Related Experiment Video
Updated: Dec 22, 2025
07:24
Genotyping Single Nucleotide Polymorphisms in the Mitochondrial Genome by Pyrosequencing
Published on: February 10, 2023
1.8K
Mitochondrial Genome Polymorphisms in the Human Pathogenic Fungus Cryptococcus neoformans
Yue Wang1, Jianping Xu1,2
1Department of Biology, McMaster University, Hamilton, ON, Canada.
Frontiers in Microbiology
|May 7, 2020
Summary
Mitochondrial genomes of Cryptococcus neoformans vary in size due to introns, revealing dynamic evolution and distinct sub-clades within this fungal pathogen. These findings enhance our understanding of Cryptococcus neoformans evolution.
Area of Science:
- Mycology
- Genomics
- Evolutionary Biology
Background:
- The *Cryptococcus* complex causes significant fatal human infections globally.
- *Cryptococcus neoformans* is the dominant lineage, comprising VNI, VNII, and VNB clades, with complex mating and diploidization events.
- Understanding the genetic diversity and evolution of *C. neoformans* is crucial for public health.
Purpose of the Study:
- To analyze the mitochondrial genomes (mitogenomes) of 184 *C. neoformans* strains.
- To investigate the impact of mitochondrial introns on mitogenome size and variation.
- To elucidate the evolutionary relationships and dynamics within *C. neoformans* clades using mitogenome data.
Main Methods:
- Sequencing and analysis of 184 *C. neoformans* mitogenomes.
- Comparative analysis of mitogenome size, gene content, and gene order.
- Phylogenetic analysis using concatenated mitochondrial exon sequences and intron-exon pairs.
- Investigation of intron distribution and its evolutionary implications.
Main Results:
- All analyzed mitogenomes shared the same 15 protein-coding genes but varied in size (24,740–31,327 bp) due to mitochondrial introns.
- Phylogenetic analyses of exon sequences largely supported existing clade structures (VNI, VNII, VNB) but revealed novel relationships and hybrid mitogenome inheritance.
- Evidence of frequent mitochondrial intron gains and losses was observed, suggesting a dynamic evolutionary process.
- Recombinant mitogenomes were identified in diploid hybrids, including those between *C. neoformans* and *C. deneoformans*.
Conclusions:
- Mitochondrial genome evolution in *C. neoformans* is dynamic, characterized by significant variation in intron content and frequent intron turnover.
- Mitogenome data provides valuable insights into the population structure and evolutionary history of *C. neoformans*, supporting further division into sub-clades.
- The study highlights the complexity of mitochondrial genome inheritance in fungal hybrids.
More Related Videos
Related Concept Videos
01:28Fungal Phylum Microsporidia
321
Microsporidia are a group of obligate intracellular fungi that were initially classified as protists but were later reclassified based on phylogenetic, molecular, and structural evidence linking them to the Chytridiomycota. These unicellular, non-motile organisms are highly specialized parasites that infect a wide range of animal hosts, including humans. They have evolved extensive genomic and metabolic reductions, making them highly dependent on their hosts for survival.Morphology and Genomic...
321
02:59Animal Mitochondrial Genetics
8.8K
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
8.8K
01:18Mutations in Microorganisms
423
Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,...
423
02:16Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes
14.9K
The present-day mitochondrial and chloroplast genomes have retained some of the characteristics of their ancestral prokaryotes and also have acquired new attributes during their evolution within eukaryotic cells. Like prokaryotic genomes, mitochondrial and chloroplast genomes neither bind with histone-like proteins nor show complex packaging into chromosome-like structures, as observed in eukaryotes. Unlike mitotic cell divisions observed in eukaryotic cells, mitochondria and chloroplasts...
14.9K
02:26Comparing Copy Number Variations and SNPs
18.5K
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
18.5K
01:05Single Nucleotide Polymorphisms-SNPs
17.7K
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
17.7K