Mitochondrial DNA Sequences Research Articles

Molecular phylogenetic and historical biogeographical relationships of Laudakia (Squamata: Agamidae) and intraspecific differentiation of L. stoliczkana inferred from mitochondrial DNA sequences

The rock lizard genus Laudakia is representative agamid species from the arid zone, and its genus division has not been resolved yet. Laudakia stoliczkana, which occurs in both Xinjiang, China, and the Gobi Altai, Mongolia, is divided into two subspecies, Laudakia stoliczkana stoliczkana and Laudakia stoliczkana altaica, based on morphological differences, but little is known about the molecular genetic differences between the two subspecies. This study reconstructs the phylogenetic tree of Laudakia and analyses molecular differences between two subspecies of L. stoliczkana by DNA barcoding (COI and 16S). Our results show that: (1) Laudakia is monophyletic and the phylogenetic tree is broadly divided into three main branches, namely branch A (L. caucasia and L. stoliczkana), which occurs mainly in Central Asia and the Gobi Altai region to the north, branch B (L. stellio), which occurs in the Middle East, and branch C (L. tuberculata, L. papenfussi, L. himalayana, L. wui, L. stellio), which occurs mainly near the Himalayas; (2) The biogeographic analysis of Laudakia suggests that the genus probably originated at 43.72 Ma (95% confidence interval HPD: 23.53–66.12Ma) and is associated with the uplift of the Tibetan Plateau and the aridification of Central Asias subsequently; (3) Molecular genetic distances and morphological differences support the delimitation of the two subspecies of L. stoliczkana, with divergence between the two subspecies estimated to have occurred at 3.27 Ma (95% confidence interval HPD: 1.58–5.87Ma), in associated with the recent uplift of the Tian Shan Mountains. The results highlight the importance of the uplift of the Central Asian mountains and the Tibetan Plateau for the divergence of Laudakia.

Jellyfish Venom Peptides Targeting Human Potassium Channels Identified through Ligand Screening: Morphometric and Molecular Identification of the Species and Antibiotic Potential.

The relative lack of marine venom could be attributed to the difficulty in dealing with venomous marine animals. Moreover, the venom of marine animals consists of various bioactive molecules, many of which are proteins with unique properties. In this study, we investigated the potential toxic proteins of jellyfish collected for ligand screening to understand the mechanism of the toxic effects of jellyfish. Since taxonomic identification is problematic due to the lack of proper keys, we conducted morphological and molecular mitochondrial DNA sequencing from COI and ITS regions. The venom extract from nematocysts found along the bell margins was used for protein characterization using SDS-gel electrophoresis and nano-liquid chromatography-tandem mass spectrometry. Ligand screening for the most potent toxin and antibacterial and cytotoxicity assays were carried out. The phylogenetic tree showed distinct clustering from other Catostylus sp. The proteomic analysis revealed venom with many bioactive proteins. Only 13 venom proteins were identified with molecular weights ranging from 4318 to 184,923 Da, exhibiting the venom's complexity. The overall toxin protein composition of Catostylus sp. venom was dominated by potassium channel toxin alpha-KTx. Molecular docking of toxin alpha-KTx 1.13 revealed high specificity towards the human voltage-gated potassium channel Kv3 with a high fitness score and a minimum energy barrier of -17.9 kcal/mol. Disc diffusion and cytotoxicity assays revealed potent antibacterial activity against Klebsiella pneumoniae with no cytotoxicity. Further studies on detailed characterization and therapeutic potentials are warranted.

Investigating the relative role of dispersal and demographic traits in predictive phylogeography

