Quiz 2 Lecture Material Flashcards
Sex determination in mammals
XX or XY
What gene determines male or female
Sex-determining region Y
SRY gene
y linked- only found on Y chromosome
XXY
Klinefelter’s syndrome
sterile- testicular hypoplasia
XO
Turner’s syndrome
sterile- inactive ovaries
Why is only one X expressed in females
one is inactivated to prevent too many proteins
The sequence of development of the reproductive system
Indifferent stage
development of gonads
development of the tubular reproductive tract
development of external genitalia
sexual development of the brain
Indifferent stage
bipotential gonad
has the potential to be either
Gonads by default will go towards the
ovary
female tract
female genitalia
genital ridge
structure in the embryo that develops into gonads
Wilms Tumor gene
suppresses steroidogenic factor 1 to avoid the development of steroidogenic cells instead of supporting cells
Steroidogenic factor
when not inhibited will create steroidogenic cells
- cells that produce gametes and hormones
What causes the development of gonads
migration of primordial germ cells from the yolk sac to the genital ridge
How does SRY gene differentiate the gonad
SRY leads to the Soc9 transcription factor that codes for Sertoli cell formation
– makes testis
The job of Sertoli cells
support of spermatogenesis- making sperm cells
Development of tubular male reproductive tract
Testes produce testosterone which stimulates the growth of the wolfian ducts
and Antimullerian hormone which inhibits the growth of the mullerian (female) tract
Development of tubular female reproductive tract
default
- no testosterone or antimullerian= female
Cryptorchidism is when
one or two testes stay tucked up near the abdomen
if they stay there too long then the testes will degrade- sterile