CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 16 Development, Stem Cells, and Cancer
© 2014 Pearson Education, Inc. Concept 16.1: A program of differential gene expression leads to the different cell types in a multicellular organism ▪_________________________________________ _________________________________________
© 2014 Pearson Education, Inc. Figure 16.2 (a) Fertilized eggs of a frog 1 mm (b) Newly hatched tadpole 2 mm
© 2014 Pearson Education, Inc. Figure 16.3 (a) Cytoplasmic determinants in the egg(b) Induction by nearby cells Unfertilized egg Early embryo (32 cells) Sperm Fertilization Nucleus Two-celled embryo Mitotic cell division Zygote (fertilized egg) Molecules of two different cytoplasmic determinants Signal transduction pathway Signaling molecule (inducer) Signal receptor NUCLEUS
© 2014 Pearson Education, Inc. ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Sequential Regulation of Gene Expression During Cellular Differentiation ▪________________________________________ ________________________________________ ▪________________________________________
© 2014 Pearson Education, Inc. Figure Other muscle-specific genes Nucleus Master regulatory gene myoD DNA OFF Embryonic precursor cell
© 2014 Pearson Education, Inc. Figure Other muscle-specific genes Nucleus Master regulatory gene myoD DNA OFF mRN A OFF Embryonic precursor cell MyoD protein (transcription factor) Myoblast (determined)
© 2014 Pearson Education, Inc. Figure Other muscle-specific genes Nucleus Master regulatory gene myoD DNA OFF mRN A MyoD Embryonic precursor cell MyoD protein (transcription factor) Another transcription factor Myosin, other muscle proteins, and cell cycle– blocking proteins Myoblast (determined) Part of a muscle fiber (fully differentiated cell) mRN A
© 2014 Pearson Education, Inc. Apoptosis: A Type of Programmed Cell Death ▪________________ is the best-understood type of ________________________________________
© 2014 Pearson Education, Inc. Figure mm Interdigital tissueCells undergoing apoptosis Space between digits
© 2014 Pearson Education, Inc. Genetic Analysis of Early Development: Scientific Inquiry ▪_________________________________________ _________________________________________ _________________________________________ ___
© 2014 Pearson Education, Inc. Figure 16.8 Wild type Eye Antenna Mutant Leg
© 2014 Pearson Education, Inc. Totipotent cells ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Figure Frog embryo Less differ- entiated cell Results Enucleated egg cell Donor nucleus trans- planted Experimen t Frog egg cell Frog tadpole Donor nucleus trans- planted Fully differ- entiated (intestinal) cell Egg with donor nucleus activated to begin development Most develop into tadpoles. Most stop developing before tadpole stage. UV
© 2014 Pearson Education, Inc. Figure Grown in culture Results Cell cycle arrested, causing cells to dedifferentiate Implanted in uterus of a third sheep Cultured mammary cells Embryonic development Technique Mammary cell donor Egg cell donor Egg cell from ovary Nucleus removed Nucleus from mammary cell Surrogate mother Cells fused Early embryo Lamb (“Dolly”) genetically identical to mammary cell donor
© 2014 Pearson Education, Inc. Figure 16.13
© 2014 Pearson Education, Inc. Stem Cells of Animals ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Figure Stem cell Precursor cell Fat cells Cell division and or Bone cells White blood cells
© 2014 Pearson Education, Inc. Figure Cultured stem cells Embryonic stem cells Liver cells Nerve cellsBlood cells Adult stem cells Different culture conditions Different types of differentiated cells Cells that can generate all embryonic cell types Cells that generate a limited number of cell types
© 2014 Pearson Education, Inc. ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Concept 16.3: Abnormal regulation of genes that affect the cell cycle can lead to cancer ▪_________________________________________ _________________________________________ _________________________________________
© 2014 Pearson Education, Inc. Types of Genes Associated with Cancer ▪__________________________________________ ▪__________________________________________ __________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Figure within a control element Proto-oncogene Gene amplification: multiple copies of the gene Proto-oncogene Point mutation: within the gene Translocation or transposition: gene moved to new locus, under new controls Normal growth- stimulating protein in excess New promoter Oncogene Normal growth- stimulating protein in excess Normal growth- stimulating protein in excess Hyperactive or degradation- resistant protein
© 2014 Pearson Education, Inc. ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. Inherited Predisposition and Other Factors Contributing to Cancer ▪__________________________________________ __________________________________________
© 2014 Pearson Education, Inc. ▪__________________________________________ thus the risk of cancer can be lowered by minimizing exposure to agents that damage DNA, such as ultraviolet radiation and chemicals found in cigarette smoke ▪__________________________________________ __________________________________________ by donating an oncogene to a cell, disrupting a tumor-suppressor gene, or converting a proto-oncogene into an oncogene