3. Reproductive physiology of the pig

Question 1

Role of pigs

Answer 1

• pork
• biological model for human research (anatomy, physiology)
• European standards for minipig research
• production of active substances, organs
• surgical model

Question 2

Porcine genital tract

Answer 2

Question 3

Major functions of the ovary

Answer 3

1. Cyclic production of fertilisable ova
2. Production of balanced ratio of steroid hormones
   - development of the genital tract
   - migration of the early embryo
   - implantation

The follicle fulfills the dual function of gametogenesis and steroidogenesis

Question 4

Ovarian features during estrous cycle

Answer 4

Question 5

Life cycle of the porcine ovary

Answer 5

-> primordial follicle -> primary follicle -> secondary follicle -> early antral follicle -> atretic follicle -> Graafian follicle -> ovulation -> early corpus luteum -> mature corpus luteum -> corpus albicans -> repeat

Question 6

Primordial follicle

Answer 6

• follicle with central located oocysts and single layer of granulosa cells
• oocyte in an arrested meiotic prophase
• gonadotropin independent growth

Question 7

Primary follicle

Answer 7

• follicle growth, proliferation of granulosa cells, zona pellucida formation (role: protection of oocyte), then a cell differentiation
• fully grown oocyte
• gonadotropin dependent growth

Question 8

Secondary follicle

Answer 8

• follicle growth, increased number of granulosa cell layers
• fully grown oocyte
• gonadotropin dependent growth

Question 9

Early tertiary (antral) follicle

Answer 9

• formation of antrum, increased number of granulosa cell layers
• fully grown oocyte
• gonadotropin dependent growth
• secretion of steroids by granulosa and the a cells

Question 10

Pre-ovulatory follicle

Answer 10

• secretion of androstendion by theca cells and estradiol by granulosa cells.
• oocyte at Metaphase II stage.
• large amount of FF with high concentrations of estradiol in follicular phase and progesterone at ovulation

Question 11

Peri-ovulatory/ luteinizing follicle

Answer 11

• follicle rupture, discharge of a mature, fertilisable ovum
• development of lutein cells
• synthesis and secretion of progesterone
• formation of luteum tissue starts couple of hours before ovulation

Question 12

Ovulation. Follicle rupture

Answer 12

“Flow out” of a mature follicle and discharge of a n oocyte (cumulus-oocyte-complex) into the oviduct

Question 13

Cumulus-oocyte-complex

Question 14

Ovulation - an inflammatory-like process?

Question 15

Formation of a pig corpus luteum

Question 16

Corpus luteum cell types

Answer 16

Question 17

Luteolysis — ?

Answer 17

The process whereby the corpus luteum degenerates near the end of the nonfertil estrous cycle

Question 18

Mechanisms regulating the lifespan of corpora lutea

Answer 18

• reduction of LH pulse amplitude
• increase in estrogen secretion
• influence of PGF2-alpha

Question 19

Ovarian development and hormone. Secretion during the estrous cycle

Answer 19

Question 20

Dynamic of follicular growth. Recruitment? Selection?

Answer 20

Recruitment — the process wherein the follicle departs from the resting pool to begin a pattern of growth and development. Though recruitment is obligatory, it does not guarantee ovulation

Selection — the final winnowing of maturing follicular cohort by atresia down to a size equal to the special-characteristic ovulatory y quota
????

Question 21

Question 22

Question 23

1 vs 2 waves of follicular development

Answer 23

Question 24

Recruitment and selection of follicles during the oestrus cycle

Question 25

Dual function of the follicle

Question 26

Follicular fluid

Question 27

Follicular fluid

Question 28

Intrafollicular oocyte development