BioQuakes

AP Biology class blog for discussing current research in Biology

Author: xraychristollography

CRISPR Technology is Finding Its Place in the Agricultural Industry

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On March 12, 2019

In Student Post

CRISPR technology is now laying a foundation in the agricultural world, trying to help corn growers improve the speed, versatility, and output of their crops. It has been difficult to implement CRISPR technology thus far, as the cells walls of plants, at a microscopic level, are particularly tough to penetrate. Fundamentally, CRISPR “…consists of enzymatic scissors called Cas9 that a guide made from RNA shuttles to an exact place in a genome.” The difficulty with plants cells is that, in comparison to animal cells, the extra-rigid cell walls make it immensely difficult for the guide RNA (gRNA) and the Cas9 to reach their destination on the genome. In response to this problem researchers have come up with what is described as an “inelegant” solution to this problem where they “…splice […] CRISPR genes into a bacterium that can breach the plant cell wall or put them on gold particles and shoot them with what’s known as a gene gun.” Unfortunately, this method doesn’t work in the crucial corn varieties where it is needed. However, a team of researchers in North Carolina, Timothy Kelliher and Quideng Que of Syngenta, in Durham, North Carolina have come up with an even more ingenious solution to deal with the stubborn plant cell walls. Haploid induction “…allows pollen to fertilize plants without permanently transferring ‘male’ genetic material to offspring. The newly created plants only have a female set of chromosomes – making them haploid instead of the traditional diploid. Haploid induction itself can lead to increased breeding efficiency and higher yielding plants.” This same method has been found to work in wheat and even Arabidopsis, “…a genus of plants related to cabbage, broccoli, kale, and cauliflower.” Yet again, sadly, CRISPR faces another drawback as scientist not that “…if it were done in the field, the changes wouldn’t spread because the male genome in the pollen – which carries the CRISPR apparatus – disappears shortly after fertilization.” However, there is still much hope for CRISPR technology, and it is without a doubt that we are making big strides into the future with gene editing technology.

“And Then There Were None.” Not An Agatha Christie Murder Mystery, but an Eye-Opening Story of Extinction

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On January 15, 2019

In Student Post

 

A Land Snail

George the Snail

On January 1st, while we were all blissfully celebrating the transition from 2018 to 2019, the last land snail of the species Achatinella apexfluva, which had thrived for many years on the Hawaiian island of Oahu, had gone extinct.

The name of the snail was George. It was given to him by researchers so that he may be remembered and not simply become an extinct species left unknown to most. Researcher Michael Hadfield notes “You anthropomorphize it [i.e. George the snail] and people pay attention.” More importantly, though, is George’s story. He was “…born in the early 2000’s to parents that had been captured in the mountains [by scientists] in an effort to protect them from predators.” Then, there was a sudden mass extinction event. What researchers believe to be some form of a pathogen annihilated the remains of George’s already endangered species. George was the lone survivor of this unfortunate phenomena.

George’s species is not the only one to face extinction on the Hawaiian Islands. “At one point there were more than 750 species of land snails identified…” George’s species, however, was the first. Unfortunately, Dr. Sischo, who directs the state-run Snail Extinction Prevention Program, mentions that estimates say that “more than half of those species are already extinct.” There were other factors, other than the elusive pathogen, that have afflicted the land snails over a much longer period of time: “…invasive predators like rats and wolfsnail, which eats other snials. They also face habitat destruction and the effects of climate change; drier conditions have reduced the inhabitable land on the islands,” Dr. Sischo says.

In 2017, researchers removed a two-millimeter section of his foot and have preserved it in a “deep-freeze container” according to the Department of Land and Natural Resources. “The hope is that someday soon, scientists will develop the technology to clone a snail.”

What are Biofilms?

