Introduction Arctic fish display a remarkable case of adaptation, living in in low temperatures around 0˚C with areas of ice that can be -1.9˚C (DeVries, 1971). The ability for Arctic fish to thrive in such a low temperature environment is made possible by a class of proteins called Antifreeze proteins. Antifreeze proteins (AFPs) and Antifreeze glycoproteins (AFGPs) are polypeptides that are biosynthesized in animals, plants and fungi that prevent ice crystal formation (Griffith & Ewart, 1995). The most widely accepted mechanism for the prevention of ice formation by AFPs and AFGPs is called the adsorption-inhibition mechanism, which describes that the protein binds to water molecules and separates water molecules at a certain distance. This separation distance is large enough to inhibit ice crystal formation and prevent recrystallization (Raymond et al., 1977). The complexity of AFPs and AFGPs provoke several important questions regarding their origins, such as: From where did AFPs and AFGPs originate? How conserved are AFPs and AFGPs among different species of polar fish, are they conserved? Through what mechanisms have antifreeze proteins, and antifreeze glycoproteins evolved? What environmental or ecological stresses influenced the proliferation of AFPs and AFGPs in cold-water fish? The stunning amount of diversity found in antifreeze proteins is evident of a fascinating evolutionary story. Exploring the phylogenetic and molecular data from different species of cold-water fish is a common starting point for determining the origins of antifreeze proteins. Antifreeze proteins can be divided into two groups, the AFPs and AFGPs. Of the AFPs, there are currently four known types: I, II, III and IV (Cheng et al., 1998). By examining... ... middle of paper ... ... similarities between proteins exhibiting homology, and inspecting the AFP nucleic acid sequence in comparison with proteins showing similarities. The driving force for most of these evolutionary events is supported by colder climates. Oceanic cooling most certainly added selective pressures towards polar fish, bearing in mind the evidence that suggests protein homology, it is possible to propose that the aforementioned AFPs are derived from different proteins seen today. Environment stress influencing AFP and AFGP proliferation is most supported by glaciation and cooling periods. Evidence from Pleistocene cooling events covers several AFPs and the AFGPs as a relevant selective pressure. As the ever-expanding amount of protein sequences become more available, I also expect the accuracy for pinpointing protein homology to elucidate explicit evolutionary mechanisms.
2)Campbell, Neil A., and Jane B. Reece. Biology. San Francisco, CA: Benjamin Cummings, 2008. Print.
Abiotic factors of the arctic tundra are strong winds, little precipitation. Also very short summer days, instead there are very long and cold winters. There is poor soil and a permafrost which is a layer of permanently frozen subsoil. The biotic factors are that plants and mosses have to adapt to the long and cold winters, since the sun does not come up during winter. Also the wildlife animal that live there are Snowy owls, reindeer, white foxes, lemmings, arctic hares, wolverines, caribou, migrating birds, mosquitoes, black flies, and the chief predator the Polar
Acknowledgements: Slides of dead fish courtesy of OKDEQ. We would like to thank our students Trevor Nance Jr, and Matt Ward for their help in the laboratory sample preparations. We would also like to thank OKDEQ (Chris Armstrong) and EPA Region 6 (Rick McMillin) for their patience.
Thewessen, J. G. M., Williams, E. M., Roe, L. J. & Hussain, S. T. Nature 413, 277-281.
The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides. Each nucleotide has three components; a phosphate group, a sugar and a base that contains nitrogen within its structure. The sugar moiety in DNA oligonucleotides is always dexoyribose, and there are four alternative bases: adenine (A), thymine (T), guanine (G), and cytosine (C). The phosphate groups and the deoxyribose sugars form the backbone of each DNA stand. The bases are joined to the deoxyribose sugar and stick out to the side. Both oligomers, DNA and RNA, consist of 5’->3’ phosphodiester-linked nucleotide units that are composed of a 2’-deoxy-D-ribose (DNA) or D-ribose (RNA) in their furanose forms and a heteroaromatic nucleobase (A, T, G, and C; A, U, G, C), and the resulting oligonucleotide chain is composed of a polar, negatively charged sugar-phosphate backbone and an array of hydrophobic nucleobases. The amphiphilic nature of these polymers dictates the assembly and maintenance of secondary and tertiary structures the oligonucleotides can form. In the DNA duplex structure, genetic information is stored as a linear nucleotide code. This code can be accessed and replicated. RNA, or ribonucleic acid, is another structurally related essential biopolymer. RNA differs from DNA in having the sugar ribose in place of the deoxyribos...
"Polymerase Chain Reaction (PCR) Fact Sheet." National Human Genome Research Institute. 10 Dec. 2007. National Institutes of Health. .
The heavily armored jawless fish had many adaptations that permitted them to still move and hunt successfully. Can you postulate on the details of exactly how heavily armored jawless fish caught and ingested their prey without the mechanical advantages of a hinged jaw?
Ice is one of the major abiotic factor in the arctic, without the ice, many organism such as polar bears would be left without a place to live and even with seals, it would be unsafe for them because without ice, there will be no places to hide from predators. Other factors are permafrost, strong winds, poor soil, long winters and short summer.
In 1758, a Swedish naturalist named Carolus Linneas gave the Atlantic salmon its scientific name, Salmo salar which Latin for “the leaper” (Atlantic Salmon Museum, 2014). Today, it still continues to be a well-known and vital part of oceans ecosystems. They are sometimes referred to as the ‘king of fish’ (The North Atlantic Salmon Conservation Organization, 2014).
Cold water is the key aspect in the phenomenon called the mammalian diving reflex. This reflex has been beneficially used for thousands of years by whales, dolphins, seals and other mammals that inhabit the frigid waters of the world. The diving reflex slows heart rate and causes peripheral vasoconstriction to keep blood and oxygen to the brain and other vital core organs. This reflex allows these mammals to conserve oxygen and stay submerged over longer periods of time, providing them more time for finding food, protection and travel.
Life on the melting Artic is hard and unforgiving for all animals that rely on the annual ice change to obtain their food source or as a habitat. Increased ice melting rate and degrading habitat from global warming has altered polar bear life expectancy in the West Hudson Bay. Counterclockwise marine currents in the Hudson Bay “behaves essentially as a closed ocean body in that the duration of the ice thickness and ice cover is essentially controlled by air temperature and variations” (Gagnon and Gough, 372). Simple changes within the atmosphere can have a detrimental effect on the duration of ice thickness and covers and will affect the polar bear survival success rate. Thinner ice will be melted during the summer and lower the available hunting
Amblyopsis spelaea, the first cavefish species to be described in 1842, was also found to be blind (Juan, Guzik, Jaume, & Cooper, 2010). Today, biologists are carrying out numerous investigations on the Astyanax cavefish species, which have eye degenerative traits. The degree of functi...
Michener, William K. and Haeuber, Richard A., Bioscience. American Institute of Biological Science. Sep98. Vol. 48. Issue 9. p677.
It is an unquestioned fact that the climate is changing. There is abundant evidence that the world is becoming warmer and warmer. The temperature of the global land average temperature has increased by about 8.5 degrees centigrade from 1880 to 2012 (Karr, et al 406). The one or two degrees increase in temperature can cause dramatic and serious consequences to the earth as well as humans. More extreme weather occurs, such as heat waves and droughts. The Arctic Region is especially sensitive to global climate change. According to the data in recent decades, the temperature in the Arctic has increased by more than 2 degrees centigrade in the recent half century (Przybylak 316). Climate change has led to a series of environmental and ecological negative
Campbell, N. A. & J. B. Reece, 8th eds. (2008). Biology. San Francisco: Pearson Benjamin Cummings.