CSB349L3 - CSB349H1 Lecture 3 September 20th 2010 The topic...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CSB349H1 Lecture 3 September 20 th , 2010 The topic for today is a continuation on the question of what is really in the human genome. A large part of our genome is repeats and most of it isn’t even genes (or human genes), they are transposons, etc. Only 20,000-25,000 genes is still a huge number of genes. Questions for today’s class: Where do these genes come from? How do we detect genes changes in copy number? The major mechanism of the origin of genes is gene duplication and divergence; the vast majority of genes came from other genes. There are many different mechanisms for gene duplications and for gene divergence after duplications. The mechanism represented is gene duplication by retrotransposition, where our own genes can make copies of themselves. The CDC14B gene on chromosome 9. The figure illustrates four different alternative splice sites for the gene). The reason we know this gene CDC14B retrogene is on chromosome 7 and was created by retrotransposition as it shows the structure of an RNA element even though it is DNA and was copied from RNA back into DNA...hallmark is _____________________________. Tandem gene duplication (getting two gene copies on the same chromosome): Gene dupliplication on the chromosome, creates tandem repeats on the genome (most prevelant form of gene duplication). What happens to genes after they duplicate? One of the copies is generally lost as natural selection makes it require mutations, become non-functional, and be deleted. On some occasions, the genes stay similar and stay on the genome. Sub-functionalization may also occur, where the functions of the ancestral gene is divided among the two genes. Neofunctionalization may occur where there is still selection to preserve the original function of the gene, but mutations allow for a new function on the other gene to occur.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern