Related Experiment Video
Updated: May 9, 2026

Assessment of DNA Contamination in RNA Samples Based on Ribosomal DNA
Published on: January 22, 2018
Multiple group I introns in the small-subunit rDNA of Botryosphaeria dothidea: implication for intraspecific genetic
Chao Xu1, Chunsheng Wang, Xinyao Sun
1Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
Abstract:
Botryosphaeria dothidea is a widespread and economically important pathogen on various fruit trees, and it often causes die-back and canker on limbs and fruit rot. In characterizing intraspecies genetic variation within this fungus, group I introns, rich in rDNA of fungi, may provide a productive region for exploration. In this research, we analysed complete small subunit (SSU) ribosomal DNA (rDNA) sequences of 37 B. dothidea strains, and found four insertions, designated Bdo.S943, Bdo.S1199-A, Bdo.S1199-B and Bdo.S1506, at three positions. Sequence analysis and structure prediction revealed that both Bdo.S943 and Bdo.S1506 belonged to subgroup IC1 of group I introns, whereas Bdo.S1199-A and Bdo.S1199-B corresponded to group IE introns. Moreover, Bdo.S1199-A was found to host an open reading frame (ORF) for encoding the homing endonuclease (HE), whereas Bdo.S1199-B, an evolutionary descendant of Bdo.S1199-A, included a degenerate HE. The above four introns were novel, and were the first group I introns observed and characterized in this species. Differential distribution of these introns revealed that all strains could be separated into four genotypes. Genotype III (no intron) and genotype IV (Bdo.S1199-B) were each found in only one strain, whereas genotype I (Bdo.S1199-A) and genotype II (Bdo.S943 and Bdo.S1506) occurred in 95% of the strains. There is a correlation between B. dothidea genotypes and hosts or geographic locations. Thus, these newly discovered group I introns can help to advance understanding of genetic differentiation within B. dothidea.
More Related Videos
06:58Isolation, Behavioral Identification, and Pathogenicity Assessment of Entomopathogenic Fungi from a Forest Wood Borer
Published on: September 29, 2023
12:01A PCR-based Genotyping Method to Distinguish Between Wild-type and Ornamental Varieties of Imperata cylindrica
Published on: February 20, 2012
Related Concept Videos
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Evolutionary Relationships through Genome Comparisons
Genetics of Speciation
Genetic Variation
Genes exist in different versions called alleles, which...
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Diversity of Protists IV