Many studies suggest that aside from environmental variables, such as topography and climate, species‐specific ecological traits are relevant to explain the geographic distribution of intraspecific genetic lineages. Here, we investigated whether and to what extent incorporating such traits systematically improves the accuracy of random forest models in predicting genetic differentiation among pairs of localities. We leveraged available ecological datasets for birds and tested the inclusion of two categories of ecological traits: dispersal‐related traits (i.e. morphology and foraging ecology) and demographic traits (such as species survival rate and generation length). We estimated genetic differentiation from published mitochondrial DNA sequences for 28 species of birds (1578 total genetic samples, 391 localities) in the Atlantic Forest of South America. Aside from the aforementioned ecological traits, we included geographic, topographic and climatic distances between localities as environmental predictors. We then created models using all available data to evaluate model uncertainty both across space and across the different categories of predictors. Finally, we investigated model uncertainty in predicting genetic differentiation individually for each species (a common challenge in conservation biology). Our results show that while environmental conditions are the most important predictors of genetic differentiation, model accuracy largely increases with the addition of ecological traits. Additionally, the inclusion of dispersal traits improves model accuracy to a larger extent than the inclusion of demographic traits. Similar results are observed in models for individual species, although model accuracy is highly variable. We conclude that ecological traits improve predictive models of genetic differentiation, refining our ability to predict phylogeographic patterns from existing data. Additionally, demographic traits may not be as informative as previously hypothesized. Finally, prediction of genetic differentiation for species with conservation concerns may require further careful assessment of the environmental and ecological variation within the species range.

Disparities in Genetic Diversity Drive the Population Displacement of Two Invasive Cryptic Species of the Bemisia tabaci Complex in China.

Within the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) complex, two cryptic species, namely Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), are important invasive pests affecting global agriculture and horticulture. They were introduced into China sequentially in the mid-1990s and around 2003, respectively. Subsequently, the latter invader MED has outcompeted the earlier invader MEAM1, becoming the dominant population in the field. Although extensive studies have explored the underlying mechanisms driving this shift, the contribution of population genetics remains notably underexplored. In this study, we analyzed the genetic diversity and structure of 22 MED and 8 MEAM1 populations from various regions of China using mitochondrial DNA sequencing and microsatellite genotyping. Our results indicate low and moderate levels of genetic differentiation among geographically separate populations of MED and MEAM1, respectively. Median-joining network analysis of mtCOI gene haplotypes revealed no clear geographic structuring for either, with common haplotypes observed across provinces, although MED had more haplotypes. Comparative analyses revealed that MED presented greater genetic diversity than MEAM1 on the basis of two markers. Furthermore, analysis of molecular variance supported these findings, suggesting that while some genetic variation exists between populations, a significant amount is also present within populations. These findings reveal the population genetics of the two invasive cryptic species of the B. tabaci complex in China and suggest that the disparities in genetic diversity drive the displacement of their populations in the field. This work also provides valuable information on the genetic factors influencing the population dynamics and dominance of these invasive whitefly species.

Joint and Individual Mitochondrial DNA Variation and Cognitive Outcomes in Black and White Older Adults.

Mitochondrial dysfunction manifests in neurodegenerative diseases and other age-associated disorders. In this study, we examined variation in inherited mitochondrial DNA (mtDNA) sequences in Black and White participants from 2 large aging studies to identify variants related to cognitive function. Participants included self-reported Black and White adults aged ≥70 years in the Lifestyle Interventions and Independence for Elders (LIFE; N = 1319) and Health Aging and Body Composition (Health ABC; N = 788) studies. Cognitive function was measured by the Digit-Symbol Substitution Test (DSST), and the Modified Mini-Mental State Examination (3MSE) at baseline and over follow-up in LIFE (3.6 years) and Health ABC (10 years). We examined the joint effects of multiple variants across 16 functional mitochondrial regions with cognitive function using a sequence kernel association test. Based on these results, we prioritized meta-analysis of common variants in Black and White participants using mixed effects models. A Bonferroni-adjusted p value of <.05 was considered statistically significant. Joint variation in subunits ND1, ND2, and ND5 of Complex I, 12S RNA, and hypervariable region (HVR) were significantly associated with DSST and 3MSE at baseline. In meta-analyses among Black participants, variant m.4216T>C, ND1 was associated with a faster decline in 3MSE, and variant m.462C>T in the HVR was associated with a slower decline in DSST. Variant m.5460G>C, ND2 was associated with slower and m.182C>T in the HVR was associated with faster decline in 3MSE in White participants. Among Black and White adults, oxidative phosphorylation Complex I variants were associated with cognitive function.

