University of Central Florida, Biological Sciences Building, 4110 Libra Dr., Orlando, FL, 32816, USA.
Heredity (Edinb). 2024 Dec;133(6):418-425. doi: 10.1038/s41437-024-00726-w. Epub 2024 Oct 5.
Mother's curse refers to male-biased deleterious mutations that may accumulate on mitochondria due to its strict maternal inheritance. If these mutations persist, males should ideally compensate through mutations on Y-chromosomes given its strict paternal inheritance. Previous work addressed this hypothesis by comparing coevolved and non-coevolved Y-mitochondria pairs placed alongside completely foreign autosomal backgrounds, expecting males with coevolved pairs to exhibit greater fitness due to Y-compensation. To date, no evidence for Y-compensation has been found. That experimental design assumes Y-chromosomes compensate via direct interaction with mitochondria and/or coevolved autosomes are unimportant in its function or elucidation. If Y-chromosomes instead compensate by modifying autosomal targets (or its elucidation requires coevolved autosomes), then this design could fail to detect Y-compensation. Here we address if Y-chromosomes ameliorate mitochondrial mutations affecting male lifespan in Drosophila melanogaster. Using three disparate populations we compared lifespan among males with coevolved and non-coevolved Y-mitochondria pairs placed alongside autosomal backgrounds coevolved with mitochondria. We found coevolved pairs exhibited lower mortality risk relative to non-coevolved pairs. In contrast, no such pattern was observed when coevolved and non-coevolved pairs were placed alongside non-coevolved autosomes, as with previous studies. These data are consistent with Y-compensation and highlight the importance of autosomes in this capacity. However, we cannot fully exclude the possibility that Y-autosomal coevolution independent of mitochondrial mutations contributed to our results. Regardless, modern practices in medicine, conservation, and agriculture that introduce foreign Y-chromosomes into non-coevolved backgrounds should be used with caution, as they may disrupt Y-autosome coadaptation and/or inadvertently unbridle mother's curse.
母亲的诅咒是指由于线粒体严格的母系遗传，可能在其中积累的男性偏向的有害突变。如果这些突变持续存在，由于其严格的父系遗传，男性应该理想地通过 Y 染色体上的突变进行补偿。以前的工作通过比较放在完全外来常染色体背景下的共同进化和非共同进化的 Y-线粒体对来解决这个假设，期望共同进化的 Y-线粒体对中的雄性由于 Y 补偿而表现出更大的适应性。迄今为止，还没有发现 Y 补偿的证据。该实验设计假设 Y 染色体通过与线粒体的直接相互作用进行补偿，并且/或者共同进化的常染色体在其功能或阐明中不重要。如果 Y 染色体通过修饰常染色体靶标进行补偿（或者其阐明需要共同进化的常染色体），则该设计可能无法检测到 Y 补偿。在这里，我们研究 Y 染色体是否可以改善影响黑腹果蝇雄性寿命的线粒体突变。使用三个不同的种群，我们比较了放在常染色体背景下的共同进化和非共同进化的 Y-线粒体对中的雄性的寿命。我们发现共同进化的对相对于非共同进化的对表现出较低的死亡率风险。相比之下，当共同进化和非共同进化的对放在非共同进化的常染色体旁边时，没有观察到这种模式，就像以前的研究一样。这些数据与 Y 补偿一致，并强调了常染色体在这种能力中的重要性。然而，我们不能完全排除 Y-常染色体的共同进化独立于线粒体突变对我们结果的贡献的可能性。无论如何，现代医学、保护和农业实践中引入非共同进化背景的外来 Y 染色体应该谨慎使用，因为它们可能会破坏 Y-常染色体的共同适应，或者无意中释放母亲的诅咒。
