Increased frequency of coilin-containing spermatogenic cells is associated with AZF deletions in azoospermic patients

Background. It is of particular importance to study how AZF locus deletions on the Y chromosome impact male fertility, particularly through disruptions in mRNA biogenesis regulated by the coilin protein.

Objective. The study aims to investigate associations between the content and distribution of coilin in spermatogenic cells and the type of AZF locus deletion in azoospermic patients.

Methods. The study was performed on testicular biopsies from 12 azoospermic patients. The AZF locus was analyzed by PCR, and coilin was detected by immunohistochemistry.

Results. Analysis of the AZF locus revealed no deletions in 4 samples, gr/gr deletions in 4 samples, and AZFc or AZFb+c deletions in  4  samples. Coilin was localized in the nuclei of only certain spermatogenic cells. In samples with gr/gr deletions, among spermatogonia A, spermatogonia B, spermatocytes I, and haploid spermatogenic cells, the proportion of coilin-positive cells was significantly higher than in samples without AZF deletions (chi-square test, р<0.025 and р<0.001).).

Conclusion. An increased proportion of coilin-positive cells at any stage of spermatogenesis suggests its role in the pathogenesis of male infertility associated with AZF locus deletions. Elevated coilin levels in spermatogenic cells from biopsies with gr/gr deletions indicate its potential involvement in compensatory mechanisms to sustain spermatogenesis.

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