1. Epididymis, Ejaculation and Semen
Animal Science 434
Epididymis, Ejaculation and Semen

2. Sperm Structure Head Neck Middle Piece Annulus Principal Piece
Acrosome
Neck
Middle
Piece
Annulus
Principal
Piece
End Piece

3. Sperm From Different Species

4. Sperm Head
(Equatorial Segment)
Nucleus
Nucleus

5. Acrosome
Plasma Membrane
Nucleus
Acrosome Reaction
Acrosomal Enzymes
Acrosin
Hyaluronidase

6. Laminated columns (flexibility)
Posterior head
Capitulum
Laminated columns (flexibility)
Mitochondrial helix
(energy)
Middle
piece
Axoneme
( )
[Bending]
Course outer
fibers

7. Fibrous Sheath or helix
Annulus
Midpiece
Principal
Piece
Fibrous
Sheath or helix

9. Sperm Tail Mitochondrion Dense Fibers PM Long. Column Fibrous Rib
Middle Piece
Principal Piece

10. Axoneme

11. Microtubule Sliding in Sperm Tail

12. Sperm Metabolism Glucose Hexokinase Glucose-6-phosphate Anerobic
Phosphohexoisomerase
Anerobic
Metabolism
(Glycolysis)
Fructose-6-phosphate
Fructose
Hexokinase
Lactate + 2 ATP + 2 H2O
Fatty Acids
Aerobic
Metabolism
Tricarboxcylic Acid
Cycle
36 ATP/Glucose
36 ATP/Fructose

13. Sperm Metabolism Glucose Hexokinase Glucose-6-phosphate Anerobic
phosphatase
Hexokinase
Glucose-6-phosphate
Glucose
Phosphohexoisomerase
Anerobic
Metabolism
(Glycolysis)
Fructose-6-phosphate
Fructose
Hexokinase
Lactate + 2 ATP + 2 H2O
Fatty Acids
Aerobic
Metabolism
Tricarboxcylic Acid
Cycle
36 ATP/Glucose
36 ATP/Fructose

14. ATP Utilization in Sperm
motility (60%)
substrate cycling (40%)
wasted
maintenance of ionic gradients
very small amount
transcription and translation
none after condensation of nucleus and loss of residual body

15. Sperm Metabolism Temperature dependent
ATP production increases as temperature increases
ATP dependent processes are temperature dependent
motility increases with increasing temperature

16. Effect of Temperature on Motility

17. Transport of Sperm Vas Efferentia fluid flow cilia Caput contractions
Deferens
Rete
Testis
contractions
fluid flow
RT secretion
Corpus
contractions
Seminiferous
Tubule
bulk fluid flow
contractions of of myoid cells
Cauda
contractions

18. Epididymal Function Maturation Concentration change in fertility
develop motility
nuclear condensation
cytoplasmic droplet
Concentration
remove water

19. Epididymal Function Secretion Transport Storage T DHT
energy substrates (GPC, free fatty acids, carnitine)
glycoproteins, lipids, enzymes
Transport
smooth muscle contraction
Storage
cauda

20. Hormonal Control of Epididymis
Absolute need for Androgen
Caput
tubal testosterone
Corpus
tubal dihydrotestosterone (DHT)
vascular testosterone
Cauda
tubal DHT

21. Ejaculate Characteristics
Species Time lapse for Composition of
Bull 1 second single fraction
Ram 1 second single fraction
Boar minutes fractionated sperm-free sperm-rich coagulum
Stallion seconds fractionated sperm-free sperm-rich mucus
Human seconds single fraction but coagulated

22. Components of Semen water sperm substrates inorganic salts proteins
fructose
sorbitol
inositol
glycerol phosphatidyl choline (GPC)
citric acid
inorganic salts
sodium, potassium, calcium, magnesium, chloride
proteins

23. Initial Semen Evaluation
color
volume
concentration
motility
viability
morphology

24. Semen Color and Volume Color Volume Concentration
White to cream color - good
Yellow – urine present
Clear or thin in appearance – few sperm
Volume
Weight, 1 ml = 1 gm
Concentration
Hemocytometer – gold standard
Spectrophotometer, photometer, fluorometer(measure DNA)

25. Motility Evaluation Also a viability evaluation
Visual estimation – Nearest 5% estimate
Total motility – all the moving sperm
Progressive motility – those sperm moving in a straight line
CASA – Computer aided sperm analysis
Tracts individual sperm and computes a variety of statistics on the sample
Sample preparation is key to usefulness of data obtained!!!

26. Fluorescent Sperm Viability Assay
Sybr14 / PI
Green = viable
Red = dead
Adaptable to Microscopy or Flow cytometry

27. Morphology Variety of sample preparations and methods for evaluation
Stain vs. no stain
Wet mount vs. dried or fixed
Magnification of observation
Computer systems require training samples

28. Morphology Classifications
Scheme A
Primary – Head abnormalities
Secondary – Tail abnormalities
Scheme B
Tertiary – Cytoplasmic droplets

31. Ejaculate Characteristics
Species Ejaculate Sperm Total Sperm % % Volume Conc. (x109) Motile Normal (x109/ml) /Ejaculate
Bull
Ram
Boar
Stallion
Man