Biology 2581B Lecture Notes - Lecture 18: Ribosomal Rna, Horizontal Gene Transfer, African Trypanosomiasis
23 Apr 2016
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Department
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Professor
Readings: Trypanosome genomes and editing
http://www.nature.com/scitable/topicpage/kinetoplastids-and-their-
networks-of-interlocked-dna-14368046 ; A somewhat "fluffy" but
interesting blog on alternative genetic codes http://nautil.us/issue/6/secret-
codes/creating-life-as-we-dont-know-it; RNA editing pg. 614, Nonstandard
genetic code pg 227-228. 614
Genetic Modifications: significant genetic alterations that are often not apparent or obvious given
the primary DNA sequence alone
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Cox gene uses different codes between different species/organelles
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You would get stop codons and such if you didn't use the right code
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Knowing the code is crucial, when the code changes it can have a big impact on how we perceive
information
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Understanding the modification: methylation, non-standard codes, or other modification is crucial
because it helps with the interpretation of the information
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We expect T DNA = U RNA, but this is not always true
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What are genetic modifications?
Generates transcripts on the RNA level
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RNA editing (post-transcriptional editing)
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Lots of CG editing sites that are changed
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Central Dogma: DNA gets transcribed to RNA
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DNA does not always reflect the RNA
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It uses the standard code
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It is unusual to see this editing
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From the DNA sequence, you would get a AA sequence and after the editing, the changes of AA
sequence is visible
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There are proteins (free) that bind to the RNA and have to edit that sequence to U
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It is useless
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To make 1 protein and you might need 100s editing proteins to correct it
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We need 100s of editing proteins to make that one protein
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Mitochondrial Genome
Unique to land plants
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Various degrees of RNA editing in mitochondrial and chloroplast genomes
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Tree of land plants and green algae
RNA Editing: specific alteration of genetic sequence carried within an RNA molecule after
transcription is completed
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Including bacteria and nuclear genomes of eukaryotes
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Has evolved many times independently through the tree of life
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RNA Editing
Sleeping sickness
Trypanosomes - single large mitochondrion - the kinetoplast - which contains much more DNA
than the mitochondrion of other organisms and which has a series of interlocking maxi and
minicircles
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Lecture 18: More on Modifications & Some Bioinformatics
Thursday, April 21, 2016
12:30 AM
Final Page 1
Document Summary
Lecture 18: more on modifications & some bioinformatics. Readings: trypanosome genomes and editing http://www. nature. com/scitable/topicpage/kinetoplastids-and-their- networks-of-interlocked-dna-14368046 ; a somewhat fluffy but interesting blog on alternative genetic codes http://nautil. us/issue/6/secret- codes/creating-life-as-we-dont-know-it; rna editing pg. Genetic modifications: significant genetic alterations that are often not apparent or obvious given the primary dna sequence alone. Knowing the code is crucial, when the code changes it can have a big impact on how we perceive information. Cox gene uses different codes between different species/organelles. You would get stop codons and such if you didn"t use the right code. Understanding the modification: methylation, non-standard codes, or other modification is crucial because it helps with the interpretation of the information. We expect t dna = u rna, but this is not always true. Lots of cg editing sites that are changed. From the dna sequence, you would get a aa sequence and after the editing, the changes of aa sequence is visible.
