PT  - JOURNAL ARTICLE
AU  - de Almeida, Bruno Rafael Ribeiro
AU  - Noronha, Renata Coelho Rodrigues
AU  - da Costa, Marlyson Jeremias Rodrigues
AU  - Nagamachi, Cleusa Yoshiko
AU  - Pieczarka, Julio Cesar
TI  - Meiosis in the scorpion <em>Tityus silvestris</em>: new insights into achiasmatic chromosomes
AID  - 10.1242/bio.040352
DP  - 2019 May 15
TA  - Biology Open
PG  - bio040352
VI  - 8
IP  - 5
4099  - http://bio.biologists.org/content/8/5/bio040352.short
4100  - http://bio.biologists.org/content/8/5/bio040352.full
SO  - Biology Open2019 May 15; 8
AB  - Achiasmatic male meiosis in scorpions is characterized by a high frequency of gaps, asynaptic regions and multivalent associations. Here, we performed an immunocytogenetic analysis to investigate recombination, and synapsis and chromatin-remodeling events during meiosis of the scorpion Tityus silvestris. Our results demonstrate that the synaptonemal complex (SC) begins its organization in the zygotene stage and persists until metaphase I. The advancement of the synaptic process is related to the epigenetic modification histone H3 lysine 27 trimethylation (H3K27m3). The distribution and dynamics patterns of variant γH2AX and recombinase Rad51 during achiasmatic meiosis suggests formation and repair of DNA double-strand breaks (DSBs) during early stages of prophase I. The epigenetic modifications, histone H3 lysine 4 trimethylation (H3K4m3) and histone H3 lysine 9 acetylation (H3K9ac), showed a dispersed distribution along the bivalents, suggesting that transcriptional activity is maintained constitutively during prophase I. However, H3K9ac modifications are absent in constitutive heterochromatin carrying the 45S rDNA in pachytene and post-pachytene stages. Collectively, our data demonstrate that T. silvestris exhibits adaptations to the achiasmatic mode, and suggest that epigenetic modifications may act in the regulation of these mechanisms to favor the normal continuation of meiosis in this scorpion.