Mitochondrial DNA Research Articles

Major depressive disorder is associated with mitochondrial ND6 T14502C mutation in two Han Chinese families

BACKGROUND Globally, the World Health Organization ranks major depressive disorder (MDD) as the leading cause of disability. However, MDD molecular etiology is still poorly understood. AIM To explore the possible association between mitochondrial ND6 T14502C mutation and MDD. METHODS Clinical data were collected from two pedigrees, and detailed mitochondrial genomes were obtained for the two proband members. The assessment of the resulting variants included an evaluation of their evolutionary conservation, allelic frequencies, as well as their structural and functional consequences. Detailed mitochondrial whole genome analysis, phylogenetic, and haplotype analysis were performed on the probands. RESULTS Herein, we reported the clinical, genetic, and molecular profiling of two Chinese families afflicted with MDD. These Chinese families exhibited not only a range of onset and severity ages in their depression but also extremely low penetrances to MDD. Sequence analyses of mitochondrial genomes from these pedigrees have resulted in the identification of a homoplasmic T14502C (I58V) mutation. The polymorphism is located at a highly conserved isoleucine at position 58 of ND6 and distinct mitochondrial DNA (mtDNA) polymorphisms originating from haplogroups M10 and H2. CONCLUSION Identifying the T14502C mutation in two individuals with no genetic relation who exhibit symptoms of depression provides compelling evidence that this mutation may be implicated in MDD development. Nonetheless, the two Chinese pedigrees that carried the T14502C mutation did not exhibit any functionally significant mutations in their mtDNA. Therefore, the phenotypic expression of the T14502C mutation related to MDD may be influenced by the nuclear modifier gene(s) or environmental factors.

Deciphering Codon Usage Patterns in the Mitochondrial Genome of the Oryza Species

Rice (Oryza) is a genus in the Gramineae family, which has grown widely all over the world and is a staple food source for people’s survival. The genetic information of rice has garnered significant attention in recent years, prompting numerous researchers to conduct extensive investigations in this field. But rice mitochondrial codon usage patterns have received little attention. The present study systematically analyzed the codon usage patterns and sources of variance in the mitochondrial genome sequences of five rice species by the CodonW and R software programs. Our results revealed that the GC content of codons in rice mitochondrial genome genes was determined to be 43.60%. Notably, the individual codon positions exhibited distinct GC contents: 48.00% for position 1, 42.65% for position 2, and 40.16% for position 3. These findings suggest the preference of the rice mitochondrial genome for codons ending in A or U. A weak codon bias was observed, with the effective number of codons (ENC) varying between 40.02 and 61.00, with an average value of 54.34. Subsequently, we identified 25 identical high-frequency codons in five rice mitochondrial genomes, with 11 codons ending in A and 12 codons ending in U. The regression lines in the neutrality plot exhibited slopes of less than 0.5 in five rice species, indicating a predominant role of natural selection, while mutation pressure remained relatively insignificant. In the PR2-plot analysis, most of the genes were located in the right half of the plot, indicating that the third base of the synonymous codon was preferred to end in G than C. Additionally, the ENC plot and ENC ratio analysis unveiled that codon preferences in the rice mitochondrial genome were predominantly influenced by natural selection rather than mutational pressure. The analysis of correspondence revealed distinct variations in the codon usage pattern across five rice mitochondrial genomes. Based on the RSCU values of species, a cluster tree was inconsistent with the mitochondrial genetic data, indicating that RSCU data could not be used as a basis for classification at the species level in the Oryza genus. These results will help decide the specific types of natural selection pressures influencing codon usage and improve the expression of exogenous genes in rice mitochondrial genomes by optimizing their codons.

Maternal Genetic Diversity Analysis of Guanling Cattle by Mitochondrial Genome Sequencing

Maternal Genetic Diversity Analysis of Guanling Cattle by Mitochondrial Genome Sequencing

Genetic and linguistic comparisons reveal complex sex-biased transmission of language features

The history of people’s movements and interactions shapes both genetic and linguistic variation. Genes and languages are transmitted separately and their distributions reflect different aspects of human history, but some demographic processes can cause them to be similarly distributed. In particular, forms of societal organization, including movements in and out of a community, may have shaped the transmission of both genes and languages. If children were more likely to learn their mother’s language than their father’s when their parents were from populations that spoke different languages or dialects, then language variation might show a closer association with maternally transmitted genetic markers than autosomal ones; this association could be further reinforced if children reside with predominantly maternal kin. We analyze the worldwide relationship between linguistic and genomic variation, leveraging the sex-biased transmission of X chromosomes to assess whether language has tended to be preferentially transmitted along the male or female line. In addition, we measure the effects of postmarital residence with female kin, matrilineal descent, and endogamy on the covariation of mitochondrial DNA and languages, using mtDNA because genomic data were available for very few populations with these ethnographic traits. We find that while there is little evidence for a consistent or widespread sex bias in the transmission of language, such biased transmission may have occurred locally in several parts of the world and might have been influenced by population-level ethnographic characteristics, such as female-based descent or residence patterns. Our results highlight the complex relationships between genes, language, ethnography, and geography.

