Lecture 6 - role of the oviduct

Question 1

What is the role of the oviduct microenvironment?

Answer 1

Provides stable temp, optimal pH and dynamic fluid secretions to support embryo development

Question 2

What helps move the egg toward uterus?

Answer 2

Cilia

Question 3

How does the oviduct guide the sperm?

Answer 3

Rheotaxis (swim in opposite direction), chemotaxis (cumulus cells express P4) and thermotaxis (ovary is warmer)

Question 4

How does the oviduct assist in embryo development?

Answer 4

Early stage - pyruvate and lactate in oviductal fluid
Late stage - glycogen
Assists mitochondrial maturation
Secretes embryotrophic factors (EGF, TGF, FGF, IGF)

Question 5

What does oxidative stress do to the embryo?

Answer 5

Can lead to: mitochondrial dysfunction, decreased MPF, perturbed Ca homeostasis, decreased membrane fluidity

Question 6

How does the oviduct protect the embryo from stress?

Answer 6

HSP25 and HSP70 - handle heat stress
Catalase, SOD1/2, GPX4 - handle ROS
E2/ESR1 sig - protects against immune response

Question 7

Draw the E2 and P4 pathways

Answer 7

DO IT

Question 8

What are the essential roles of the oviduct?

Answer 8

Protection, assist in cleavage and development, transport, nutrients, epigenetic regulation?

Question 9

What is the effect of insulin on the follicle?

Answer 9

Synergise with LH and FSH 
Stim oestradiol (follicle and oocyte growth, oestrous behaviour and ovulation)

Question 10

What is the effect of insulin on the corpus luteum?

Answer 10

Synergise with LH
Stim progesterone (acts on FRT and promote embryo growth and development)

Question 11

What is the effect of insulin on the tract?

Answer 11

Acts on secretory epithelia. Increase embryo growth and decreases embryo loss

Question 12

What is the role of IGFBPs?

Answer 12

Inhibit IGF1/2. They need to be shed in order for IGF to function