Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Perimetral da Ciência, km 01, Guamá, Belem 66075-750, PA, Brazil.
Instituto Federal de Educação, Ciência e Tecnologia do Pará, Campus Itaituba, R. Universitário, s/n, Maria Magdalena, Itaituba 68183-300, PA, Brazil.
Int J Mol Sci. 2022 Aug 16;23(16):9179. doi: 10.3390/ijms23169179.
Several species of (Scorpiones, Buthidae) present multi-chromosomal meiotic associations and failures in the synaptic process, originated from reciprocal translocations. Holocentric chromosomes and achiasmatic meiosis in males are present in all members of this genus. In the present study, we investigated synapse dynamics, transcriptional silencing by γH2AX, and meiotic microtubule association in bivalents and a quadrivalent of the scorpion . Additionally, we performed RT-PCR to verify the expression of mismatch repair enzymes involved in crossing-over formation in gonads. The quadrivalent association in showed delay in the synaptic process and long asynaptic regions during pachytene. In this species, γH2AX was recorded only at the chromosome ends during early stages of prophase I; in metaphase I, bivalents and quadrivalents of exhibited binding to microtubules along their entire length, while in metaphase II/anaphase II transition, spindle fibers interacted only with telomeric regions. Regarding , genes involved in the recombination process were transcribed in ovaries, testes and embryos, without significant difference between these tissues. The expression of these genes during achiasmatic meiosis is discussed in the present study. The absence of meiotic inactivation by γH2AX and holo/telokinetic behavior of the chromosomes are important factors for the maintenance of the quadrivalent in and the normal continuation of the meiotic cycle in this species.
几种（Scorpiones，Buthidae）存在多染色体减数分裂关联和突触过程失败，源于相互易位。这种属的所有成员都存在着着丝粒染色体和雄性非联会减数分裂。在本研究中，我们研究了突触动态、γH2AX 介导的转录沉默以及双价体和四价体的减数分裂微管关联。此外，我们进行了 RT-PCR 以验证与减数分裂交叉形成相关的错配修复酶在 性腺中的表达。在 中观察到四价体关联在粗线期突触过程延迟和长的非突触区域。在这个物种中，γH2AX 仅在前期 I 的早期阶段记录在染色体末端；在中期 I 中，双价体和四价体都沿着整个长度与微管结合，而在中期 II/后期 II 转变期间，纺锤体纤维仅与端粒区域相互作用。关于 ，参与重组过程的基因在卵巢、睾丸和胚胎中转录，这些组织之间没有显著差异。本研究讨论了这些基因在非联会减数分裂中的表达。γH2AX 介导的减数分裂失活的缺失和染色体的全/动粒行为是维持 四价体和该物种减数分裂周期正常进行的重要因素。
