Author Archives: sydneyschnell

A Gene for Skinny Jeans!

The person sitting beside you in your morning lecture is slurping down an extra-large iced cap, with whipping cream AND chocolate drizzle. Those french fries in the cafeteria at lunchtime are looking deliciously tempting, and when you get home from your long day your roommate has a fresh batch of chocolate chip cookies sitting on the counter.

Chocolate Chip Cookies! Christie @ Love From the Oven via Flickr Creative Commons.

Oh the temptations, but with “beach season” soon approaching, it makes for a hard choice between those deliciously fattening foods and a trim waistline. What if I told you that soon, you may be able to indulge in all of your favorite foods, never hit the gym, and still turn heads in your swimsuit this summer?!

Miguel Angel via Flickr Creative Commons.

Genetics researchers at the University of Colorado’s School of Medicine, led by Professor James McManaman, have recently discovered a gene that appears to be directly related to obesity. This gene, called Perilipin 2 (Plin2), produces a protein that plays a key role in regulating fat storage and metabolism. When mice lacking this gene were fed an obesity-inducing diet, they were observed to be resistant to becoming obese!

In fact, not only did these mice stay lean, they appeared to be much healthier than the mice with a functional Plin2 gene. Compared to normal mice, their fat cells were 20% smaller, they showed an absence of fatty-liver disease, they had lower triglyceride levels, and they were more insulin-sensitive. When both normal mice and mice lacking the Plin2 gene were placed on an obesity-inducing diet, the Plin2-lacking mice showed surprising restraint when eating their food (normal mice will eat until all food is gone!), and were also more active.

Obese mouse and normal mouse. Bigplankton via Wikimedia Commons.

What does this mean for us?

Obesity is quickly becoming a dominant health concern throughout North America (see famous chef Jamie Oliver discussing the obesity trend here), indirectly causing a long list of medical complications such as type 2 diabetes, hypertension, coronary heart disease, and stroke.

Obesity, an increasing trend in North America. Malingering via Flickr Creative Commons.

The interesting thing is, humans also have a Plin2 gene. If researchers can find a way to target the Plin2 gene, these findings may result in an effective treatment for obesity. This would lead to a slimmer, healthier nation, and reduce the financial strain  that obesity-related complications place on our health care systems!

However, don’t book your reservation at the neighbourhood all-you-can-eat buffet just yet. Before any human applications can be made, we must better understand what other roles the Plin2 gene may play, and how removal of this gene will influence health and behavior on a long-term scale.

– Sydney Schnell

Uncovering the Secret Sexual Side to Our Favorite Fungus!

With Valentine’s Day only a few days away, love is definitely in the air. As it turns out, even fungi are in the mood!

Valentine’s Day Cupcakes. Sugar Daze via Flickr Creative Commons.

A recent study has discovered that Penicillium chrysogenum (P. chrysogenum) have a sexual side. While you may not recognize the name P. chrysogenum, it is likely that at some point in your life you have depended on this fungus to help you feel better. P. chrysogenum is popularly known for its production of the antibiotic penicillin, which has been used for treating bacterial infections since it was discovered by Sir Alexander Fleming in 1928.

Penicillin works by preventing bacteria from building cell walls. Lacking this external support, the bacterial cell is very fragile and bursts, resulting in death of the cell (click here to watch this process). As we do not possess the same cell wall components as bacterial cells, penicillin is an effective treatment for human bacterial infections, as the antibiotic interferes with bacterial cells but not our own cells!

Penicillium Growing on Bread. Logan Sakai via Flickr Creative Commons.

Previously, it was thought that P. chrysogenum only underwent asexual reproduction. In this reproductive strategy, fungal cells duplicate their genetic material and divide, resulting in two identical clones called daughter cells.

However, researchers suspected that P. chrysogenum would be able to sexually reproduce if provided with the right conditions, as the genetic sequences required for mating could be found within the DNA of this species. Supporting this belief, a recent experiment by Bohm et. al has shown that when proper conditions are met, P. chrysogenum fungi will sexually mate to produce new genetic strains of offspring.

