Development of cortical granules and the cortical reaction in rat and Hamster eggs

Szöllősi, Dániel

doi:10.1002/ar.1091590412

Cited by 190 publications

(89 citation statements)

References 37 publications

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“…It is unlikely that there was any permanent effect on the function of the cortical granules (see Szollosi, 1962Szollosi, , 1967 or on the block to polyspermy since only a very limited number of spermatozoa, usually two, entered the polyspermic eggs. On the other hand, the involvement of progesterone in development of the acrosome reaction has been suggested (Austin, Bavister & Edwards, 1972), and the possibility of steroid involvement in the capacitation of porcine spermatozoa has been dis¬ cussed (Hunter, 1972).…”

Section: Discussionmentioning

confidence: 99%

Local Action of Progesterone Leading to Polyspermic Fertilization in Pigs

Hunter¹

1972

Reproduction

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Polyspermic fertilization was found in 32\m=.\3% of the eggs recovered from the progesterone-treated tubes compared with 9\m=.\7% of those from the control tubes (P<0\m=.\01). The number of tubes yielding polyspermic eggs was also significantly higher on the progesterone-treated side (P<0\m=.\01).Injection of progesterone 8 hr before ovulation resulted in 38\m=.\2%polyspermic eggs from the treated tubes, dispermy being the principal anomaly of fertilization. In both dispermic and trispermic eggs, the female and a single male pronucleus were uniting, the accessory male element(s) remaining in the opposite hemisphere of the egg.It is concluded that relaxation of the oedematous tissues of the isthmus and uterotubal junction occurs after local injection of progesterone. In these circumstances, polyspermy is thought to originate principally from increased numbers of spermatozoa reaching the site of fertilization, although a direct effect of progesterone on the membranes of the gametes cannot be excluded. The disposition of the accessory male pronuclei in the polyspermic eggs raises the question whether polyploids usually arise from polyspermy or whether delayed cleavage and cytoplasmic fragmentation are more frequent sequelae to this condition in pigs.

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Section: Discussionmentioning

confidence: 99%

Local Action of Progesterone Leading to Polyspermic Fertilization in Pigs

Hunter¹

1972

Reproduction

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“…Aged eggs in a variety of species (mouse, rabbit, rat, hamster) have been reported to undergo spontaneous CG loss (i.e. without fertilisation; Szollosi 1967;Longo 1974aLongo , 1974bXu et al 1997). It is not clear that aged eggs have a reduced ability to exocytose CGs if fertilised, although this is a possibility because sperm-induced Ca 2+ oscillations are abnormal in aged mouse eggs compared with eggs collected near the time of ovulation (Igarashi et al 1997;Gordo et al 2002) and this abnormal Ca 2+ signalling may affect egg activation responses, such as CG exocytosis.…”

Section: Blocks To Polyspermymentioning

confidence: 99%

Mammalian membrane block to polyspermy: new insights into how mammalian eggs prevent fertilisation by multiple sperm

Gardner

Evans

2006

Reprod. Fertil. Dev.

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Abstract. To inhibit fertilisation by more than one sperm (a condition known as polyspermy), eggs have developed preventative mechanisms known as blocks to polyspermy. The block at the level of the egg extracellular coat (the zona pellucida in mammals, the vitelline envelope in non-mammals) has been well characterised in many different animal species and the block at the level of the egg plasma membrane is understood in some non-mammalian species. However, virtually nothing is known about the membrane block to polyspermy in mammalian eggs, despite data dating back 50-90 years that provide evidence for its existence. In the present review, we will discuss the background on blocks to polyspermy used by animal eggs and then focus on the membrane block to polyspermy in mammalian eggs. This will include a summary of classical studies that provide evidence for this block in mammalian eggs, assays used to study the mammalian membrane block and what has been elucidated from recent experimental studies about the cellular signalling events that lead to membrane block establishment and the mechanism of how the membrane block may prevent additional fertilisation.

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“…However, vesicle fusion waves are well known in other fish eggs, in the Xenopus egg and in various echinoderm eggs (Table III). Moreover, exocytosis (without evidence of its spatiotemporal course) seems to be a nearly universal concomitant of egg activation from algae (39,48) through mammals (35,53), and even man (45). One, therefore, wonders whether calcium waves may not accompany egg activation quite generally.…”

Section: Are There Calcium Waves Through Other Eggs?mentioning

confidence: 99%