Категории: Все - development - mutations - genetics - redundancy

по Brian Wu 16 лет назад

237

Developmental Genetics and age of mutants IIA

The field of developmental genetics delves into the intricate processes governing how genes control the growth and development of organisms. Key challenges in this area include pleiotropy, where single genes affect multiple traits, and redundancy, where genes working in parallel pathways obscure phenotypes unless all are disrupted.

Developmental Genetics and age of mutants IIA

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