Brown Bull have responded by evolving various mechanism to evolve resistance to pollutants, in order to have a superior performance. These contaminations can cause changes in brown bullhead’s behavior, physiology and dispersal as a adaptive response to pollution (Breckels et al. 2010) to increase their survival (Wilson and Franklin et al. 2002). These changes allowed them to increase their life span and gain highest fitness in stressful conditions. Any of these response observed in organism are the result of variation on gene transcription (Söderberg et al. 2013). Genes are encoded on DNA and are transcribed in mRNA, which are later translated into amino acid sequences, which results into functional proteins or remain as regulator mRNA transcripts. Many gene transcription is either elevator or decrease in expression as adaptive response to contamination, in order to maintain the homeostasis. For example, one such is the response …show more content…
is the change in the gene cytochrome P450 1A in stressful environment (Waldman et al. 1998) or change in metallothioneien cause by metals (Bervoets et al. 2013), or estradiol’s inducing changes in vitllogenine expressions (Mortensen et al. 2007). Brown bullhead has adaptive various defense mechanism by changing their transcription profile by having a varying gene expression. Therefore, any initial response to harmful chemicals can controlled at the transcriptional level (Söderberg et al. 2013), like changes to controlling cancer rates, physiological disruption or reduced reproductive ability (Söderberg et al. 2013). Epigenetic mechanism is critical for successful maintenance and development of specific readout of genome under non homeostatic conditions.
Epigenetic is defined by mitotically or meiotically changes in genome which does not result because of base pair sequence alteration (Cosma et al. 1999). Epigenetic caused by methylation is the addition of methyl groups on genome and is necessary for many important development process in like genomic imprinting, X-chromosome inactivation and repression of carcinogenesis (Schär et al. 2010). Brown bullhead can acquire resistance to the mutagenic compounds by covalently modifying their cellular DNA by physically blocking the miscoded bases or activating certain pathways through methylation. DNA methylation only covalent bounds to the 5’ position of cytosine residues on genome to reduce gene expressions (Schär et al. 2010). It is found where cytosine nucleotide is followed by the guanine nucleotide, thus primarily occurring in CpG dinucleotides, thus changing the biochemistry of DNA (Schär et al.
2010). Methylation is an effective adaptive mechanism towards resistance of many deleterious effects of different mutagens and chemicals. Some of these includes protection from alkylating agents, tumors, lesions, reproductive impairment, oxygen radical damage in DNA. These adaptive strategies have been conserved throughout evolution to promote survivorship through methylation of specific specific DNA sequence for methylation. A recent study conducted by (Söderberg et al. 2013), has analysis 128 gene response to toxicity on Detroit River in brown bullhead as an exposure to B[a]P (Söderberg et al. 2013). However, there have been no studies conducted on the methylation mechanisms of brown bullhead as the biological side effects of contaminants. The molecular mechanism of methylation has been well-studies in human tumourigenesis, however, further studies need to be conducted on aquatic species. In this studies, I plan to study the alteration in the DNA methylation patterns in Brown Bullhead as an evidence of alterations in DNA profiles as the result of exposure to pollutants.
However, evidence such as fossils is more than enough to lend support and disprove any other theory to the development of species. Examples used by Root-Bernstein and McEachron also provide strong support to evolution. The authors detail how natural selection works in both insects and germs to create organisms better adapted to methods of control. Disease used to run rampant, until the creation of vaccines which led to many diseases becoming extinct. Root-Bernstein and McEachron note that the diseases that have survived to this day have been constantly mutating and evolving to become more resistant to any attempts at suppression. The same can be said for insects that have been consistently exposed to pesticides. The ones that survived the pesticides were able to reproduce and pass along a resistance to their offspring which in turn makes the species more resilient and better suited to their
3 Leicht B. G., McAllister B.F. 2014. Foundations of Biology 1411, 2nd edition. Southlake, TX: Fountainhead Press. Pp 137, 163-168, 177-180,
Miller, Kenneth R. and Joseph S. Levine. “Chapter 12: DNA and RNA.” Biology. Upper Saddle River: Pearson Education, Inc., 2002. Print.
An increasing number of pit bull attacks have occurred over past decade. People who are attacked by pit bulls always suffer serious injuries because of the pit bulls’ sharp teeth and strong muscles. In October 19, 2009, Dr Hugh Wirth who is the RSPCA’s Victorian president renewed calls for American pit bull terriers to be bred out of Australia. The current laws require owners of pit bulls to register their pit bull. While some people are satisfied with the laws because they think that they are safe, others disagree. From my own perspective, the laws should be improved. The government should ban these fierce dogs and wipe them out instead of just registering them. In my opinion, there are three reasons why I am in favour of Dr Wirth’s proposal.
