Binding of morphologically abnormal sperm to mouse egg zonae pellucidae in vitro

Kot, Mary C.; Handel, Mary Ann

doi:10.1002/mrd.1120180107

Cited by 50 publications

(32 citation statements)

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“…However, when the percentage of abnormal spermatozoa was very high in the insemination medium, no significant difference existed between frequencies of abnormal spermatozoa bound to the ZP and in the insemination medium (Kot & Handel, 1987). In the present study, using the conventional method for assessing spermatozoal morphology under 1000 magnification with oil immersion, we found that abnormal spermatozoa bind to the ZP at significantly lower rates than normal spermatozoa.…”

Section: Discussioncontrasting

confidence: 66%

Morphology of spermatozoa bound to the zona pellucida of human oocytes that failed to fertilize in vitro

Liu¹,

Baker²

1992

Reproduction

127

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Summary. The morphology of spermatozoa bound to the zona pellucida (ZP) of 264 oocytes that had failed to fertilize in 58 in vitro fertilization procedures was studied by light microscopy. The percentage of spermatozoa with normal morphology bound to the ZP (mean 77, range 8\p=n-\100) was significantly higher than in the insemination medium (mean 42, range 2\p=n-\80). The abnormal spermatozoa bound to the ZP had small oval (47%), pyriform (46%), amorphous (5%) and tapering (2%) heads. Other abnormalities of morphology were not observed in ZP-bound spermatozoa. The mean rates of binding to the ZP of spermatozoa with normal morphology (44, 95% confidence limits 42\p=n-\46,number bound/ZP/105/ml inseminated) were much higher than for abnormal spermatozoa with small oval 6\m=.\5 (5\ m=. \ 5\ p=n-\ 7\ m=. \ 6), pyriform 5\ m=. \ 9 (4\ m=. \ 8\ p=n-\ 7\ m=. \ 3), amorphous 1\m=.\0 (0\ m=. \ 5\ p=n-\ 2\ m=. \ 0) and tapering 2\m=.\5 (1\ m=. \ 2\ p=n-\ 5\ m=. \ 3) heads. The morphologically abnormal forms not found on the ZP were infrequent in the insemination medium (tail defects, large oval, round, pin and duplicate heads and cytoplasmic droplets) but upper 95% confidence limits for standardized binding ratios of <60% indicated that these were unlikely to bind to the zona with rates approaching those of normal spermatozoa (standardized binding ratio 180%). A large number of uniformly normal spermatozoa bound to the ZP when the percentage normal morphology in the insemination medium was >40%. The proportions of abnormal spermatozoa on the ZP were significantly correlated with the proportions of abnormal spermatozoa in the insemination medium. Spermatozoon head dimensions were measured with a micrometer in samples from 14 patients. While there were no consistent changes in all samples, the means for head width and area were significantly larger and the ratio of the length to width was smaller for spermatozoa on the ZP than for those in the insemination medium. The head length and ratio of length to width of spermatozoa in samples with good morphology were significantly less than in samples with poor morphology. The percentage of spermatozoa with normal morphology, motility and the ratio of head length to width in the insemination medium were positively correlated with the percentage of spermatozoa with normal morphology bound to the ZP. Logistic regression analysis showed that the diagnosis of tubal infertility and the rate of binding of spermatozoa with normal morphology to the ZP were positively related to fertilization rates in vitro while the rate of binding of spermatozoa with pyriform heads was negatively related. In conclusion, human ZP are highly selective for spermatozoa with normal morphology. The frequency of binding of abnormal spermatozoa to the ZP was mainly dependent on semen quality. Detailed analysis of spermatozoa bound to the ZP should be useful for determining the range of morphology characteristics of spermatozoa with good or poor fertilizing potential.

