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Carbon Dioxide Affects Fish Ear Structure

Jun 30

Susan SteinhardtIndustry News 1 Comment

Levels of carbon dioxide, the dangerous greenhouse gas responsible for global warming, are increasing at an alarming rate. And not just in the air. The ocean’s absorption of CO₂ from the atmosphere has resulted in increasingly acidic waters. Scientists have already begun to see the global effects of ocean acidification as carbonic acid, a by-product of CO₂, has begun to destroy coral reefs as it hinders shell formation by corals, which in turn has lead to a forced habitat relocation for coral-dependent species. Scientists at the University of California in San Diego (UCSD) Scripps Institution of Oceanography led by biological oceanographer David Checkley, have recently discovered that the high levels of carbon dioxide in the oceans are causing mutations in fish, specifically affecting the bones in a fish’s ear.

As in humans, fish’s ears are important for survival as they perform a major role in the animal’s acceleration and orientation. The ear structure in fish is known as otoliths and is composed of minerals. The Scripps team assumed that since acidic waters weaken and dissolve shells made up of minerals, the otoliths of fish living in waters with high levels of CO₂ should grow very slowly and even possibly result to smaller otoliths. Fish ears are inside their bodies, and therefore the change would not be noticeable by simply looking at the fish.

Checkley and his research team began their experiment by incubating the eggs of white sea bass in seawater that contained more than six times the normal amount of carbon dioxide. When the fish were between seven and eight days old, the scientists measured their otoliths and were met with quite a surprise. Contrary to the researchers assumptions, the young fish had otoliths that were 15 to 17 percent larger than normal. They repeated the experiment, only to receive the same results. The Scripps team then performed another experiment by reducing the carbon dioxide in the water to roughly 3.5 times the normal level. In contrast to the first experiments results, the otoliths in these fish were only 7 to 9 percent larger than normal.

The Scripps team published their conclusions in the June 26th issue of Science. The researchers state they found that the otoliths extreme growth mutation caused the animals to become disoriented and incapable of surviving in their normal environment. They also found that the fish’s body sizes did not grow proportionally to their ear bones.

Checkley has stated that this finding raises further questions that he and his research team hope to explore. Specifically in determining how the additional carbon dioxide the water affects the otoliths in addition to researching if similar otoliths deformities are occurring in fish other than the sea bass. Checkley also said that they will look at whether having larger ear bones affects a fish’s survival and behavior.

“If fish can do just fine or better with larger otoliths, then there’s no great concern. But fish have evolved to have their bodies the way they are. The assumption is that if you tweak them in a certain way it’s going to change the dynamics of how the otoliths helps the fish stay upright, navigate and survive… At this point one doesn’t know what the effects are in terms of anything damaging to the behavior or the survival of the fish with larger otoliths. The assumption is that anything that departs significantly from normality is an abnormality and abnormalities at least have the potential for having deleterious effects.”

To read the study:

Checkley, D., Dickson, A., Takahashi, M., Radich, J., Eisenkolb, N., & Asch, R. (2009). Elevated CO2 Enhances Otolith Growth in Young Fish Science, 324 (5935), 1683-1683 DOI: 10.1126/science.1169806

Science News: Week of June 21, 2009

Jun 24

Susan SteinhardtIndustry News No Comments

Science News: Week of June 14, 2009

Jun 18

Susan SteinhardtIndustry News No Comments

Our weekly compilation of science news for the week of June 14, 2009.

Climate Change is already affecting the United States: A new government report says climate change’s measurable effects include drought and erosion.

Feather growth limits size of flying birds: Time required for moulting may be a more important factor than weight.

Major breakthrough in early detection and prevention of AMD: Kentucky researcher identifies CCR3 as key molecular target in leading cause of age-related blindness.

Nanocrystals reveal activity within cells: Researchers at the US Department of Energy’s Lawrence Berkeley National Laboratory have created bright, stable and bio-friendly nanocrystals that act as individual investigators of activity within a cell.

Not 1, but 2 kinds of males found in the invasive round goby: Scientists have found the existence of two types of males of a fiercely invasive fish spreading through the Great Lakes, which may provide answers as to how they rapidly reproduce.

Origins of the swine flu virus: Researchers use evolutionary history to trace the early days of the pandemic.

