Stabilizing rôle of epididymal plasma in relation to the capacitation time of boar spermatozoa

Hunter, Richard; Holtz, W.; Herrmann, H.H.

doi:10.1016/0378-4320(78)90024-6

Cited by 22 publications

(12 citation statements)

References 14 publications

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“…In accordance with this view of it, capacitation occurred sooner in mature porcine spermatozoa obtained from above the cauda, compared to those released from the cauda itself (Hunter, Holtz & Henfrey, 1976), and was prolonged when spermatozoa from the upper epididymis were first exposed to cauda secretions (Hunter, Holtz & Hermann, 1978). In the same vein, the time required for capacitation was reduced in hamster spermatozoa obtained from a cauda suppressed by body temperature (Bedford & Yanagimachi, 1991), which reduces production of certain proteins (Esponda & Bedford, 1986), including the sperm coating glycopeptide, CD52 (Derr et al, 2001).…”

Section: Enigmas Of Mammalian Gamete Form and Functionsupporting

confidence: 72%

Enigmas of mammalian gamete form and function

Bedford¹

2004

Biological Reviews

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The gametes of man and some other Eutheria have been manipulated successfully for practical reasons, but many gaps remain in our basic understanding of the way that they function. This situation stems not least from a failure to recognize the extent to which eutherian spermatozoa and eggs, and elements related to their operation, have come to differ from those of other groups. Novel features in the male that reflect this include a radical design of the sperm head with the acrosome seeming to function primarily in egg-coat binding rather than its lysis, a multifaceted post-testicular sperm maturation and an androgen/low-temperature-regulated system of sperm storage--both tied to the epididymis, a variable male accessory sex gland complex, and descent of the testis and epididymis to a scrotum. In the female, such novelties are represented in a need for sperm capacitation, in an unusual regulation of sperm transport within the oviduct, in the cumulus oophorus and character of the zona pellucida around the small egg, and in a unique configuration of gamete fusion. The collective evidence now suggests that many of these features reflect a new fertilisation strategy or its consequences, with most being causally linked. One initial 'domino' in this regard appears to be the small yolkless state of the egg and its intolerance for polyspermy, as determinants of the unusual mode of oviductal sperm transport and possibly the existence and form of the cumulus oophorus. However, a particularly influential first 'domino' appears to be the physical character of the eutherian zona pellucida. This differs from the egg coats of other animal groups by virtue of a resilient elasticity and thickness. These qualities allow this primary and often only coat to stretch and so persist during later expansion of the blastocyst, usually until close to implantation. At the same time, the dimensions, physical character, and particularly the relative protease-insensitivity of the zona appear to have had profound effects on sperm form and function and, more indirectly, on sperm-related events in the male and the female tract. Marsupials display some similarities and also some strikingly different features, against which the enigmas of the eutherian situation can be evaluated.

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Section: Enigmas Of Mammalian Gamete Form and Functionsupporting

confidence: 72%

Enigmas of mammalian gamete form and function

Bedford¹

2004

Biological Reviews

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“…There is an increasing consensus, however, that in some species including man capacitation involves a loss or redistribution over both the sperm head and tail surfaces of molecules acquired in the lower corpus/upper cauda regions of the epididymis that may act to prolong the life of sperm there -specifically sperm membrane cholesterol (Cross, 1998;Osheroff et al, 1999), and of certain glycoproteins (Yeung et al, 2000). In general accord with this concept, mature porcine spermatozoa from the upper epididymis developed the ability to fertilize in the oviduct sooner than those from the lower cauda (Hunter, Holtz and Henfrey, 1976), whereas capacitation was prolonged if they were first exposed to cauda secretions (Hunter, Holtz and Hermann, 1978). Similarly, capacitation occurs sooner in hamster spermatozoa from a cauda epididymidis suppressed by body temperature (Bedford and Yanagimachi, 1991), which reduces the cauda's production of certain proteins, including the sperm-coating glycopeptide, CD52.…”

Section: Sperm Capacitationsupporting

confidence: 64%

Puzzles of mammalian fertilization and beyond

Bedford¹

2008

Int. J. Dev. Biol.

