, and injected Pax6 sgRNA and Cas9 protein at the ventral cephalic side in the third batch. A 100% editing rate was obtained. Sanger sequencing of the TA clones showed that 73.3% (for Mrjp1) and 76.9% (for Pax6) of the edited current-generation embryos were biallelic knockout mutants. These results suggest that the CRISPR/Cas9 method we established permits one-step biallelic knockout of target genes in honeybee embryos, thereby demonstrating an efficient application to functional studies of honeybee genes. It also provides a useful reference to gene editing in other insects with elongated eggs.

Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated gene Cas9 represent an invaluable system for the precise editing of genes in diverse species. The CRISPR/Cas9 system is an adaptive mechanism that enables bacteria and archaeal species to resist invading viruses and phages or plasmids. Compared with zinc finger nucleases and transcription activator-like effector nucleases, the CRISPR/Cas9 system has the advantage of requiring less time and effort. This efficient technology has been used in many species, including diverse arthropods that are relevant to agriculture, forestry, fisheries, and public health; however, there is no review that systematically summarizes its successful application in the editing of both insect and non-insect arthropod genomes. Thus, this paper seeks to provide a comprehensive and impartial overview of the progress of the CRISPR/Cas9 system in different arthropods, reviewing not only fundamental studies related to gene function exploration and experimental optimization but also applied studies in areas such as insect modification and pest control. In addition, we also describe the latest research advances regarding two novel CRISPR/Cas systems (CRISPR/Cpf1 and CRISPR/C2c2) and discuss their future prospects for becoming crucial technologies in arthropods.

Keywords: CRISPR/Cas9, insects, non-insect arthropods, research progress, prospects.

Genome editing technologies are useful for understanding the functions of target genes in diverse organisms (Segal and Meckler, 2013). Before the CRISPR/Cas9 system was discovered, zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) technologies were used for genome modification; both technologies can be used to design a DNA-binding domain that can effectively recognize and modify virtually any sequence, and both technologies have been widely applied in various fields (Gaj et al., 2013). ZFNs and TALENs, however, require the use of a variety of nucleases, and the off-target effects of nucleases can lead to cellular toxicity. In addition, methods using ZFNs and TALENs are complex and labor-intensive (Kanchiswamy et al., 2016). These two genome-editing systems have been recently replaced by the CRISPR/Cas9 system, which is far more convenient and effective than ZFNs and TALENs (Lander, 2016; Mohanraju et al., 2016; Wang H. et al., 2016; Westra et al.

Initially discovered in bacteria, CRISPR-based genome editing endonucleases have proven remarkably amenable for adaptation to insects. To date, these endonucleases have been utilized in a plethora of both model and non-model insects including diverse flies, bees, beetles, butterflies, moths, and grasshoppers, to name a few, thereby revolutionizing functional genomics of insects. In addition to basic genome editing, they have also been invaluable for advanced genome engineering and synthetic biology applications. Here we explore the recent genome editing advancements in insects for generating site-specific genomic mutations, insertions, deletions, as well as more advanced applications such as Homology Assisted Genome Knock-in (HACK), potential to utilize DNA base editing, generating predictable reciprocal chromosomal translocations, and development gene drives to control the fate of wild populations.

With advancements in stem cell therapy, scientists have now engineered stem cells that can treat metastatic bone cancer without damaging surrounding tissue.

Stem cells hold so much potential for regenerative medicine, it is understandable that so many people should be so impatient to see all that potential realized. But people, the desperately ill among them, need to recognize that stem cells aren’t talismans. In unregulated clinical settings, stem cells can be worthless or even harmful. That’s the bad news. The good news is that stem cells are giving up their profound but decidedly unmagical secrets.

What stem cells lose in mystery, they gain in practicality. They are to be seen as manageable biological units that can, given the right preparation, perform myriad therapeutic applications, less as miracle workers and more as drudges that accept reprogramming and subsequently perform their assigned tasks. They may also sacrifice some of their protean identity, turning into cells that are less stemmy but more effective (and safer) as therapeutic agents. Stemminess may even by bypassed completely, as when cells of one type are directly transdifferentiated into cells of another type.

Even as the preparation of stem cell therapeutics becomes more sophisticated, it is becoming more streamlined, more industrialized. Helping to advance both trends—greater refinement, greater manufacturability—is a new generation of biotech startups. Several of these startups are described in this article. By commercializing the latest stem cell technologies, these startups mean to add to the list of FDA-approved cell-based treatments.

This is interesting.

In 10 years, tiny nanobots in your blood might help keep you from getting sick or even transmit your thoughts to a wireless cloud.

Multilayer plastic materials are ubiquitous in food and medical supply packaging, particularly since layering polymers can give those films specific properties, like heat resistance or oxygen and moisture control. But despite their utility, those ever-present plastics are impossible to recycle using conventional methods.

About 100 million tons of multilayer thermoplastics — each composed of as many as 12 layers of varying polymers — are produced globally every year. Forty percent of that total is waste from the manufacturing process itself, and because there has been no way to separate the polymers, almost all of that plastic ends up in landfills or incinerators.

Now, University of Wisconsin-Madison engineers have pioneered a method for reclaiming the polymers in these materials using solvents, a technique they’ve dubbed Solvent-Targeted Recovery and Precipitation (STRAP) processing. Their proof-of-concept is detailed today (November 20, 2020) in the journal Science Advances.