The spermatozoa of most invertebrates (e.g., sea urchins) and nonmammalian vertebrates (e.g., fishes and amphibians) have full capacity to fertilize eggs upon leaving the testis. Testicular spermatozoa of mammals, on the other hand, do not possess the ability to do so. Their fertilizing capacity develops as they pass through the epididymis (Young, 1931; Nishikawa and Waide, 1952; Blandau and Rumery, 1964; Bedford, 1966; Orgebin-Crist, 1967). This process, apparently “unique” to mammals, is referred to as the epididymal maturation of spermatozoa. Even after their maturation, however, spermatozoa require an additional phase of maturation or capacitation within the female genital tract before they are able to fertilize eggs (Austin, 1951, 1952; Chang, 1951a). Thus, epididymal maturation and capacitation are two extra steps that mammaliam spermatozoa must take before they can effect fertilization. In this chapter, I will discuss how mammalian spermatozoa prepare themselves for fertilization and how the spermatozoa and eggs interact during fertilization. The process and mechanisms of sperm transport in the female genital tract will not be dealt with extensively here. Readers are referred to Bishop (1961, 1969), Blandau (1969), Bedford (1970b, 1972b), Thibault (1972, 1973a), Zamboni (1972), Blandau and Gaddum-Rosse (1974), Hafez and Thibault (1975), Overstreet and Katz (1977), Overstreet and Cooper (1978, 1979b), Overstreet et al. (1978), Shalgi and Kraicer(1978), Cooper et al. (1979) and Hunter (1975, 1980). The rejection or elimination of extra spermatozoa by the fertilized egg, one of the most fascinating events in fertilization, will not be discussed here. Instead, readers are referred to the chapter by Dr. Wolf in this volume. The physiology of egg activation has been described and discussed to some extent by Gwatkin (1977) and Yanagimachi (1978a). There are numerous reviews dealing with general aspects of mammalian fertilization. The following are recommended to aid in grasping the outline of mammalian fertilization: Austin and Bishop (1957), Austin and Walton (1960), Austin (1961, 1968), Blandau (1961), Piko (1969), Thibault (1969), Bedford (1970a,b, 1972b), Gwatkin (1976, 1977), Yanagimachi (1977, 1978a), Bedford and Cooper (1978) and Hunter (1980).

Mechanisms of Fertilization in Mammals

Peroxidative Breakdown of Phospholipids in Human Spermatozoa, Spermicidal Properties of Fatty Acid Peroxides, and Protective Action of Seminal Plasma

Techniques for freezing bull sperm developed over the past 40 years have not yielded protocols for preserving sperm from other species. Recent advances in our understanding of cell membrane structure function and metabolism now permit alternative modes of investigation. These data will allow development of unique studies which should have a higher probability of yielding successful protocols for sperm from other species. In this review the authors will: (1) provide a general overview of cryopreservation; (2) review emerging concepts of membrane structure and the relationship of membrane composition to water and cryoprotectant movement; (3) emphasize how these parameters affect cell volume and surface areas; (4) focus attention on the concept that cryoprotectants will alter membrane structure and function in addition to their well-recognized effects on bulk solvent; and (5) emphasize the effect of the processing protocol on metabolic balance. These concepts are reintroduced in the context of the established and successful protocol for freezing bull sperm to illustrate the molecular responses that may be necessary to survive a freeze-thaw cycle.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.1939-4640.1990.tb01583.x

Cryopreservation of mammalian sperm: what we ask them to survive.

http://directory.umm.ac.id/Data%20Elmu/jurnal/A/Animal%20Reproduction%20Science/Vol62.Issue1-3.Aug2000/2030.pdf

Storage of boar semen.

Omega-3 fatty acids as cancer chemopreventive agents.

Influence of the cholesterol content of mammalian spermatozoa on susceptibility to cold-shock.

1. 1. The phospholipid-bound fatty acids of ram, bull, boar, rabbit and human spermatozoa contained high levels of polyunsaturated fatty acids. Values ranged from 70 per cent by weight of the total fatty acid fraction in the boar to approximately 40 per cent in both human and rabbit. 2. 2. Docosahexaenoic acid (22:6) was quantitatively the most important fatty acid found in all species except the rabbit. 3. 3. The major saturated fatty acid found in mammalian spermatozoa was palmitic acid. 4. 4. The predominant fatty aldehyde was palmitaldehyde (16:0) and values ranged from 91·2 per cent in ram to 51·1 per cent in human spermatozoa.

The phospholipid-bound fatty acids and aldehydes of mammalian spermatozoa

The effects of cold shock and freeze-thawing on the release of total phospholipids phosphorus and of specific phospholipids from ram, bull, and boar spermatozoa are examined. Species differences are apparent, both in the absolute amount of total phospholipids released and in the conditions required to effect a loss of individual phospholipids. The phosphoglycerides most affected by the temperature treatment are choline plasmalogen, phosphatidyl choline, and phosphat idyl ethanolamine. The loss of phospholipids is most specific in boar spermatozoa. Bull spermatozoa suffer a greater overall and more general breakdown of phospholipids, indicating disruption of the cell structure. This is in contrast to the more specific phospholipid losses from ram and boar spermatozoa, which may indicate a more localized region of damage and release of material, possibly acrosomal. The loss of phospholipid may be correlated with the species differences in the fertility of the frozen spermatozoa.

