Spermatocyte dividing

Spermatogonium. An undifferentiated germ cell of a male, originating in a seminiferous tubule and dividing into two primary spermatocytes. 

Leonard. A. Linden. G. (1972) Observation of dividing spermatocytes for chromosome aberrations induced in mouse spermatogonia by chemical mutagens. Mutat. Res., 16, 297-300 Lide. D.R.. ed. (1997) CRC Handbook of Chemistry and Physics, 78th Ed., Boca Raton, FL, CRC... 

Spermatocytes Ethylene glycol monomethyl ether (EGME) was formerly used in the semiconductor industry and has been shown to elicit a relatively specific toxicity primarily to pachytene spermatocytes. It is not EGME, but its metabolite methoxyacetic acid, that is thought to be responsible for damaging spermatocytes. It has been found that the methoxyacetic acid disrupts protein kinase activities in dividing mitotic cells, and that cotreatment of seminiferous tubules with EGME and protein kinase inhibitors blocked the cytotoxic effects to spermatocytes. 

Packer Al, Besmer P Bachvarova RF. 1995. Kit ligand mediates survival of type A spermatogonia and dividing spermatocytes in postnatal mouse testes. Mol. Re prod. Dev. 42 303-10... 

FIGURES 1. Dividing spermatogonia, 2. Dividing spermatocyte I, 3. Dividing spermatocyte II with an X chromosome, and 4. Dividing spermatocyte II with a Y chromosome. 

The characteristic meiotic configurations of spermatocyte I chromosomes at the diakinesis first metaphase stage thus provide a reliable technique for the detection of rearrangements or other chromosome aberrations induced in spermatogonia of the treated males spermatocyte test on treated males). Cytological analysis of dividing spermatocytes can also be used to confirm in Fi males the presence of translocations indicated by semisterility, the Fi females being indirectly tested by examination of sons F translocation test) (Table 1). 

The following types of structural and numerical changes can be observed in dividing spermatocytes I (Figs. 5-12) after treatment of spermatogonial stages. 

FIGURES 5. Tetraploid dividing spermatocyte I, 6. Octoploid dividing spermatocyte I, 7. Dividing spermatocyte I with X-Y univalents, and 8, Dividing spermatocyte I with 18 bivalents and a chain quadrivalent. 

FIGURES 9-12 Dividing spermatocyte I with 18 bivalents and a ring quadrivalent,... 

After irradiation of the spermatogonial stage, most (about 70%) of the quadrivalent configurations seen in dividing spermatocytes I are in the form of a ring, about 25% are in the form of a chain, and less than 1 % are in the form of a trivalent plus univalent. Some cells can be found with two, three, four, or five translocations. No evident correlation is observed between the X-ray dose and the complexity of the chromosome rearrangements (Table 2). Figure 13 demonstrates that the... 

Types of aberrations other than translocations are much less frequent. Small fragments are sometimes observed in dividing spermatocytes of mice given X-irradiation, but their incidence is always very low. 46-48) The mean number of X-Y univalents remains unaltered in most animals, although a few individuals can display an increase to as much as 40%. The causes and the meaning of this high incidence are so far unknown, and no relation seems to exist between the type of treatment and the number of animals with a high rate of X-Y univalents. Finally, the incidence of polyploidy seems not to increase after irradiation. 

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