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A complexity imposed on the events of conception during the evolution of eutherian mammals is reflected not only in the placenta but also in a series of gamete-related novelties that involve the design of sperm and eggs, their interactions leading to fertilization, epididymal function, and even the scrotal state. While their functional significance has been difficult to determine, I suggest on the basis of present evidence that the genesis of these novel features relates ultimately to changes in the egg associated with nidation, that they imply a new fertilization strategy, and that most are causally linked -a major first 'domino' being the formidable zona pellucida. The eutherian zona pellucida stands out by virtue of an elastic resilience and thickness which allow it to stretch around the expanding blastocyst. However, this quality of the zona together with its relative protease-insensitivity creates a physical challenge which appears to have determined the design of the sperm head, its behaviour at fertilization, and indirectly even the pattern of sperm maturation in the epididymis. In turn, that pattern appears to have evoked the development of the sperm storage function of the cauda region, with both sperm capacitation and the scrotal state as ultimate legacies of this. Coincidentally, the vulnerability of the small yolkless egg to polyspermy appears to have selected for a unique parsimonious pattern of sperm transport in the Fallopian tube, and possibly for the role of the cumulus oophorus as a sperm sequestering device. These ideas are supported generally by evidence from marsupials, as well as by the deviant patterns seen in some insectivorous mammals.

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“…Although Fertilization and the male reproductive tract R47 it is often stated that epididymal maturation brings about the ability to undergo capacitation, it appears rather that capacitation is necessitated by the state of the sperm plasmalemma established in the cauda, with some of the preliminaries for this initiated more proximally (Rifkin & Olson 1985). Thus, spermatozoa fertilize sooner if recovered before they enter the cauda region (pigs - Hunter et al (1986)) or come from a temperaturesuppressed cauda (hamsters - Bedford & Yanagimachi (1991)). The fact that spermatozoa acquire a further complement of macromolecules in the upper cauda and so finally have developed the ability to fertilize suggests that this acquisition is related to their viability there -in a sense placing them in a physiological 'cocoon'.…”

Section: Sperm Capacitationmentioning

confidence: 99%

Singular features of fertilization and their impact on the male reproductive system in eutherian mammals

Bedford

2014

Reproduction

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Therian (marsupial and eutherian) mammals have evolved a suite of novel reproductive features -seen variously in their gametes, the steps of fertilization and the male reproductive tract -whose adaptive significance remains unclear. Present evidence for the betterunderstood eutherian mammals suggests that the 'prime mover' in their evolution has been the character of the egg coat, with other such features being adaptations to the consequences of this. Its elastic thickness allows the zona pellucida to stretch to a variable degree and yet remain around the blastocyst during much or all of its expansion before implantation, but its character represents an unusual challenge for spermatozoa. Novel aspects of the acrosome related to this challenge enable it to maintain a relatively prolonged binding after the onset of the acrosome reaction, and the structure, shape and behaviour of the sperm head point to physical thrust as a major element of zona penetration -with the unique configuration of gamete fusion as a sequela of this strategy. In the male, such adaptations are reflected in sperm head formation in the testis and in sperm maturation in the epididymis involving at least the sperm head's structure, plasmalemma and acrosome. This complexity allied to a slow epididymal sperm transport, a relatively modest sperm production and the brief life span of mature spermatozoa kept above the cauda epididymidis could account for the evolution of the sperm storage function -a development seemingly linked, in turn, to the need for sperm capacitation and scrotal evolution.Reproduction (2014) 147 R43-R52

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Stabilizing rôle of epididymal plasma in relation to the capacitation time of boar spermatozoa

Cited by 22 publications

References 14 publications

Enigmas of mammalian gamete form and function

Enigmas of mammalian gamete form and function

Puzzles of mammalian fertilization and beyond

Singular features of fertilization and their impact on the male reproductive system in eutherian mammals

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