Today we were back onto our lecture track, bright and early at 8:30 am (I know, not that bad). Carolyn gave us a very interesting lecture on invertebrate immunity, which is completely new to me (kind of ridiculous considering the research I’ve done revolved around coral disease). The most evolutionary basal (?, I know primitive is an unpopular term) category of immune systems is innate immunity, which is generally non-specific and short-term. While different types of pathogens may be recognized and addressed differently, the response is general and cannot distinguish closely related taxa. The more sophisticated system, adaptive immunity, is considered characteristic of vertebrates. In adaptive immunity, pathogens can be recognized and addressed specifically with a significant amount of memory. There is some evidence, though, that invertebrates can have a form of quasi-adaptive immunity – for example, shrimp exposed to white spot syndrome virus are more resistant to infection as compared to naive shrimp, even about a month later. It seems, though, that the mechanisms for this memory is different than the vertebrate adaptive immunity we’re more familiar with.
After lecture, we head over to lab 10 where we got our PCR reactions going. The repetitive nature of pipetting was quite calming. It went very smoothly, and we were able to get our reactions set up and going in the thermocyclers quite quickly. Again, I was completely new to this except for reading about it in genetics. I was very excited, since PCR is such a powerful tool that opens the door to many other molecular techniques.
Sarah and I used the West Coast 18S primers for amplifying laby DNA. We made our master mix using a rule that I’ve never hear of and is quite ingenious – we made mix for 10% more reactions than we needed to, which ensures we have enough reagent for all of the reactions (as some is inevitably lost to pipetting error). After that was all done, Lisa and Collin programmed the thermocyclers to get our reactions going.
AND THEN THERE WAS LUNCH!
Post-lunch, Steve gave a lecture on host response in pathogen-host interactions. It was great to consider how the host changes during and after infection from both an individual and population level. Disease is a powerful driver of natural selection – it does not just kill off individuals, but it changes the genetics of the populations it encounters! This has significant implications of this on disease impacts and the future of disease.
After the lecture, we finished off the day with running gels of our PCR products! If all goes well, this will let us screen the samples for the presence/absence of the pathogen (laby for eelgrass and putative virus for the sea stars).
SHABAM! Here’s the gel for the laby DNA (except for one culture on the sea star plate). It looks like Sarah’s and my primer pair worked out pretty well, showing nice bands on the UH (unhealthy) eelgrass extractions and a few (and dim?!) bands on the ICH (Healthy) extractions. Our negative came out clean as well!