Cambell Biology 14Th Ed. Chapt 18.4

Front 1

A program of differential gene expression leads to the different cell types

Back 1

During embryonic development, fertilized egg makes different cell types

Cells are organized into tissues organs organ systems and organism

Gene expression orchestrates the developmental programs of animals

Front 2

Differentiation

Back 2

Process by which cells become specialized in structure and function

ie: special cells to form liver. Turn certain ends on/off for this to occur

Front 3

Morphogenesis

Back 3

Physical process that gives an organism its shape

Front 4

Materials in the egg set up a program of ___That is carried out as cells divide

Back 4

Gene regulation

Front 5

Cytoplasmic determinants

Back 5

Maternal substances in the egg that influence early development

Cytoplasm contains RNA, proteins, and other substances

When zygote divides, uneven distribution of cytoplasmic determinants which leads to different gene expression

Front 6

Another source of developmental info in embryonic development...

Back 6

Environmental info and signals from other cells (Induction)

Front 7

Induction

Back 7

Signal molecules from embryonic cells cause changes in nearby target cells (cell signaling)

These interactions induce differentiation of specialized cell type

Front 8

Determination

Back 8

Commits a cell to becoming a particular type

Precedes differentiation

Precursor cell-determined cell-differentiated cell (molecular change)

ie: MyoD and myoblast

Front 9

Marked by the production of tissue-specific proteins

Back 9

Cell differentiation

Differentiation is specific structure and function

Front 10

Example of cell differentiation

Back 10

Myoblast cells are determined to form muscle cells and produce large amounts of muscle-specific proteins —>

MyoD (master regulator gene) encodes a transcription factor that commits cell to becoming skeletal muscle—>

Some target genes for MyoD encode additional muscle specific transcription factors

Front 11

Pattern formation

Back 11

Development of spatial organization of tissues and organs

Begins with establishment of major axes in animals

Front 12

Positional information

Back 12

Molecular cues control pattern formation

Tells cell it’s location relative to the body axes and to neighbor cells

Front 13

Life cycle of drosophila(pattern formation)

Back 13

Cytoplasmic determinants in unfertilized egg determine the axes before fertilization

After fertilization, embryo develops into segmented larva w three stages

Then forms pupa, metamorphosis into an adult

Front 14

Homeotic genes

Back 14

Control pattern formation in the late embryo, larva, and adult stages

Nobel prize for finding this in Lewis, nusslein-volhard, and wieschaus

Front 15

Maternal effect genes

Back 15

Encode auto plastic determinants that initially establish the axes of the drosophila

Also called egg-polarity genes

ie: biocides gene

Front 16

Egg polarity genes

Back 16

Also called maternal effect genes

Control orientation of the egg and consequently the fly

Front 17

Bicoid gene

Back 17

Maternal effect gene that affects front half of body

An embryo who’s mother has no bicoid gene functioning lacks the front half of its body and has duplicate posterior ends

Front 18

Morphogens

Back 18

Substances that establish an embryos axes and other features of its form

Morphogen gradient hypothesis

Front 19

Morohogen gradient hypothesis

Back 19

There are gradients of morphogens

Experiments showed that bicoid is distributed in an anterior to posterior gradient in the early embryo

Front 20

Bicoid research was groundbreaking for 3 reasons...

Back 20

1. Identified specific protein required for early steps in pattern formation

2. Increased understanding of mothers role in embryo development

3. Demonstrated a gradient of molecules determine polarity and position in embryo

Front 21

Evolutionary developmental biology

Back 21

Evo-devo

Study of genes and how they shape the development of the body

Molecular development