Molecular analysis of a t(11;22) translocation junction in a case of Ewing's sarcoma.

Polymerase chain reaction (PCR)-directed sequence analysis was performed to characterize the genomic and cDNA breakpoint junctions of t(11;22) (q24;q12) translocation in a case of Ewing's sarcoma, in which the EWS gene located on chromosome 22 is rearranged with the FL11 gene located on chromosome 11. RNA-PCR revealed the novel chimeric product of EWS/FL11 gene on the derivative chromosome (der) 22, resulting from a probable fusion of EWS exon 7 to FL11 exon 9. Sequencing of the PCR-amplified genomic fragments of the fusion genes showed that the breakpoints on der(22) occurred in EWS intron 7 and, most probably, in FL11 intron 8.

C-band fusion and behaviour of the involved chromosomes during meiotic prophase I of the male domestic pig.

Behaviour of acrocentric chromosome synaptonemal complexes (SCs) and constitutive heterochromatin (C-band) during meiotic prophase I of the male domestic pig was studied using surface spreading and silver staining techniques. At late zygotene C-band regions of complete or incomplete SCs of the acrocentric chromosomes are represented by enlarged structures. At the same time these structures commenced fusion, which is accomplished at pachytene.

Sequential analysis of synaptonemal complexes in the repopulating spermatocytes of Rattus norvegicus after restricting the germ cell population to spermatogonia by gossypol treatment.

Synaptonemal complexes of the repopulating spermatocytes of male rats were analyzed day by day using silver-stained surface spread nuclei between 8 and 25 days after restricting the germ cell population to spermatogonia by treatment of gossypol acetic acid at 30 mg/kg body weight/day for 70 days. The method allowed sequential analysis of male meiotic prophase on successive days after the last day of treatment. The leptotene cells appeared on day 11 and were characterized by a network of lateral elements and large nucleolar bodies in a diffuse mass.

Effects of the male contraceptive agent gossypol on meiotic chromosomes of the male rat.

Synaptonemal complexes (SCs) of rat spermatocytes were analyzed in silver-stained meiotic preparations 10-24 days after treatment with gossypol acetic acid, 30 mg/kg/day, for 70 days. Gossypol did not affect SC formation or function, as judged by the absence of pairing anomalies, SC fragmentation, or presynaptic arrest. The unpaired lateral axes could be seen at zygotene, and at pachytene normal SCs could be observed.