Correlation between circulating cell-free mitochondrial DNA content and severity of knee degeneration in patients with knee osteoarthritis: a cross-sectional study

Correlation between circulating cell-free mitochondrial DNA content and severity of knee degeneration in patients with knee osteoarthritis: a cross-sectional study

Improving onchocerciasis elimination surveillance: trials of odour baited Esperanza Window Traps to collect black fly vectors and real-time qPCR detection of Onchocerca volvulus in black fly pools

Abstract Background Entomological data for onchocerciasis surveillance relies on sampling black flies through human landing collectors in the field and laboratory testing of the flies for infection using pooled screening O-150 PCR-ELISA assay. Both techniques require improvements. This study aimed to optimize the Esperanza Window Trap (EWT) for black fly collection. We tested alternative carbon dioxide (CO2) mimics to attract black flies to the traps. Additionally, we evaluated new quantitative PCR (qPCR) methods that target mitochondrial DNA markers and have been proposed to enhance the sensitivity and specificity for detecting Onchocerca volvulus infections in blackflies. Methods Traps baited with low, medium and high release rates of either 2-butanone or cyclopentanone as CO2 mimics were field tested against traps baited with organically generated CO2 in four ecological zones in Nigeria: Guinea savannah, derived savannah, rainforest and montane forest. The performance of EWTs baited with CO2 or in combination with 2-butanone (low release) were subsequently evaluated against the human landing collection (HLC). Trap scaling was also pilot tested by comparing two EWTs to a single HLC team. Collected black flies were used to test detection of O. volvulus in black flies using Ov ND5 real-time PCR (qPCR) compared to the conventional pool screening O-150 PCR. Results EWTs baited with 2-butanone caught similar numbers of black flies (Simulium damnosum s.l.) to those baited with CO2, while cyclopentanone collected significantly fewer flies in all locations. The low release of 2-butanone was the most effective overall, although HLCs collected higher numbers of black flies than EWT baited with CO2 either singly or in combination with low-release 2-butanone. The combination of two EWTs baited with CO2 and deployed 100 m apart from each other collected similar numbers of flies as one HLC. More black fly pools were positive for O. volvulus by Ov ND5 qPCR compared with O-150 PCR in derived savannah (31.15 vs. 15.57%), montane forest (11.54 vs. 0%) and rainforest (23.08 vs. 2.56%), with only one positive pool in Guinea savannah detected by both methods. Conclusions The 2-butanone has potential to be used in xenomonitoring as a standardized replacement for organically generated CO2. Ov ND5 qPCR detected more positive pools than O-150 PCR. The positive pools found in foci hitherto considered to have interrupted/eliminated onchocerciasis highlight the need for more sensitive and specific methods that support programmatic assessments to identify and combat recrudescence. Graphical Abstract

Construction of molecular subtype and prognostic model for gastric cancer based on nucleus-encoded mitochondrial genes

Construction of molecular subtype and prognostic model for gastric cancer based on nucleus-encoded mitochondrial genes

Genomic Single Nucleotide Polymorphism (SNP) markers and mitochondrial haplotypes illuminate the origins of Crown-of-Thorns Starfish (Acanthaster solaris) outbreaks in the South China Sea.

