Repro: Estrus, Pheromones, Mating

Question 1

What is estrus the result of?

Answer 1

High estrogen, progesterone also required

Question 2

What functions do progesterone serve?

Answer 2

Association with estrogen: initiates sexual behaviors

Continuation of cycle: as estrogen levels fall, inhibits sexual behavior

Question 3

What are some estrus behaviors in species?

Answer 3

Cow: bulling
Mare: raising tail, vulval “winking” when teaser stallion used
Ewe: color mark with vasectomized ram
Sow: standing still when pheromone sprayed
Bitch: restlessness, licking vulva, vaginal secretions
Queen: lordosis, treading with back legs, calling

Question 4

What type of pheromones are there?

Answer 4

Releaser: trigger specific behavioral response (eg nipple searching in rabbit kits)

Primer: elicit more slowly developing and longer lasting changes (eg acceleration of puberty by male urine in pre-pubertal female mice)

Question 5

What are some uses for pheromones?

Answer 5

Behavior effects: sexual, territorial
Health/fitness: mate choice to avoid incest
Kin recognition
Lactation: mom-baby bonding

Question 6

Vandenbergh Effect

Answer 6

acceleration of female puberty when exposed to sexually mature male mouse urine; male does not have to be present

Question 7

Whitten Effect

Answer 7

Induction and synching of estrus by male mouse urine; females will become anestrus in absence of males; male odor synchs up females

Question 8

Lee Boot Effect

Answer 8

Synching and prolongation of estrus cycles of mature mice when females are housed in groups and isolated from males by female mouse urine; increased occurrence of spontaneous pseudopregnancy; small groups will synch, 30+ enter anestrus

Question 9

Bruce Effect

Answer 9

Termination of pregnancy due to stranger male mouse urine

Question 10

What are the functions of semen?

Answer 10

Flush out urethra
Provide metabolic substrate for sperm
Suspending and activating medium
Uterine stimulation
Decapacitation factor 
Leukocytes