Credit: Michael Shribak, Marine Biological Laboratory, Woods Hole, MA
Birds do it, bees do it, and even educated fleas do it. No, not fall in love, as the late Ella Fitzgerald so famously sang. Birds and insects can see polarized light—that is, light waves transmitted in a single directional plane—in ways that provides them with a far more colorful and detailed view of the world than is possible with the human eye.
Still, thanks to innovations in microscope technology, scientists have been able to tap into the power of polarized light vision to explore the inner workings of many complex biological systems, including the brain. In this image, researchers used a recently developed polarized light microscope to trace the spatial orientation of neurons in a thin section of the mouse midbrain. Neurons that stretch horizontally appear green, while those oriented at a 45-degree angle are pinkish-red and those at 225 degrees are purplish-blue. What’s amazing is that these colors don’t involve staining or tagging the cells with fluorescent markers: the colors are generated strictly from the light interacting with the physical orientation of each neuron.
Malaria has afflicted humans for millennia. Even today, the mosquito-borne, parasitic disease claims more than a half-million lives annually . Now, in a study that has raised both hope and concern, researchers have taken aim at this ancient scourge by using one of modern science’s most powerful new technologies—the CRISPR/Cas9 gene-editing tool—to turn mosquitoes from dangerous malaria vectors into allies against infection .
The secret behind this new strategy is the “gene drive,” which involves engineering an organism’s genome in a way that intentionally spreads, or drives, a trait through its population much faster than is possible by normal Mendelian inheritance. The concept of gene drive has been around since the late 1960s ; but until the recent arrival of highly precise gene editing tools like CRISPR/Cas9, the approach was largely theoretical. In the new work, researchers inserted into a precise location in the mosquito chromosome, a recombinant DNA segment designed to block transmission of malaria parasites. Importantly, this segment also contained a gene drive designed to ensure the trait was inherited with extreme efficiency. And efficient it was! When the gene-drive engineered mosquitoes were mated with normal mosquitoes in the lab, they passed on the malaria-blocking trait to 99.5 percent of their offspring (as opposed to 50 percent for Mendelian inheritance).
It’s the time of year when thoughts turn to buying school supplies and heading back to the classroom or off to university. So, throughout the month of August, I’ll be sharing LabTV profiles of young people whose learning experiences have set them on the path to becoming biomedical researchers.
One of the great things about college is that you never know where those four years might lead you. Elyse Munoz, who’s the focus of today’s video, offers an excellent case in point. Upon enrolling at Arizona State University, Tempe, she chose political science as her major—only to find the classes “incredibly boring.” Then a friend talked Munoz into taking an anatomy class, and suddenly everything clicked: she discovered biology was her true calling.
Now, Munoz is a candidate for a Ph.D. in genetics at Pennsylvania State University, State College. Working in the lab of molecular parasitologist Scott Lindner, Munoz is contributing to the search for promising vaccine targets for malaria, a mosquito-borne disease that kills more than a half-million people, mainly children under the age of 5, around the globe each year.
Malaria has confounded biomedical researchers for decades because it’s been impossible so far to develop a vaccine that offers a high level of protection. But, thanks to a different approach to vaccine design and delivery, there’s hope that we may have finally turned the corner in the fight against this mosquito-borne health threat. Continue reading →
It turns out that one of the most innovative and effective strategies to fight malaria might involve harnessing a bacterium called Wolbachia. This naturally occurring genus of bacteria infects many species of insects, including mosquitoes. The reason this is important is that Wolbachia-infected mosquitoes become resistant to the parasite Plasmodium falciparum, which causes some 219 million cases of malaria worldwide and more than 660,000 deaths . Wouldn’t it be amazing if Wolbachia-infected mosquitoes blocked the transmission of malaria?
Unfortunately, Wolbachia don’t normally pass from generation to generation in Anopheles, the mosquitoes that spread malaria. But that hurdle has now been overcome. Continue reading →