Unlabelled: Chromoanagenesis is a catastrophic event that involves localized chromosomal shattering and reorganization. In this study, we report a case of chromoanagenesis resulting from defective meiosis in the MEIOTIC ASYNAPTIC MUTANT 1 (asy1) background in Arabidopsis thaliana. We provide a detailed characterization of the genomic structure of this individual with a severely shattered segment of chromosome 1. We identified 260 novel DNA junctions in the affected region, most of which affect gene sequence on 1 or both sides of the junction. Our results confirm that asy1-related defective meiosis is a potential trigger for chromoanagenesis. This is the first example of chromoanagenesis associated with female meiosis and indicates the potential for genome evolution during oogenesis.
Plain Language Summary: Chromoanagenesis is a complex and catastrophic event that results in severely restructured chromosomes. It has been identified in cancer cells and in some plant samples, after specific triggering events. Here, we identified this kind of genome restructuring in a mutant that exhibits defective meiosis in the model plant system Arabidopsis thaliana.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9911071 | PMC |
http://dx.doi.org/10.1093/g3journal/jkac185 | DOI Listing |
Reproduction
January 2025
D Cohen, Fundación IBYME. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)., Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina.
Artificial oocyte activation (AOA) with Ca2+ ionophores is an experimental procedure that benefits patients who fail to obtain fertilized eggs. However, the impact of non-physiological Ca2+ increases on cellular events involved in egg-embryo transition and early development remains poorly understood. Using the mouse model, this study compares common Ca2+ ionophore protocols applied in clinical practice - one or two exposures to A23187 or a single exposure to ionomycin - focusing on embryonic development and cellular events associated with egg activation.
View Article and Find Full Text PDFClin Transl Med
January 2025
State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, China.
Background: Numerous pathogenic variants causing human oocyte maturation arrest have been reported on the primate-specific TUBB8 gene. The main etiology is the dramatic reduction of tubulin α/β dimer, but still large numbers of variants remain unexplained.
Methods: Using microinjection mRNA and genome engineering to reintroduce the conserved pathogenic missense variants into oocytes or in generating TUBB8 variant knock-in mouse models, we investigated that the human deleterious variants alter microtubule nucleation and spindle assembly during meiosis.
Nat Commun
January 2025
State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, China.
Transcription elongation, especially RNA polymerase II (Pol II) pause-release, is less studied than transcription initiation in regulating gene expression during meiosis. It is also unclear how transcription elongation interplays with transcription initiation. Here, we show that depletion of NKAPL, a testis-specific protein distantly related to RNA splicing factors, causes male infertility in mice by blocking the meiotic exit and downregulating haploid genes.
View Article and Find Full Text PDFNat Struct Mol Biol
January 2025
Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China.
Up to an estimated 10% of women experience miscarriage in their lifetimes. Embryonic aneuploidy is a leading cause for miscarriage, infertility and congenital defects. Here we identify variants of ELL3, a gene encoding a transcription elongation factor, in couples who experienced consecutive early miscarriages due to embryonic aneuploidy.
View Article and Find Full Text PDFSci China Life Sci
January 2025
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Mitochondrial Rho-GTPase 1 (MIRO1) is an outer mitochondrial membrane protein which regulates mitochondrial transport and mitophagy in mitosis. In present study, we reported the crucial roles of MIRO1 in mammalian oocyte meiosis and its potential relationship with aging. We found that MIRO1 expressed in mouse and porcine oocytes, and its expression decreased in aged mice.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!