/pdf/the-effect-of-cold-shock-and-freeze-thawing-on-release-of-2acdylbz9a.pdf

The Effect of Cold Shock and Freeze-Thawing on Release of Phospholipids by Ram, Bull, and Boar Spermatozoa

Recent work has established the composition ofphospholipids and phospholipid\x=req-\ bound fatty acid esters and aldehydes in ram, bull, boar, human and rabbit spermatozoa (Scott, Voglmayr & Setchell, 1967; Pursel & Graham, 1967; Neill & Masters, 1972, 1973; Johnson, Pursel & Gerrits, 1972; Poulos & White, 1973; Poulos, Darin-Bennett & White, 1973; Darin-Bennett, Poulos & White, 1973b). These data led Poulos, Darin-Bennett & White (1973) to suggest that the spermatozoa of these species could be allocated to two groups on the basis of the ratio of the phospholipid-bound polyunsaturated:saturated fatty acids, which could be correlated with sensitivity to cold-shock. Thus, the ratio for the spermatozoa of ram, bull and boar, which are known to be very susceptible to cold-shock, is approximately three times the ratio found for the less sensitive spermatozoa of the rabbit and human (Darin-Bennett et al., 1973a). In view of this apparent correlation, it was decided to examine the phospholipids of the spermatozoa of two other species, the dog and the fowl, which are relatively resistant to cold-shock (Wales & White, 1959), and to determine whether the spermatozoa of these species can also be grouped according to their phospholipid-bound fatty acid and aldehyde content. Semen was collected by massage and analyses were undertaken on pooled specimens containing a minimum of three ejaculates. Spermatozoa were separated and lipids were extracted as described by Poulos, Darin-Bennett & White (1973). Two-dimensional thin layer Chromatographie estimations of phospholipid composition were performed according to the methods of DarinBennett et al. (1973b). The phospholipid-bound fatty acid esters and dimethylacetals were prepared and estimated by gas-liquid chromatography (Poulos, Darin-Bennett & White, 1973). The percentage composition of the phospholipids and phospholipid-bound fatty acids and aldehydes of the dog and fowl spermatozoa are shown in Tables 1, 2 and 3. The dog spermatozoa contained large amounts of phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin and ethanolamine plasma¬ logen and only small amounts of choline plasmalogen (Table 1 ). Fowl sperma¬ tozoa appeared to be different. Although phosphatidyl choline was the major component and the level of choline plasmalogen was quite low, there was no * Present address : Department of Biochemistry, Adelaide Childrens Hospital, King William Road, North Adelaide, S.A. 5006, Australia.

/pdf/the-phospholipids-and-phospholipid-bound-fatty-acids-and-wrp18hcjoi.pdf

The phospholipids and phospholipid-bound fatty acids and aldehydes of dog and fowl spermatozoa.

Lardy & Phillips (1941a,b) postulated that the endogenous phospholipids are used as a source of oxidizable energy by bull spermatozoa in the absence of sugar. Their results were not confirmed by the later work ofBomstein & Steberl (1957) with bull spermatozoa, or by Poulos & White (1973) with human spermatozoa. Hartree & Mann (1959, 1961) examined the effect of aerobic and anaerobic incubation of washed ram spermatozoa on the utilization of endogenous phospholipids and their results, though different from those of Lardy & Phillips (1941a,b), supported the latter's original hypothesis. Scott & Dawson (1968) briefly examined the effect of incubation on the phospholipids of washed ram spermatozoa and did not detect the same degree of plasmalogen loss as did Hartree & Mann (1961). The latter authors also found that incubation resulted in the release of phospholipid-bound fatty acid esters, specifically myristic and palmitic acids. However, in view of the established presence of large amounts of docosahexaenoic acid in ram spermatozoa (Dott & Dingle, 1968; Poulos, Darin-Bennett & White, 1973), it was decided to re-examine the effects of incubation on the phospholipids and phospholipid-bound fatty acids. Washed suspensions ofspermatozoa from Merino rams were prepared accord¬ ing to the method described by Hartree & Mann (1961). The semen was pro¬ cessed within 60 min of collection, during which time the samples were kept at 20° C and only those displaying good initial motility were used. Triplicate aliquots were removed for counting in a haemocytometer and the spermatozoa incubated at 37° C for 3 or 4 hr at a mean concentration of 7-5 IO8 cells/ml. An analysis of the fructose concentration by the method of Mann (1948) of the prepared sperm suspensions revealed a fructose content of less than 2 μg| l. Sperm suspensions contained streptomycin (1500 units/ml) and penicillin (7300 units/ml) and samples were incubated in both test-tubes and conical flasks, with constant shaking. To ensure fully anaerobic conditions, oxygen-free Krebs-Ringer solution was used for anaerobic experiments, the samples were flushed with nitrogen and incubated in ground-glass stoppered containers. After incubation, the phospholipids were extracted from the spermatozoa and the phospholipid fatty acid esters were prepared and estimated as described in Poulos et al. (1973). The composition of the phospholipids was determined after thin-layer chromatography. Plates were developed in single dimension in

/pdf/a-re-examination-of-the-role-of-phospholipids-as-energy-51rb23vkzc.pdf

Annabelle Darin-Bennett

Papers

Influence of the cholesterol content of mammalian spermatozoa on susceptibility to cold-shock.

The phospholipid-bound fatty acids and aldehydes of mammalian spermatozoa

The Effect of Cold Shock and Freeze-Thawing on Release of Phospholipids by Ram, Bull, and Boar Spermatozoa

The phospholipids and phospholipid-bound fatty acids and aldehydes of dog and fowl spermatozoa.

A re-examination of the rôle of phospholipids as energy substrates during incubation of ram spermatozoa