Abstract
The present study involved three male lamas (Lama glama). Mitotic preparations from fibroblast culture and an electron microscopic observation on the synaptonemal complexes (Scs) were reported. Special attention was given to the morphology and behaviour of the chromosomes at the zygotene and pachytene substages of prophase I in primary spermatocytes from lamas. Analysis of mitotic preparations show diploid and triploid cells, with a relatively high frequency of polyploidy. Analyses of synaptonemal complexes in primary spermatocytes were carried out, on 89 cells. Pairing abnormalities were only recorded in an average of 63% of the cells of the animal Tabasco. The other two animals were normal. The photographed cells give an upper limit estimate of the existing abnormalities, as there was a deliberate tendency towards selecting abnormal cells for photography. The presence of degenerating primary spermatocytes in SC preparations as well as in testicular sections, and the absence of spermatozoa in ejaculates confirm the chromosomally derived male sterility of one animal.