Role of Membrane Lipid Fatty Acids in Sperm Cryopreservation

Table 1

Different animals/species and cryopreservation methods.

Animal	Cryopreservation methods	Reference number
Human
	Semen was diluted using human sperm preservation medium, TEST-Yolk buffer, or glycerol, subjected to slow manual cooling in liquid nitrogen (LN2) vapour, and stored in LN2.	[47]
	The procedure is based on the program of cooling speed doubling: from 20 to 5°C at 0.5°C/min; from 5 to 4°C at 1°C/min; from 4 to 3°C at 2°C/min; from 3 to 2°C at 4°C/min; from 2 to 1°C at 8°C/min; from 1 to −80°C at 10°C/min. After being held 10 minutes at the final temperature, −80°C then were transferred to LN2.	[62]
	Normozoospermic, oligozoospermic, asthenozoospermic, and oligoasthenozoospermic semen samples were frozen in pellets on the surface of dry ice using a glycerol-based cryoprotectant with egg yolk.	[65]
	Sperm cells were frozen or cold-shocked by lowering the temp. rapidly from 37 to 0°C on melting ice.	[66]
	Sperm cells were frozen using the programme: from 20 to −4°C at 5°C/min; from −4 to −30°C at 10°C/min; from −30 to −140°C at 20°C/min and then were transferred for storage to LN2.	[67]
Ram and goat
Merino rams	Ejaculates were obtained by electrical stimulation. Semen was also collected from the caput and cauda epididymis. Spermatozoa were cold-shocked by placing tubes containing the semen held at 37°C into a bath at 0°C for 10 min.	[20]
Zandi rams	The diluted semen was cooled at 4 to 5°C for 2 h. Then the samples were placed into the LN2 vapor at a height of 4 cm above the liquid for 8 minutes, and then the straws were plunged into LN2.	[80]
Goat	Epididymal sperms were cryopreserved using programmable freezer: from 30 ± 2° to 5°C at 0.25°C min, from 5 to −20°C at 5°C min, and from −20 to −100°C at 20°C min then transferred to LN2.	[81]
Goat	Semen was frozen in pellet form on dry ice, and then plunged into LN2.	[82]
Mahabadi bucks	Ejaculated semen samples were diluted and equilibrated at 5°C for 150 min. Samples were frozen in LN2 vapor, 4 cm above the L, for 7 min; subsequently the straws were plunged into the LN2 for storage.	[83]
Blanca-Celtiberica buck	Diluted semen was cooled to 5°C for 2 h, diluted further, and held at 5°C for 2 h; another sample was cooled to 5°C for 4 h; both samples were frozen over N2 vapour for 10 min, 4 cm above N2 level, plunged, and stored in LN2.	[84]
San Clemente bucks; and Tennessee; Myotonic buck	Semen aliquots were cooled on ice for 1 h before transfer to a 5°C refrigerator and kept for total of 1-2 h; then extender was added. Fully extended semen was equilibrated at 5°C for 2 h. Semen was frozen by suspending straws in N2 vapour for 10 min, then plunging into LN2.	[85]
Saanen bucks	Semen samples were cryopreserved using programmable freezer using a fast freezing curve (from 25°C to 5°C at 0.25°C/min and from 5°C to −120°C at 20°C/min) that started at 28°C. After reaching a temperature of 5°C (~80 min), the straws were subjected to an equilibration time for 120 min. The freezing curve was implemented immediately after the equilibration time and was sustained until the temperature reached −120°C, then were placed in LN2.	[87]
Spanish ibex; (Capra pyrenaica)	The diluted sperm suspension was cooled to 13°C in a water bath, further cooled to 5°C over 1 h, kept for 2 more h, and frozen by placing in N2 vapour 5 cm above the surface of LN2 for 10 min before plunging into the LN2 .	[102]
Bull
Friesian bull	Semen was cooled to 5°C over 30 min, equilibrated for 6 h at 5°C, and frozen above the surface of LN2 (a temperature of −120°C was attained in 7 min).	[73]
Holstein bulls	Semen was cooled to 5°C in 1 h; after 4 h it was pellet-frozen on solid CO2.	[74]
