Day DateReadingTopic T10/15no class – October Vacation Th10/17More plant development T10/22Ch. 8Mechanisms of morphogenesis Th10/24More morphogenesis.

Day Date Reading Topic T 10/15 no class – October Vacation Th 10/17 More plant developmentT 10/22 Ch. 8 Mechanisms of morphogenesisTh 10/24 More morphogenesisT 10/29 Ch. 10 Cell differentiationTh 10/31 Happy Halloween! Stem cellsT 11/5 quiz on Flowering video handout

Ch. 11 Organogenesis Th 11/7 More OrganogenesisT 11/12Th 11/14 Ch. 12 Development of the nervous system

T 11/19 EXAM 2 Chapters 2, 7, 8, 10 Drosophila, plants, cell biology, differentiation

Th 11/21 Ch. 9 The saga of the germ cell

T 11/26 More on reproduction Your term paper is due at the beginning of class on Tuesday, 11/19

Th 11/28 no class – Thanksgiving Break

Also remember there are two, short writing assignments, each worth 20 points. Pick any topic in developmental biology (except your term paper topic) and learn more about it. Then write a two page paper and include all the sources you used (those can include any sources including web sites, newspapers, TV, etc). These are due anytime.

Comparing animals and plants:

Invented multicellularity independently

Some differences:

No germ line cells in plants(plants are easy to clone. No maternal factors???)

No morphogenesis in plants(very simple fate maps)

Plant cells contain plasmodesmata(a type of gap junction between cells)

Comparing animals and plants:

Invented multicellularity independently

Some similarities:

Totipotency(each cell retains the entire genome = genomic equivalence)

Stem cells (called initials in plants)

Stem cell niches (called meristems in plants)

Homeotic genesBUT the genes are different in plants vs animals (they are not orthologs)

Animal terms = totipotent, pluripotent

Plant term = indeterminant

7.46 leaf shape

Evolution of meristems:

Pteridophytes, like ferns, have a single meristematic cell.

Gymnosperms have a multicellular, but less defined organization (For example, they don’t have the organized layers cells of the tunica and corpus.)

Angiosperms have the highest degree of organization.

Several orthologs are found in the meristem cells of all plants.

7.10 stem/leaf pattern

7.21 root meristem

7.15 chimera

7.16 corn meristem fates

7.13 apical meristem

7.12 stem cell regulation

STEM CELL NICHE

7.1 Arabidopsis thaliana

7.24 inflorescence meristem

http://en.wikipedia.org/wiki/Florigen

Thigmomorphogenesis =development affectedby touch, breeze, etc.

Examples of regulation of plant development by auxin

1.) patterning the early embryo (proteins pump auxin)

2.) patterning leaf primordia = phyllotaxy

3.) patterning lateral bud growth = apical dominance

6.18 leaf primordia

phyllotaxy

7.19 leaf lateral inhibition (incorrect hypothesis)

7.20 auxin and leaf primordia