Group II introns are usually removed from precursor RNAs as lariats comprised of a circular component and a short 3' tail. We find that group II introns can also be excised as complete circles. Circle formation requires release of the 3' exon of a splicing substrate, apparently by a trans splicing mechanism. After 3' exon release, the terminal uridine of the intron attacks the 5' splice site, releasing the 5' exon and joining the first and last intron residues by a 2'-5' phosphodiester bond. RNA isolated from yeast mitochondria also contains circles, indicating that at least one group II intron (aI2) forms circles in vivo. Furthermore, analysis of RNA and DNA from certain mutant yeast strains shows that circular DNA introns exist and are produced by reverse transcription of RNA, rather than by ectopic homing.
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http://dx.doi.org/10.1016/s1097-2765(01)00300-8 | DOI Listing |
Clin Genet
December 2024
IBMC-Institute for Molecular and Cell Biology, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
Hereditary spastic paraplegias (HSP) are a diverse group of neurodegenerative diseases characterized by lower limb spasticity and weakness. To date, over 80 genes have been associated with HSP, but many families remain without a molecular diagnosis. In this study, linkage analysis and whole-exome sequencing (WES) were performed to identify the causal gene in a HSP family with autosomal recessive inheritance.
View Article and Find Full Text PDFBMC Plant Biol
December 2024
College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.
Late Embryogenesis Abundant (LEA) proteins are extensively distributed among higher plants and are crucial for regulating growth, development, and abiotic stress resistance. However, comprehensive data regarding the LEA gene family in Ipomoea species remains limited. In this study, we conducted a genome-wide comparative analysis across seven Ipomoea species, including sweet potato (I.
View Article and Find Full Text PDFJ Nutr Biochem
December 2024
Research Group Nutrigenomics of Obesity and Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany; German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany; Research Group Molecular and Clinical Life Science of Metabolic Diseases, Faculty of Health Sciences Brandenburg, University of Potsdam, Brandenburg, Germany. Electronic address:
Alternative splicing contributes to diversify the cellular protein landscape, but aberrant splicing is implicated in many diseases. To which extent mis-splicing contributes to insulin resistance as the causal defect of type 2 diabetes and whether this can be reversed by lifestyle interventions is largely unknown. Therefore, RNA sequencing data from skeletal muscle and adipose tissue of diabetes-susceptible NZO mice treated with or without intermittent fasting and of healthy C57BL/6J mice subjected to exercise were analyzed for alternative splicing differences using Whippet and rMATS.
View Article and Find Full Text PDFJ Mol Evol
December 2024
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, 3Er Circuito de Ciudad Universitaria, Coyoacán, 04510, Mexico City, Mexico.
The massive increase in the amount of plastid genome data have allowed researchers to address a variety of evolutionary questions within a wide range of plant groups. While plastome structure is generally conserved, some angiosperm lineages exhibit structural changes. Such is the case of the megadiverse order Asterales, where rearrangements in plastome structure have been documented.
View Article and Find Full Text PDFFront Genet
December 2024
Research Group Animal Immunogenomics, CEITEC - VETUNI Brno, Brno, Czechia.
Manul () is the only representative of the genus which makes up the Leopard Cat lineage along with the genus . Their habitat is characterized by harsh environmental conditions. Although their populations are probably more stable than previously thought, it is still the case that their population size is declining.
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