As discussed in our last unit of freshman biology (can’t believe its almost over!), there are ways that ecologists and other scientists can predict global warming based on historical trends. In the textbook, the warming preceding the last ice age was characterized by glaciers and trees retreating to the north and south poles. It further states that based on the rate at which the biosphere is warming now, trees would need to retreat at about a 7-9 km rate whereas they are only moving at about a .2 km rate currently. The latest National Climate Assessment, released May 6, outlines the climate changes in the US; I have skimmed through the introduction (the whole document is 840 pages!) and have found a section on melting ice and glacier migration – here is a paragraph I found both relevant to our current unit (tundra biome, chemical cycles, and global warming) and interesting: “Glaciers are retreating and/or thinning in Alaska and in the lower 48 states. In addition, permafrost temperatures are increasing over Alaska and much of the Arctic. Regions of discontinuous permafrost in interior Alaska (where annual average soil temperatures are already close to 32°F) are highly vulnerable to thaw. Thawing permafrost releases carbon dioxide and methane – heat-trapping gases that contribute to even more warming. Recent estimates suggest that the potential release of carbon from permafrost soils could add as much as 0.4ºF to 0.6ºF of warming by 2100.” There are many implications associated with the many areas affected by dramatic climate change, and we must bring them to our attention. Good luck all on your finals! It’s been a great semester.
Author Archives: kyracurtis
A few weeks ago, I went to Baylor College of Medicine with SIGHT, and spent the day with the National School of Tropical Medicine. We toured their lab and I was pleased at how well I knew the things that they were talking about! From PCR to synthesizing vectors, it was very exciting to see all of the things we have worked hard at learning applied in real life settings. As an aspiring doctor and researcher, I am grateful for experiences like these to keep me with a vision of what to look forward to, and motivation to keep doing well in school! The opportunity to learn first-hand research methods in our lab has truly built a foundation for us to engage in further research, as the methods we have used will surely be applied in future settings.
Scientists recently discovered a 30,000 year old virus in north-eastern Siberia, Russia. This virus has been shown to closely resemble the Pandoravirus, but the Pithovirus has significantly less genes (500), and only one or two proteins similar to the Pandoravirus. The Pithovirus also relies less on the ameba nucleus and more on its components in the cytoplasm. Although this virus infects only amebas, its discovery may hint to future public health risks as global warming melts the permafrost where we now know preserve such ancient, and harmful, viruses. Discoveries such as these remind us of the discoveries we are making in lab currently! Of the genes my group has identified, only a couple have remotely matched any known proteins. We have such a great opportunity in our hands to make significant scientific discoveries! Its so very exciting.
Evolution and Interconnection
As we speak on the topic of human evolution, a recent study has shown that nearly 20% of the Neanderthal DNA is matched in the human genome, including numerous skin genes that may have contributed to our adaptation to the ancient environment. Benjamin Vernot, a population geneticist at the University of Washington, speaks on the importance of technology in making such discoveries: “I think it’s really interesting how careful application of the correct statistical and computational tools can uncover important aspects of health, biology and human history.” This is applicable to both our topics in class and in lab – the very techniques we are utilizing in lab are very much alike to those that other genetic scientists are using! From studying molecular trends we can attribute those findings to larger forms of life, and how they are all interconnected. He also stated that in the future, scientists may be able to examine and determine hominid ancestors just by studying human DNA: “…the “fossil free” method of sequencing archaic genomes… holds promise in revealing aspects of the evolution of now-extinct archaic humans and their characteristic population genetics…scientists will be able to identify DNA from other extinct hominid, just by analyzing modern human genomes.” This is both very exciting for in shedding new light on human evolution, but also emphasizes that the research we are performing on bacteriophages can relate to the data analyzation that scientists are using in their own labs, and that it is indeed the future of science. Pretty cool!
I recently read an article that was mentioned in bioremediation presentation last week, building off of the clean up of the 2010 Deepwater Horizon disaster in the Gulf of Mexico; this article discusses its affect on marine life in the area. Researchers have found from samples of the area that the crude oil prolonged the action potential (up to 90%) of isolated cardiomyocytes in juvenile tuna neurons, thus blocking potassium reabsorption during the repolarization period following synapse. This was also found to decrease the calcium current that in turn disrupted excitation-contraction coupling in cardiomyocytes.
