Developmental Genetics Flashcards
Only ___% successfully implant
20-50%
____% of those that implant survive to term
40%
___% of those who survive have birth defects
2.5%
Malformation
inherent issue with development
Deformation
constraint on the fetus
Disruption
outside force causes improper development of the body
Forward genetics
- Random mutations
- see what mutations cause phenotypes that interest you, then map the mutations
Reverse genetics
-start with a gene of interest and knockout or knockdown expression to see what happens
Homologous structure
- same evolutionary origin
- similar structure, different function
- divergent evolution
- i.e. flipper of whale and wing of bat
Analogous structure
- very different evolutionary origin
- but similar function
- i.e. wings of different animals
- convergent evolution
mid-blastula transition
zygotic gene transcription activated, maternal transcripts degraded
maternal effect genes
things that are loaded into oocyte by mom
syncytial cells
- only goes through nuclear division not cytoplasmic division
- Drosophilia embryos
When bicoid is translated upon fertilization, it represses _____ translation.
caudal
When nanos is translated upon fertilization, it represses _____ translation.
hunchback
What are bicoid, hunchback, and caudal?
mRNAs loaded into oocyte by mom
Leibenburg Syndrome
-partial transformation of forelimbs to hindlimb specificity
Rules of maternal effect genes
- Mom’s genotype determines child’s phenotype.
“If mom is a mutant child looks like a mutant no matter what the genotype is.” - Mom supplies RNAs and proteins into oocyte.
Primary sex determination
development of the bipotential gonad into either testes or ovaries
Secondary sex determination
hormones made by the gonads determine male/female phenotype
SRY gene
- sex determining region of Y
- carries testis-determining factor
anti-Mullerian hormone
made by future testis cells (XY)
What duct develops with estrogen?
Mullerian duct
What duct is maintained with testosterone?
Wollfian duct
