Chapter 19 - Chapter 19: Differential Gene Expression in...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 19: Differential Gene Expression in Development I. Processes of Development a. Development i. Process multicellular organism progressively changes which characterizes its life cycle b. Embryo – plant/animal in earliest stages i. Protected in: 1. Seed 2. Egg shell 3. Uterus ii. Animal 1. Divide to form blastula iii. Plant 1. Octant, then globular, heart and torpedo embryos c. Four processes of development: i. Determination 1. Sets the fate of the cell 2. Ex. Going to be liver cell 3. Turns on and off genes to let cell become what it’s supposed to be ii. Differentiation 1. Phenotypically distinct cells arise 2. Physically looks like cell it’s going to be iii. Morphogenesis 1. Differentiated cells shape into organs iv. Growth 1. Increase in body size by cell division and cell expansion 2. Organism can actually grow II. Determination a. Fate i. Function of differential gene expression and morphogenesis b. Early embryonic cells have range of possible fates i. But possibilities restrict with development c. Outside/inside cell both influence genome and differentiation d. In vivo – once cell is determined it is committed to differentiating along that path i. Location within body only matters prior to determination ii. Doesn’t matter where it is in body, once signal tells it what to be it will grow to be that e. Determination is followed by differentiation i. Gene expression changes III. Differentiation a. A zygote is totipotent , it can give rise to every cell type in the adult body. i. Cells lose totipotency as they develop and specialize
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
ii. But most cells have the capacity for totipotency 1. Because retain the entire genome IV.Morphogenesis a. b. Animals: Organizaed divisioin/expansion and cell moves c. Apoptosis (programmed cell death) i. Must be initiaited in cells not needed 1. Ex. Our hands – cells die so webbed fingers don’t occur V. Is Cell Differentiation Irreversible? a. Plants i. All cells usually totipotent. ii. Differentiated cells can be removed from a plant and grown in a culture 1. Eventually form a genetically identical plant—a clone 2. Agricultural biotechnology a. Resistance to weed killer b. Animal i. Somatic cells can be totipotent because have all of genome ii. Differentiated cell nucleus + enucleated eggs (cytoplasm of cell not differentiated w/o nucleus) = normal adults 1. (Animal clone) iii. Genomic equivalence 1. No genetic information is lost as the cell develops iv. Cytoplasm can change cell’s fate v. Pharming
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/27/2011 for the course BIOSC 0160 taught by Professor Bledsoe during the Spring '08 term at Pittsburgh.

Page1 / 7

Chapter 19 - Chapter 19: Differential Gene Expression in...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online