RT Journal Article
T1 B chromosome transcriptional inactivation in the spermatogenesis of the Grasshopper Eyprepocnemis plorans
A1 Santos Coloma, Juan Luis
A1 Parra, María Teresa
A1 Arévalo, Sara
A1 Guajardo Grence, Andrea
A1 Page, Jesús
A1 Suja, José Ángel
A1 García de la Vega, Carlos
A1 Viera, Alberto
AB Background/Objectives: We analyzed the relationship between synapsis, recombination, and transcription during the spermatogenesis of the grasshopper Eyprepocnemis plorans carrying B chromosomes (type B1). Methods: The progression of synapsis was interpreted according to the dynamics of the cohesin subunit SMC3 axes. DNA double-strand breaks were revealed by RAD51 immunolabeling, while transcriptional activity was determined by the presence of RNA polymerase II phosphorylated at serine 2 (pRNApol II) immunolabeling. The two repressive epigenetic modifications, histone H3 methylated at lysine 9 (H3K9me3) and histone H2AX phosphorylated at serine 139 (γ-H2AX), were employed to reveal transcriptional inactivity. Results: During prophase I, spermatocytes with one B1 chromosome showed overall transcription except in the regions occupied by both the X and the B1 chromosomes. This transcriptional inactivity was accompanied by the accumulation of repressive epigenetic modifications. When two B1 chromosomes were present, they could appear as a fully synapsed monochiasmatic bivalent, showing intense H3K9me3 labeling and absence of pRNApol II, while γ-H2AX labeling was similar to that shown by the autosomes. Conclusions: According to our results, B1 transcriptional inactivation was triggered in spermatogonia, long before the beginning of meiosis, and was accompanied by H3K9me3 heterochromatinization that was maintained throughout spermatogenesis. Moreover, when two B1 were present, the transcriptional inactivation did not preclude synapsis and recombination achievement by these chromosomes.
PB MDPI
YR 2024
FD 2024-11
LK https://hdl.handle.net/20.500.14352/118067
UL https://hdl.handle.net/20.500.14352/118067
LA eng
NO Santos JL, Parra MT, Arévalo S, Guajardo-Grence A, Page J, Suja JÁ, García de la Vega C, Viera A. B Chromosome Transcriptional Inactivation in the Spermatogenesis of the Grasshopper Eyprepocnemis plorans. Genes. 2024; 15(12):1512. https://doi.org/10.3390/genes15121512
NO Ministerio de Ciencia e Innovación (España)
DS Docta Complutense
RD 7 abr 2025