Developmental Genetics

in 1952 the first animal cloning experiment produced

cloned frogs

in 1997 the first mammal was cloned from

an adult cell

cloning shows that adult differeniated cells retain

a complete set of genetic information

early in devlopment

axis are specified

maternal genes

establish anterior posterior polarity and dorsal ventral polarity

Maternal genes are _______ during egg development

transcribed

maternal genes are

translated after fertilization

segmenetatin genes

affect the number and polarity of segments

hommeotic genes

determine the identity of each segment

bicoid mRNA is

anchored at anterior end

bicoid mRNA is translated into bicoid protein

that diffuses from the anterior end

Nanos mRNA is

anchored at posterior end

Nanos mRNA is translated into Nanos

protein that diffuses from the posterior end

motheres nuclear genotypes determines the progeny

phenotype

Egg can not be ______ and have an anterior develop

bcd-/bcd-

bicoid and nanos regulate zygotic

translation of maternal genes hunchback and caudal

hunchback and caudal mRNAs are

distributed uniformly throughout the oocyte

bicoid in the anterior represses

caudal mRNA translation by binding to caudal mRNA 3 UTR

caudal protein acts as a

TF to regualte genes for differentiona of the posterior part of the embryo

bicoid stimulates

hunchback expression by binding a TF upstream of hunchback

hunchback protein is produced from its RNA and then acts as a

TF to regualte genes for differention in the anterior of the embryo

nanos inhibits

hunchback translation

How does NANOS inhibit hunchback translation?

by causing degredation of its mRNA causing anterior-posterior hunchback protein gradient