Developmental Biology

Developmental Biology

1. Fertilization

   • Chemoattraction
     • contact
       • molecular handshake
         • fusion of plasma membrane
           • Nuclear fusion
   • Oocyte
     • Blocks polyspermy after fertilization
       • Slow Block
         • wave of intercellular calcium
       • Fast block
         • Depolarization of membrane through influx of sodium
     • Spermatozoa
   • Cleavage
     • Division
       • Nuclear division
         • Contributions from male and female
           • Centrosome (pair of centrioles)
       • cytoplasmic division
         • Contributions From Female only
           • Spindle fibers, contractile ring, cortical proteins, pre-existing mRNAs and proteins, yolk, and mitochondria
     • Distribution
     • Differentiation
     • Described in various ways
       • Yolk content
         • isolecithal
         • telolecithal
         • centrolecithal
       • Completeness of cleavage furrow
         • Holoblastic
         • meroblastic
       • daughter cell size
         • symmetric
         • asymmetric
     • Blastula
       • mid-blastula transition or "maternal zygotic transition"
         • cell goes from transcripting egg DNA to transcripting zygotic DNA
         • Gastrula
           • Formation of Germ layers
             • Ectoderm
               • Skin, CNS/PNS, brain, spinal cord, nerves
               • Neurulation
                 • rearrangement of a subset of the embryonic ectoderm to become the nervous sytem, including the brain, spinal cord, and PNS
             • Mesoderm
               • heart, blood vessels, blood cells, muscles, bones and cartilage
             • Endoderm
               • Lining of the gut
           • Potency of Cells
             • totipotent
               • can become anything
             • Pluripotent
               • can become some, but not all cells; ex: bone marrow
             • terminally differentiated
               • one role
           • Gastrulation
             • Morphogenetic movements during gastrulation
               • delamination
               • epiboly
               • immigration
               • invagination