Author Archives: Prof. Seto

Tips for the future Bio1101 class

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You’ve just completed a semester of General Biology at the college level. You may recall that one of my former students came to class to answer questions regarding his success in the class. What advice would you offer to others in future sections of this course? Please comment on the following (by class on May 23):

  • What were your expectations of the class coming in and what was your previous college/science background?
  • How would you approach the class differently now that you’ve completed the semester? Would you study differently? Would you read the book differently? Would you be more active in pursuing help? Would you try to find a friend in class to help? Would you take the Blackboard quizzes more seriously?
  • What was the most challenging part of the course? Topic? Personal circumstance?
  • How did your preconceptions change over the course of the semester? Did your prior knowledge influence/enhance/deter the way you learned?

DNA Repair and Preventative Surgery

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Angelina-Jolie

Angelina Jolie has recently undergone a double mastectomy (as reported in this article) as a preventative measure. The actress has a family history of breast cancer and her mother died at an early age of 56 after battling breast cancer for a decade. She carries a defective version of the gene BRCA1, a DNA repair enzyme.
Protein BRCA1 PDB 1jm7

BRCA1 acts to repair double-strand DNA breaks through homologous recombination with intact DNA from the homologous chromosome, sister chromatid or within the same chromosome. Women who carry a mutation to BRCA1 are at greater risk of developing ovarian and breast cancer. In the article, she states:

My doctors estimated that I had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer, although the risk is different in the case of each woman.
Only a fraction of breast cancers result from an inherited gene mutation. Those with a defect in BRCA1 have a 65 percent risk of getting it, on average.

Only a fraction of breast cancers result from an inherited gene mutation. Those with a defect in BRCA1 have a 65 percent risk of getting it, on average.

She goes on to indicate the hurdles genetic screening:

Breast cancer alone kills some 458,000 people each year, according to the World Health Organization, mainly in low- and middle-income countries. It has got to be a priority to ensure that more women can access gene testing and lifesaving preventive treatment, whatever their means and background, wherever they live. The cost of testing for BRCA1 and BRCA2, at more than $3,000 in the United States, remains an obstacle for many women.

Flood of invasives

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Urban Roadkill
Photo:Urban Roadkill

Rains and flooding will cause the critters that live underground to emerge. Just be glad it’s been a relatively dry April. Here’s an article about something that can happen during extreme flooding as seen with Hurricane Sandy.

Here’s an image for you to get out of your head:

Sandy has brought a feast to their feet. New sources of food are washing out of the waterways and along flooded streets, including loads of rotting trash, other rats, pigeons, and fish. The well-fed rats will burrow beneath buildings under cover of night to establish new homes, sliding into holes as small as a half inch (1.3 centimeters)—the width of their skulls—even though their bodies can measure up to 18 inches (46 centimeters) long.

Carbon Neutral Fuel

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Fishing egretPhoto: An egret fishes in a kettle full of algae

We often hear about “carbon footprint“. What does this actually mean? A carbon footprint refers to the amount of carbon dioxide equivalent is being produced for an action or activity. When we refer to carbon neutrality, we’re speaking about ways in which the output of these gasses can be reclaimed to offset the production. Essentially, this means we are offsetting the carbon footprint.

We know that many of the “greenhouse gasses” come from industry, particularly with the burning of fuel. A recent article illustrates one possible way to address this.

The article states:

(Petroleum) was simply ancient algae that had been covered over by shallow seas and then was covered over by silt and dirt,” said Mayfield. “The algae’s proteins and carbohydrates degraded away, leaving the fat, which we call crude oil. So the algae we produce in ponds today makes the same stuff.

So indirectly, this is a roundabout way of harnessing solar energy… but less roundabout than before.

Creating new organs

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Hanging out
Photo: Organs

Rat Kidneys Made in Lab

A recent development in bioengineering has resulted in the production of replacement kidneys that function in rats. This has a great potential for a shortage of organ donations in humans. You can read about this in this article.

About 17,000 people with end-stage kidney disease receive a donor organ each year in the United States, but more than five times as many patients are on waiting lists. In 2011, nearly 5,000 people died while awaiting transplants. Bioengineered kidneys, especially if made using nonhuman sources, could ease or eliminate this organ shortage.

