Developmental Genetics and age of mutants IIA

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Community

Szerző: Charis Fisher

Agile

Szerző: Mary Loftus

Reproduction in Animals

Szerző: XuenYun Tan

TOOLSET

Szerző: Stefano Di Persio

Developmental Genetics and age of mutants IIA

zygotic vs maternal effect phenotypes

based on mom, must be homozygote dominant mutant for offspring to express trait

drawbacks

only works in few animals or plants

need sort generation time and easy lab culture

redundancy

genes in parallel don't show phenotype until entire set knocked out

pleiotropy

genes are invovled many tissues, hard to implicate one

many mutant embryos die

logic of developmental genetics

enough genetic info, specific gene disrupted can be indetified and studied molecularly

requires no previous information

A) loss of function reveals normal functionc

reverse genetics and knockouts

developmental genetics in Drosophila

maternal acting genes that control earliest stage sof development

characterized homeotic genes that act later in development

genomic equivalence

genes act in both early and late stages of development

showed genes are regulated differently in different cell types during devlopment

still question of nature vs nurture

experiments to prove

cloning of somatic nuclei

albino parents of nucleus donor to wild type donor of enucleated eggs

are all albino

regeneration experiments

loss of limbs of salamanders

early steps towards developmental genetics

mouse mutation Brachyury

homozygous - die before birth

fly mutations affect wing development

brachyury mutants aka T have defects in posterior part early embryo

disruption of notochord

heterozygoud mice - short tail

background

genes

two demands

how chromosomes indential in every cell type can produce cytoplasm with different properties

needed to show could control earliest most basic phases of development

thought came from cytoplasm

political

tought variations were too subtle

these cytoplasmic factors could control cell fate