Holstein, Jersey,; and Guernsey	The semen was cooled immediately after collection to 15 to 20°C and held at this temperature for one-half to one hour; then diluted semen was cooled slowly to a storage temperature between 4 and 7°C.	[76]
Prim Holstein	Electroejaculated semen samples were cooled from 34 to 4°C in 1.5 h, held for 2 h, and then descended in LN2. Rate: 4 to −10°C at 0. 7°C/10 s; −10 to −150°C at 7°C/10 s.	[77]
Holstein	Fresh sperm samples were cooled to 4°C and held for 1 h (addition of diluent). Cryostraws were placed ~5 cm above the LN2 surface for 10 min and then put directly into the LN2 for storage	[78]
Swiss brown bull	Diluted semen was cooled to 4-5°C over 2 h and then frozen by being placed into the LN2 vapor at a height of 4 cm above the liquid for 8 min; after that, the straws were plunged into LN2.	[79]
Boar
	The semen was cooled to 22°C over 2 h and further cooled to 5°C over 3 h by placing in a cold room. Samples were then frozen in LN2 vapors at 30°C/min from 5°C a final temperature of −70°C. Then straws were plunged directly into LN2.	[38]
Norwegian Landrace and Duroc	The diluted semen was cooled at 15°C over 3 h and then cooled to 4°C over 2 h period. Semen was frozen in a controlled rate freezer for 9 min. The freezing chamber was precooled to −100°C. Immediately after the straws were transferred to the chamber it was warmed at 10°C/min to −70°C and held for 1 min before lowering the temperature to −120°C at 50°C /min. The straws were held at −120°C for 4 min before transferring to LN2.	[11]
Landrace, Large; White, and; commercial; hybrids	Semen was cooled at 15°C for 3 h and was further cooled in a programmable freezer to 5°C over 90 min; samples were cryopreserved using programmable freezer. The freezing chamber was precooled to −110°C. Immediately after loading the straws it was warmed at 45°C/min to −60°C and held for 1 min before lowering the temperature to −130°C at 20°C/min. The straws were plunged into LN2.	[41, 90]
Marsupial
Eastern grey kangaroo; (Macropus giganteus)	Epididymal sperms were subjected to cold shock by rapid cooling.	[91]
Koala; (Phascolarctos  cinereus)
Common wombat; (Vombatus ursinus)
Canine samples
Blue fox; (Alopex lagopus)	Semen was cryopreserved in different extenders; FA and sterols of plasma membrane were analysed.	[10]
Red/silver fox; (Vulpes vulpes)	Cooling at a moderate rate (2–5°C/min from 4-5°C to below the freezing point, i.e., from −7 to −15 or −20°C) and freezing at a rapid rate from −20 to −50 or −70°C.	[92, 94, 95]
Dog	Cooling at a moderate rate (2–5°C/min from 4-5°C to below the freezing point, i.e., from −7 to −15 or −20°C) and freezing at a rapid rate from −20 to −50 or −70°C.	[94]
Beagle and Golden; Retriever	The samples were maintained at a temperature of 4°C for total 1 h 30 min. Then the canine semen was frozen in LN2 vapours (4 cm above the level of the LN2) at −110°C for 10 min then immersed vertically in LN2 for storage at −196°C.	[99]
Elephant
African Elephant; (Loxodonta Africana)	Ejaculated semen samples were stored at −70°C or cryopreserved in LN2.	[9]
Asian Elephant; (Elephas maximus)
Stallion
Andalusian stallions	The spermatozoa were slowly cooled to 4°C within 1 h and frozen horizontally in racks placed 4 cm above the surface of LN2 for 10 min, after which they were directly plunged in LN2.	[100, 101]
Bats/flying fox
Indian flying-fox; (Pteropus  giganteus)	Electroejaculated semen samples were cooled at 50°C/min to 4°C.	[12]
Variable flying-fox; (Pteropus hypomelanus)
Grey-headed flying-fox; (Pteropus poliocephalus)
Rodrigues flying-fox; (Pteropus rodricensis)
Large flying-fox; (Pteropus vampyrus)