Lecture, chapter 4 - Modes of inheritance and variations in gene expression

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Polydactyly and camptodactyly,
traits with incomplete penetrance and variable expressivity
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Today we finished chapter 4, on pedigree analysis.

We talked about the last couple of modes of inheritance: Y-linked traits and mitochondrial inheritance. Then we talked about variations in gene expression: Age-related phenotypic expression, penetrance, and expressivity.

By the end, we had a discussion about genetics in the news. People were passionate about it and it was fun and productive. We talked about the case of the California octuplets that was recently on the news (need an update/reminder? Click here!).
It was a good exercise and it may happen again. Should we do it every Friday? Should we call it "Genetics news Friday" or something along those lines? If you read this blog comment on this. If not... We may do it any way.

You could (should) subscribe to science podcasts and/or RSS feeds to keep abreast of the latest news...there is more out there than you think.

On Monday: We will start chapter 5 in our textbook.

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Lecture, chapter 4 - Pedigree analysis

Click on image for a full size pedigree

Today we continued chapter 4 in the textbook.

We started with a little overview of, and a demonstration on how to use, the Online Mendelian Inheritance in Man (OMIM) catalogue. The catalogue of human Mendelian traits.

Then we started covering the modes of inheritance that can be inferred from pedigree analysis. We went over autosomal recessive and autosomal dominant traits, and we started sex-linked traits, with X-linked dominant and X-linked recessive traits. We examined pedigrees and observed the characteristics they exhibited.

We discussed examples of diseases inherited in each one of these modes.

Tomorrow: More about modes of inheritance, and variations of gene expression. Oh, and possibly an activity to wake up people during class...

Huh...? What is this guy doing in a genetics class blog?

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Lab 02 - Mendelian genetics

Today we did a lab in which we examined a little bit of Mendelian genetics, faking crosses in fruit flies.

We focused on monohybrid and dihybrid crosses in, both, autosomal and X-linked traits. Students did observations that illustrated the principles of segregation and independent assortment, mainly based on test crosses.

Next week: Lab 03 - Epistasis and hypothesis testing

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Lecture, chapters 3 and 4 - Mendelian inheritance and Pedigree analyses

Today we finished chapter 3 in the book, on Mendelian inheritance, covering some of the variations on Mendel's findings: codominance, multiple alleles, and gene interaction, including epistasis.

On the other hand we began chapter 4, on pedigree analysis, talking about the six modes of inheritance we will be covering, in addition to the basic reasons for which pedigrees are so important when studying human genetics.

Tomorrow in lab: Mendelian genetics. The lab is being re-written so it will be posted late, but it will be up.

For Thursday: Read the remaining of chapter 4, and access the OMIM database, to get familiar with the kind onf information you can find there

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