04 Cleavage to Blastulation

Cards (39)

  • developmental properties of cleaving embryos
    - regulative development
    - totipotent
  • at the end of blastula mammalian has
    2 distinct populations of cells
  • at the end of blastula avian has
    stack of cell layers
  • at the end of blastula amphibian has
    ball of cells
  • translucent area in avian embryo
    area pellucida
  • area that appears dark in avian embryo
    area opaca
  • what layer is formed when cells on top of the avian embryo fall off
    hypoblast
  • what cavity is formed when cells on top of the avian embryo fall off
    subgerminal cavity
  • the first plane of cleavage in the avian involves
    blastodisc
  • what type of cleavage does mammalian have
    holoblastic rotational
  • what type of cleavage does frog have
    holoblastic radial
  • three distinct regions recognized after blastula
    - gray crescent
    - vegetal region
    - animal region
  • late cleavage to blastula transition
    morula
  • how many cells does the embryo have when a cavity is formed
    128
  • formed due to cortical reaction where there is mass movement of pigment towards sperm entry
    gray crescent
  • telolecithal cleavage pattern
    meroblastic
  • - isolecithal and mesolecithal
    - complete
    - proceeds from animal hemisphere going down to vegetal hemisphere
    holoblastic
  • - concentration of yolk at the center of the oocyte
    centrolecithal
  • - dense amount of yolk
    - heavily concentrated on one pole
    telolecithal
  • - moderate amount of yolk
    - slightly concentrated on one pole
    mesolecithal
  • - small amount of yolk
    - evenly distributed
    isolecithal
  • factors influencing cleavage pattern
    - maternal cytoplasmic factors
    - amount and distribution of yolk
  • site of first cleavage furroe
    angle of mitotic spindle
  • what is required for the cell to grow
    new players/regulators and addition of gap phases
  • what controls the cell cycle
    m phase promoting factor
  • what stage has the characteristic of a mature cell cycle
    late embryonic cell
  • when embryo stops dividing, it results in
    - zygotic genome activation
    - synchronous cell division is lost
  • what happens when maternal derived cyclin b and cell cycle factors deplete
    switch to zygotic transcription
  • what is the source of mpf in the embryo
    cyclin b
  • protein involved in spindle fiber organization
    regulatory cytoplasmic proteins
  • protein involved in nuclear membrane depolarization, breakdown and degradation of nuclear membrane
    nuclear membrane proteins
  • proteins involved in chromatin condensation and become distinct chromosomes
    histone
  • enzyme that phosphorylates a target protein inside the cell
    cyclin b-cdc2 complex
  • what happens with kinase during s phase
    it gets synthesized and forms a complex with cdc2 and gets reactivated
  • what inactivates the kinase
    breakdown of cyclin b during mitosis
  • 2 subunits of MPF
    cyclin b and cdc2/cdk1
  • fuel molecule for the transition from zygote to cleavage stage
    mitosis promoting factor
  • when does cell division slow down?
    when a balance or set point is attained
  • what are the characteristics of cleavage
    - generates large number of cells
    - generates many copies of the zygotic genome
    - segregates cytoplasmic components into different blastomeres
    - increases the ratio of nuclear volume: cytoplasmic volume