Origine Des Spermatozoïdes Diploïdes Présents Dans l'ÉJACULAT d'UN Taureau Charolais

Esnault, C.; Ortavant, R.; Nicolle, J.C.

doi:10.1051/rnd:19670102

Cited by 9 publications

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“…Significant differences between sire lines indicated a genetic cause, and diploid spermatozoa were sometimes associated with low fertility. Esnault & Ortavant (1967) suggest suppression The genetics of the mammalian gamete…”

Section: Behavioural and Other Biological Attributes Of Spermatozmentioning

confidence: 99%

The Genetics of the Mammalian Gamete

Beatty

1970

Biological Reviews

170

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Summary 1. Study of the association of the somatic and gametic genotypes with the gametic phenotype has been termed the genetics of gametes. The latter is closely associated with problems of fertility and infertility; with the general validity of the postulate of random union of the gametes; with experimental attempts to control sex ratio or other Mendelian segregations; and with the study of chromosomal anomalies. Effects of the post‐segregational genotype (after meiosis) are of exceptional interest. 2. The dimensions of mammalian spermatozoa show numerous patterns of genetic behaviour, such as strain and breed differences, additive variation, heterosis, high heritability, maternal effects, and a tentative ‘paternal cytoplasmic effect’. The high degree of additive genetic determination is reflected in the smooth progress of a genetic selection programme that brought into existence strains of mice with either long or short spermatozoan midpieces. The balance sheet of variation in mammalian spermatozoan dimensions is as follows. Apart from the natural variation between individual spermatozoa of a male, the paramount factors are the genetic ones. Variation is extraordinarily independent of other biological sources of variation and of environmental ones. The high heritability of most spermatozoan dimensions suggests that they are not closely associated with reproductive fitness, whereas a measure of fitness (resistance of spermatozoa to eosin staining) shows a low heritability. 3. Post‐segregational gene action has been sought but not conclusively demonstrated in attempts to recognize X‐ and Y‐bearing spermatozoa visually, and in attempts to control sex ratio by separating them according to electrophoretic or sedimentation behaviour. 4. Variations in the DNA content of spermatozoa, and gross morphological defects, are associated with infertility and their incidence is often genetically controlled. 5. There is controversy over the balance between specific spermatozoan antigens and ‘coating antigens’ acquired from the seminal fluid. Reports that AB individuals (heterozygous for blood‐group antigens) produce phenotypically A and B spermatozoa would indicate post‐segregational gene action but are also controversial. Sex ratio has not yet been controlled by subjecting spermatozoa to anti‐Y‐chromosome antibodies. Genetic (strain) differences exist in spermatozoan antigens. 6. The incidence of non‐eosinophil spermatozoa is a measure of semen fertility. Strain and breed differences exist but the heritability is low. An absence of demonstrable genetic variation in spermatozoan motility may be due to a swamping effect of non‐genetic factors. 7. Diploid spermatozoa differ genetically and phenotypically from the normal haploid ones. The incidence of diploid spermatozoa is associated with infertility and is controlled genetically. The incidence of polyspermy and of supplementary spermatozoa are also controlled genetically. 8. Heterospermic (mixed) insemination from two or more sires discriminates efficiently between the sires in...

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Section: Behavioural and Other Biological Attributes Of Spermatozmentioning

confidence: 99%