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Biomedical subjects

G W Salisbury

Publications and source records attributed to G W Salisbury.

At least 19 recordsLinked to original sources
PubMed1977

The spermatozoan genome and fertility.

The strategy for effective reproduction by eliminating genetically unbalanced gametes during spermatogenesis and transport varies in degree of success within as well as among species, but in no animal has it been reported to be completely effective. In the human subject, for example, it is estimated that one in every 50 ejaculated spermatozoa is genetically abnormal. The causal basis of these anomalies is poorly understood. Meiotic accidents, environmental mutagens, and gamete senescence in utero are all implicated. However, many of these abnormal cells are fertile. This fact plus the weight of the evidence reviewed suggest that fertility differences among males which cannot be ascribed to measurable differences in semen characteristics reflect, in large part, the increased opportunity of nuclear defective gametes in the semen of some males to effect fertilization. The elimination of embryos arising from eggs fertilized by genetically defective spermatozoa through spontaneous abortions, although biologically costly, must be viewed as the final check for the elimination of genetic detritus of the species.

Abortion, Spontaneous↗
PubMed1977

The spermatozoon.

Explore the source record for details and available documents.

Adenine Nucleotides↗
PubMed1977

In vitro aging of frozen bull semen.

The change in fertility of bull semen with time in storage at -196 C was examined in data on inseminations by the Michigan Animal Breeders Cooperative over 5 yr. Intervals from collection to use were grouped by 10 days for the 1st yr, 30 days for the 2nd yr, 180 days for the 3rd yr, and a single class for semen stored 4 or 5 yr. There were 97,586 first inseminations from bulls with 10 or more ejaculates and from ejaculates with four or more classes. Nonreturn rates for 50-, 60-, 90-, and 180-day intervals post-breeding were calculated. Heterogeneity of quadratic regressions of nonreturn rates on semen age was unimportant. Both regression and least squares analyses were used. Nonreturn rates increased to about 115 days of storage and remained there through the 4 and 5 yr age group. The lowest and highest nonreturn rates for a return interval differed by approximately 4%. Maximum differences in nonreturn rates for different intervals were at the lowest nonreturn rates.

Animals↗