生殖系中染色体动力学的精确调节对于跨物种的繁殖成功至关重要。然而,许多物种尚未完全了解减数分裂染色体事件的潜在机制,例如同源配对和染色体分离。这里,我们使用OligopaintDNAFISH来研究全中心食品蛾减数分裂同源配对和染色体分离的机制,普洛迪亚穿孔虫,并将我们的发现与蚕蛾的新研究和以前的研究进行比较,家蚕,与1亿年前的P.interpunctella不同。我们发现,Bombyx和Plodia精子发生的配对都是在富含基因的染色体末端开始的。此外,这两个物种在中期I形成杆状十字形二价体。然而,与在家蚕中观察到的以端粒为导向的染色体分离机制不同,Plodia可以在中期I以多种不同的方式定向二价。令人惊讶的是,在这两个物种中,我们发现动子在非端粒基因座上始终向染色体中心组装,而无论染色体中心位于二价中的何处。此外,姐妹kinetochores似乎在这些物种中没有配对。相反,尽管如此,在中期I很容易观察到四个不同的动子,我们发现了清晰的末端微管附件,而不是将这些分离的动体连接到减数分裂纺锤体的外侧微管附件。这些发现挑战了配对的经典隔离观点,减数分裂中准确的同源分离需要面向极点的动体I。我们在这里的研究强调了在非模型系统中探索基本过程的重要性,因为使用新的生物体可以导致新生物学的发现。
Precise regulation of chromosome dynamics in the germline is essential for reproductive success across species. Yet, the mechanisms underlying meiotic chromosomal events such as homolog pairing and chromosome segregation are not fully understood in many species. Here, we employ Oligopaint DNA FISH to investigate mechanisms of meiotic homolog pairing and chromosome segregation in the holocentric pantry moth, Plodia interpunctella, and compare our findings to new and previous studies in the silkworm moth, Bombyx mori, which diverged from P. interpunctella over 100 million years ago. We find that pairing in both Bombyx and Plodia spermatogenesis is initiated at gene-rich chromosome ends. Additionally, both species form rod shaped cruciform-like bivalents at metaphase I. However, unlike the telomere-oriented chromosome segregation mechanism observed in Bombyx, Plodia can orient bivalents in multiple different ways at metaphase I. Surprisingly, in both species we find that
kinetochores consistently assemble at non-telomeric loci toward the center of chromosomes regardless of where chromosome centers are located in the bivalent. Additionally, sister
kinetochores do not seem to be paired in these species. Instead, four distinct
kinetochores are easily observed at metaphase I. Despite this, we find clear end-on microtubule attachments and not lateral microtubule attachments co-orienting these separated
kinetochores. These findings challenge the classical view of segregation where paired, poleward-facing
kinetochores are required for accurate homolog separation in meiosis I. Our studies here highlight the importance of exploring fundamental processes in non-model systems, as employing novel organisms can lead to the discovery of novel biology.