Mechanisms of Development - Lec 7b - IN Flashcards
define homologous genes
genes that can function interchangeably during development between different species
what is genome equivalence
all cells contain the same set of genes - but different cells express different sets of genes
how can you prove genomic equivalence
through somatic nuclear transfer (cloning) - dolly
define differential gene expression
only a small percentage of the genome is expressed in each cell type
how is differential gene expression regulated
differential gene transcription, selective nuclear RNA processing, selective mRNA translation, and differential protein modification
what are the processes that differential gene expression controls
cell proliferation, specialization, interactions, and movement
what is induction
one group of cells changes the behavior of adjacent set of cells
what are the two components of inductive interactions
1 - inducer - tissue that provides the signal
2 - responder - tissue that is being induced - must be competent to respond
define morphogen
paracrine signaling molecules that cause concentration dependent effects
what is kartagener’s triad
bronchiectasis, infertility, situs inversus
what do Nodal and pitx2 signaling accomplish?
transfer of molecular left-right asymmetry to organs
what does the optic vesicle tell us about induction
that its a thing. also that you need the inducer signal and also a responder tissue thats competent to that specific tissue - if the optic vesicle is moved to the trunk, no lens develops as it should, bc only the head ectoderm is competent to the inducer, not the trunk ectoderm
define aniridia
failure in optic vesicle rim to develop bc of an autosomal dominant mutation in PAX6
how is dorsal/ventral polarity of the neural tube accomplished
floor plate has a stronger Shh gradient (ventral), while roofplate has a stronger BMP/WNT gradient (dorsal)
where is pitx2 expressed in development
left side, strong side
