Sperm maturation

Question 1

List sperm changes during post testicular maturation (6)

Answer 1

Motility
Migration of cytoplasmic droplet
Proteome changes
Membrane lipid change
Glycocalyx changes 
Non-coding RNA changes

Question 2

Caput epididymis sperm characteristics

Answer 2

immotile
Infertile
Proximal cytoplasmic droplet

Fx of caput part of epiddiyimes
absorption of rete testis fluid
Distal head = secretion of epididymis

Question 3

Corpus epididymis

Answer 3

Sperm
motile maybe after dilution
Fertile maybe (can bind oocytes)
Translocating cytoplasmic droplets

Fx of epididymis in corpus region
- secretion of fluid and extracellular vesicles (epididymosomes)

Question 4

Cauda epididymis

Answer 4

sperm
motile after dilution
Fertile
Distal or no cytoplasmic droplet

Epididymis fx this region
Reabsorption of fluid (to concentrate)
Storage for ejaculation (distal tail)

Question 5

Epididymal transit timing and why is it important?

Answer 5

Time is relative consistent between species = around 2 weeks

• important = need to factor in time in if calculating when reassess semen quality after an insult. Do not just time of spermatogenesis

Question 6

What influences the amount of sperm for ejaculation in the cauda part of the epididymis (2)

Answer 6

Ejaculation frequency

Regular voiding via urine

Question 7

Is there more maturation after sperm in caudal?

Answer 7

Yes

This maturation is due to
Seminal plasma and female tract

Question 8

List parameters of sperm assessment (5)

Answer 8

Volume
Colour/consistency
Motility
Morphology
concentration

Question 9

Sperm volume

Answer 9

Differs a lot between species

This often has stages

Question 10

Assessing motility

Answer 10

Dilute semen, with osmotic appropriate medium

The things counted

1. Total motility (% sperm with any movment)
2. Progressive motility (% sperm with strong forward movement)

Question 11

Wave motion

Answer 11

Mass motility in undiluted samples at low mag, scored 0 none to 5 (rapid)
- this is correlated to ‘total motility’ and ‘progressive motility’

Question 12

Process of assessing sperm motility

Answer 12

neutral buffered formalin (stop motility)
Create a wet mount (DIC) or smear (stained) and asses (min) 100 sperm for (structural abnormatilies %)

Basic
Intermediate
Advanced

XXX at from the lecture

Question 13

Sperm concentration

Answer 13

Maemocytometer (manual)
Spectrophotometer (automatic)

We want to know conc of the raw ejaculate - to assess fertility and for concentration standardisation for insemination or research)

Concentration threshold for fertility

Question 14

Sperm handling

Answer 14

Clean
Warm
Dry (sperm does not like water as it is hypotonic)