Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading:...
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Transcript of Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading:...
![Page 1: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/1.jpg)
Lecture 10
Gene Control in DevelopmentCell type specification
Development of an organism
Reading: Chapter 11:471-2
Chapter 15.1; 15.3; 15.4
Chapter 22.2
Molecular Biology syllabus web site
![Page 2: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/2.jpg)
Cell type specification in the yeast
model system
![Page 3: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/3.jpg)
![Page 4: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/4.jpg)
![Page 5: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/5.jpg)
![Page 6: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/6.jpg)
![Page 7: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/7.jpg)
MCM1 is a general transcription factor found in all cell types
Different mating types express specific transcription factors that form complexes with MCM1
![Page 8: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/8.jpg)
![Page 9: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/9.jpg)
![Page 10: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/10.jpg)
![Page 11: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/11.jpg)
Transcription factors and lessons from yeast
• Factors may act alone or in combinations
• The same factor in different combinations may contribute to complexes that act as repressors or activators.
![Page 12: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/12.jpg)
Cell type specification in animals
![Page 13: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/13.jpg)
Cell type specification in mammals: skeletal myogenesis proceeds through
three stages
![Page 14: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/14.jpg)
How to identify factors involved in muscle development?
To identify transcription factors that may play a role in “determination” of cells destined for a specific organ:
• Isolation of cDNAs by subtractive hybridization (fibroblasts vs. myoblasts)
• Testing by transformation of undetermined cell types to demonstrate effect on “determination”
• Create “Knockouts” to confirm information on the stage at which a specific factor acts
• Characterization: function as heterodimers (key to specificity is the interaction with other factors) and belong to family of basic helix-loop-helix DNA binding transcription factors (bHLH)
MRFs, muscle regulatory factors binding to “E” box in many genes
![Page 15: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/15.jpg)
Microarray analysis shows global patterns of gene expression during differentiation
![Page 16: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/16.jpg)
Development of an organism: Drosophila melanogaster
![Page 17: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/17.jpg)
Drosophila has two life forms
![Page 18: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/18.jpg)
Patterning information is generated during oogenesis and early
embryogenesis
![Page 19: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/19.jpg)
Formation of the blastula during Drosophila early embryogenesis
![Page 20: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/20.jpg)
Four maternal gene systems (anterior, posterior, terminal, dorsoventral) control early
patterning in fly embryos
![Page 21: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/21.jpg)
Mechanisms controlling pattern formation
![Page 22: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/22.jpg)
Morphogens regulate development as a function of their concentration: maternal bicoid
gene specifies anterior region in Drosophila
Yellow: even-skippedOrange: fushi tarazu
Red: hunchbackGreen: Krupple
![Page 23: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/23.jpg)
Maternally derived inhibitors of translation contribute to early
Drosophila patterning
![Page 24: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/24.jpg)
Nanos regulates the translation of Hunchback and
helps to establish the Hunchback
gradient
![Page 25: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/25.jpg)
Use of mutants to characterize Nanos as a translational inhibitor
![Page 26: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/26.jpg)
HOX genes and transcription factors discovered through “homeotic mutants” showing transformation of one body part
into another
![Page 27: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/27.jpg)
Expression domains of Hox genes in Drosophila and mouse embryos
![Page 28: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/28.jpg)
Specification of floral-organ identity in Arabidopsis: flowers contain four different
organs
![Page 29: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/29.jpg)
Three classes of genes control floral-organ identity
![Page 30: Lecture 10 Gene Control in Development Cell type specification Development of an organism Reading: Chapter 11:471-2 Chapter 15.1; 15.3; 15.4 Chapter 22.2.](https://reader035.fdocuments.in/reader035/viewer/2022081513/551a5551550346a4248b622c/html5/thumbnails/30.jpg)
Expression patterns of floral organ-identity genes