10/19 Embryo of Female Reproductive Flashcards
What is the genetic determinate of sex?
46 XY – Male
46 XX – Female
What are some genetic disorders of sexual development that are common?
45,X – Turners syndrome and variants
47, XXY – Klinefelters syndrome and varients
45, X/46,XY – mixed gonadal dysgenesis, ovatesticular DSD
46, XX/46,XY – Chimeric, ovotesticular DSD
the differentiation of the gonads is very dependent on what chromosome?
Y !
The embryo that has do differentiation between gender yet..
Bipotential embryo
How could you end up with a chimaric individual that is differentated in multiple sexes….
Fusion of embryos
How long does the bipotential embryo last?
until 7 weeks… with external genitalia until the end of 3rd month
individuals with tissues having both male and female genetic sex
True hermaphrodism
individuals with a single genetic sex but with phenotypic elemnets of both sexes
pseudohermaphrodism
where does the hormonal signal come from to infjlueence the internal development of sex organs
Gonads
what is the origin and the migration of the primordial germ cells
first redcognized in yolk sac at 24 days. migrate via hindgut and its mesentery; go to the genital ridge. Mitosis during migration.
what if the primordial germ cells arive at the wrong location?
They can cause serious tumors called the ectopic PGCs becoming teratomas
what do the PGC cells become i female?
the oocytes
what do the PGC cells become in males
spermatogonia
what do the somatic support cells (epithelium or cortical sex cord cells.) of the genital ridge become in male and female?
F: follicle cell
M: sertoli cell
What do stromal (mesenchymal interstitial cells) in the genital cleft become?
M: leydig cell
F: thecal cell
What are the char. of the phenotypic sex determinats?
internal organs of reproduction external genitalia (may not be the same as the gonadal sex = discordant)
what is hermaphroditic
representing elements of both sexes phenotypic out and inside organs
Describe how the embryo has both the male and the female internal organs originally…
The early embryo develops both the mesonephric duct and paramesonephric duct. The male embryo develops the mesonephric duct and the paramesonephic duct degenerates. The female develops the paramesonephric duct and the mesonephric degenerates.
What does teh mesonephric duct become in the male and the paramesonephric duct become in the female?
male:
Mesonephric: ducts of the testis and the ductus defrens etc.
Female:
Paramesonephric duct: Fallopian tubes, and the uterus and upper vagina.
how does the bipotential gonad become the male?
Sry induces a male pattern by upregulating Sox9, which inhibits Wnt4/Rspo1
how does the bipotential gonad become the female?
Wnt4 and Rspo1 shut down Sox9 and you get female
What is turner syndrome?
45 XO : webbed neck, shield chest, widely spaced nipples, delayed puberty, short stature, sterility.
why do you not really consider the female development as the “default” development?
even though it seems that a lack of Y is therefore a default as a female considering turner syndrome where there is only one X…the phenotype is different than a normal female and only has vetigial ovary, and therefore sterile.
Where would Wnt4 and Dax1 be expressed for normal gonadal development?
in the genital ridge.
would you expect that Wnt4 and Dax1 would be expressed the same i both males and females at the gonads?
Wnt4 is expressed the same in the bipotential gonad and then down regulated in male by the SOX9 gene. Dax1 only expressed in female!
what would be the phenotype of an individual with a 46xx genotype who has a null mutation in Wnt4 or Dax1?
would have female genotype and male phenotype
what is the molecular control path for male?
SRY up regs. SOX9 which ups SF1 and other genes and inhibits WNT4 to give testes and the male phenotype
what is the path of female molecular development?
WanT4 up regs. DAX1 (which down regs. SOX9) and Other genes to give Ovaries and female phenotype.
how do the female and male molecules inhibit eachother?
Sox9 inhibits WNT4 and DAX1 inhibits SOX9
Expressed in the kidney and bipotential gonad of both males and females.
Wnt4
Describe the formation of the vagina:
Fused paramesonnephric duct attaches to the urogential sinus and forms the uterus and the upper part of the vagina
Hollowing of uterovaginal plate forms the lower vagina.
Canalization is required to hollow the vagina
the Hymen is a mesodermal mesenchyme that separates the lumen of the vagina from the urogenital sinus.
The urinary and vagina then achieve seperate openings!
a uterus with two seperate uturus and vagina and connections to the uterine tubes.
uterus didelphys
what does the mesonephros duct require in order to persist in the embryo?
requires testosterone.
What are some determinates of gender?
Genetic; Gonadal (Testis versus ovary); Phenotypic (Reproductive deucts, External genitalia)
How would an ultrasound before the end of the third month be rather indeterminate for the gender of the baby?
the external genitalia is bipotential through the third month.
what are the components of the bipotential external genitalia?
genital tubercle at the top,
genital swelling (labioscrotal swellings) around the genitalia,
cloacal/Genital fold that becomes the urethral folds and anal fold as the anus pinches off;
(genital still closed off by cloacal membrane)
What do the parts of the bipotential external genitalia become in the male and female?
Genital Tubercle:
Female: clitoris / Male: Glans and shaft
Genital folds:
Female: Labia minora / Male: Penile urethra
Genital swellings:
Female: Labia Majora / Male: Scrotum
Persists in ovary and down regulated in the testis by Sox9
Wnt4
Molecular signal expressed only in female gonads
Dax1
what does the paramesonephric (mullerian) duct become in the female?
Persists and
cranial becomes the Uterine (fallopian) tubes
Caudal tubes fuse and become the uterus and upper vagina
(hormones not strictly required for this)
What happens to the mesonephric (woffian) ducts in females?
they regress since there is not testosterone.
contribute to ovarian and uterine ligaments.
uterus with indentation into the uteral space from the top layer of tissue
uterus arcuatus
A uturus with one vagina but a split of the uterus into two almost seperate uterus spaces (like to utuerie that are fused together to the same vagina)
uterus bicornis
a uterus that is connected to one vagina and to only one uteral tube and the other uteral tube has an small uterus that is not connected to the vagina
uterus bicornis unicollis
uterus that has a closed off cervix
atresia of cervix
uterus that has a closed off vagina
atresia of vagina