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Section: Discussioncontrasting

confidence: 66%

Morphology of spermatozoa bound to the zona pellucida of human oocytes that failed to fertilize in vitro

Liu¹,

Baker²

1992

Reproduction

127

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“…The homozygosity for azh mutation has a dramatic effect on male fecundity, yielding males that are almost completely infertile [15,16]. It was reported that spermatozoa from azh/azh mice failed in binding to the zona pellucida [19], which suggested that the major cause of infertility in azh/azh mice is at the level of binding and penetration of the zona pellucida. It was later shown that mice homozygous for azh mutation were unable to fertilize intact oocytes but were able to fertilize zona-free eggs [20].…”

Section: Introductionmentioning

confidence: 99%

Intracytoplasmic Sperm Injection Effects in Infertile azh Mutant Mice1

Ward

2005

Biology of Reproduction

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Several reports in the literature describe men with infertility resulting from abnormal sperm head shape or decapitation defects of their spermatozoa. These defects are similar to those shown for the spermatozoa from azh (abnormal spermatozoon head shape) mice. The present study examines the efficiency and effects of intracytoplasmic sperm injection (ICSI) in successive generations of azh mice generated with this method. Three successive generations of azh mice were produced with ICSI. In all three ICSI series, more than 80% of 2-cell embryos were obtained, and more than 35% of embryos transferred gave rise to normal live offspring. In addition, ICSI was used to cross homozygous azh/azh males with homozygous azh/azh females, and live offspring were obtained. The ICSI-derived males were tested for their fecundity and abnormalities of sperm morphology. Spermatozoa from ICSI-derived azh/+ males did not show any impairment of fecundity in in vitro fertilization. These spermatozoa successfully fertilized oocytes from both C57BL/6 and B6D2F1 females, with fertilization rates ranging from 70%- 92%. The proportion of morphologically normal spermatozoa was similar in azh/+ males from three successive generations of ICSI (57.8%, 54.8%, and 49.0%, respectively), and no differences were noted when comparing ICSI-derived males with males derived by mating (57.6%) and with wild-type controls (61.6%). Detailed analysis differentiating between specific types of anomalies of sperm morphology did not reveal significant differences among the examined groups. The results of the present study demonstrate that ICSI does not enhance the azh mutation phenotype in the offspring and brings no risks when applied continuously. Moreover, serial (successive generations) ICSI is highly efficient in maintaining valuable mice with fertility problems.

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“…The proportion varies depending upon the species or the strains (Beatty & Sharma, 1960;Beatty, 1972; Wyrobek, 1979;Krzanowska, 1981), from 4% in SW mice (Wyrobek et ai, 1975;Pogany, 1987) to 99% in the azh/azh strain (Kot & Handel, 1987). The mechanisms responsible for nuclear deformation in these cells are not understood, but deformed spermatozoa are known to penetrate the zona pellucida of oocytes in vitro (Kot & Handel, 1987) and to fertilize eggs (Moore Smith, 1970; Krzanowska & Lorenc, 1983). Deformed spermatozoa may also contribute to reproductive dysfunctions and are suspected to cause habitual abortions (Giarola & Ballerio, 1962).…”

Section: Introductionmentioning

confidence: 99%

Quantitative fluorometry of abnormal mouse sperm nuclei

Pogany¹,

Balhorn²

1992

Reproduction

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Summary. An extensive quantitative analysis of deformed mouse spermatozoa was undertaken. Improvements over previous studies included the isolation and purification of sperm nuclei, a multifaceted analytical approach using several fluorochromes and the analysis of individual nuclei classified into shape categories.Malformed sperm nuclei in BALB/c mice could not be distinguished from normal ones in terms of total and basic proteins, sulfhydryl and disulfide group concentration, DNA concentration and chromatin organization. The shape of sperm nuclei is therefore probably determined by the manner in which the internal biochemical components are assembled.

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Binding of morphologically abnormal sperm to mouse egg zonae pellucidae in vitro

Cited by 50 publications

References 11 publications

Morphology of spermatozoa bound to the zona pellucida of human oocytes that failed to fertilize in vitro

Morphology of spermatozoa bound to the zona pellucida of human oocytes that failed to fertilize in vitro

Intracytoplasmic Sperm Injection Effects in Infertile azh Mutant Mice1

Quantitative fluorometry of abnormal mouse sperm nuclei

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