Gonadal Differentiation - Final Exam Flashcards
What is sexual differentiation in mammals driven by?
The presence of androgens in males and their decreased amounts in females.
What do androgens have a big impact on? Example
The developing fetus.
- Eg. Secondary sexual characteristics
How does WHO define gender?
Refers to the socially constructed roles, behaviours, activities and attributes that a given society considers appropriate for men and women.
What 2 factors have a big effect on what we refer to as gender?
- Environment
2. Society
What are 2 examples of sex categories?
- Male
2. Female
What are 2 examples of gender categories?
- Masculine
2. Feminine
What aspects of sex will/ will not vary substantially?
- Will not = aspects between different human societies
2. Will = aspects of gender
What happens if you change the receptor for gonadal differentiation?
The you change the presentation of the phenotype that would be displayed
What is helpful in chromosomal gene/region ID
FISH
SRY
Sex-determining region Y protein
What is SRY?
It is a DNA binding protein
What does SRY initiate?
Testes
What is SF-1 important for? (4)
- Gonadal and adrenal development
- Reproduction
- Anti-mullerian hormone
- Phenotypic presentation
SF-1
Steroidogenic factor 1
What are 2 potential problems that mutations in SF-1 can create?
- Adrenal insufficiency 46XY females (low androgens)
2. Gonadal dysgenesis
What can mutations in SF-1 lead to? (3)
- Lack of development of a reproductive system
- eg) testes and ovaries - High risk for cancer
- Problems with production on hormones or change in receptor
What is the default with the absence of androgens in the early stages of development?
Females
What does translocation/mutation of SRY lead to? (2)
- 46XX males
2. 46XY females
What 2 factors influence testicular and ovarian differentiation?
Combination of…
- Hormones
- Environmental
What is the unique characteristic of undifferentiated gonads?
Having the potential to form either of 2 organs: testes or ovaries
How many genes are there that regulate sex differentiation?
More than 50
What do sex differentiation genes encode? (4)
- Transcription factors
- Gonadal steroids
- Peptide hormones
- Tissue-specific receptors
What are mullerian ducts?
They are paired ducts of the embryo that run down the lateral sides of the urogenital ridge
What do mullerian ducts give rise to?
Fallopian tubes
How are fallopian tubes developed? (2)
- In the presence of estrogen
2. Lack of androgens
What is formed in the female with the presence of estrogen and lack of androgens? (3)
- Fallopian tubes
- Uterus
- Upper portion of the vagina
What is the Wolffian duct?
Is a paired organ also found in humans during embryogenesis that is developed when exposed to testosterone
What does the wolffian duct develop into when exposed to testosterone or increase in androgens? (3) What takes place here?
- Epididymis
- Vas deferens
- Seminal vesicle
- -> Spermatogenesis takes place here
What is spermatogenesis?
Is the process in which spermatozoa are produced from spermatogonial stem cells by way of mitosis and meiosis
What is critical that the wolffian ducts most be exposed to during embryogenesis?
Testosterone
What family is anti-mullerian hormone part of?
Transforming growth factor beta family
What are anti-mullerian hormones produced by?
Sertoli cells