The time is zooming by so fast; I am starting to lose track of our days here. It seems like only yesterday was our first day here and now we are already in week 6! This past weekend all the REU interns and I went to the Hatfield Marine Science Center and the Oregon Coast Aquarium. Although the Hatfield Marine Science Center is popular and usually full of tourists, we had the chance to go behind the scenes. Α master’s student at the Hatfield marine center lead our tour; our first stop was a hallway full of posters dictating the center’s history. We saw the changes that were made as time progressed through a hallway of aerial pictures. We learned that the center is actually owned and operated through Oregon State University. This center’s resources are so sought after, that there are several governmental agencies that work there. This is all due to biodiverse habitat of the marina. Next, we visited the labs, classrooms, and the library. Finally, we met up with the REU interns from Hatfield for an ice cream social. They were all really interesting and the ice cream was great! Last week, I had a lot of trouble raising cultures of starfish, sand dollars and sea urchins, due to little mistakes that I kept making and an influx of bacteria in the cultures. This really stalled the progress of my tracking development of my partial larvae. Although the bacteria has remained a problem, I decided to add more antibiotic to my cultures and to change their water sooner. These changes allowed me to finally grow a successful culture of the sand dollars. This week I also attempted growing some cultures of jellyfish, Clytia gregaria. In order to have a successful spawning of eggs and sperm, the organisms need to be freshly caught; this will also facilitate fertilization. However, this week I could not find my organisms. I did catch several Beroe gracilis. These jellyfish are mostly transparent, but they generally have a pink hue. Their food source are other jellyfish like Pleurobrachia, or Bolinopsis. They have 8 comb rows and are quite fast at swimming. In my experience, they are pretty elusive; they are slimier than the other jellyfish I have worked with and whenever I try to catch them they slip away! Here is a video of the Beroe gracilis in natural sea water. I recorded a high-speed video of a 10 day old sand dollar larva trying to capture Rhodomonas, their algal prey. In the video, the algae is escaping the mouth of the larva.
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Contrary to the title of this week's blog, this is not a romantic comedy. Sorry to disappoint you there. What was central to this week was presenting and editing my research proposal. On Tuesday of last week, a research proposal was due. Approximately half of the interns presented that day, while the rest of us presented this past Tuesday. Although the writing portion of this assignment was the hardest, I have to admit that the presenting section stressed me out the most.
I am generally an extrovert so one would assume that I would be a good public speaker. Personally, I find public speaking very challenging, regardless of the atmosphere or topic, even introducing myself for 3 minutes in front of a crowded lecture hall gives me anxiety. The fact that I had to present my research proposal was almost excruciating. I woke up early to practice presenting my proposal and to ensure that my presentation was within the time limit. Once I had dotted the I's and crossed my final t's, I printed it. At that point, it was 2:57, T-minus 3 minutes ‘til I had to present. I walk in and essentially all the interns are there as are the principal investigators and before I knew it I volunteered myself to present first. I reach the podium; blood pumping through my veins, I can feel my heart beat quicken, my hands starting to tense all before I have spoken a word. The timer starts and I start presenting. I wish I could tell you that it went smoothly, but that would be a lie. My hands were shaking the whole time, even my voice trembled, but I reached the end of my proposal. I made it… All I could think about at that moment was "I am so glad it's over". The rest of the interns presented their proposals as well and I was able to be attentive and enjoy their presentations. Even though I had a hard time with this assignment, I want to state how clarifying and helpful it was. This proposal allowed me to organize my thoughts, to work on my scientific writing skills, and to compile all my knowledge to understand what I am researching this summer, finally reaching a comprehensive and important point in this REU experience. I now know that I need to work on presenting a little more. I want to be able to conquer the inability to overcome the anxiety of public speaking. Hopefully, by the end of this REU program, I will have done just that. Thanks for tuning in this week! Welcome back to week 4 everybody! "What do you want to hear first the bad or the good news?" Everyone has received and used this question at least once, and here I am essentially asking you which order you prefer. For those of you who