Lecture 7 Flashcards
study of the relationships between gene regulation and cell differentiation during development
Developmental Genetics
process of regulated growth that results of the interaction of the genome with the cytoplasm and the environment
development
what does the development involves?
-programmed sequence of phenotypic events typically irreversible
-differentiation
-formation of different cell types, tissues, and organs through specific regulation of gene expression
differentiation
development of the embryo
embryogenesis
-a point wherein when the cell reaches the point, it makes an irreversible commitment to follow a certain development path
(ex: formation of proteins by the eyes for the lenses)
determination
molecules of the cells found in the cytoplasm/cytoplasmic effector substances wich cause the cells to become irreversibly committed to perform a specialized function
determinants
T or F: determinants are only considered from maternal interaction
F: there are also proteins, and other molecules found in the cytoplasm that can be considered as determinants
the expression of cells’ specialized roles
differentiation
cells producing specialized proteins derived from luxury genes
specialized cells
where are specialized cells derive
luxury genes
genes that encode gene products that are not needed for survival
luxury genes
what are examples of luxury genes
RBC - hemoglobin (once they make hemoglobin, they make immature RBC)
beta cells of pancreas - insulin (once they make insulin, then there are comitted to become the beta cells of pancreas)
central question in developmental genetics
how does one cellular genotype give rise to many different cellular phenotypes
sets the initial cytoplasmic environment
maternal genome
triggers the switching on and off of genes as the zygote becomes an embryo and increases the number of cells
initial cytoplasmic environment
for initial cytoplasmic environment, the gene products will occupy a specific position in the egg
-the distribution is equal or not?
NOT - it is not necessary to be equal
when the cell divides, the cyclomatic environment of each cell witll be ____ from each other
distributed unequally
IMPORTANT POINTS TO REMEMBER
differential gene function is fundamental and intrinsic aspect of cell differentiation
Cell phenotype is a consequence of differential gene action or selective expression of its genes
IMPORTANTS POINT TO REMEMBER
transcriptional control in eukaryotes examples
Lac and Trop Operon
stage in the transcriptional control of eukaryotic gene expression where there is a selective DNA replication
pre-transcriptional
in the formation of organelles you need to have ___
ribosomal rna or ribosomes
euchromatin tightly or loosely
loosely packed
heterochromatin - tightly or loosely packed
tightly packed
when the gene is in heterochromatin form, the expression is genes is turned ___ ON OR OFF
off because the tight coiling does not allow the entry of enzymees
when the gene is in euchromatin form, the expression is genes is turned ___ ON OR OFF
on; it is active because it is loosely packed
addition of methly group to Cystosine will lead to compact coiling of DNA; thus genes will be silenced
DNA methylation
stage in the transcriptional control of eukaryotic gene expression where there is Differential RNA synthesis
Transcriptional Control
the RNA is ____ (number; quantity) during meiosis or after fertilization in transcriptional control stage
0
the sythesis of RNA in transcriptional control resumes during
Gastrulation
process in animals where there is formation of germ layers
gastrulation
if the TATA box is farther from the gene is used, then you will have a _______ (longer or shorter) transcript
longer
if the TATA box is closer from the gene is used, then you will have a _______ (longer or shorter) transcript
shorter
this is the process in which the length of the transcript is dependent on the position of the TATA box from the gene
differential polyadenylation
if the poly A is site is farther from the gene you will have a ____ mRNA
longer
if the poly A is site is closer from the gene you will have a ____ mRNA
shorter
this is the process in which the length of the transcript is dependent on the position of the poly A from the gene
differential polyadenylation
process where the cell has a choice depending on the signal as to which type of exons it will put together in transcriptional control
differential splicing
mRNAs are degraded during differential splicing if they are not needed T or F
T
stage in the transcriptional control of eukaryotic gene expression where there is selective translation
translational control
process where there will be some mRNAs are selectively translated because they are needed
selective translation
stability of mRNA
-the longer the poly A tail ____ the (more or less) stable the mRNA is in translational control
more
once there is no more need for a specific protein, these particular proteins now help signal the mRNA coding for them
autoregulation
stage in the transcriptional control of eukaryotic gene expression where there is modification of protein
post-translational control
modification of a protein
polypeptides or proteins are modified in order for them to become functional
example of marcomolecular synthesis
DNA synthesis or DNA replication in the nucleus
two Nucleo-cytoplasmic interactions
-molecular exchanges
-control of macromolecular synthesis in the nucleus by the cytoplasm
development of the form of the individual or morphology
morphogenesis
Gene effects on the system of embryonic induction
gene effects on the regulation of growth and metabolism
-effect of the metabolic process or pathway that is of prime importance to the organism
-a metabolic process is affected to some degree
Gene effects on migrating cells
-genes affect differentiation and migration of cells to other regions
examples of gene regulation in humans
-development of the fetus
1st trimester - head grows fast compared to other parts of the baby
-later part of 1st trimester and 2nd trimester where limbs develop faster and the development of the trunk
-development of the nose
-at birth infants have pug nose
-early child’s nose develops fastest and large nose in proporition to the other parts of the face
-after adolescene nose stops growing
-other parts of the face are growing
T OR F: genes alone dictate the differences
FALSE it depends on molecular switches that tell genes when and where to turn on and off