Ctenotus rungulla sp. nov. (Scincidae; Sphenomorphinae), a new sandstone-associated skink that highlights reptile endemism in Queensland's Gregory Range

Cuckoo wasp strip.jpg Open-access, online, rapid taxonomy Australian Journal of Taxonomy AJT Home | Taxonomy Australia Home https://doi.org/10.54102/ajt Ctenotus rungulla sp. nov. (Scincidae; Sphenomorphinae), a new sandstone-associated skink that highlights reptile endemism in Queensland's Gregory Range Stephen M. Zozaya, Dylan W. Case, &amp; Conrad J. Hoskin Author details ⏷ Abstract We describe a new sphenomorphine skink, Ctenotus rungulla sp. nov., currently known only from sandstone habitats in the Gregory Range of inland northern Queensland. Ctenotus rungulla sp. nov. would be identified as C. brevipes or C. terrareginae using keys available at the time of publication. The new species differs most obviously from the regionally sympatric C. brevipes in having 5–6 distinct ear lobules, which are entirely absent in C. brevipes. The new species differs from the allopatric C. terrareginae in being smaller and in various aspects of colour-pattern. Mitochondrial DNA sequence data, however, indicate that C. rungulla sp. nov. is most closely related to the allopatric C. ingrami, from which the new species differs in being smaller, lacking a vertebral stripe, possessing a red-orange flush on the hindbody, and in having a higher midbody scale row count. Ctenotus rungulla sp. nov. is now the fourth reptile species known to be endemic to the Gregory Range, highlighting the biodiversity values of this remote rocky region.

Integrative Taxonomy Suggests Resurrection of Species of the Astyanax bimaculatus Group (Characiformes, Characidae).

Using integrative tools can be effective for species identification, especially in complex groups like Astyanax. Astyanax bimaculatus group is composed of six valid species, including A. lacustris. "A. altiparanae", "A. asuncionensis", and "A. jacuhiensis" are considered as junior synonyms of A. lacustris. Seeking to test the operational taxonomic unit (OTU) status of the junior synonyms of A. lacustris ("A. altiparanae", "A. asuncionensis", and "A. jacuhiensis"), we used analyses through mitochondrial DNA (COI and Cytb), cytogenetic markers (classical and molecular), and morphometry ("truss network"). Analysis of mitochondrial DNA sequences separated A. lacustris from the other synonymized species. The cytogenetic and morphometric analyses did not corroborate the synonymization and suggest that besides A. lacustris, the OTUs A. altiparanae, A. asuncionensis, and A. jacuhiensis are valid species. The analysis of different characters proposed by the integrative taxonomy used on the same individuals could provide greater reliability and minimize the underestimation of biodiversity.

Origins and taxonomic status of Hemidactylus geckos on the Îles Éparses of the Western Indian Ocean

Distinguishing between anthropogenic introductions and natural colonizations can be complex, especially in groups that are evidently both capable natural colonizers and anthropophilic, such as some geckos of the genus Hemidactylus. However, such information is fundamental both for constructing appropriate conservation approaches, as well as to identify biogeographical patterns. Here we assessed the origins and taxonomic status of the Hemidactylus geckos found on the Îles Éparses, disjunct small islands of the western Indian Ocean located around Madagascar, using partial mitochondrial DNA sequences. Hemidactylus platycephalus was confirmed on Juan de Nova, presumed introduced from continental Africa. The H. mabouia-mercatorius complex was identified on Juan de Nova, Europa, Tromelin, and Grande Glorieuse, with H. mabouia (sensu stricto) on Juan de Nova and H. mercatorius on Europa, from where it is likely to have been introduced to Tromelin. An unnamed lineage within H. mercatorius, previously known only from the Aldabra Islands, was identified on Grande Glorieuse, and further demonstrated the unexpectedly high genetic diversity within this lineage.

Drawing mitochondrial genomes with circularMT.

Mitochondrial DNA sequences are used extensively in phylogeographic and phylogenetic studies for a wide range of organisms. With the advent of low-cost, high throughput 'next generation' DNA sequencing, and user-friendly bioinformatics pipelines for generating and annotating whole mitochondrial genome assemblies, the analysis of whole mitochondrial genomes has become an important component of phylogenomic studies for taxa with high species diversity but limited coverage for other genomic resources. An important step in characterizing de novo mitochondrial genome assemblies is to evaluate and describe structural rearrangements relative to reference taxa. Accessible tools are needed to help visualize gene and noncoding feature complement, their order and strand orientation. However, there are few dedicated applications that generate high quality genome diagrams. Here we present circularMT and circularMT-console that allow users to create highly customizable, publication quality images, of linear and circular mitochondrial genome maps, either individually, or integrated into an analysis pipeline. Both applications are implemented in C#, with binaries, source code and user guides available on GitHub (https://github.com/msjimc/circularMT). An archive of the published version is available on Zenodo (https://zenodo.org/records/10912319). This paper has no supplementary data.

Morphological, Molecular Identification and Genetic Diversity Assessment of Three Terrestrial Isopods from the High-Altitude Region

Terrestrial specimens were collected from Ashshafa, a south-western highland area in Saudi Arabia. Three species, i.e., Porcellio laevis, Porcellionides pruinosus (Porcellionidae), and Armadillidium vulgare (Armadillidiidae), were identified in this study based on their morphological characteristics. Partial mitochondrial cytochrome C oxidase subunit I (COI) gene sequences were used for DNA barcoding and biodiversity assessments. A phylogenetic tree of 22 haplotypes from 35 specimens of the three isopod species was drawn from the most similar sequences obtained from BLAST with the associated accession numbers. The tree included two clades. The first clade included samples of P. laevis and P. pruinosus, whereas the second clade included samples of A. vulgare. Each identified species formed a distinct subclade within the main clade, along with similar sequences obtained from the NCBI database. The heat map of genetic distance among haplotypes shows the haplotype diversity (Hd) ranged from 0.590 to 0.933 (mean = 0.767) and total nucleotide diversity (πT) ranged from 0.001 to 0.089 (mean=0.049), with a similar trend observed for nucleotide diversity per site (θw) ranged from 0.001 to 0.80 (mean = 0.049). In contrast, synonymous nucleotide diversity (πs), mean=0.009, was low compared to nonsynonymous nucleotide diversity (πs), mean=0.060, across all species. In conclusion, the morphological identification of terrestrial isopods was confirmed using COI gene sequencing of mitochondrial DNA. These results will be helpful in developing a deeper isopod identification method.

Insight into the genetic diversity of Selle Français horse populations based on whole D-loop sequencing of mitochondrial DNA

The Selle Français (SF) breed originated from native France horses crossed with Thoroughbreds, Arabs, Anglo-Arabs and French Trotters, which allowed for individuals to be obtained with excellent predispositions and a versatile usage for equestrian sports. The performance of the SF horse is widely accepted in the fields of show jumping and eventing; however, they have successfully started to compete in other areas such as dressage, vaulting, carriage driving and TREC competitions. To date, information about the genetic structure of the SF breed has been very limited. In the present report, Sanger sequencing was applied to analyse the whole D-loop of mitochondrial DNA of 98 samples representing Selle Français horses originating from two populations: Algerian (n=47) and French (n=51). The result obtained showed the presence of 19 SNPs, which allowed us to divide the samples into 41 haplotypes (OR909723‐OR909773). A higher number of haplotypes was detected in the Algerian population (n=24) compared to the French population (n=14), but both populations did not represent unique clusters and showed a high degree of genetic similarities. The result showed that the identified haplotypes of the SF belonged to four clades: L, A, B and G. The present report gives strong evidence that the Selle Français breed has been established based on a great influence of the Thoroughbred, whose close connection is more visible in the French population. The haplogroup assignment to L clades proved that the SF breed has European origin as ancestral haplogroup L was assigned to West and South Europe while A to West Asia and G and B to Middle East. Our results show SF as an example of a contemporary breed of sport horses with European roots further influenced by local breeds.

Constraining the radiocarbon reservoir age for the Southern Ocean using whale bones salvaged from early 20th century whaling stations

Radiocarbon dating is arguably the most common method for dating Quaternary deposits. However, accurate age assignments using radiocarbon dating are dependent on knowing the radiocarbon reservoir. For the coastal waters across Antarctica, the radiocarbon reservoirs show significant variation, ranging from 700 to 6000 years depending on the material dated and the period in question. In this study, we examine the radiocarbon reservoir age for the shallow waters of the Southern Ocean using 23 whale bones salvaged from commercial whaling operations on or near the Western Antarctic Peninsula between 1904 and 1916. The species origin of the bones had been identified previously as humpback, fin, or blue whales using sequences of mitochondrial (mt)DNA. We find an average reservoir age of 1050 ± 135 years for these 23 whale bones, with a <100-year difference in the reservoir age by species. A comparison between our results and other studies through the Holocene suggest that the Southern Ocean surface water radiocarbon reservoir age is of a similar magnitude across much of Antarctica and has not significantly changed for the last 14,000 years. Combining our new ages with existing data sets provides insight to the stability of the Southern Ocean marine radiocarbon reservoir age, enhancing our understanding of ocean ventilation and upwelling dynamics throughout the Holocene.

Genetic Diversity and Population Structure of the Endangered Salamander Hynobius yiwuensis Inferred from Mitochondrial DNA Sequences.

Understanding the genetic diversity patterns of endangered species is crucial for biodiversity conservation. The endangered salamander Hynobius yiwuensis, endemic to the mainland and Zhoushan Island in Zhejiang, China, has suffered from sharp population declines due to habitat loss. However, the levels and patterns of genetic diversity, differentiation, and population structure of H. yiwuensis remain poorly understood. Here, we explored the genetic diversity and phylogeography of H. yiwuensis based on partial mtDNA sequences (Cytb and CO1) through 111 individuals collected from seven localities. Relatively high overall haplotype diversity (h = 0.965) and low nucleotide diversity (π = 0.013) were detected. Our results, through phylogenetic trees and haplotype network analyses, revealed two divergent haplogroups, mainland and island, and the estimated divergence time indicated they diverged ~2.44 million years ago, which coincided with the period when Zhoushan Island became separated from the mainland.

The discovery of a ten-generation m.C1494T pedigree in the east of England with probable links to King Richard III

This paper reports the discovery of a m.C1494T pedigree in the east of England made during a search for matrilineal relations of King Richard III.The mitochondrial DNA variant m.C1494T has been associated with aminoglycoside-induced deafness. This variant is very uncommon. although pedigrees with this variant have previously been found in China and Spain. The members of the newly identified pedigree all belong to the mitochondrial haplogroup J1c2c3, which is also the haplogroup of King Richard III. The presence of a few people in the USA from the same haplogroup has previously been noted, and it is now known that one of the people can show his descent from a couple who lived in Nottinghamshire, England, in the late 1700's. The mitochondrial DNA sequence of this man, at present living in the USA, and of his 4th cousin, twice removed, living in Lincoln, England, has shown they belong to haplogroup J1c2c3 and both have the variant m.C1494T; thereby, allowing the production of a multi-generational pedigree originating in the east of England. Fortunately, deafness has not been found in any living member of this large pedigree. It was also noted that the link to the family of King Richard III has not been firmly defined; however the circumstantial evidence is strong as many of his family members lived in this part of England.

The complete mitochondrial genome of a Biwa goby, Gymnogobius isaza (Tanaka, 1916)

We determined the complete mitochondrial DNA sequence of a Biwa goby, Gymnogobius isaza (Tanaka, 1916) using next-generation sequencing methods. The composition of its mitogenome is the same as that observed in most other vertebrates, comprising of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two control regions. Our molecular phylogenetic analysis confirmed the close phylogenetic relationship between G. isaza and G. petschiliensis. This mitogenome information will be useful for distribution surveys using environmental DNA and the development of conservation strategies for this species.

Human cystic echinococcosis: first molecular identification of Echinococcus canadensis G7 in Brazil.

Echinococcus granulosus sensu lato (s.l.) is a species complex with the potential to cause cystic echinococcosis (CE). Contact with the feces of domestic dogs (Canis familiaris) fed with raw viscera of intermediate livestock hosts is a risk factor for this infection in the southern region of Brazil. Although the region has been considered endemic to CE for many years, molecular data regarding the species of the complex causing CE in humans are scarce. This study aimed to perform a molecular analysis of the biological fluid from a human liver cyst to investigate the species responsible for CE. Genetic material obtained from the hydatid fluid of a hepatic cyst from a human with CE was subjected to PCR to amplify mitochondrial and nuclear DNA sequences. The phylogenetic analysis confirmed the human infection by Echinococcus canadensis G7 in the state of Paraná, Brazil. This is the first molecular record of E. canadensis G7 infecting a human in Brazil, and it is important to reiterate the risk of human CE caused by this species in South America, as reported by a previous study in Patagonia, Argentina. From the epidemiological point of view, this finding is of great relevance for the southern region of Brazil, since this parasite has previously only been detected in pigs in the state of Rio Grande do Sul, neighboring Paraná. The finding points to the importance of this identification in the molecular epidemiology of E. granulosus s.l., especially in South America.

