Table 3. Changes in sperm lipid content during epididymal maturation in different species.

Data reviewed from studies that compared lipids of whole cells or membrane extracts of sperm recovered from caput and cauda epididymis. Arrows are indicative of an increase (↑) or decrease (↓) in the percentage of lipid during sperm maturation; ND is indicative of no published data.

SPECIES	Boar	Goat	Hamster	Human	Mouse	Ram	Rat
Phospholipids out of Total phospholipids
Phosphatidylcholine (PC)	↑	↓	=	↑	↑a ↓b	↑	↓
Posphatidylethanolamine (PE)	↓	↓	=	↓	↓b	↓	↓
Phosphatidylinositol (PI)	↓	ND	=	ND	↑b	↓	=
Phosphatidylserine (PS)	↓	ND	=	↓	=b	↓	↓
Sphyngomyelin (SM)	↑	↓	ND	↓	↑a,b	ND	↑
Sterols
Cholesterol	↓	↑	↓	ND	↓b	↓	↓
Desmosterol	↑	↓	↑	ND	ND	↓	↑b
Membrane Fluidity	ND	ND	↑	↑	↑b	↑b	↑
References	Nikolopoulou et al. 1985	Rana et al. 1991	Awano et al. 1993, Awano et al. 1989	Haidl et al. 1997	a: Pyttel et al. 2014 b: Rejraji et al. 2006	a: Parks et al. 1985 b: Christova et al. 2004	a: Aveldano et al. 1992 b: Lindenthal et al. 2001

Letters (a) and (b) indicate the references.