Morphogenetic Gradient in Egg Cytoplasm Flashcards
morphogenetic gradient in egg cytoplasm of sea urchins:
from veg pole develop into ectoderm and endodermal structures
Macromeres
morphogenetic gradient in egg cytoplasm of sea urchins
from animal pole into most of ectoderm of the larva
Micromere
what causes the vegetalization or animalization of the larva?
splitting of blastomeres into vegetal and animal pole cells
who experimented sea urchins that resulted to observations of morphogenetic gradient in egg cytoplasm?
Sven Horstadius
Sven Horstadius observed that
if there is only _______ : (blue: extent of ________ cells) become animalized; na exaggerate ang expression of the cells that will become the ________ cells
animal pole
Sven Horstadius observed that
if there are equal parts, the embryo ______ its animalization will become normal
- if there are only vegetal parts: only gut and very little parts
- there has to be a balance in the animal pole and vegetal pole cells to give rise to a normal, fully developed embryo
loses
what separates animal and vegetal pole?
Blastocoel
it forms where there is not heavily laden with yoke
blastocoel
seen in _______: marginal area at the point of meeting of the two poles; marginal area: mesoderms
Xenopus
If there is no blastocoel, most will become _______; no ectoderm
mesoderm
it will determine the phenotypic expression of the offspring
maternal genotype
genes in the cells of the maternal body will determine the ______ of the egg in the early development
peculiarity
guess the animal
Lymnea peregra (_____)
-dextrality or sinistrality
determined by genotype of the mother
obliqueness of the spindle fiber
-dextral: dominant
DD (father) x dd (mother)
Dd (heterozygous dextral)
Phenotype: sinistral
- Dd (mother) x Dd (father)
DD Dd dd
Phenotype: Dextral
freshwater snail
guess the animal
Ambystoma mexicana: (______)
-maternal inheritance of the lethal “o” gene
-corrective factor is found in the nucleus of the normal egg
axolotl