Alien Invasion!

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Seafood Salad
Photo: Flotsam and leftover sea life

Aliens invade Florida

Here’s an article about an emerging problem involving an invasive species of snails. These snails (Giant African Land Snail) originally come from Africa. They are highly confiscated at airports because they are typically smuggled in for the pet trade. In the wild, they don’t have native predators so they can explode in numbers. They’re pests because they like to devour stucco in buildings for the calcium content since this helps them grow their shells.

I usually have a pretty good way to deal with such pests. However, these snails can carry disease, like rat lungworm that can cause meningitis in humans.

Skin Swap and Contact Sports

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Brooklyn Bombshells Blockers

Photo: Gotham Girls Roller Derby Championship


Ever wonder how many germs transfer between people on contact? Ever wonder if contact would change the distribution of microbes on your body? A recent paper reveals just that.

Wired magazine states:

After each bout, though, the samples told a different story: the teams’ microbiomes converged, having more species in common. For example, before Emerald City played Silicon Valley, members of the two teams shared 28.2% of their bacterial communities. After the bout, the overlap was up to 32.7%, the team reports today in PeerJ.

The article states:

In these culture-based studies, handshaking, as well as hand-contact with other parts of the body and room surfaces, have been identified as strong vectors of health care service infections, such as with methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella spp.(Casewell & Phillips, 1977; Davis et al., 2012; Pittet et al., 2006). Given that human contact with surfaces, and especially the skin surfaces of others, has been shown to transfer individual microbial taxa, activities which involve human to human contact could be hypothesized to result in the sharing of skin microbial communities.

How does this make you feel?

Citation:
Meadow et al. (2013) Significant changes in the skin microbiome mediated by the sport of roller derby. PeerJ 1:e53 http://dx.doi.org/10.7717/peerj.53

Diversity and Variation .. the key to evolution

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Nicobar pigeon
Photo: Above features a Nicobar Pigeon (Caloenas nicobarica), not a Rock Dove.

The genome of the Rock Dove -aka Pigeon, flying rat, etc.- (Columba livia) has been sequenced. In this article, you can see the great diversity of this invasive species that originated in Eurasia and brought over as a food item.

Mouth full of feathers
Photo: Rock dove as a food item to a Buteo jamaicensis.

Fancy breeds of pigeon were developed over time since they also served as pets to humans. As with other pets, multiple breeds were developed that preferentially display different variations of traits. Sequencing genomes of other organisms is useful for us to understand the common toolkit that all life forms on this planet share and the effects of carrying specific variations of genes.

The article states:

But Dr Mike Shapiro says the pigeon may lead us to some very useful information about ourselves.

“Just about all animals use the same toolkit of genes to build their bodies and to control similar processes during development,” the University of Utah, Salt Lake City, researcher explained.

“By understanding how these processes work in other animals, we can in turn learn more about normal and abnormal variation in humans as well. If you take the gene we identified, this EphB2 gene – this is a gene that has also been implicated in particular types of cancers. It may also have a role in the progression of Alzheimer’s disease,” he told BBC News.

Balance

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Fall

Photo: A dead gray squirrel after a juvenile hawk dropped it in the Mill Pond of Van Cortlandt Park

Here’s an article about an invasive species and the effects on a native species.

In this article, we see that the Gray Squirrel (Sciurus carolinensis), a creature we are all too familiar with, invading the domain of the Red Squirrel (Sciurus vulgaris). These two squirrels are highly related. As we can see, they fall within the same Genus. While the Grey Squirrel species adapted to the North American environment, the red squirrel adapted to Eurasia. Here, we see the effects of introducing an invasive (in the late 1800s) and the effect on a native species. Both squirrels share a similar diet and physical form that is specialized for a very similar environment. So why are the Grays of North America out-competing the Reds? The article points to the resistance of the Grays to pox viruses.Some time in history, resistance to pox viruses was a selective pressure. Those who carried the resistance trait lived and propagated this feature. Now, it is a further advantage when competing with the native Red Squirrel species.

Where else have we seen something like this historically even within the same species? Think about the Columbian Exchange and how that reshaped the booming population of the world at that time.