During early fish development, embryos are significantly vulnerable to high PAH (hydrocarbon constitute in crude oil) toxicity levels resulting from such disasters, and ultimately lead to long term acute and chronic side effects. Although the exact mechanisms leading to such cardiac functions are unknown, there is plenty of evidence validating the toxicity effects on marine life; following the Exxon Valdez spill, exposed fish embryos characterized significant heart failure, bradycardia, arrhythmias, reduction of contractibility, and edema surrounding the heart.
To explore these mechanisms, researchers assessed juvenile bluefin and yellowfin tuna captured in the area and held at the Tuna Research Conservation Center for observation. The cardiotoxic effects of four crude oil samples were assessed. The cardiac depolarization disorder is suggested to lead to cardiac arrhythmias, as the human homolog for the disorder causes such conditions and can lead to death. With PAHs interfering with EC coupling, lowered Ca2+ output levels during shortened depolarization (blockage of K+ pores in ion channels) periods result in the deficiency in producing contractile movements in cardiomyocytes.
With these findings, it is critical to understand the devastating effects of such disasters, and the need to control and properly clean up such events.
The Future of Gene Sequencing is Here
I was reading an article today about the progress of gene expression analysis over the years which is very relevant to the topics we are discussing in class! As we know, sequencing has increased from 10,000 bases per day to around a billion base pairs a day and the price has been cut significantly, almost reaching the $1000 mark. With prices and time cut, this allows whole genome sequencing (WGS) to be utilized in diagnoses and treatments like cancer. Currently, WGS is helping in the study of the genetics of acral melanoma (20% lower survival rate than non-acral melanoma) in order to create an effective treatment. With WGS, researchers can now measure tumor-specific alterations in chromosome structure, point-mutations and gene expression via a combination of whole genome, whole exome and RNA sequencing. With these approaches, it is hopeful that treatments will be personalized in the future. The “improvement” of genome sequencing over the years is very exciting, and there will undoubtably be more applications and technologies in the years to come!
Cloning Advance: Caffeine
I don’t know if y’all have read through the entire chapter 20 yet, but the next section covers cloning. I remembered reading a recent article about new stem cell research they have been investigating, so I thought i would share. As you know, stem cell research has been an ethical concern due to the harvesting of embryos. Adult stem cells aren’t as versatile, but they have found a new twist that may cease the use of ES cells.
Scientists at the Oregon National Primate Research Center have found that dunking adult stem cells in caffeine provides the desirable environment for reprogramming of the cell. Somatic cell nuclear transfer replaces the nucleus of a cell with a nucleus from an adult cell. Caffeine presence provides the suitable condition for human cells to transform to embryonic stem cells; research is still being preformed to uncover the suitable conditions for other organisms. This could transform the way stem cells are produced and utilized.
Borna Disease Virus
Last week I decided to research the Borna Disease Virus (BDV), partially because I love neuroscience and partially because it isn’t a commonly known virus! BDV a neurotropic virus that is most common in horses and other animals that usually causes abnormal behavior and fatality. It is still controversial if BDV plays any role in human mental disorders, although there has been recorded linkage between BDV and bipolar and schizophrenia (present BDV antibodies detected). It is thought that it is transmitted through saliva or nasal secretions. Through experiments with rats, it appears that the virus causes learning impairments and altered social behavior (in some cases meningitis). Its been demonstrated that the virus infects the limbic system (emotion). As the disease develops, seizures, ataxia, paraplegia, and other neurodegenerative symptoms persist; the immune response usually results in immune-mediated death of infected and neighboring cells, thus degradation of mental processes.
BDV is non-segmented, negative-sense ssRNA virus with at least six identified orfs producing proteins N, P, M, G, L, and p10 (uses enzymes to create a + strand). It is known to replicate in the nucleus of neural cells. The method of transmission is still unclear.
Comment on Previous Post by kyracurtis
I love the name! Its great how each of our phages are unique in their characteristics. This has been quite a journey – next semester will be too!