Outbreaks of the coral predator Crown-of-Thorns Starfish (CoTS) pose a severe threat to coral reefs in the Indo-Pacific Ocean. In 2018, the South China Sea (SCS) experienced significant CoTS outbreaks, leading to extensive coral mortality across the Xisha, Zhongsha, Dongsha, and Nansha Islands, severely impacting the coral reef ecosystem. To explore the origins of these outbreaks, we conducted a comprehensive genomic analysis using data from genomic single nucleotide polymorphism sites (SNPs) and mitochondrial haplotypes. Our analysis reveals that CoTS populations in the SCS, which exhibit moderate genetic diversity and may have undergone positive selection or population expansion. There was limited genetic differentiation among CoTS populations from XS, ZS, and NS groups. Especially between the XS and ZS groups, there was almost no genetic differentiation. The populations from XS, ZS, and NS groups have strong genetic connections with populations in Vietnam and the Philippines. There was high gene flow from Vietnam to the Xisha Islands and from the Philippines to the Nansha Islands, suggesting that the CoTS populations in these regions primarily originate from these neighboring countries. The comprehensive analyses of SNP and mitochondrial genomes have provided valuable insights into the population genetics of CoTS. This research has generated significant genomic resources and facilitated important studies on the genetics of the CoTS species. By identifying potential source populations and understanding the genetic basis of their spread, managers can develop more effective conservation strategies to protect vulnerable coral reef ecosystems in the SCS.

Testing the informativeness of Y-STR and mitochondrial DNA control region markers in an attempt to predict ancestry of World War II victims from Slovenian mass grave.

Identification of human remains is a challenge in forensic genetics without relatives or personal items available. In Slovenia, a Konfin II mass grave from the Second World War (WWII) was found, containing skeletal remains of 65 victims. The archival documents detailing victims' information describe 45 persons of which 33 could be considered Germanic and 12 Slavic. This study aims to check for concordance between the victim list and actual victims found by using uniparental markers to differentiate between Slavic and non-Slavic origin by attempting to infer ancestry by analyzing the control region (CR) of mitochondrial DNA (mtDNA) and Y-chromosomal STRs. Diaphyses of femurs were used as a DNA source. Next Generation Sequencing (NGS) technology was used for mtDNA- namely HID Ion Chef™ Instrument, Precision ID mtDNA Control Region Panel, and Ion GeneStudio™ S5 System. For the Y-chromosome, PowerPlex® Y23 System (Promega) kit and SeqStudio™ for human identification (HID) were used. European DNA Profiling mtDNA Population Database (EMPOP) and Y-Chromosome STR Haplotype Reference Database (YHRD) were searched for haplotype matches. Closest haplogroups were predicted using EMPOP, Y-DNA Haplogroup Predictor- NevGen, and Whit Athey's Haplogroup Predictor. Despite mitotypes being more diverse than Y-haplotypes, the Y-haplotypes had more database matches and more unequivocal differentiation between populations. 16 victims could be considered Slavic, 15 non-Slavic, and the remaining 34 had a rather scarce informativeness- either unclear or not providing any match. To address ancestry inference more comprehensively, analysis of autosomal ancestry informative markers as well as expansion on haploid markers will be conducted in future research.

Repeat-rich regions cause false positive detection of NUMTs: a case study in amphibians using an improved cane toad reference genome.

Mitochondrial DNA (mtDNA) has been widely used in genetics research for decades. Contamination from nuclear DNA of mitochondrial origin (NUMT) can confound studies of phylogenetic relationships and mtDNA heteroplasmy. Homology searches with mtDNA are widely used to detect NUMTs in the nuclear genome. Nevertheless, false positive detection of NUMTs is common when handling repeat-rich sequences, whilst fragmented genomes might result in missing true NUMTs. In this study, we investigated different NUMT detection methods and how the quality of the genome assembly affects them. We presented an improved nuclear genome assembly (aRhiMar1.3) of the invasive cane toad (Rhinella marina) with additional long-read Nanopore and 10x linked-read sequencing. The final assembly was 3.47 Gb in length with 91.3% of tetrapod universal single-copy orthologs (n=5,310), indicating the gene-containing regions were well assembled. We used three complementary methods (NUMTFinder, dinumt and PALMER) to study the NUMT landscape of the cane toad genome. All three methods yielded consistent results, showing very few NUMTs in the cane toad genome. Furthermore, we expanded NUMT detection analyses to other amphibians and confirmed a weak relationship between genome size and the number of NUMTs present in the nuclear genome. Amphibians are repeat-rich, and we show that the number of NUMTs found in highly repetitive genomes is prone to inflation when using homology-based detection without filters. Together, this study provides an exemplar of how to robustly identify NUMTs in complex genomes when confounding effects on mtDNA analyses are a concern.

Endurance exercise attenuates Gαq-RNAi induced hereditary obesity and skeletal muscle dysfunction via improving skeletal muscle Srl/MRCC-I pathway in Drosophila.