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On November 19, 2018

In Student Post

 

Biofilm being formed. (Pixnio)

Medicine has made great advancements in patient care and treatment over the last decade. However, everyday viruses and bacteria alike have become stronger and more resilient – even to the latest antibiotics. One such threat that has led to “…thousands of deaths…” in “…American Hospitals alone…” are biofilms. These bacterial cells “…gather [together] and develop structures that bond them in a gooey substance…” insulating them from the outside world. Biofilms ability to become impervious to antibiotics at a moment’s notice has led biologists to wonder both how they develop, and how to stop them.

To find out how and why these bacteria form biofilms, researchers at the Levchenko Lab, at Yale University, as well as from the University of California – San Diego, “…designed and built microfluidic devices and novel gels that housed uropathogenic E. coli cells, which are often the cause of urinary tract infections. These devices mimicked the environment inside human cells that host the invading bacteria during infections.” From this experiment, the scientist discovered that the bacteria would multiply until physical constraints inhibited them from further reproduction. At this point, the bacteria would become “stressed” and thus this “stress would induce the formation of a biofilm.

With the numerous mimicking devices that the researchers utilized in the experiment, they can now create many biofilms in predictable ways, and further analyze their behavior in similar environments. “This would allow for screening drugs that could potentially breach the protective layer of the biofilms and break it down.”  It is an amazing solution to a stubborn and persistent biological threat, that has already robbed enough, otherwise healthy, people of their lives.

It is imperative that we continue to make great strides in the advancement of medical technologies and treatments, as this will enable us to live healthier, more disease-free lives for the future to come. As viruses and bacteria get stronger, we need to make sure to keep up.

Did You Know Plants Can Talk?

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On October 14, 2018

In Student Post

 

For thousands of years language has been a crucial part of cultures around the world, and a method unique to humanity of transmitting ideas, thoughts, emotions between us. Language has allowed us to work harmoniously together for our mutual improvement and survival. Recently, however, two researchers, Dr. Kim Valenta and her colleague Omar Nevo, have discovered that plants too, have developed their own unique and intricate method of conveying information to their pollinators; “the easier it is for fruit eaters to identify ripe fruits, the better the chance for both [, the plant and the fruit,] to survive.

The most vivid example of plant communication can be found in Madagascar’s Ranomafana National Park and Uganda’s Kiabale National Park where berry plants have evolved “to match each animal’s sensory capacities, [thus] signal[ing] dinner time in the jungle…” Dr. Valenta and Nevo analyzed the exact colors of each fruit with a spectrometer, and “with a model based on the visual capacities of the seed-dispersing animals, they also determined who was most likely to detect different fruit colors contrasting against an assortment of backgrounds.” The researchers concluded that “the colors of each fruit were optimized against their natural backdrops to meet the demands of the visual systems of their primary seed dispersers,” i.e. pollinators. Thus, red-green color-blind lemurs, in Madagascar were best able to detect the fruit with a blue yellow color scheme and monkeys and apes in Uganda, with tricolor vision like humans, were clearly able to distinguish red berries against a green backdrop.

Also recently discovered was that plants can communicate to their pollinators through scent. Dr. Nevo performed a scent-based study on the lemurs in Madagascar. His team collected various ripe and unripe fruits from all over the jungle of Ranomafana. “He suspected the leumur-eaten fruits would have a greater difference in odor after they ripened than the bird-eaten fruits.” To discover exactly how this scent-based communication worked, Nevo used the “semi-static headspace technique.” From this experiment it was confirmed that “fruits dispersed solely by lemurs produced more chemicals and a greater assortment of compounds upon ripening. It is now known that wild lemurs actually spend quite a lot of time smelling for the vivid difference in odor between ripe and unripe fruits in the jungle.

It is astonishing how plants have evolved over the years to be able to communicate with their pollinators for the betterment and expansion of their species. I would be interested to find out, what other organisms communicate (single cellular, multi-cellular, etc.) and what kind of information they find necessary to convey to others for their survival?

 

 

 

 

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