How is it that all cells in our body have the same genes, yet cells in different tissues express different genes? A basic notion in biology that most high school students fail to conceptualize is the fact that all cells in the animal or human body contain the same DNA, yet different cells in different tissues express, on the one hand, a set of common genes, and on the other, express another set of genes that vary depending on the type of tissue and the stage of development. In this video lesson, the student will be reminded that genes in a cell/tissue are expressed when certain conditions in the nucleus are met. Interestingly, the system utilized by the cell to ensure tissue specific gene expression is rather simple. Among other factors - all discussed fully in the lesson - the cells make use of a tiny scaffold known as the “Nuclear Matrix or Nucleo-Skeleton”. This video lesson spans 20 minutes and provides 5 exercises for students to work out in groups and in consultation with their classroom teacher. The entire duration of the video demonstration and exercises should take about 45-50 minutes, or equivalent to one classroom session. There are no supplies needed for students’ participation in the provided exercises. They will only need their notebooks and pens. However, the teacher may wish to emulate the demonstrations used in the video lesson by the presenter and in this case simple material can be used as those used in the video. These include play dough, pencils, rubber bands (to construct the nuclear matrix model), a tennis ball and 2-3 Meters worth of shoe laces. The students should be aware of basic information about DNA folding in the nucleus, DNA replication, gene transcription, translation and protein synthesis.
Rabih Talhouk, Professor of Cell and Molecular Biology, has served at the American University of Beirut (AUB) as Chair of the Biology Department, and has held leadership positions on several university committees. Currently he is Chair of the University Graduate Council. Rabih Talhouk has significant scientific contributions to the study of the role of membrane proteins, namely gap junctions, in regulating breast epithelial cell differentiation and transformation. He also conducts interdisciplinary research on anti-inflammatory activities in plants available in Lebanon and used in traditional medicine. In 2011 he received the AUB teaching excellence award. Read more at: http://www.aub.edu.lb/fas/biology/Pages/talhouk.aspx
Elia El Habre is a graduate student in the Cell and Molecular Biology program at the American University of Beirut (AUB). She is currently working on her thesis examining the role of connexin overexpression in epithelial polarity. The models she is using are breast cancer cell lines. She is intimately involved in teaching undergraduate labs and private tutoring for high school and college students. Being heavily involved in the local Scouts, Biology Student Society and Greenpeace club, she shows strong dedication and passion to natural sciences and their impact on the community. Having finished her B.Sc. with distinction, she will be applying to join PhD programs as she concludes her MSc studies.
This is a Wikipedia discussion of the Nuclear Matrix.
This is a scholarly article on the subject of this lesson, featured in the journal, Nucleic Acids Research, and presented on the website of the National Center of Biotechnology Information.
|Tissue Specific Gene Expression (English, Quicktime)||English||Quicktime||Download|
|Tissue Specific Gene Expression (English, mp4)||English||MPEG 4||Download|
|Tissue Specific Gene Expression (Portuguese Subtitles, mp4)||English-Portuguese SubtitlesEnglish-Portuguese Subtitles||MPEG 4||Download|