G protein alpha q subunit (Gαq) can binds to the G protein-coupled receptor (GPCR) for signaling and is closely related to lipid metabolism. Endurance exercise is an effective means of combating acquired obesity and its complications, but the mechanisms by which endurance exercise modulates hereditary obesity and its complications are unknown. In this study, we achieved knockdown of Gαq in drosophila adipose tissue and skeletal muscle by constructing the Gαq-UAS-RNAi/Ppl-Gal4 and Gαq-UAS-RNAi/Mef2-GAl4 systems. Drosophila were subjected a three-week endurance exercise intervention, and changes in relevant indicators were detected and observed by RT-PCR, ELISA, oil red staining, immunofluorescence staining, and transmission electron microscopy. The results showed that knockdown of Gαq in both adipose tissue and skeletal muscle induced a significant increase in triglycerides accompanied by a decrease in rapid climbing ability, a decrease in Superoxide Dismutase (SOD) activity level, and a decrease in Mitochondrial respiratory chain complexI (MRCC I) content in Drosophila whole body and skeletal muscle, and down-regulated the expression of the G protein alpha q subunit (Gαq), the skeletal muscle myosin heavy chain expression gene (Mhc), mitochondrial biogenesis gene Spargal(the PGC-1alpha homologue in Drosophila). Endurance exercise significantly improved the triglyceride levels in the whole body and skeletal muscle of drosophila with Gαq knockdown in adipose tissue and skeletal muscle, as well as their ability to climb, increased SOD activity level and MRCCI content level, and up-regulated the expression of Gαq, Mhc, and Spargal(Srl). Thus, the present findings suggest that genetic defects in the Gαq gene in adipose and skeletal muscle tissues induce hereditary obesity and skeletal muscle dysfunction, and that endurance exercise attenuates this hereditary obesity and concomitant skeletal muscle dysfunction in drosophila by improving skeletal muscle fiber contractile proteins, mitochondrial function and function, and antioxidant capacity via mediating the Gαq/Mhc, Gαq/Srl/MRCC-I, and Gαq/SOD pathways.

A new blood parasite of the accentor birds: description, molecular characterization, phylogenetic relationships and distribution.

Haemoproteus bobricklefsi sp. nov. (Haemosporida, Haemoproteidae) was found in the dunnock Prunella modularis and represents the first blood parasite described in accentor birds of the Prunellidae. The description is based on the morphology of blood stages and includes information about a barcoding segment of the mitochondrial cytochrome b gene (lineage hDUNNO01) and the full mitochondrial genome, which can be used for identification and diagnosis of this infection. The new parasite can be readily distinguished from described species of haemoproteids parasitizing passeriform birds due to markedly variable position of nuclei in advanced and fully grown macrogametocytes. Illustrations of blood stages of the new species are given, and phylogenetic analyses based on partial mitochondrial cytochrome b gene sequences and the full mitochondrial genome identified the closely related lineages. DNA haplotype networks showed that transmission occurs in Europe and North America. This parasite was found in the dunnock in Europe and several species of the Passerellidae in North America. It is probably of Holarctic distribution, with the highest reported prevalence in the UK. The parasite distribution seems to be geographically patchy, with preference for areas of relatively cool climates. Phylogenetic analysis suggests that H. bobricklefsi sp. nov. belongs to the Parahaemoproteus subgenus and is probably transmitted by biting midges belonging to Culicoides (Ceratopogonidae). The available data on molecular occurrence indicate that this pathogen is prone to abortive development, so worth attention in regard of consequences for bird health.

The discovery of an overseen pygmy backswimmer in Europe (Heteroptera, Nepomorpha, Pleidae).

The Pleidae, or pygmy backswimmers, is a family of aquatic bugs (Hemiptera, Heteroptera, Nepomorpha) containing four genera. Here, we describe Plea cryptica sp. nov. and redescribe its sister species, Plea minutissima Leach, 1817. Whereas the morphological distinction of these closely related species is only possible for males, molecular data clearly separate them. As part of our taxonomic study, we provide comprehensive molecular data including more than 200 DNA barcodes from all over Europe, complete nuclear ribosomal DNA, full mitochondrial genome data, and 3D scans for both species. Furthermore, the same molecular markers are also presented for Neoplea striola (Fieber, 1844). We used Maximum Likelihood (ML) analyses to reconstruct the phylogeny of the Pleidae and Notonectoidea based on available mitogenomic data. Our study represents a successful implementation of the proposed concept of taxonomics, using data from high-throughput sequencing technologies for integrative taxonomic studies, and allowing high confidence for both biodiversity and ecological research.