would like the good news first skip to the third paragraph, for the rest of you who want the "bad" news first continue reading in the normal order. Here they come! As I previously mentioned we are working on a multitude of organisms with the same question in mind. This week, my mentor took off our training wheels so to speak. We repeated the experiment from last week. Here is a little overview of what we did, we took sand dollar gametes and induced fertilization. After a couple of other steps, we dissociated the embryos into half-sized, or quarter-sized cells to see how their development will progress. Unfortunately, we ran out of our beginner's luck and forgot some steps which affected our results negatively and prompted us to replicate this experiment a total of 4 times. We are hoping that this fourth time, we did things right. I will have to let you know next week about our results. Those were the "bad" news. They weren't so bad, right? Well now that you've read them go ahead and let me know in the comments your opinion and whether your choice in selecting reading them first or last was a good one. The good news! I suppose I can consider myself an honorary camper now. A couple of us REU interns decided to go camp and visit the Redwoods for 4th of July weekend. We were well on our way to California and were just entering the state park when all of a sudden Wyatt's car starts to sputter and kick. I know what you're thinking, now what? We pulled to the side; then Wyatt and Chris got out to check on the car. They determined that the issue was probably the transmission fluid, so then we turned around and went to the nearest gas station to buy transmission fluid. As we are driving there we are all hoping and praying that the car doesn't break down otherwise how could we return to OIMB? We reach the station and attempt to fix the problem. Under the notion that we had fixed it we drove back to the redwoods but to a nearer campsite. Halfway to our destination, we feel the kicking again. Uh oh, we all thought. Just as we thought we made; it's déjà vu. We drive to the nearest mechanic and an older gentleman named Jake takes the car for a spin around the block to hear the engine and feel out the issues the car may have. We all start to have a discussion about the myriad of ways we could spend our afternoon and night. As we are wrapping up that conversation, Jake comes back and pull into the back calling Wyatt over. After about 15 minutes, Wyatt comes back and states that it was the transmission fluid and that it would only cost 10 dollars. In my book, this was a miracle. How many times does something go wrong with a car and it ends up not being expensive or seemingly take forever? In my experience, that has never happened. After this string of events, we finally go and reach our campsite. We decide to eat, set up half of our camp and go for a 6-mile hike. We did the mill creek trail and the stout trail. It was so beautiful, the trees were… you guessed it! Red. Their height was unimaginable and truly a magnificent view. We reached the stream and played around in it and headed back from there. We then reached our campsite ate dinner, talked, laughed and bonded over making smores over our campfire. At 10 pm we headed for bed and we were off the next morning to OIMB. I guess you could say we were out of the woods! Fertilization is defined as the fusion of gametes, in humans known as an egg and sperm. This fusion produces a zygote that will develop over time into an organism. When a zygote develops, it goes through a number of divisions, otherwise known as cleavages, so it can become that organism. The organism begins at a one cell stage and cleaves until a whole organism is formed. After each cleavage, more cells are distinguishable; each cell is now called a blastomere. After waiting until the third cleavage, which is when there is a horizontal division between the four previously produced cells, another four cells are produced. These four cells are a grouped into two pairs each consisting of two cells. Each pair will move to the opposite sides of the zygote. The bottom pair is located at the vegetal pole. This pair will divide further into macromeres and micromeres. Now at this stage, the larvae are at the 16 cell stage. Previously discovered, micromeres are responsible for the development of the larval skeleton. The experiment we focused on this week was ablating sea urchin larvae’s micromeres to see whether their development affects how they retain the algae they eat, Rhodomonas. We believe that there is an effect(or correlation) between the mouth’s size and the frequency of keeping such jumpy prey in their mouths. What we did was fertilize sea urchin eggs and wait until they had reached their 16-cell stage. Once the larvae reached this stage we ablated their micromeres away. We recovered those larvae and will now observe their reactions to this phenomenon. The slideshows underneath show the current stage of our original cultures from week 1. The order goes from left to right: Sand Dollars(leftmost), Sea Urchins(), and lastly the Starfish().
