AP Biology class blog for discussing current research in Biology

Author: rysharifov

CRISPR: how one tool can change an entire generation (of invasive mice).

In recent years, technology has heavily impacted scientists abilities to change the world. CRISPR is a recently discovered gene editing tool that is revolutionizing the way scientists are treating patients and curing diseases. Recent research has also found that CRISPR can be used to help mice infestations in certain parts of the world (random, but cool)!

CRISPR logoMice infestations are a problem in many islands, and CRISPR is here to help. Scientist believe they had found a way to make an entire mice population extinct (in a few decades) by using gene editing via CRISPR. In order to understand exactly how scientists plan on doing this, it is important to understand what a “haplotype” is. A haplotype is a set of genes that are inherited by the next generation together. The “regular house mouse” has what’s called a “t-haplotype,” and it’s passed down roughly 95% of the time (a lot compared to the normal 50%). The study states that male house mice with two t-haplotype copies become infertile, and females with two t-haplotype copies will become sterile as well. As we know from AP-Biology, when an organism has two copies of some gene, it is known as homozygous- meaning it has two of the same alleles of some gene. In this case the phenotype that makes the mouse homozygous would be the altered t-haplotypes. If a mouse has two of these altered t-haplotype genes, it becomes sterile and cannot reproduce.

Mouse white background

CRISPR plays a crucial role here – by using gene editing through CRISPR technology, scientists are able to edit the t-haplotype of the M. musculus house mouse so that next time a male M. musculus mates with a female, the offspring will become infertile. That’s right, CRIPSR can be used to completely alter and wipe an an entire M. musculus population over the course of a few years. By using computer technology, scientists predict that by adding just 256 “altered” mice to a certain island population of mice, an island of 200,000 mice can be fully wiped out within about 25 years.

Researchers in laboratoryScientists are hopeful, optimistic, and invested in CRISPR technology. The “25 years later” prediction is a long time to wait, and scientists hope that sometime in the future, CRISPR will be able to work faster, allowing problems to be solved more quickly and more efficiently. I think that this study is an important part of CRISPR potential, and it makes me very curious to see what CRISPR has in store for the future, and what other kinds of animal related issues it can help solve.

Can Cancer in Dogs be Predicted?

Cancer in dogs is not an uncommon thing. While unfortunate, about 1 in 4 dogs unexpectedly develop cancer throughout their lifetime. Scientists have recently raised the question of the possibility of predicting when a dog might develop cancer. Veterinary Oncologist and researcher Andi Flory and her team at PetDX (pet-diagnostics firm) began research to find out if certain traits and factors are associated with a dog’s development of cancer.

As an AP Biology Class, we have gained a significant amount of background information on cancer as a result of our studies throughout this unit. Cancer in dogs is very similar to cancer in humans. As we know from class, when a cell becomes cancerous, it divides uncontrollably, and its DNA becomes damaged as a result of some form of mutation (as a result of radiation, high fat, etc.). Unlike a healthy cell, a cancer cell does not stop dividing when it is crowded, and through metastasis, cancer cells travel through the blood system and create tumors. Cancer treatment for both dogs and humans can also be very similar, one major example (similarity) being chemotherapy, a process in which chemicals attempt to kill the fast-spreading cancer cells in a living organism.

Differences in glycolysis pathways between normal cells and cancer cells

After using data and samples from three previous studies, one at University of California- Davis combined with Colorado State University, the second at Ohio State University, and the last at the University of Wisconsin- Madison, Flory and her team concluded their results. They concluded that the median age for cancer development and discovery in dogs was approximately 8.8 years old, with the males being slightly younger than females during cancer diagnosis. They found that neutered and spayed dogs, on average, were diagnosed later than those who have not been “fixed.” With regards to breeds, the study found that West Highland White Terriers and American Staffordshire Terries formed cancer the latest out of all breeds, and Mastiffs and Saint Bernards formed cancer the earliest compared to other breeds. These results may be useful to anyone looking to get or adopt a new dog.

West Highland White Terrier PippaAmericanStafforshireTerrierMastiff - English MastiffGrupp 2 SANKT BERNHARDSHUND, Dein Hards Monday Muffin (24180113462)

As a result of this study, specifically the fact that, on average, the younger ages of cancer diagnosis in dogs was around 7 years old, veterinarians recommend that dog owners begin cancers screening right around the 7 years-old-mark. While there isn’t enough technology yet to detect cancers at very early stages, scientists and veterinarians still say that it is better to begin cancer checkups early rather than later. As a dog owner, I agree with the fact that cancer screenings in dogs should start earlier rather than later. Even though it might be an added expense, if cancer happens to be detected earlier, the dog will begin treatment sooner, and the chance for recovery increases.

