Analysis of pachytene chromosomes in testicular tissue of 11 subjects was conducted. A total of 158 acrocentric bivalents from group D and 50 from group G were studied. It was established that each of these five acrocentric bivalents showed a characteristic chromomere pattern, that is, number, size, shape, staining intensity, and tendency to aggregation versus disaggregation between adjacent or homologous chromomeres. Specificity of chromomere organization in acrocentric bivalents at the pachytene stage might provide a basis for their identification.