On to our previous weekend, the REU interns went camping at Cape Arago. There we had the chance to meet the other interns at the main University of Oregon campus. Personally, I had only camped once before this excursion, so I was ecstatic to do it again. I am so surprised and happy with my camping experience. The campsite was clean and the people seemed friendly.The weather was so nice and warm perfect for a day at the beach, so we set up camp and walked over. After half an hour, some REU interns and I decided to go on a hike. The best points of our hike were the overlooking and astonishing views of the beach, watching harbor seals jump into the ocean and seeing the historical site, which contained a rose garden and greenhouse. Once we got back down we started to have dinner and ended that meal with a campfire smores and attempted scary stories. It was exactly how I pictured camping the only thing that exceeded my expectations was the amount of fun I had! Fast forward to the 4th of July, we had the day off . We all enjoyed some extra sleep time and met up with each other at the picnic. There we had great food and great company. After lunch, we did an egg toss. It was my first time participating in this activity so I will explain what it is. You and a partner stand across from each other and you toss an egg. After each throw, both partners take a step back and the game keeps going until all the eggs have cracked. My partner was Nancy, although we lost it still was loads of fun. We were both pleasantly surprised that we had made it so far in the game.
References: Hardin, Jeff. Figure 3.1-3.15 “ Characteristic stages during early development in Lytechinus variegatus.” Chapter 3, The sea urchin embryo in “Embryos: Color Atlas of Development” (J.Bard,ed.) London, Wolfe Publishing embryoworms.zoology.wisc.edu/publications/publications.html#research_urchins SeaUrchin Clipart Image #16. Digital Image. Clipground. http://clipground.com/sea-urchin-clipart.html Welcome back, guys!
It is officially week 2 at OIMB and things have progressed. My mentor, George, my lab partner, Ana, and I all sat down to talk about our research project and what our goals are for this summer. In order to delve into our project, I will introduce some background information you will need to know. Cilia Microtubule protrusions that are attached to a cell Pilidium The larval stage of a nemertean Larva "Free-living, sexually mature form in some animal life cycles that may differ from the adult stage in the morphological, dietary and habitual senses" (Campbell 1414) Cryptophyte/Cryptomonad A group of algae that when irritated it jumps Ex: Rhodomonas Ejectisome A piece of a cell that will eject the content that is within it. One kind of ejectisome is the cryptomonad. Most organisms eat, but not all eat in the same way or use the same feeding apparatus. Cilia are conserved in essentially all invertebrate groups and used in one way or another to attain food. There are multiple methods to achieve this. One of which is using their cilia to reverse the beat and move the food towards their back where the other cilia will beat in the opposite direction so that it will enter the food groove. This area tells the food where to go and with the help of the cilia the food is led to the mouth; organisms like these are called downstream collectors. There are also organisms called upstream collectors; they move their cilia away from the mouth and a beat reversal occurs when food is recognized in the near area causing the cilia to then lead it to the mouth in order to be ingested. A new method of ingestion was found in the Pilidium. A current is made which allows parcels of food and other things to pass by the cilia; next, the muscle fibers under the ciliated band change the shape of the lappets. This in effect allows the organism to swallow the prey and the water. Once this is accomplished the cilia from different parts of the body cause the prey to end up in the stomach. In lab, our Pilidium and our echinoids larvae are often fed Rhodomonas. Recent observations show that Rhodomonas, a type of cryptophyte, is an escape prey due to a large number of ejectisomes. Pilidium can move the Rhodomonas deeper into themselves, due to a deep mouth, in order to avoid that situation. Pilidium appears to have adapted to eat this specific. In our experiment, we want to answer the question of whether or not the size of a mouth affects the capture of prey in ciliated invertebrate larvae. In order to answer this question, we will observe development and feeding of certain invertebrate larvae and compare certain traits that we deem impressionable to keeping their prey in them, and we will embryologically manipulate the mouth’s size which will help determine if it has anything to do with keeping the escape-prone prey. We will compare the larvae of sand dollars, sea urchins and starfish and the partial larvae in these organisms using the confocal microscope. Through high-speed video microscopy, we will observe if smaller mouth sizes affect how well they keep the escape-prone prey or the size and defense level of the prey affect its retention. |
AuthorHi! My name is Kostantina Orselli and I am transferring to California State University of Northridge. My interests include hiking, kayaking, playing with my dog, hanging out with friends, watching movies and more. I am ecstatic to be experiencing this opportunity at OIMB! Archives
August 2018
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