Avian Brain: Proof that Bigger Doesn’t Always Equal Better

There is a common misconception that a bigger brain size always means a smarter living creature or animal. Recent research done by German avian neuroscientist, Kaya von Eugen, from Ruhr University Bochum in Germany, compared neuron activity in the brain of a pigeon to that of other mammals to see if such thought was true.Ruhr University Bochum (37339321200)

Neurons were a substantial part of our learning curriculum in AP Biology. As such, we know their main function to be transmitting impulses and messages from the environment around us, to signal certain body parts to function. This helps us gain a better understanding of von Eugen’s research as it allows us to comprehend the goal of her experiment and how crucial a knowledge of neurons was to it.

Complete neuron cell diagram tr

To aid in her research, von Eugen turned to an experiment conducted in 2016, where scientists injected molecules resembling glucose into pigeons’ veins, and later tracked radioactivity in these pigeons by tracking the “glucose” molecules. By examining both the radioactivity and the blood of the pigeons, scientists were not only able see how much glucose the brain tissue used, but they were also able to calculate how much glucose was used by each neuron every minute.

Von Eugen’s research continued as she compared neuron energy from the pigeon to that of other mammals, and she came to the conclusion that the neuron of a pigeon used around 3 times less energy that the neuron of an average mammal. So, despite the brain size of a bird, or pigeon in this case, being multiple times smaller than the brain size of other animals, it is clear that intelligence and smarts do not depend on brain size.

Afraid of needles? No Problem- inhale a covid vaccine!

Its been a few years now since the first COVID-19 vaccine became available to the public. And since then, there has been a multitude of people who have been hesitant to receive a vaccine. Some people don’t believe in the vaccine – or even in the virus itself, some are just anti-vaxxers, some however, are simply afraid of needles. A Chinese pharmaceutical company based in Tianjin, China, CanSino Biologics, has recently created a COVID-19 vaccine you can inhale – and hopefully with this introduction, people will be more likely to get vaccinated as the “fear of the needle” with disappear.

The vaccine is called, “Convidecia Air.” And while you may be skeptical about it since it’s not really a “real vaccine that is injected into your body, the nasal flu vaccine has been around for years now and it enters your body the same way as Convidecia Air. I have personally received both the nasal vaccine (the one you inhale), and the needle vaccine (injection) from the flu, and I feel that they have worked the same in the past- which is why I’m optimistic about Convidecia Air.

CanSino Convidecia

As we’ve talked about in AP Biology recently, a regular (via injection) COVID-19 vaccine enters your body, and T-lymphocytes and B-lymphocytes remain in the body as a result. These lymphocytes function as both a Cell-Mediated Response and a Humoral Response, respectively, to try to fight off invading pathogens and prevent re-infection. With this new vaccine that enters the body via inhaling, the same T-cells and B-cells remain in the body after it is introduced to you.


CanSino Biologics logo

The introduction of this new type of COVID-19 vaccine seems promising to scientists, as by entering the body the same way as the actual SARS-CoV-2 Virus- through the lungs and mouth- scientists believe that an inhaled vaccine might be more effective in terms of preventing disease and stopping the spread since it is also enters the body via the lungs and mouth.

Overall, scientists are hopeful that with the introduction of this new type of “inhaled COVID-19 vaccine,” people will remain healthier, and the pace at which the world recovers during its post-pandemic state will increase.


Bacillus Subtilis: Back from the Dead

Bacillus subtilis, a type of bacteria, has the power to come back from the dead- sort of.

At some point in their short lives, Bacillus subtilis bacteria become dormant. A recent report and study examined what causes Bacillus subtilis to “revive” themselves. As I mentioned before, the Bacillus subtilis cells go dormant. This just means it goes through a period of inactivity. Dormancy isn’t unique to Bacillus subtilis. Another group of cells that can lie dormant for a long period of time are cancer cells. However, while scientists can only predict what causes cancer cells’ dormancy and awakening, a study has been done to figure out how Bacillus subtilis withdraw from this state.

Being a bacterium, the Bacillus subtilis is a prokaryote, which, as we learned in AP Biology, means that is a single celled organism with no nucleus. The Bacillus subtilis falls under the category of bacteria that forms spores to protect themselves from threatening or potentially dangerous situations.

Bacillus subtilis Spore


While the cell itself may be dormant and have no energy, the spores’ potassium ions (positively charged) can move around without using energy, which is why Gürol Süel and her team of researched deduced that the potassium ions is what “revives” the cells. Tracking the cell’s potassium ions’ motion activity, the team saw that as the ions moved out of the spore’s core, the cell became more electronegative, provoking Bacillus subtilis‘ “awakening” (growth).

Can Bacillus subtilis really die and come back to life? Well, no. But due to its unique spores and potassium ions reviving its dormant state, it’s not too far off.

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