The number of meiotic crossovers is tightly controlled and most depend on pro-crossover ZMM proteins, such as the E3 ligase HEI10. Despite the importance of HEI10 dosage for crossover formation, how HEI10 transcription is controlled remains unexplored. In a forward genetic screen using a fluorescent crossover reporter in Arabidopsis thaliana, we identify heat shock factor binding protein (HSBP) as a repressor of HEI10 transcription and crossover numbers. Using genome-wide crossover mapping and cytogenetics, we show that hsbp mutations or meiotic HSBP knockdowns increase ZMM-dependent crossovers toward the telomeres, mirroring the effects of HEI10 overexpression. Through RNA sequencing, DNA methylome, and chromatin immunoprecipitation analysis, we reveal that HSBP is required to repress HEI10 transcription by binding with heat shock factors (HSFs) at the HEI10 promoter and maintaining DNA methylation over the HEI10 5′ untranslated region. Our findings provide insights into how the temperature response regulator HSBP restricts meiotic HEI10 transcription and crossover number by attenuating HSF activity.

中文翻译：

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拟南芥热休克因子结合蛋白是限制减数分裂交换和 HEI10 转录所必需的


减数分裂交换的数量受到严格控制，并且大部分取决于促交换 ZMM 蛋白，例如 E3 连接酶 HEI10。尽管 HEI10 剂量对于交叉形成很重要，但HEI10转录的控制方式仍有待探索。在拟南芥中使用荧光交叉报告基因的正向遗传筛选中，我们鉴定出热休克因子结合蛋白（HSBP）作为HEI10转录和交叉数的抑制因子。利用全基因组交叉作图和细胞遗传学，我们发现hsbp突变或减数分裂HSBP敲低会增加 ZMM 依赖性的端粒交叉，反映了HEI10过表达的影响。通过 RNA 测序、DNA 甲基化组和染色质免疫沉淀分析，我们揭示了 HSBP 通过与HEI10启动子处的热休克因子 (HSF) 结合并维持HEI10 5' 非翻译区的 DNA 甲基化来抑制HEI10转录。我们的研究结果提供了关于温度响应调节因子 HSBP 如何通过减弱 HSF 活性来限制减数分裂HEI10转录和交换数量的见解。