The complete mitochondrial DNA of the carnivorous sponge Lycopodina hypogea is putatively complemented by microDNAs

Carnivorous sponges (Porifera, Demospongiae, Cladorhizidae), contrary to the usual filter-feeding mechanism of sponges, are specialized in catching larger prey through adhesive surfaces or hook-like spicules. The mitochondrial DNA of sponges overall present several divergences from other metazoans, and while presenting unique features among major transitions, such as in calcarean and glass sponges, poriferan mitogenomes are relatively stable within their groups. Here, we report and discuss the mitogenome of Lycopodina hypogea (Vacelet & Boury-Esnault, 1996), which greatly vary from its subordinal counterparts in both structure and gene order. This mitogenome is seemingly multipartite into three chromosomes, two of them as microDNAs. The main chromosome, chrM1, is unusually large, 31,099 bp in length, has a unique gene order within Poecilosclerida, and presents two rRNA, 13 protein and 19 tRNA coding genes. Intergenic regions comprise approximately 40% of chrM1, bearing several terminal direct and inverted repeats (TDRr and TIRs) but holding no vestiges of former mitochondrial sequences, pseudogenes, or transposable elements. The nd4l and trnI(gau) genes are likely located in microDNAs thus comprising putative mitochondrial chromosomes chrM2, 291 bp, and chrM3, 140 bp, respectively. It is unclear which processes are responsible for the remarkable features of the of L. hypogea mitogenome, including a generalized gene rearrangement, long IGRs, and putative extrachromosomal genes in microDNAs.

Global Invasion of Thrips parvispinus (Karny) (Thysanoptera: Thripidae) Across Three Continents Associated With Its One Haplotype

ABSTRACTThrips parvispinus (Karny) is an exotic pest that has invaded many regions around the world in the last three decades. It was first detected in Florida in 2020 on ornamental plants (Hoya and Anthurium) in greenhouses and subsequently on ornamental plants in residential landscapes (Gardenia) in 2021. However, its first report on open vegetable field crops (Capsicum) in Florida was in 2022. We conducted field surveys and genetic analysis to answer three questions: (1) Is the population of T. parvispinus that invaded Florida the same as the one that has spread globally in the last few decades? (2) Is the host expansion to Capsicum in Florida a new population or the extension of the existing population reported on ornamental plants? and (3) What are the native and invaded distribution ranges of T. parvispinus? We analysed the genetic variation in the mitochondrial gene cytochrome oxidase I (COI) to address these questions. The global genetic diversity analysis of T. parvispinus revealed 18 haplotypes (populations) worldwide based on available data, but only one population (Hap1) invaded three continents: Africa, Europe, and North America. Based on available data, the highest haplotype diversity was observed in India, suggesting India may be part of the presumed native range (South and Southeast Asian countries) of T. parvispinus. Our survey of retail plant stores across 10 Florida counties indicated that plant trade is the source of T. parvispinus in open vegetable field crops and ornamental landscape plants. The outcome of this study will assist with regulatory and management decisions of T. parvispinus in Florida and elsewhere.

Peripheral immune cell abundance differences link blood mitochondrial DNA copy number and Parkinson's disease.

Mitochondrial dysfunction plays an important role in Parkinson's disease (PD), with mitochondrial DNA copy number (mtDNA-CN) emerging as a potential marker for mitochondrial health. We investigated the links between blood mtDNA-CN and PD severity and risk using the Accelerating Medicines Partnership program for Parkinson's Disease dataset, replicating our results in the UK Biobank. Our findings reveal that reduced blood mtDNA-CN levels are associated with heightened PD risk and increased severity of motor symptoms and olfactory dysfunction. We estimated blood cell composition using complete blood cell profile when available or RNA-sequencing data as a surrogate. After adjusting for blood cell composition, the associations between mtDNA-CN and PD risk and clinical symptoms became non-significant. Bidirectional Mendelian randomization analysis also found no evidence of a direct causal relationship between blood mtDNA-CN and PD susceptibility. Hence peripheral inflammatory immune responses rather than mitochondrial dysfunction underpin these previously identified associations in PD.

Circulating levels of Low Density Granulocytes and cell-free DNA as predictors of cardiovascular disease and bone deterioration in SLE patients.

