I do not care what this page looks like, because I really think the educational value will be far beyond belief when you have the pictures to follow along with. I think you’ll find this blog interesting enough– I mean it’s a story much bigger than ourselves, which was the initial appeal to myself.
Why lab work really knocks my flip flops off… WHAT I HAVE BEEN DOING FOR A LIVING!
Lake Victoria (pictured above) is the 2nd largest freshwater lake in the world, bordering Uganda, Tanzania, and Kenya. The lake is relatively young; around 14,500 years ago there actually was no lake but just a big ditch. The diversification of the species is really interesting to think about when you have such a short amount of time and over 400+ species to date. Anyways, to boost fisheries, the NILE PERCH was introduced to the lake in the 1950s. The population stayed at a low rate until a boom in mid 1980s. NILE PERCH, pictured below. Also, look at man in middle, yes it’s okay to laugh. Okay, so this fish is huge.
When initially introduced, this fish was smaller–but it started eating everything. So a group of scientists in 1984 teamed with the Kenyan government and built sampling stations in different types of waters, tracking native cichlid species. Of the 123+ species originally caught at sampling stations, 80 had disappeared from the catches after 1986. And to make matters more murky, 75% of the Nile Perch caught are exported to different parts of Europe, North/South America, and parts of East Asia. And the perch are eating everything the fishermen used to catch for themselves to eat, so this situation didn’t go as well as planned.
Typically three factors reduce populations to sizes where they are susceptible to stochastic (random) events: 1) genetic diversity 2) species diversity and 3) ecosystem diversity. In my lab we are considering all three, but genetic diversity is easy to evaluate when you have samples that are worth considering.
So the Toledo Zoo contacted my professor to look at the genetic diversity of a species of cichlid that is extinct in the wild, but they have 9 generations in the zoo. COOL! I’d love to help! If the younger generations continue to mate with themselves, this obviously is bad for many self explanatory reasons. There are four other zoos/aquariums that have this fish–3 are sending us samples to check out.
Using a PCR machine (polymerase chain reaction) [BELOW, but mine are way more trendy] you can amplify microsatellite loci. Meaning you can tag certain alleles that label the animals as homozygotes, heterzygotes, but wait more specifically: you can actually put florescent markers on these alleles so when analyzed in a really trendy machine…. you can specifically identify what allele you are looking at. This is extremely helpful in estimating relatedness of individuals. To amplify the specific region on the DNA however, you need to know the sequence of the DNA pretty close to exact. So for the first few months I worked here, I was running primers against the DNA to check and see if they even amplified anything at all. (We are using 14, which is quite a few. This is good)
So after a cycle is run in a PCR machine, I use my imagination and look at the clear liquid in the tubes. To see if something actually happened, we are able to use GEL ELECTROPHORESIS. When learning what I was doing in lab, I thought this part was the coolest but really I have to do a whole lot of waiting after I load the gel. And one more side note: if you’re looking for a profession, harvest seaweed. When purified properly and used in agar, this shit goes for $400 bucks a pound. I’m clearly going into the wrong field. But after you have amplified a certain region of DNA, you can run the sample in what looks like a pretty clear-light-purplish color of jello (which you would NEVER eat, because I have to wear gloves when handling), and with a positive current, the negatively charged DNA will travel down the gel and you can take a picture using UV light! I run like 80 samples at a time. That person clearly has a lot of waiting to do if they are only loading 3 samples at a time.
Then I take pictures! We are just getting to the part where we can look at the alleles, and see which samples I need to re-run because the PCR didn’t work for that individual, for whatever reason. i.e., I hate fish #7 from the 7th generation, because I have to re-do that one for EIGHT primers. That’s a lot of re-doing.
I hope this has shed light on what the Toledo zoo saw fit to apply for a grant and hire me to see if we can reintroduce fish that helped the quality of Lake Victoria remain diverse and beautiful! I want to go there some day!
Mad love, and more to come about our amazing wine party!!!