HOX Flashcards
essential processes by which a multicellular org is made?
cell proliferation, specialisation, differentiation, interaction
describe a morphogen
diffusable molecules that influence cell fate in a concentration dependent manne
describe combinatorial gene regulation
different combinations of regulate genes can result in different cell fates
what are the basic stages of development
cleavage gastrulation pattern formation morphogenesis cell differentiation cell growth
describe lineage tracing
markers put on embryo. enables us to track where organs etc go from the embryo; can then trace back to embryo
describe transplantation experiment of dorsal lip of the blastopore
these cells important in gastrulation
result in conjoined
describe transplantation of general cells from embryo
eg if taken from leg bud to wing bud, later a leg may grow on top of he wing
describe the effect of ethyl methane sulfonate screen on drosophilia
EMSS causes random point mutations. males and females crossed, relating to peculiar development and the genes controlling this can be determined.
what are transcription factors?
proteins produced by regulatory genes which bind to structural genes to influence cell fate
describe master regulator genes
produce master regulators which can act as genetic switches
describe homeobox genes
regulatory genes which control development
homeobox genes encode
homeodomains (which bind to structural genes)
how are mammalian homeobox genes organised?
can be dispersed through genome or put together as Hox gene clusters
compare drosophilia and mammalian hox clusters.s
drosophilia have 1 cluster on one gene. because 4 rounds of genome division occured for mammals during evolution, they’re on 4 chromosomes for mammals (one cluster each)
–>mammalian HOX genes are therefore homologous to that of the drosophilia
describe relation of gene position to body location
lower is near the head (anterior)
