Changes in Concentrations of Circulating Gonadotropins following Administration of Equine Follicular Fluid to Ovariectomized Mares1

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Abstract
Spermatogenic dysfunction, characterized by varying degrees of spermatogenic arrest and enhanced production of morphologically abnormal spermatozoa, has been reported in mammals heterozygous for certain chromosome translocations, especially those involving an X chromosome. However, the effects of chromosome translocations on spermatogenesis and fertility in organisms with male homogameity, such as birds, remain largely unknown. To investigate possible spermatogenic anomalies owing to translocation heterozygosity, we used domestic fowl singly or doubly heterozygous for 2 different Z-autosome translocations. The analysis of 10 different semen characteristics in groups of cockerels bearing the translocations revealed no significant difference from a control group bearing the normal chromosome complement. Estimates of the fertilizing ability of spermatozoa collected from cockerels within each karyotypic group also were not significantly different. These results indicate that 1) neither the fertilizing ability nor the phenotype of spermatozoa is adversely affected by their chromosome complement and 2) the spermatogenic process in the domestic fowl is not arrested by meiotic barriers which, as reported for mammals, act to prevent the transmission of certain chromosome translocations. Results obtained from the domestic fowl are discussed in terms of proposed genetic mechanisms for spermatogenic dysfunction in mammalian translocation heterozygotes.