Scanning Electron Microscope (SEM) Image of P. chrysogenum Fungus. Engineering at Cambridge via Flickr Creative Commons.

This discovery has been dubbed the “secret sex life” of P. chrysogenum. So, light the candles, turn on some romantic music, and spread out the rose petals?

Not quite; these fungi require a special “love potion”. After testing a variety of light and nutrient conditions, experimenters found that P. chrysogenum engaged in sexual mating when grown in darkness, in an oatmeal base supplemented with biotin (a vitamin).

Fungi Love Potion? Oatmeal! Nillerdk via Wikimedia Creative Commons.

Furthermore, researchers found that fungi engaging in sexual activity also produced more penicillin than asexual fungi. These findings are important on an industrial level, as sexual strains can be used to maximize penicillin output when synthesizing this antibiotic for medical usage. While high antibiotic-producing strains have been engineered before, they are genetically unstable and have short lifespans. However, knowing that sexual reproduction in P. chrysogenum occurs, engineered strains can be sexually mated with normal strains to produce offspring that are both genetically stable and produce large quantities of antibiotic.

While I can’t promise that oatmeal and biotin will help you get lucky this Valentine’s Day, it appears that you won’t need to worry about a penicillin shortage in the near future!

– Sydney Schnell

Pest Control – How Far is Too Far?

When asked to think of the most dangerous animals on Earth, we often imagine large creatures like sharks, bears, or lions. However, you may be surprised to discover that the most dangerous creature in the world is actually… a mosquito!

Anopheles stephensi mosquito, a known carrier of Malaria. Rsabbatini via Wikimedia Creative Commons.

Mosquitoes are summertime pests; those annoying and unwelcome guests at a family barbecue, picnic in the park, or day at the beach. While the itchy bumps they cause are irritating, bites are rarely fatal here in North America. However, in tropical and sub-tropical regions, mosquitoes act as transmitters for potentially fatal diseases, such as Malaria and Dengue fever. Causing over one million deaths each year, mosquito transmitted diseases kill more humans than any other animal-related incident.

A child being treated for Malaria. Ashley Jonathan Clements via Flickr Creative Commons.

This has prompted scientists to consider proactive options for fighting these diseases – namely, to prevent people from becoming infected in the first place. As common insect-reducing methods (such as insecticide spraying) often kill other species within the ecosystem too, controlling mosquito populations through genetic modification is becoming more popular. While similar strategies have been used before – the sterile insect technique (SIT) was developed in the 1950’s, whereby genetically-engineered sterile insects are released into the environment – a new technology developed by Oxitec laboratories is at the forefront of the mosquito combat.

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(TEDtalksDirector via YouTube)

Above, Hadyn Parry (CEO of Oxitec) discusses disease transmission by mosquitoes, and how Oxitec proposes to alleviate this issue.

Oxitec is a British biotech company that, under the leadership of Luke Alphey, has produced the RIDL method, by which mosquitoes are genetically modified to carry lethal alleles.

What does this mean?

Essentially, male mosquitoes are engineered in a laboratory and then released. The concept here is simple – the mutations inflicted have no direct impact on the mosquitoes’ fitness (that is, the genetically modified males compete for female mates equally as well as wild-type males), but the mosquitoes will die if not given tetracycline during development. Therefore, when these RIDL males mate, all offspring will receive one dominant lethal allele. Over time, without the presence of tetracycline, all mosquitoes carrying this allele will die, effectively diminishing the mosquito population. Luke Alphey explains these concepts in the video below.

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(WorldEconomicForum via YouTube)

While the RIDL method shows promise for controlling mosquito populations, many parties contend that there are unintended side effects. For example, the removal of mosquito populations threatens to disrupt surrounding ecosystems, as many species, such as bats and spiders, rely on mosquitoes for nourishment. Furthermore, it has been suggested that mosquitoes could develop resistance to the lethal allele, resulting in a stronger subsequent generation and thereby amplifying disease transmission.

However, Oxitec scientists seem confident that the RIDL technique will provide a safe, effective way to manage mosquito populations. If true, we may be about to witness a new era of disease prevention.

– Sydney Schnell