...plicates the identification of the loss of tumor suppressor gene (TSG) is epigenetic changes in the gene promoter. Hypomethylation of DNA and hyperacetylation of histones in the promoter region leads to successful transcription of the DNA. Therefore, any alteration in either of the two will disrupt the gene transcription.
The premise of Theo Colborns’ research was to find the connection between the rising incidences of cancer and environmental contamination in the Great Lakes region. However, during field and laboratory studies, Colborn discovered that there was no direct link between the contamination and cancer. However, Colborn did find reoccurring patterns of abnormal behavior and deformed offspring amongst the wildlife populations in the Great Lakes region. Elevated levels of polychlorinated biphenls (PCBs), pesticides dieldrin, DDT, lindane and chlordane were found during tissue analysis of the wildlife in the Great Lakes region (Colborn et. Al 1996). These elevated levels were found in offspring of the wildlife who appeared to be healthy. This supported Colborns’ hypothesis that these contaminations disrupt hormones produced by the endocrine system during growth and development, which will then cause physical and behavioral abnormalities in the fetus.
"Epigenomics Fact Sheet." National Human Genome Research Institute. N.p., 7 May 2012. Web. 04 Apr. 2014. .
Hypermethylation of CpG islands at tumor suppressor genes turns them off, while hypomethylation leads to the instability and inappropriate activation of oncogenes and transposable elements. Methylation can be directly related to genetic mutations, an example of this case is methylated cytosine. Methylated cytosine mutates spontaneously in vivo through deamination to give thymine. According to Andy Bannister (n.d.), “37% of somatic p53 mutations and 58% of germ line mutations occur at methylated...
The Pitbull used to be one of the most popular family dogs. I myself own a Pitbull. They are some of the most mis-treated breeds of dog. This is because of their supposedly aggressive behavior. But research has proven that no one breed of dog is more aggressive than any other. So why is there such a stereotype that Pitbulls are mean and aggressive?
One of the most commonly described mechanisms is altered DNA methylation, which has been noted in paternal folate deficiency7, maternal under-nourishment during pregnancy6,7, paternal high fat diets2, and paternal low protein diets3. Another mechanism is established by microRNA’s ability to regulate DNA methylation. Certain microRNA’s are known to downregulate DNA methyltransferase enzymes that function to maintain global methylation status in the genome.6 It has been proposed that environmental exposures, like nutrition, can change sperm microRNAs leading to modifications in DNA methylation.11 Histone modifications in spermatids, such as acetylation, occur in another commonly described mechanism. These diet related changes affects the structure of chromatin, which can lead to increased risk damage to DNA and thus poor sperm outcomes.6 Further influences that lead to epigenetic changes during spermatogenesis include the following: increased testicular temperature, hyperleptinemia, hyperinsulinemia, and genotoxic metabolites due to paternal fat accumulation causing increased oxidative injury to sperm cell DNA.6 These epigenetic changes are thought to influence and accelerate genetic variation that is thought to drive the evolution of a
...oney, Andrew A. and Daniel B. Pickford. 1995. Organisation versus Activation: The role of Endocrine-disrupting Contaminants (EDCS) during Embryonic Development in wildlife. Environmental Health Perspective’s. 103 (Suppl 7): 157-164.
It is likely that gene regulation is affected by certain enzymes after initial hormone binding. Genes may be altered by secondary and tertiary messengers of a cellular cascade as well. Hormones may indirectly control gene expression through these enzymes and messengers at a number of control sites such as transcription, mRNA processing, mRNA stability, translation, and post-translation
According to World WildLife Fund, many ecosystems around the world are being destroyed, eliminating many plant and animal species that inhabit them (“Pollution”).
" Society & Animals 18.2 (2010): 183-203. Academic Search Premier -. EBSCO. Web. The Web. The Web.
Evolution is defined as the change of hereditary characteristics of populations over generations (Caroll, 2009). The environment is continually changing therefore organisms have to change in order to stand the changes in environment so they can survive and reproduce (Caroll, 2009). Regular change in genetic material of organisms over generations can lead to the development of new species that are more adapted to the environment (Caroll, 2009). It is said that failure to evolve may lead to extinction of a species (Caroll, 2009).