Testing immediate dosage compensation by irradiation of heavy-ion beams to Drosophila miranda
Testing immediate dosage compensation by irradiation of heavy-ion beams to Drosophila miranda
复制标题
通过重离子束照射米兰达果蝇来测试即时剂量补偿
DOI：
10.1101/2023.04.10.536214
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Nozawa M
中科院分区：
文献类型：
--
作者：
Ogawa M;Tsuneizumi K;Abe T;Nozawa M
许多具有异形性染色体的生物体具有剂量补偿（DC）机制，其中X连锁基因在雄性中上调以减轻性别之间和染色体之间的剂量不平衡。然而，DC在进化过程中建立的速度仍然是难以捉摸的。在这项研究中，将重离子束照射到具有年轻性染色体（所谓的neo-sex chromosomes）的果蝇Miranda，我们诱导neo-Y染色体上的缺失，以模拟Y染色体变性的情况，其中功能性neo-Y连锁基因只是非功能化，并测试它们的neo-X连锁配子体是否立即上调。由于2-戈伊铁离子束照射的雄性表现出较低的生育力，我们对来自这些雄性的6个F1雄性的基因组和转录组进行了测序。我们的管道确定了82个新的Y-连锁基因，其中删除预测在F1男性。然而，除了三个之外，他们中的所有人都有旁系同源物，除了他们的新X连锁配子体。此外，在其余三个基因的候选缺失，表现出一对一的配子体的关系与新的X-连锁基因发生在UTR，并没有影响这些基因的表达水平。因此，我们无法直接评估DC是否立即对neo-X-连锁基因进行操作，以响应其neo-Y-连锁配子体的破坏。然而，我们的观察结果是，在一对一配子体中缺失发生的频率较低，这间接表明DC不可能在米兰达中的neo-Y-连锁配子体假基因化后立即对neo-X-连锁基因进行操作。因此，由于没有旁系同源物的新Y-连锁基因中的缺失导致的剂量不平衡可能没有得到有效补偿，并且具有这种缺失的个体可能变得致命。我们推测，在D. mirandama的neo-sex染色体可能太年轻，以建立直接DC。今后对不同年龄性染色体的研究将进一步评价我们的初步结论。
Many organisms with heteromorphic sex chromosomes have a mechanism of dosage compensation (DC) in which X-linked genes are upregulated in males to mitigate dosage imbalance between sexes and between chromosomes. However, how quickly the DC is established during evolution remains elusive. In this study, irradiating the heavy-ion beams toDrosophila mirandathat have young sex chromosomes, the so-called neo-sex chromosomes, we induced deletions on the neo-Y chromosome to mimic the situation of Y-chromosome degeneration in which functional neo-Y-linked genes were just nonfunctionalized and tested if their neo-X-linked gametologs were immediately upregulated. Since the males with the 2-Gy irradiation of iron-ion beam showed a lower fertility, we sequenced the genomes and transcriptomes of six F1males derived from these males. Our pipeline identified 82 neo-Y-linked genes in which deletions were predicted in the F1males. However, all but three of them had paralogs in addition to their neo-X-linked gametologs. Moreover, candidate deletions in the remaining three genes that showed one-to-one gametologous relationship with the neo-X-linked genes occurred in UTRs and did not affect the expression levels of these genes. Therefore, we were unable to directly evaluate whether DC immediately operated on the neo-X-linked genes in response to the disruption of their neo-Y-linked gametologs. Yet, our observation that the deletions occurred less frequently in one-to-one gametologs indirectly suggests that DC unlikely operated on the neo-X-linked genes immediately after the pseudogenization of their neo-Y-linked gametologs inD. miranda. Therefore, dosage imbalance due to deletions in the neo-Y-linked genes without paralogs may not have effectively been compensated and individuals with such deletions could have become lethal. We speculate that the neo-sex chromosomes inD. mirandamay be too young to establish the immediate DC. Future studies on sex chromosomes with different ages will further evaluate our tentative conclusion.
影响因子：
1.5
作者：
Steinemann, M;Steinemann, S
通讯作者：
Steinemann, S
影响因子：
10.5
作者：
Alekseyenko, Artyom A.;Ellison, Christopher E.;Kuroda, Mitzi I.
通讯作者：
Kuroda, Mitzi I.