Animal Science 434

Lecture 15: Gamete Transport

Sperm Transport in the Male TractFluid Flow Cilia

Fluid FlowMuscle Contractions

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

Sperm Transport in the Male Tract

Addition ofDecapacitation

Factor Addition of DFFrom AccessoryGland Secretions

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

Site of EjaculationSite of ejaculation Semen Characteristics Species

Vagina slight coagulation of ejaculate human, rabbitvagina semen with high sperm cattle, sheep

concentration

uterus voluminous, distention of cervix horsecervix, uterus voluminous, retention of penis dog, pig

during copulationuterus vagina plug rodents

Sperm Loss From Female Tract

• retrograde flow• phagocytosis by neutrophils

Experiment on Retrograde Flow inthe Cow

Uterine Horn

Uterine Body

Cervix

Inseminationat 3 different

spots

0

5

10

15

20

Cum

ulat

ive

% S

perm

Re

cove

red

From

Vag

ina

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

0

10

20

30

40

50

60

cervix

0 1 2 3 4 5 6 7 8

Hour After Insemination

Cum

ulat

ive

% S

perm

Rec

over

edFr

om th

e Va

gina

Hours After Insemination

Cervix

Uterine Horn

Evolutionary Strategies for DealingWith Retrograde Flow of Semen

• coagulation of semen or a plug• concentrated semen• semen deposited in uterus

Sperm Loss From Female Tract

• retrograde flow• phagocytosis by neutrophils

Neutrophile Infiltration of Uterus

Phases of Sperm Transport• rapid

»15-30 min• sustained

»6 - 12 hr• oviductal

»at ovulation

Evidence for Sustained Transport

Ligatures atUtero-tubal

Junction

Effect of Oviduct Transection onFertilization in Heifers

Interval from mating* to Oocytes Fertilizedtransection of UTJ

6 0%8 50%

12 83%

* Mating was done at the start of estrus.

4540353025201510500

20

40

60

80

100

Effect of Isthmus Transection on Fertilization in the Pig

Time From Mating to Transection (hr)

Pe

rce

nta

ge

of

Oo

cy

tes

Fe

rtil

ize

d

Control (no transection)

Transected Isthmus Ovulation

Isthmus

Uterus

Ligationto Transectthe Isthmus

Ampulla

Ovary

Sperm Transport

}

2 cm

Sperm Transport in the PigPe

rcen

tage

of O

ocyt

es F

ertil

ized

}

Ovulation

OocyteCumulus CellsFollicular Fluid Cue for ovulation may

effect isthmus to triggeroviductal transport

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

Cervix

Barriers To Sperm Transport

Uterotubal Junction

Ovulation

OocyteCumulus CellsFollicular Fluid

Fluid Flow

Factors Regulating OocyteTransport in the Oviduct

Remains closed untilday 3 - 5 post ovulation

Toward Uterus

TowardAmpulla

Total Fluid Production

Factors Regulating OocyteTransport in the Oviduct

Cilia

Fluid FlowFluid FlowMuscleContractions

No Contractions

Remains closed untilday 3 - 5 post ovulation

Site ofFertilization

Site ofFertilization

Now view the videopodcast entitled

Ovulation and Oocyte Transport

Obtain from Lean@UW podcastlinks for this course in theLecture area.