developmental genetics Flashcards
describe the developmental potential of a zygote
totipotent
what is cell lineage
the process of tracing the lineage of a mature cell back to the totipotent zygote. fate mapping is the reverse
what is a/symmetric self renewal division
division where either one or both daughter cells produced are identical to the parent and haven’t differentiated
what is a/symmetric divison
division where neither of the daughter cells are the same as the parent cell, but the daughters themselves are the same or different
how is division regulated pre- midblastula
by maternal RNA/proteins- the zygotic DNA is not yet being transcribed
describe the influence of compensation in development
compensation does exist, meaning lost cells in the embryo can be replaced by new, undifferentiated cells. this is despite earlier theories that cells did not communicate and therefore did not compensate
what is ‘cell fate specified’
the trajectory of specialisation has been given and, with no influence of new signals, it will differentiate to this cell. this is conditional
what is ‘cell fate determined’
the trajectory of the cell’s differentiation is set and will not change, irrespective of new incoming signals. this is autonomous
what is germ plasm
in some species it’s a conserved region of cytoplasmic morphological determinants by which cells that possess it enter the germ line autonomously
what gives evidence for differential gene expression
‘puffs’ in polytene chromosomes are located in different places in different cell types
how can we measure differential gene expression
by monitoring the levels of different products- RNA and proteins
what causes differential gene expression
either a loss of genetic material (chromosome diminution) or epigenetics
euchromatin
loosely packed DNA which is highly accessible
heterochromatin
tightly packed DNA which is inaccessible
describe the role of transcription factors
they have different DNA binding domains and influence transcription by helping RNAP to bind and and making DNA more accessible- it does this by recruiting enzymes to demethylate and loosen histone- histone interactions
