Is there a DNA trait that links to palatability? 

Alyssa's lab research involved LOTS of chemistry! She has been looking at many traits of each type of seaweed to understand which ones are more palatable. Some of these traits include: 

• protein content
• carbon and nitrogen ratios
• organic content
• insoluble sugars
• amount of calcium carbonate

When researching certain traits, Alyssa must look at the genetic coding found in the cells of seaweed, DNA that is! In order to look at a specific trait, DNA must be extracted from the seaweed's cell and run as a gel in a PCR machine in order to identify specific genes.

Here are pages out of Alyssa's lab notebook. It has two pictures of the gels ran through the gel electrophoresis machine. Each number represents a different seaweed. If black bands show up, it means that the DNA extraction worked. 

After assessing the various traits listed above, Alyssa begins to run experiments called feeding assays. Click here to find out more!

data ANALYSIS 

After running many  PCR, Alyssa must analyze her data. Sometimes the DNA sequences that Alyssa ran did not work, so she must troubleshoot and run them again! Below is a picture of what a good sequence result looks like versus a bad sequence. 

conclusions: Chemistry's role in palatability

Chemistry plays a role in the palatability of seaweeds.  Alyssa analyzed the nutritional content of her seaweed samples by measuring percent carbon, nitrogen, and ash-free dry mass. She found that the latitude from which the seaweeds lived was related to the nutritional content. Seaweeds from higher latitudes (polar and temperate regions) are more palatable then those from tropical regions. 

Polar seaweeds are much more rich in nitrogen, which is very appealing to herbivores. So overall if given the option, herbivores will choose polar seaweeds versus the tropical ones. 

Protein content was also analyzed, but there were no significant relationships between latitudinal origin or palatability.