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<li>relationship bewteen genomics. genome is the basis for the transcriptome. although only small portion of gene is transcribed (less than 5%[2]), it is useful to figure out the pattern of gene expression. especially multicellular organism, there are different type of cells having same genome, which is called genomic equivalence. transcription of genes is the first stage of gene expression, transcriptomic is the valuable source for understanding the gene expression of genome.</li>
<li>what is mRNA? mRNA is the molecule carrying genetic information for protein synthesis. it is trasncripted from nucleus, exported to cytosol, and recognized by ribosome with its unique modification moiety such as 5'-cap and poly A tail.</li>
<li>how to measure mRNA expression[5]?to measure mRNA expression, extracted mRNA should be identified and quantified. there're largely two methods - microarray and RNA-seq. 1)microarray is blotting method with hybridization probe on solid(microchip). only RNAs complementary to probes bind to the probes and quantified under fluoroscent microscopy. such hybridization can occurs simultaneously, it provides high throughput. Microarray has limitation that it could detect RNAs only complementary to probes, being improper to detect novel RNA. Also, fluoroscent light gives good comparison for quantification, however, it does not give absolute quantification. Finally, microarray can't distinguish difference in expression of isoforms. 2)RNA-seq is kind of second-generation sequencing, which offers robust sequencing. It consists of three steps - library preparation, deep sequencing, and data analysis. Compared to microarray, this technique sequences RNA de novo - which is called "hypothesis-free approach" - so that it provides absolute abundance of RAN and is good at detecting low abundant or novel RNA. However, its data analysis is more complex than microarray, and expansive.</li>
<li>relationship between trasncriptome & proteome. to cell function, a set of proteins are needed. Due to the fact that mRNA translates proteins it is easy to consider that linear correlation bewteen transcriptome and proteome, low correlation sometimes come up with the post translational modification[3]. but still transcriptomic is the middle step of understanding bewteen genetic code and the functioning molecule.</li>
<li>what is UTR[4]? UTR is abbreviation for untranslated region. it is the portion of mRNA which is not translated. there are two UTR - one is on the 5' end(5'-UTR), another on the 3' end(3'-UTR). those UTRs are related to modification and lifespan of mRNA. for example, polyadenylation is an addition of 200 ~ 300 adenine to 3' end of mRNA making poly A tail. this process depends on AATAAA sequence on the 3'-UTR.</li>
<p>[3] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3637682/</p>
<p>[4] Gilbert, Scott F. <i>Developmental Biology</i>. Sunderland, MA: Sinauer Associates, 2010. Print.</p>
<p>[5] https://www.youtube.com/watch?v=2c3t3tDEmsU</p>
