Lencina Franco, Prina Alberto R, Pacheco María G, Kobayashi Ken, Landau Alejandra M
Instituto Nacional de Tecnología Agropecuaria (INTA), Instituto de Genética, Dr. Nicolás Repetto y De Los Reseros s/n, Hurlingham 1686, Buenos Aires, Argentina.
Laboratorio de Agrobiotecnología, Grupo Biología Molecular Vegetal Aplicada, Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA, CONICET-UBA), Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires 1891, Argentina.
Int J Mol Sci. 2025 Sep 5;26(17):8644. doi: 10.3390/ijms26178644.
A mutation detection strategy based on mismatch digestion was applied previously in barley seedlings carrying the chloroplast mutator () genotype through many generations. Sixty-one mutations were detected along with four large indels: a 15 bp insertion in the intergenic region between and genes, a 620 bp deletion in the gene, a 79 bp deletion in the intergenic region between and genes and a 45 bp deletion in the gene. The present investigation aims to understand the mechanisms producing the large indels and to better characterize the mutagenic effect. Whole plastome sequencing revealed novel polymorphisms that were identified either in regions not previously examined or in regions that were explored but not detected through celery juice extract (CJE) digestion. The 620 bp deletion in the gene was lethal when homoplastomic, whereas the 45 bp deletion in the gene did not affect the viability of the seedlings even in homoplastomy. The presence of direct repeats at the borders of large indels suggests that they could have originated by illegitimate recombination because of CPM protein malfunction. A truncated mismatch repair MSH1 protein identified in seedlings suggests that CPM is involved in organellar genome stability maintenance.
一种基于错配消化的突变检测策略先前已应用于经过多代携带叶绿体突变体（）基因型的大麦幼苗中。检测到61个突变以及4个大的插入缺失：在和基因之间的基因间隔区有一个15 bp的插入，在基因中有一个620 bp的缺失，在和基因之间的基因间隔区有一个79 bp的缺失，在基因中有一个45 bp的缺失。本研究旨在了解产生大插入缺失的机制，并更好地表征诱变效应。全质体基因组测序揭示了新的多态性，这些多态性要么在以前未检测的区域中被识别，要么在通过芹菜汁提取物（CJE）消化探索但未检测到的区域中被识别。基因中的620 bp缺失在同质性时是致死的，而基因中的45 bp缺失即使在同质性时也不影响幼苗的活力。大插入缺失边界处存在直接重复序列表明，它们可能是由于CPM蛋白功能异常通过非法重组产生的。在幼苗中鉴定出的截短的错配修复MSH1蛋白表明CPM参与了细胞器基因组稳定性的维持。
