2. Early development and aging

3. I. Embryonic development A. Cleavage 1. zygote to morula to blastula 2. blastocyst 3. cleavage position and fate 4. the beginning of differentiation 5. accomplishments of cleavage B. Gastrulation 1. the main events 2. 3 germ layers a. endoderm b. mesoderm c. ectoderm 3. two great groups of animals C. Neurulation

4. Day 1: fertilization 10 hours

5. 1. Cleavage Two accomplishments of cleavage morula blastula

6. 1. Cleavage

7. 2. Gastrulation blastopore ectoderm endoderm mesoderm Germ layers

8. 3. Fate of the germ layers Blastopore?

10. Two great groups of animals Protostomes: blastopore becomes a mouth Deuterostomes: blastopore becomes an anus

11. Deuterostomes

12. Neurulation Neural tube develops from the endoderm

13. II. HOX genes Evolutionarily conserved gene sequences

14. Genetic clock theory 1. Protein in non dividing cells 2. Telomeres and embryonic cells 3. Diseases of aging: Progeria and Alzheimer’s 5. Genes for aging in fruit flies and mice Wear and tear theory 1. Errors in DNA replication 2. Accumulation of metabolic garbage 3. Environmental insults Reproductive obsolescence 4. Organs programmed III. Theories of aging 6. Ink4 protein

15. The new generation Japan, Australia, France, Sweden, Spain, Italy US: 24 th Lowest 23: sub- Saharan Africa

16. The End