3.5 Maternal Recognition of Pregnancy

Question 1

How is its lifespan regulated in the non-fertile cycles​?

Answer 1

the functional lifespan of the Corpus luteum is terminated (in order that another cycle may commence) by a process termed “luteal regression”

• Changes in levels of oestradiol, PGF2α and oxytocin are all thought to be involved
• In domestic ungulates, PGF2α is considered to be the endogenous luteolysin
• The appearance of the uterine oxytocin receptor is instrumental in determining the timing of luteolysis

Question 2

• How is its lifespan regulated in fertile cycles?

Answer 2

the lifespan of the CL needs to be extended for the successful establishment of pregnancy.

Question 3

fertile cycle CL extension: ruminants

Answer 3

the extension is achieved through means of IFNt which by inhibiting the expression of ESR1 and then uterine oxytocin receptors prevents luteal regression

Question 4

fertile cycle CL extension: pigs

Answer 4

life of the corpora lutea are extended by a combination of increased secretion of oestradiol and decreased secretion and redirection of PGF2 alpha

Question 5

fertile cycle CL extension: equids

Answer 5

the maternal recognition of pregnancy signal is NOT known and is NOT equine chorionic gonadotrophin (eCG).

Question 6

fertile cycle CL extension: canine

Answer 6

the lifespan of the non-pregnant CL is longer than gestation, hence, no requirement for a maternal recognition of pregnancy signal

Question 7

fertile cycle CL extension: feline

Answer 7

PRL is the possible candidate with respect to the signal for MRP