final review

final review - In Class Final 3:30-4:45pm Thursday June 5...

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In Class Final: 3:30-4:45pm, Thursday June 5, 2008 P-elements are transposon. Transposons are special pieces of DNA capable of replicating transposition. They can make a copy of themselves and leave a copy where they were and move. Most of them have control elements that prevent them from doing this frequently. These transposable elements are in business for themselves. They do not make a positive contribution to the organism they reside as long as they are good at propagating themselves. Organism is deleterious. Host-parasite relationship. Cannot kill organism or they’re without a host. So it became quite apparent that p-elements were spreading throughout drosophila like gang-busters. Within 5 decades, there was a world-wide sweep. Australia and the far east had the latest onset. Then it was found that a distantly related drosophila actual had p-elements in all of the versions collected. It is highly suggested that there was a lateral gene transfer from the wilistonia species to the melanogaster species. The most common vector is a virus. Any virus that co-infects two species. Alu Concensus Sequence: that little sequence of 300 nucleotides is a very big portion of your DNA. Make up 5-10% of the genome. This is a transposable element. Most transposable elements have internal genes that mitigate their transmission. It does not code for a protein. Cannot detect RNA. Has a lot of GC dincleotides. GC dinucleotides are highly biased against. C is frequently methlyated to thymine. So those are biased out. As you look at alu sequences, most of the GCS have been removed, but the source still has the GC present in it. No transciprt or gene product that we know of. Problematic of what keeps that source. Lots of DNA but poorly understood. NOT YOUR FRIEND. # of examples being transferred to a critical gene. Frequent through the genome. Target for recombination. Can pull out required portion of the genome. NOT ADVANTAGEOUS. They are highly derived process. 7SL RNA is a functional RNA. Part of the docking proteins for ribosome to attach through membranes. It’s a very convoluted version of it. Present in chimp and gorilla, present before the split. Triosphosphate. Exercise. Used to distinguish if introns were a later addition or a loss. It’s more reasonable that they were added late. Added at eukaryotic lineage. Progenitor = early part. Easier to add them in than to dock them out. Concerted evolution: multigene families. Classic is histone. Ribosomal RNAs. What happens is in this multigene family, virtually all of the copies are identical to one another. However, if you
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look at them relative to other species, they’re drifting relative to one another. The whole family then appears to be acting as a single gene. This is called concerted evolution. This is some kind of copy, correction mechanism. That element sweeps through whole population or reverted to original. Don’t get a spectrum of diversity. Natural selection is not effective on individuals of large multigene family. If one of it picks up a mutation, the rest of them will cover for it. If there
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This note was uploaded on 07/14/2008 for the course EEB 121 taught by Professor Dontknow during the Spring '08 term at UCLA.

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final review - In Class Final 3:30-4:45pm Thursday June 5...

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