Smith, G., Vijaykrishna, D., Bahl, J., Lycett, S., Worobey, M., Pybus, O., Ma, S., Cheung, C., Raghwani, J., Bhatt, S., Peiris, J., Guan, Y., & Rambaut, A. (2009). Origins and evolutionary genomics of the 2009 swine-origin H1N1 influenza A epidemic Nature DOI: 10.1038/nature08182

Plump youngsters show heart-y risks: Even fat 7-year olds show they’re developing a risk of blood clots and other impacts of cardiovascular disease.

Powerful nutrient cocktail can put kids with Crohn’s into remission: Tel Aviv University researcher promotes liquid nutrition to combat inflammatory bowel disease.

Report on Gene for Depression Is Now Faulted: The celebrated finding that a single gene helps determine one’s risk of depression has not held up to scrutiny.

Caspi, A. (2003). Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene Science, 301 (5631), 386-389 DOI: 10.1126/science.1083968

TRAPping proteins that work together inside living cells: New way to probe for proteins working together reveals never-before-seen details of RNA polymerase in bacteria.

ChemBioChem, 10 (9), 1507-1518 DOI: 10.1002/cbic.200900029

Science News: Week of June 7, 2009

Jun 11

Susan SteinhardtIndustry News No Comments

Our weekly compilation of science news for the week of June 7, 2009.

Biologist discovers pink-winged moth in Chiricahua Mountains: University of Arizona biologist and amateur insect collector Bruce Walsh has published his discovery of a new species of moth.

China launches green power revolution to catch up on west: Beijing aspires to hit 20% renewable target by 2020 with $30 billion for low-carbon projects.

Concern over breast cancer patients taking high-dose vitamin supplements: Many women receiving treatment for breast cancer may unknowingly undermine the chances of it working by taking high-dose antioxidant vitamins.

Evolution can occur in less than 10 years: UC Riverside-led study shows wild Trinidadian guppies adapted in less than 30 generations to a new environment.

Galactic black holes may be more massive than thought: Predictions and observations could resolve seeming mismatch between close and distant giants.

New Technologies Allow Scientists to Watch Cells in Motion: Some cells are slow, some fast, and some are dangerous wanderers.

Nicotine’s role in SIDS: New study in rats explains how smoke exposure may increase risk of sudden infant death syndrome.

Off-label morning sickness drug deemed safe for fetuses: Collaborative research findings published in New England Journal of Medicine support safe use of metoclopramide for morning sickness nausea.

Study says colorectal cancer increasing in young adults: The authors theorize that these increases may be related to rising rates of obesity and changes in dietary patterns, including increased consumption of fast food.

Profile: Dr. Menachem Moshelion

Jun 09

Susan SteinhardtFeatured Scientist No Comments

Known for his work in plant aquaporins, Dr. Menachem Moshelion has published many papers concerning his research. He has been running a lab for the past five years at Hebrew University’s Institute of Plant Sciences and Genetics in Agriculture located in Rehovot. Moshelion’s interest in science began at the age of five, “I’ve always been interested in science. I knew it, somehow… I didn’t have excellent marks [in school], but in Biology – I always got an A.” Moshelion “always knew” he wanted to be involved in the biology field. Although he started in animal science, one course in plants was enough to change his direction. After completing all of his degrees at Hebrew University, Moshelion did his post-doctorate in Louvain-la-Neuve, Belgium – a small city 30 kilometers from Brussels.

Dr. Moshelion first began his study of aquaporins in plants toward the end of his PhD. Aquaporins are membrane channels in a cell that allow water and other small substances to go through. He continued with this subject during his postdoctoral research. Once he returned to Hebrew University and opened his lab, Moshelion enlarged and expanded his research by moving from specifically the cell to the whole plant’s water relations. His main question was how plants can survive in rough or harsh environments, where they may or may not have water. “My question always began at the cellular level. I wanted to understand how a cell can control the whole plant’s water regulations and what are the cellular mechanisms involved in this process,” Moshelion explains, “Aquaporins are a main part of this. I was sucked into the question of how could we improve a crop’s stress resistance.” He found that by modifying some plants aquaporins, a lot can be learned about cellular regulation and the plant’s adjustment to stress resulting in either more or less yield.

Moshelion’s lab focuses on molecular modification where they use a lot of genetical engineering to change specific aquaporins in the cell and modify them. In the beginning, Moshelion and his students, studied aquaporins the cellular level measuring the physiological impact on the cell – the RNA level, protein levels, and so on. Today, he has gradually begun to spend more time going out to the fields and greenhouses to see how the whole plant physically expresses the modified aquaporin.

