This blog is moving! Come visit us at our new home.

Hi all —

We know it’s been a while since we’ve updated this page, but it’s been for a good reason — the blog is now on our recently redesigned website! Please stop by and check it out at www.edvotek.com/News. We’ll be updating it regularly with the same quality content that we have been posting here at edvotek.info.

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Looking forward to seeing you in our new location!

Best,

The Edvotek Blog Staff

Edvotek Road Trip — NSTA Area Meeting in Richmond, VA

Last week, we kicked off our busy fall conference schedule with the NSTA Area Meeting in Richmond, VA. Richmond is just a stone’s throw away from our headquarters in Washington, D.C., so we packed up our truck and got on the road.  While in Richmond, we explored Carytown, viewed some monuments, and even managed to get a great view of the city from the other side of the James River!

Downtown Richmond from across the James River ©Edvotek 2014

Downtown Richmond from across the James River

We would have liked to have a little more time to explore more of this historic city, but we were very busy getting ready for our teachers — we actually hosted TEN hands-on workshops in Richmond!  (On a side note, I must have really developed my “teacher voices” since the last conference, because I never lost my voice!)  Our most popular workshop was “Using the Polymerase Chain Reaction to Identify Genetically Modified Organisms”.  In this experiment, students will use the Polymerase Chain Reaction (PCR) to differentiate between wild-type and GM plants at the DNA level.  My “students” were able to extract DNA, set up PCR reactions, and analyze their results using gel electrophoresis.

For more information on all of the conferences we are attending this year, please check out our NEW resources page at http://www.edvotek.com/Workshops.   We’ve posted our schedules AND the workshop presentations.  Hope to see you there!

DNA Barcoding: Identifying Organisms at the Molecular Level

fungiHow would you identifying all the species in the picture? You could consult a field guide, ask a mycologist (a person who specializes in fungi), or you could sequence its DNA. This last choice is becoming increasingly popular and is known as DNA barcoding. DNA barcoding uses short polymorphic segments of DNA to classify an organism as belonging to a particular species.

In order to enable barcoding scientist needed to first find a place in the genome that was an ideal mixture of variable and conserved. The center region of this sequence had to differentiated between even closely related species but not differ significantly between individuals within a species. On either side of this variable region they needed to find sequences that were nearly identical between all the organisms in a kingdom so that universal primers could be used. Discovering such a place was an intense search. Today we have CO1 for animals, ITS for fungi, and rbcL & matK for plants.

Analyze DNA sequences in your classroom! © Edvotek 2014

Analyze DNA sequences in your classroom! © Edvotek 2014

Sequencing is used to reveal the precise order of the nucleotides within these barcode regions. In Sanger sequencing each run is comprised of a single region from a single specimen. This works well when one specimen is being tested. Sometimes, especially when dealing with microbial diversity, the sample to be sequenced is a mixture of different species. In this case high throughput sequencing is used. High throughput sequencing, also known as massively parallel sequences, allows many sequences of DNA to be processed from the same sample.

Today barcoding is being used to look at biodiversity in new ways and new places. Hard to examine organism such as bacteria are being categorized in record numbers. Biodiversity inventories are more objective and accessible. New habitat such as a column of soil, the stomach of a bird, and the nectar of a flower are being examined and characterized. Barcoding is an excellent example of how biotechnology is contributing to diverse areas of science.

Biotechnology Basics – What is a Model Organism?

What is a model organism?

A model organism is any plant, animal or microorganism that allows us to study fundamental questions in biology that may be hard to study directly in complex organisms like humans.

What are some characteristics of a model organism?

The tiny fruit fly D. melanogaster is a powerful tool for studying genetics!  ©Edvotek 2014

The tiny fruit fly D. melanogaster is a powerful tool for studying genetics! ©Edvotek 2014

In general, model organisms have fast generation time, breed in large numbers and have a sequenced genome. Many model organisms are relatively simple and inexpensive to use,so they are widely available for use in the classroom. Common model organisms include the zebrafish, the mouse, the rat, the fruit fly D. melanogaster, the nematode C. elegans, the budding yeast, the bacteria E. coli and Arabidopsis, just to name a few!

What can a fruit fly really tell me about human biology?

Human biology is extremely complex. There’s a lot going on in our bodies that we just don’t understand. Performing experiments in humans, however, is highly unethical. We are still able to make insights into human development and disease by studying similar genes in model organisms.

Mendel discovered the rules of heredity using the humble pea plant. ©Edvotek 2014

Mendel discovered the rules of heredity using the humble pea plant. ©Edvotek 2014

Many of the basic principles of biology that were first identified in model organisms have later been demonstrated in humans. For example, Gregor Mendel used pea plants to establish that genes have different forms, or alleles, and that these alleles segregate independently from one another. Building on this work, Thomas Hunt Morgan used the fruit fly to illustrate the linkage of a gene to a particular chromosomal location. Today, we know that most human traits observe these rules of inheritance.

Analyze DNA sequences using BLAST! © Edvotek 2014

Analyze DNA sequences using BLAST! © Edvotek 2014

Modern technology has allowed scientists to determine the sequence the genome of many model organisms. DNA sequence comparison software like BLAST has allowed scientists to identify genes that are similar to those that are important for human health and development. Scientists can learn more about these genes by studying their function in a model organism. For instance, about 75% of the genes that cause disease in humans have homologs in D. melanogaster. For example, the fly model of Alzheimer’s disease has provided new information on the disease, which has allowed scientists to identify novel targets for treatment.

Interested in learning more about model organisms?  Come to our training sessions at the NSTA Conferences on Science Education!  

In this exciting workshop, you will learn how to use the nematode C. elegans to explore the effects of mutations on alcohol metabolism using a simple locomotion assay.  Ethanol has been used since ancient times for its intoxicating effects. This common recreational drug acts as a central nervous system depressant. At low blood alcohol concentrations (BAC), ethanol produces stimulating, euphoric effects. As the BAC increases, brain function is progressively reduced, leading to slurred speech, poor motor control, and sedation. At BACs over 0.4%, effects include reduced heart rate, unconsciousness, and death. Relative intoxication depends upon variables such as age, weight, sex, tolerance, and ingestion of food. Additionally, single base-pair changes in a person’s DNA can reduce the activity of enzymes that break down ethanol, leading to higher BACs that persist for longer periods of time.

C. elegans is a common model organism  ©Edvotek 2014

C. elegans can be used to study alcohol metabolism. ©Edvotek 2014

Performing experiments that characterize the human response to ethanol can be unethical and, in some situations, dangerous. In order to study the effects of mutations on ethanol metabolism, we will use the model organism C. elegans. The nematode is an ideal system for this study because mutations have been identified that render them insensitive to the effects of ethanol. In this inquiry-based experiment, you will expose wild-type and alcohol resistant C. elegans to different concentrations of ethanol. Next, you will compare the behavior of the two strains and record the effects. Finally, we will utilize critical thinking and statistics skills to interpret the data.

If you can’t make to one of our workshops, click here for a PDF download of the presentation.