Animal Science 434

Gamete Transport

1

Sperm Transport in the Male TractFluid Flow Cilia

Fluid FlowMuscle Contractions

2

Sperm Transport in the Male Tract

• No protein synthetic ability• addition or loss of plasma membrane proteins and lipids• redistribution of proteins and lipids within sperm• changes in lipid diffusion coefficients

Acquisition ofFertilizing Ability

and Motility

3

Sperm Transport in the Male Tract

Addition of Decapacitation

Factor Addition of DF From Accessory Gland Secretions

Decapacitation Factor• protein, glycolipid and/or lipid• stabilizes the plasma membrane

4

Site of EjaculationSite of ejaculation Semen Characteristics Species

Vagina slight coagulation of ejaculate human, rabbit

vagina semen with high sperm cattle, sheepconcentration

uterus voluminous, distention of cervix horse

cervix, uterus voluminous, retention of penis dog, pigduring copulation

uterus vagina plug rodents

5

Sperm Loss From Female Tract

• retrograde flow• phagocytosis by neutrophils

6

Experiment on Retrograde Flow in the Cow

Uterine Horn

Uterine Body

Cervix

Insemination at 3 different

spots

7

0

5

10

15

20

Cum

ulat

ive

% S

perm

R

ecov

ered

Fro

m V

agin

a

0 1 2 3 4 5 6 7 8Hour After Insemination

Uterine Body

Uterine Horn

Cum

ulat

ive

% S

perm

Rec

over

edFr

om th

e Va

gina

8

0

10

20

30

40

50

60

cervix

0 1 2 3 4 5 6 7 8Hour After Insemination

Cum

ulat

ive

% S

perm

Rec

over

edFr

om th

e Va

gina

Hours After Insemination

Cervix

Uterine Horn

9

Assume 10 million inseminated

Uterine Horn at 8 hr = 25% loss or 75% retained = 7.5 million sperm retained

Cervix at 8 hr = 60% loss or 40% retained = 4 million sperm retained

10

Evolutionary Strategies for Dealing With Retrograde Flow of Semen• coagulation of semen or a plug• concentrated semen• semen deposited in uterus

11

Sperm Loss From Female Tract

• retrograde flow• phagocytosis by neutrophils

12

Neutrophile Infiltration of Uterus

13

Phases of Sperm Transport• rapid

»15-30 min• sustained

»6 - 12 hr• oviductal

»at ovulation

14

Evidence for Sustained Transport

Ligatures atUtero-tubal

Junction

15

Effect of Oviduct Transection on Fertilization in Heifers

Interval from mating* to Oocytes Fertilizedtransection of UTJ

6 0%8 50%12 83%

* Mating was done at the start of estrus.

16

17

Ovulation

OocyteCumulus Cells Follicular Fluid

18

Cue for ovulation may effect isthmus to trigger

oviductal transport

19

6-12 hr18-24 hr 1-2 hrLocation of Fertilizing Sperm

20

Barriers To Sperm Transport

21

Cervix

22

23 24

Barriers To Sperm Transport

Uterotubal Junction

25 26

Ovulation

OocyteCumulus Cells Follicular Fluid

27

Fluid Flow

Factors Regulating Oocyte Transport in the Oviduct

Remains closed untilday 3 - 5 post ovulation

28

29 30

Toward Uterus

TowardAmpulla

Total Fluid Production

31

Factors Regulating Oocyte Transport in the Oviduct

Cilia

Fluid FlowMuscleContractions

No Contractions

Remains closed untilday 3 - 5 post ovulation

Site ofFertilization

32

Now view the videopodcast entitled

View Video on Ovulation and Oocyte Transport

Found at:http://www.ansci.wisc.edu/jjp1/ansci_repro/lec/lec_16_gam

ete_tran/ovulation_oocyte_trans.html

33