The lab’s model crop is tomatoes. They also work with arabidopsis, which Moshelion explains is not a crop so it doesn’t provide any economic yield. However, one can assume, under a certain amount of doubt, that if something works with arabidopsis, it should also affect crops the same way. Most of the time, experiments are first done on arabidopsis because the plant is very easy to grow, transform, work with, as well as genetically manipulate it. Once he thinks he found something, Moshelion and his students will try the same procedure out on the tomato. Of the 37 aquaporins in the tomato, Moshelion and his lab are focusing on 2 which they found had the most impact on water balance.

So far, Dr. Moshelion has found that aquaporins are changing the water balance in plants. He compares water balance in plants to balancing your bank account. A person has a specific income and certain expenses and his goal is to find the ideal middle to live. Plants absorb water from the soil and they lose it via transpiration. He explains that, “Transpiration is a side effect of photosynthesis. During photosynthesis a plant opens tiny pores in the leaf which allow CO₂ to get in, while at the same time water is going out. It in the best interest of the plant to open the stomata as wide as possible in order to maximize the CO₂ , but it loses water and water is the limiting factor. Deciding when to leave the stomata open and when to close it is a very very complex and gentle play.” When certain aquaporins are expressed, the plant can start losing all of its water and become completely dried out. Other aquaporins block the stomata, so the pores stay closed all the time and no water is released. Moshelion has realized that expressing different aquaporins has a direct effect on the plant’s water balance. “What we are looking for is to find a specific aquaporin, expressed in a specific place, in a specific time. We want to change the water balance to be more efficient, more economic to the plant. In this way, we can maximize the photosynthetic results by either minimizing the loss of water or spending more water in the hopes of maximizing photosynthetic profit.” Moshelion compared plants to gamblers. Plants have a certain amount of water and they have a choice to spend it wisely or unwisely. Some act conservatively and lose the minimum amount of water possible, however they aren’t growing so fast. Others plants, which Moshelion refers to as “risk takers” spend a lot of water. “We have found that many of the crops we are growing are risk takers. During evolution humans taught plants to be profitable, so we breed them to lose water and gain CO₂ . We are unsure whether these kinds of plants will survive in the field. Nobody knows exactly what is happening here, we are just looking at the outcome. We are looking at the plants and its measurements and ultimately are trying to learn how the aquaporins’ mechanism works.”

Moshelion is involved with research collaborations within Israel as well as abroad. His main collaboration is with others in the Soil and Water Department in Hebrew University, specifically Dr. Rony Wallach and Dr. Uri Shani. Although their questions are based around what happens to the plant’s root in the soil – collaboration is easy as both Moshelion, Wallach, and Shani’s interests are in the water. Moshelion has other collaborations with people studying aquaporins and other stress related genes. Additionally, he collaborates with other researchers working on sugar metabolism, flowers and other aspects of plants.

Moshelion’s message to those interested in starting in the Science Research field: Be ready for a lot of hard work, frustration and disappointments.

“Whether you are a PhD or even a masters student, you must know that scientific research is a very hard job. You are your own boss. Research is really independent work and while you can think together what is the best approach to ask questions, nobody can tell you what is the best way to find the answer. A PhD is a philosophy doctor and your job is to ask questions. There are many ways to ask the same question and many experiments that might answer these questions. Many times you think you have the right question and the right experiment – and its very frustrating to find out that the answer is not what you expected. You know where you want to get – but you never know where you are going. Sometimes you get different results than you expect – and it takes you out of the way – so you have to be ready for disappointment… Science is really demanding – especially when you work with living creatures because you have to make sure everything is working all the time – you can’t just leave something and go.

Science is addictive. Come to the lab at 4 AM and there is a good chance you will find people working here, sleeping here. It doesn’t feel like you are coming to a job because we are always trying to answer new questions and solve new problems. On one hand it can be fun and interesting, but on the other hand – research can be really frustrating and demanding. I always tell people – if you like research – go for it! Don’t hesitate! But, know it will be very hard.”

Dr. Moshelion loves the academic freedom that comes with academic research. He says that with biotech industrial research, “the business is the motivation, so you have very little freedom of action… You must go according to a stiff schedule and the business program… I think the whole point [of science] is not the experiment you do, its not the lab work – because its pretty boring – its the questions you ask and then the results you get back, the thinking you do.”

To learn more about Dr. Menachem Moshelion visit his website.