Biology 111 Wiki

Stephen Ross

Enzyme Communication among Bacteria

Researchers from Princeton University under Bonnie Bassler, Professor of Microbiology, et al. have discovered that bacteria use chemical signals to communicate with each other. They use a quorum sensing method with receptors essentially to count the other bacteria to know when their numbers are sufficient to complete tasks such as launch virulents and give off light. It turns out that each species of bacteria has its own molecule for this and that all of the molecules are related, having the same basic structure with only slight differences. Researchers have simply called this intraspecies communication. All bacteria also have an enzyme for interspecies communication, as bacteria often live in groups of many, many different species.

This provides the opportunity for huge advancements in medical science and to completely change how we immunise. Scientists have begun testing the use of molecules which are largely similar to the enzymes for communication in order to stop the bacteria from communicating. The enzymes would be sufficiently different that the bacteria's receptors would attempt to receive them; the look-alike molecules would then block the receptors, rendering communication impossible. Current methods simply kill bacteria, which then allows surviving populations to reproduce and over generations, they develop resisitance. This discovery has profound implications for the improvement of public health globally.

Bassler's TED Talk:

Surette, M., Miller, M., & Bassler, B. (1999). Quorum sensing in escherichia coli, salmonella typhimurium, and vibrio harveyi. Proceedings of the National Academy of Sciences, 96(4), Retrieved from

Pessimistic Puppy Dogs

A team of scientists including Mike Mendl, a prominent and prolific veterinary researcher, has discovered that some dogs feel pessimism just as some humans and that pessimistic dogs feel more anxiety due to separation than optimistic dogs. The group conducted the study in Britain, studying the behaviour of the puppies of different breeds in play rooms with the researchers. The study found that, similar to humans, dogs which see the world in a largely pessimistic point of view cope poorly with separation whereas optimistic dogs retained their positive outlook despite the abandonment. The team also studied the behaviour of dogs in searching for food in various food dishes; they determined that the dogs which went slowly amongst the food dishes did not expect to find food and were thus by definition pessimistic. Mendl noted that the pessimism may not be precisely what humans experience.

The Royal Society for the Prevention of Cruelty to Animals (RSPCA) in Britain hopes to use these findings about canine psychology to improve the adoption system for dogs in shelters, matching them with families who will meet their needs and make them happy.

Pappas, S. (2010, October 11). Pessimistic dogs have greater separation anxiety. MSNBC, Retrieved from

Biodiversity in the Amazon

In the world's largest rain forest and river basin, the Amazon, a new species is discovered once every three days. From 1999 to 2009, over 1200 species were discovered, including a gigantic primate eating catfish, a 10cm tall carnivarous plant, the fourth known species of anaconda, pink river dolphins, various ant species and a new species of turtle. The Amazon river basin is the most diverse place on Earth, having thousands of plant, animal and insect species per hectare.

The World Wildlife Foundation (WWF) compiled a report during 2009 and 2010 on the state of the rain forest and the discoveries over the past deacade, releasing it in late September, 2010. At the end of the report, the WWF called for the preservation of the Amazon, which affects the biospshere, the global markets and the welfare of all of those dependent upon both.

Ahmed, D. World Wildlife Foundation, (2010). Amazon alive!

My Opinion concerning Stem Cells (Assignment)

I am all for all forms of embryonic stem cell extraction as long as the government regulation is clear and appropriate. In the cases of the extras from IVF clinics and the use of donated occytes (the latter being used for cloning and the in vitro creation of embryos for research), nformed consent is a must for me. The people who have donated these things must be aware of how they will be used. Likewise, the government must be able to monitor the research, especially the process of cloning, to ensure that it remains purely therapeutic. I do not think that a cut-off date for extraction is necessary. As long as all of the researchers follow the government regulations and as long as those regulations are reasonable and enforcable, I do not have any problems.

The whole argument about potential life is all too tedious to me. Firstly, humankind is not at a stage where it needs to create as many children as possible. The argument is that we need to preserve life, but in asserting this the activist forgets why we are looking into stem cell research in the first place. The activist must then provide a reason why potential life is more important than presently living people.

That's just my two cents ... leave some comments if you'd like to debate the matter with me, because this particular debate really interests me.

Chemically Synthesised Genome Placed in M. mycoides

Here is the abstract from a recently published paper (May, 2010) from the Science by the J. Craig Venter Institute:

"We report the design, synthesis, and assembly of the 1.08–mega–base pair Mycoplasma mycoides JCVI-syn1.0 genome starting from digitized genome sequence information and its transplantation into a M. capricolum recipient cell to create new M. mycoides cells that are controlled only by the synthetic chromosome. The only DNA in the cells is the designed synthetic DNA sequence, including “watermark” sequences and other designed gene deletions and polymorphisms, and mutations acquired during the building process. The new cells have expected phenotypic properties and are capable of continuous self-replication."

What that means is that they created a genome from scratch, placed it in the nucleoid region of a bacteria and thus created the first "synthetic" life form. The creation of what has since been dubbed M. laboratorium has received much critical review. Some are concerned about the effects which further advancements in synthetic genomics and bioengineering will have on the environment. The Convention on Biological Diversity released a statement urging caution in keeping these chemically synthesised life forms, saying that to release them freely into the biosphere has unknown consequences.

Personally, I find this advancement very exiciting. Although it took 40 million USD and a decade to complete, the mere fact that we can create bacterial genomes and implant them within live bacteria capable of reproducing has a lot of promise. We can use this to create specific proteins en masse, to rid environments of a specific array of contamninants and much, much more. After all, bacteria are the most diverse creature on Earth. This does of course come with possibilities for harm, such as the creation of specific infectious species for biological warfare, so clear regulation and careful supervision is required here as with all other things.

Venter, J. C. et al. (2010). Creation of a bacterial cell created by a chemically synthesised genome. Science, 329(5987), Retrieved from

Why not eat Insects?

Dr. Marcel Dicke, Professor of Entomology with Wageningen University in the Netherlands, talked at the TED Conference in Amsterdam during July 2010. His topic was very interesting and one which made me a bit squeamished despite my great interest: eating insects. Dicke, himself a vegetarian, provided some interesting justifications as well as some perhaps little known facts about current insect consumption.

Firstly, 80% of the world's population already eats around one thousand species of insects. It is simply the Western nations which have a taboo surrounding it. Co-incidentally, 80% of animals are insects, meaning that there is an abundance of them. Their collective biomass far outweighs ours, according to Dicke. Additionally, insects contributed fifty-seven billion dollars to the US econony last year through pollination, decomposition and their help in fruit production.

There is no way to put the next point gently, so here it goes: all of us already eat insects indirectly. Processed foods, dyed candies and apparently certain dyed crab meats all contain insect parts within them. Every Kraft Singles slice, every processed meat, those yummy chewy bars, all of them contain insect meat. Dicke argues that, given this, there is no reason not to include them in our diet directly. Of course, this would even be healthier, for processed foods are rather bad.

The population of the Earth is growing exponentially. In 2050, there will be approximately nine billion humans. Dicke cites this overpopulation crisis as a major reason to mass produce insect meat. It is an extremely quick and easy solution to the world's food crisis. We are also have issues with deforestation and land usage generally. We can produce more insect meat than other forms with less land, less feed (freeing agricultural land for vegetables and fruits), less manure (which diminishes agrilculture's negative environmental impact) and less resulting disease among the human population. To lay it on even thicker, insects contain all of the same nutrients which the more popular meats do.

*shrugs* What do you think? Are you ready to sink into some grub or is the force of the taboo strong with you?

Dicke, Marcel. (2010, July). Why not eat insects? TED. Retrieved from