CHROMOSOME STUDIES OF GERM CELLS IN MALE INFERTILITY

Abstract

The author have examined testicular biopsy specimens obtained from 25 infertile men (8 cases of azospermia and 17 cases of oligospermia) and 2 normal men to explore chromosomal aberrations in spermatogonium and primary spermatocytes. Slide-preparations were made by the modified method of Sasaki & Makino (1965). Eighteen specimens from 27 cases examined provided a considerable number of deviding cells for investigation.
The results obtained are summarised as follows:
1) In 2 specimens from normal men, the chromosome number of spermatogonium was 46 and spermatocytic meiotic figures were also normal.
2) In 16 specimens from infertile subjects, cellularity in the preparations proved a close relation to the histological grading of spermatogenesis. In the spermatogonial metaphase, 15 specimens showed 46 chromosome numbers. The remaining one showed 46/47 mosaicism. This case, however, had no abnormality in the primary spermatocytic diakinesis and metaphase. A few aneuploid cells had chromosome numbers ranging 45, 47 and 48 and, in a majority of specimens, tetraploidy was recognized.
3) In spermatocytic analysis in 14 specimens of infertile cases, the ratio of XY bivalent cases to XY univalent cases was 79% to 21%. Chiasma formation in the XY bivalent was not exactly demonstrated, but at least the X chromosome seemed to be associated with its short arm at the distal end of the Y chromosome. Minor aberrations in spermatocytes, which showed the numerical abnormality of the autosome and the sex chromosome, were detected in 2 cases of oligospermia (1 case: multivalent spermatocyte, 1 case: 20-21 numbers of the autosome and the XY bivalent associated with one presumably extra X chromosome).