Thursday, February 23, 2012

Natural Selection and Exapatation

Natural Selection is the process in which mutations are either spread or eliminated is a crucial part of evolution. It is a process that usually takes many years, and even then, continues on. As the environment around the animal changes, so do the animals need to adapt. Useful adaptations help the animal survive to pass on their genes, including the adaptations, while hindering adaptations only prevent the animal from surviving and therefore from passing on their hindering gene. After multiple centuries, the helpful gene would have spread to most of the population of the animal while the hindering gene would have been snuffed out.

Exaptation, a close term of natural selection, is the charge of the function of a gene in a animal. An example would be the usage of feathers in a bird. Originally, for heat regulation, the feathers eventually became for the use of flying. Due to natural selection, many useful mutations grew into flight for the birds which have remained ever since.

Thursday, February 16, 2012

Cloning

Cloning, the process of creating genetically identical organisms, is currently a very promising area. Many are researching cloning and its implications on human society.

However, cloning research should be regulated by some kind of enforcer. Without such regulation, cloning research could be dangerous and unethical. If research is not regulated, the scientific community would be the only decider on whether their research has gone too far ethically. They may choose to take drastic means in order to further their research without regards to how they are doing so.

The regulation should most likely be done by the government. Constant inspection by the government with the project to shut down any experiment that proves to be unethical would help bring cloning research in check. Ballets to determine whether the experiment should be shut down would bring the population's opinion on the research to the government.

Regulation can also be done by the benefactor of the experiment. The benefactor, in a sense, could regulate the experiment by withholding the money to support the experiment. However, the ethical question would depend solely on the benefactor. In this case, the government can step in which brings this back to the above paragraph.

Tuesday, February 7, 2012

Transcription, Translation, and Protein Synthesis

TRANSCRIPTION
Transcription is the process in which a synthesis of RNA is created from a DNA template. The entire process takes three steps. Initiation, Elongation, and Termination.

Initiation
Initiation is when the DNA helix splits into a single strand, and is then attached by the RNA polymerse. The RNA attaches to the sequence of DNA that contains the promoter, which details where the RNA is to start.

Elongation 
Once properly connected to the DNA strand, the RNA begins to use the DNA strand as a template for copying the genetic material. It connects the DNA nucleotides to their appropriate, opposite nucleotides (genuine with cytosine and vice-versa).

Termination
 RNA transcription stops when the newly synthesized RNA molecule forms a G-C-rich hairpin loop followed by a run of Us. When the hairpin forms, the mechanical stress breaks the weak rU-dA bonds, now filling the DNA-RNA hybrid. This pulls the poly-U transcript out of the active site of the RNA polymerase, in effect, terminating transcription.


TRANSLATION
Translation is the process of assembling protein molecules from the information encoded in the RNA. It starts off when mRNA goes out of the nucleus and joins a group of ribosomes and together they align to form a pattern.
the tRNA in their respective amino acid go to these ribosomes. The tRNA bear their anticodons complementary to the codon of mRNA.





PROTEIN SYNTHESIS
Protein synthesis is the process in which individual cells create proteins. Both DNA and all types of RNA are involved in this process. Enzymes in the cells nucleus begin by unwinding the DNA helix.  The RNA forms as a copy of one side of the DNA strand, and is sent to other areas of the cell to aid in the bringing together of different amino acids that form proteins. Protein synthesis is so called because proteins are "synthesized" through mechanical and chemical processes in the cell.
Once the strand of RNA has been made in the nucleus, it is called messenger RNA (mRNA). The mRNA exits the nucleus through tiny openings called nuclear pores, and moves into the larger area of the cell, known as the cytoplasm. Once it exits the nucleus, the mRNA is drawn toward a structure known as a ribosome, which serves as the cell's work station for protein synthesis. At this point, only one sub-unit of the ribosome is present.

Thursday, February 2, 2012

BLAST (Basic Local Alignment Search Tool) Genes

HTT huntingtin [ Homo sapiens ] (Gene 1)

Huntingtin is a disease gene linked to Huntington's disease, a neurodegenerative disorder characterized by loss of striatal neurons. This is thought to be caused by an expanded, unstable trinucleotide repeat in the huntingtin gene, which translates as a polyglutamine repeat in the protein product. A fairly broad range in the number of trinucleotide repeats has been identified in normal controls, and repeat numbers in excess of 40 have been described as pathological. The huntingtin locus is large, spanning 180 kb and consisting of 67 exons. The huntingtin gene is widely expressed and is required for normal development. It is expressed as 2 alternatively polyadenylated forms displaying different relative abundance in various fetal and adult tissues. The larger transcript is approximately 13.7 kb and is expressed predominantly in adult and fetal brain whereas the smaller transcript of approximately 10.3 kb is more widely expressed. The genetic defect leading to Huntington's disease may not necessarily eliminate transcription, but may confer a new property on the mRNA or alter the function of the protein. One candidate is the huntingtin-associated protein-1, highly expressed in brain, which has increased affinity for huntingtin protein with expanded polyglutamine repeats. This gene contains an upstream open reading frame in the 5' UTR that inhibits expression of the huntingtin gene product through translational repression. [provided by RefSeq, Jul 2008]

ELN elastin [ Homo sapiens ] (Gene 2)

This gene encodes a protein that is one of the two components of elastic fibers. The encoded protein is rich in hydrophobic amino acids such as glycine and proline, which form mobile hydrophobic regions bounded by crosslinks between lysine residues. Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

FBN1 fibrillin 1 [ Homo sapiens ] (Gene 5)

This gene encodes a member of the fibrillin family. The encoded protein is a large, extracellular matrix glycoprotein that serve as a structural component of 10-12 nm calcium-binding microfibrils. These microfibrils provide force bearing structural support in elastic and nonelastic connective tissue throughout the body. Mutations in this gene are associated with Marfan syndrome, isolated ectopia lentis, autosomal dominant Weill-Marchesani syndrome, MASS syndrome, and Shprintzen-Goldberg craniosynostosis syndrome. [provided by RefSeq, Jul 2008]

DMD dystrophin [ Homo sapiens ] (Gene 7)

he dystrophin gene is the largest gene found in nature, measuring 2.4 Mb. The gene was identified through a positional cloning approach, targeted at the isolation of the gene responsible for Duchenne (DMD) and Becker (BMD) Muscular Dystrophies. DMD is a recessive, fatal, X-linked disorder occurring at a frequency of about 1 in 3,500 new-born males. BMD is a milder allelic form. In general, DMD patients carry mutations which cause premature translation termination (nonsense or frame shift mutations), while in BMD patients dystrophin is reduced either in molecular weight (derived from in-frame deletions) or in expression level. The dystrophin gene is highly complex, containing at least eight independent, tissue-specific promoters and two polyA-addition sites. Furthermore, dystrophin RNA is differentially spliced, producing a range of different transcripts, encoding a large set of protein isoforms. Dystrophin (as encoded by the Dp427 transcripts) is a large, rod-like cytoskeletal protein which is found at the inner surface of muscle fibers. Dystrophin is part of the dystrophin-glycoprotein complex (DGC), which bridges the inner cytoskeleton (F-actin) and the extra-cellular matrix. [provided by RefSeq, Jul 2008]