Quiz 4 Lecture Material Flashcards
Layers of the follicle
oocyte in the middle
cumulus granulosa
antrum
mural granulosa
basement membrane
theca internal
theca external
Primordial follicle characteristics
only one layer of flat granulosa cells
primary follicle characteristics
one layer of cubodial granulosa cells
Secondary follicle characteristics
two or more layers of cubodial granulosa
one theca layer is seen
Tertiary follicle characteristics
fluid can be seen but does not surround the oocyte
Two theca layers are seen
Antral follicle characteristic
ready for ovulation
antrum surrounds the oocyte
Postnatal follicles are also known as
gonadotropin independent
Do not require LH and FSH
Gonadotropin-dependent follicles need what to grow
FSH to go from secondary to tertiary
LH to go from tertiary to Graafian
Notch signaling gene
reduced germ nest breakdown and decreased the percentage of primordial follicles
NOBOX
reduced germ nest breakdown, decreasing the percentage of primordial follicle formation with high oocytes in nests and ultimately oocyte degenerate
Figla (factor in germline)
disruption of primordial follicle formation and subsequent loss of oocytes
A Nobox deleted mouse will have what type of follicles
Nest
degenerated follicles
Wildtype ovary will show what type of ovary
all follicle stages
Fox12 gene
Forkhead box L2
transcription factor required for granulosa cell differentiation
Nobox genes
oocyte specific homeobox gene
Sohlh1 and 2
oogenesis basic helix-loop-helix transcription factor that is essential for oogenesis
Lhx8
Lim homeobox gene
essential for mouse oocyte differentiation and survival
What happens if you limit
Fox12
Nobox
Sohlh1 and 2
Lhx8
only see primordial follicles
Primordial to primary follicle genes
Fox12
Nobox
Sohlh 1 and 2
Lhx8
Primary to secondary follicle genes
Growth differentiation factor 9
Kitl
Kit
Growth differentiation factor 9
GDF 9
oocyte specific
derived by Sohlh1 and 2 and Nobox
required for primary to secondary follicle transition
Kitl
kit ligand
controls oocyte growth, oocyte survival, theca cell differentiation, and protects preantral follicles from apoptosis
Kit
cKit
Kit ligand receptor
What type of follicles would you see with a deleted Gdf9 gene
only up to primary follicles
Secondary to antral follicle genes
Fsh+Fshr
Inha
Igf1
Cend2
Foxo1/3
Smad3
Taf4b
Fsh+Fshr
FSH and FSH receptor at/ after the primary follicle stage
endocrine regulators
Inha
Inhibin a
inhibits FSH secretion
Igf1
insulin like growth factor 1
increases responsiveness of follicular cells to gonadotropin
Cend2
Regulated by FSH and is required for granulosa cells proliferation
Foxo1/3
forkhead box o transcription factor-
highly expressed in granulosa cells and can regulate follicle growth or death
Smad 3
mediator of transforming growth factor beta signaling pathway and required for follicular growth
Taf4b
transcription factor that has a role in meiotic gene expression
What type of follicle is seen with a deleted FSH gene
lack antral follicles
Antral to preovulatory follicle transition genes
Esr1 and 2
Aevr2a
Gja4
Connexins
Esr1 and 2
estradiol receptor
Aevr2a
activin receptor type 2a
activin can stimulate granulosa cell proliferation and increase estradiol receptors
Gja4
gap junction protein
Connexins
blocks development after antral or primary stage depending on number
What forms the gap junctions for communication between oocytes and granulosa
projections
Zona pellucida
the extracellular matrix that surrounds the plasma membrane of the egg cell
what type of junction is between follicles and oocytes
gap junctions
gap junctions are made of
proteins called connexons composed of six subunits
Follicles and oocytes use what types of communication
gap junctions
paracrine communication
What does the oocyte secrete
GDF-9 required for follicular development past primary stage
What is the role of the oocyte in follicle growth
secretes GDF-9
affects granulosa cell differentiation
affects energy and metabolic function of granulosa cells
increase follicle cell growth and division
produces proteins for formation of zona pellicuda
Dogma of follicle development
at birth, or soon after the female is equipped with the number of germ cell for the rest of her life
Atresia
programmed cell death
what amount of follicles are destined for astresia
99%
stages of gonadotropin dependence
Gonadotropin independent
Gonadotropin responsive
gonadotropin dependent
Gonadotropin independent
initial development occurs independent of gonadotropins
Gonadotropin responsive
follicles can respond to gonadotropins but it is not required for follicle growth
Gonadotropin dependent
follicles have been stimulated to grow towards ovulation
removal of gonadotropins results inatresia
Stages of follicular recruitment
initial recruitment
cyclic recruitment
Initial recruitment
primordial follicular pool recruited into the pool of growing follicles in a continuous manner
cyclic recruitment
cohort of antral follicles are recruited to grow towards ovulation during a specific estrous cycle
Stages of the follicular waves
Recruitment
Selection
dominance
At day 0 what occurs in the follicular wave
structure- mature graafian follicle from previous cycle
ovulation occurs
hormone- estrogen is high which inhibits FSH
At ovulation what happens to the hormones
Estrogen decreases
FSH increases
stimulates follicles
Recruitment
cohort of small antral follicles initiate growth following release from the inhibition of the previously dominant follicle and an increase in circulating concentrations of FSH
Selection
typically one follicle selected for continued growth
FSH decreased in response to negative feedback of estradiol and inhibin from the growing cohort of recruited follicles
dominant follicle becomes dependent on LH
Dominance
selected follicle becomes dominant
secretes estradiol and inhibin which keeps circulating concentrations of FSH low
prevents recruitment of the next wave
purpose of miotic arrest
prevents using up all the oocytes too early