The present work evaluates the predictive value of low-density-granulocytes (LDG) for the development of cardiovascular disease (CVD) and/or bone deterioration (BD) in a six-year prospective study in Systemic Lupus Erythematosus (SLE). Considering the high SLE-LDG capacity to form Neutrophil Extracellular Traps (NETs), circulating levels of total cell-free DNA (cirDNA) and relative amounts of mitochondrial and nuclear DNA (mtDNA and nDNA, respectively) were tested as LDG-associated biomarkers to identify SLE patients at risk of CVD and BD. To this end, the frequency of total blood LDGs, as well as the CD16negCD14neg (nLDG) and CD16posCD14low (pLDG) subsets, was quantified by flow cytometry in 33 controls and 144 SLE patients. Total cirDNA and relative amounts of mitochondrial (mtDNA) and nuclear (nDNA) cell-free DNA were measured by fluorometry or qPCR in plasma from a subgroup of 117 patients and 23 controls at enrolment. Our findings showed increased blood levels of SLE-nLDGs at enrolment associated with prospective CVD development (pCVD) and the presence of BD, thus revealing LDG expansion as a predictor of both comorbidities in SLE progression. The amounts of the different types of circulating DNA analysed were increased in patients, especially those presenting traditional CV-risk factors or subclinical atheromatosis. Similar to nLDGs, the nDNA concentration could predict the development of pCVD in SLE, supporting the quantification of cirDNA levels as a surrogate marker of LDGs in clinical practice.

The genome sequence of bronze sap hoverfly, Ferdinandea cuprea (Scopoli, 1763)

We present a genome assembly from an individual Ferdinandea cuprea (bronze sap hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence has a total length of 560.20 megabases. Most of the assembly (99.92%) is scaffolded into 5 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.0 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,662 protein-coding genes.

Mitochondrial Genome Instability in W303-SK1 Yeast Cytoplasmic Hybrids

Unlike most animals, some fungi, including baker’s yeast, inherit mitochondrial DNA (mtDNA) from both parents. When haploid yeast cells fuse, they form a heteroplasmic zygote, whose offspring retain one or the other variant of mtDNA. Meanwhile, some mutant mtDNA (rho−), with large deletions in the nucleotide sequence, can displace wild-type (rho+) mtDNA. Consequently, offspring of zygotes with such rho− mtDNA predominantly carry the mutant variant. This phenomenon is called suppressivity. In this study, we investigated how the suppressivity of rho− mtDNA depends on the mitochondrial and nuclear genomes of the rho+ strain during crossing. Comparing two diverged laboratory strains, SK1 and W303, we measured suppressivity in crosses with four rho− strains. One rho− strain showed significantly higher suppressivity when crossed with SK1 than with W303. We then created cytoplasmic hybrids by swapping mtDNAs between these strains. Surprisingly, we found that the mtDNA of the rho+ strain, rather than its nuclear DNA, determines high suppressivity in crosses of SK1 rho+ with the rho− strain. Additionally, mtDNA replacement reduced respiration rate and growth rate on non-fermentable substrates while increasing the likelihood of functional mtDNA loss. Our data demonstrate that a mutant mtDNA variant’s ability to displace another mitochondrial DNA variant in a heteroplasmic cell depends more on mtDNA sequences than on the biochemical and structural context created by the nuclear genome background.

Drastic variation in mitochondrial genome organization between two congeneric species of bird lice (Philopteridae: Ibidoecus).

The over 4,100 species of bird lice are classified into 214 genera in the parvorders Amblycera and Ischnocera. Congeneric species of bird lice usually share much similarity in morphology and in mitochondrial (mt) genome organization. Two recent studies, however, reported substantial intra-genus variation in mt genome organization in bird lice. Both the ancestral single-chromosome mt genome and a fragmented mt genome with two or three minichromosomes were observed in the genera Austromenopon and Laemobothrion. To better understand intra-genus variation in mt genome organization, we sequenced the complete mt genome of the white spoonbill louse Ibidoecus plataleae and compared it with that of the glossy ibis feather louse Ibidoecus bisignatus reported previously. We found that I. plataleae had a fragmented mt genome with 12 minichromosomes; each minichromosome was 2,798 to 3,628bp in size and had 2 to 6 genes. This is in stark contrast to the mt genome of I. bisignatus, which has all genes on a single chromosome, 14,909bp in size. This is the most drastic intra-genus variation in mt genome organization observed to date in animals, indicating an unprecedented rapid process of mt genome fragmentation in the genus Ibidoecus. The divergence time between I. plataleae and I. bisignatus is currently unknown but is estimated to be less than 23million years. Either many minichromosal split events occurred after I. plataleae diverged from I. bisignatus, or one minichromosome splits into multiple minichromosomes in a single event. Sequencing and comparing more Ibidoecusi species will help understand the unusual mt genome fragmentation in this genus.