Sexual Differentiation Flashcards
What are the four main transcription factors involved in development of the genital ridge?
- IGFR1
- Wilms Tumour 1 (WT1)
- Steroidigenic Factor 1 (SF1)
- DAX1
Which gene is responsible for testicular determination in most mammals?
SRY
SRY is found solely in the ___ cells of the testis
Pre-Sertoli cells
SOX-9 is an ___ gene that completes testicular differentiation once stimulated
Autosomal gene
SOX-9 is initially transcribed by SFO1 and then is markedly upregulated by ___
SRY
SOX-9 Upregulates itself via positive feedback loop and stimulation of ___ and ___
PGD2 and FGF-9
What is the function of PGD2 in male gonadal development?
- Increases SOX-9 (paracrine)
- Recruits further cells to Sertoli cell lineage
How does FGF-9 influence male gonadal development?
- Earliest mitogen in XY gonad
- Enhances proliferation of cells that increase no. of precursors of SRY expressing cells
What evidence is there that transcriptional antagonism between male and female factors continues throughout life?
Loss of FOXL2 in adult mice causes ovaries to develop testicular functions
Where do primordial germ cells originate?
Allantois (yolk sac)
Survival of primordial germ cells in migration is dependent on ____
cKIT/Steel factor
In testis germ cells enter ___ and have mitotic arrest
In ovaries germ cells continue into early ___ before arresting
Cords
Meiosis
Which structures does the Wollfian duct differentiate to?
- Epididymis
- Vas deferens
- Seminal vesicles
Which structures does the Mullerian duct differentiate to?
- Fallopian tubes
- Uterus
- Upper 1/3 of vagina
___ cells produce AMH which causes Mullerian duct regression
Sertoli
___ cells produce testosterone which causes Wolffian structure maintenance
Leydig
What will loss of function in a gene that is critical in forming AMH or its receptor cause in a male?
- Retention of Mullerian structures in XY male
- Bilateral cryptorchidism
What will loss of function in a gene that is critical in the synthesis of testosterone or in testosterone action cause in a male?
- No internal genitalia
Differentiation of genital tubercle to dependent on exposure to high concentrations of ___
DHT
Lower concentrations of androgen or partial insensitivity will result in ____ of external genitalia
Partial virilisation
Absence or complete resistance to androgens results in _____
Female external genitalia
What condition should be considered in children with a micropenis?
Pituitary problem
What do the following differentiate to in a female?
- Labioscrotal folds
- Urethral folds
- Glans
- Labia majora
- Labia minora
- Clitoris
What do the following differentiate to in a male?
- Labioscrotal folds
- Urethral folds
- Glans
- Scrotum
- Shaft of penis
- Glans penis
