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This clicker case study follows a dialogue between two college students, Lucy and Dan, as they discover how alternative splicing of mRNA molecules can allow a single gene to code for multiple proteins. Dan is participating in a clinical trial for a drug that may treat his migraines by inhibiting calcitonin gene-related peptide, and Lucy is working in a summer research lab that studies the protein calcitonin. They soon realize that the two proteins are both encoded by the same gene, and through their questioning and dialogue they come to understand the phenomenon of alternative splicing. They also learn about other steps of mRNA processing and about monoclonal antibodies. This case was designed to be taught in a flipped classroom, but could easily be adapted for a more traditional classroom setting if content covered in the pre-class videos is covered during the case study instead. It was designed for an introductory-level molecular biology course, but could be adapted for higher levels by including more information about the physiology and regulatory mechanisms involved.

The most recent human retroviral infections leading to germ line integration took place with a subgroup of human endogenous retroviruses called HERVK(HML-2). The human genome contains ~90 copies of these viral genomes, which might have infected human ancestors as recently as 200,000 years ago. HERVs do not produce infectious virus: not only is the viral genome silenced - no mRNAs are produced - but they are littered with lethal mutations that have accumulated over time. A recent study revealed that HERVK mRNAs are produced during normal human embryogenesis. Viral RNAs were detected beginning at the 8-cell stage, through epiblast cells in preimplantation embryos, until formation of embryonic stem cells (illustrated). At this point the production of HERVK mRNA ceases. Viral capsid protein was detected in blastocysts, and electron microscopy revealed the presence of virus-like particles similar to those found in reconstructed HERVK particles. These results indicate that retroviral proteins and particles are present during human development, up until implantation.

At least 140 alternative RNA nucleotide forms exist. On mRNA, the most common is the methylation of adenosine on the N6 position (m6A).

An international team led by Professor Itai YanaAi of the Technion-Israel Institute of Technology Department of Biology made the discovery after using an extraordinarily powerful technique known as CEL-Seq. CEL-Seq monitors individual cells for their gene activity (as detected via mRNA)-and they applied it across 10 different species, with CEL-Seq being applied to 70 embryos per species. In particular, they were interested in whether the animal classification of phylum-which separates animals into groups according to their body plans-is actually a useful tool for placing animals into groups, as well as what genetic attributes are the same and different between the different phyla.

3:32 minute video about transcription and translation of insulin

Collection of video animation/movies

7 minute video; mash up of multiple cool animation videos - 0-1:20   supercoiling DNA to chromosomes 1:25- 1:40 cell division/mitosis 1:45-2:50  DNA replication  2:55-4:45   transcription  4:50-6:55  translation 7:00-7:47