Ice-inhabiting species of Bdelloidea Rotifera reveal a pre-Quaternary ancestry in the Arctic cryosphere.

Historical climate data indicate that the Earth has passed through multiple geological periods with much warmer-than-present climates, including epochs of the Miocene (23-5.3 mya BP) with temperatures 3-4°C above present, and more recent interglacial stages of the Quaternary, for example, Marine Isotope Stage 11c (approx. 425-395 ka BP) and Middle Holocene thermal maximum (7.5-4.2 ka BP), during which continental glaciers may have melted entirely. Such warm periods would have severe consequences for ice-obligate fauna in terms of their distribution, biodiversity and population structure. To determine the impacts of these climatic events in the Nordic cryosphere, we surveyed ice habitats throughout mainland Norway and Svalbard ranging from maritime glaciers to continental ice patches (i.e. non-flowing, inland ice subjected to deep freezing overwinter), finding particularly widespread populations of ice-inhabiting bdelloid rotifers. Combined mitochondrial and nuclear DNA sequencing identified approx. 16 undescribed, species-level rotifer lineages that revealed an ancestry predating the Quaternary (> 2.58 mya). These rotifers also displayed robust freeze/thaw tolerance in laboratory experiments. Collectively, these data suggest that extensive ice refugia, comparable with stable ice patches across the contemporary Norwegian landscape, persisted in the cryosphere over geological time, and may have facilitated the long-term survival of ice-obligate Metazoa before and throughout the Quaternary.

Uncovering further diversity of Ochoterenatrema Caballero, 1943 (Digenea: Lecithodendriidae) in South American bats

Ochoterenatrema Caballero, 1943 is a genus of lecithodendriid digeneans that prior to this study included 8 species parasitic in bats in the Western Hemisphere. Species of Ochoterenatrema possess a unique morphological feature in form of the pseudogonotyl on the sinistral side of the ventral sucker. In this study, we describe 2 new species of Ochoterenatrema from bats in Ecuador. The new species are readily differentiated from their congeners by a combination of morphological characters, including the distribution of vitelline follicles, length of oesophagus, sucker ratio and the body shape, among other features. We have generated partial nuclear 28S rDNA and mitochondrial cox1 gene DNA sequences from both new species. The newly obtained sequences were used to differentiate among species and study the phylogenetic interrelationships among Ochoterenatrema spp. The internal topology of the clade was weakly supported, although the cox1 tree was much better resolved than the 28S tree. Comparison of sequences revealed 0–1.2% interspecific divergence in 28S and 3.3–20.5% interspecific divergence in cox1 among Ochoterenatrema spp. The new findings demonstrate that bats in South America likely harbor multiple additional undescribed species of Ochoterenatrema. More extensive sampling from broader geographic and host ranges, especially in North America, should allow for a better understanding of the evolution of host associations and morphological traits of this lineage of lecithodendriid digeneans.

Exploring mitochondrial heteroplasmy in neonates: implications for growth patterns and overweight in the first years of life.

Mitochondrial heteroplasmy reflects genetic diversity within individuals due to the presence of varying mitochondrial DNA (mtDNA) sequences, possibly affecting mitochondrial function and energy production in cells. Rapid growth during early childhood is a critical development with long-term implications for health and well-being. In this study, we investigated if cord blood mtDNA heteroplasmy is associated with rapid growth at 6 and 12 months and overweight in childhood at 4-6 years. This study included 200 mother-child pairs of the ENVIRONAGE birth cohort. Whole mitochondrial genome sequencing was performed to determine mtDNA heteroplasmy levels (in variant allele frequency; VAF) in cord blood. Rapid growth was defined for each child as the difference between WHO-SD scores of predicted weight at either 6 or 12 months and birth weight. Logistic regression models were used to determine the association of mitochondrial heteroplasmy with rapid growth and childhood overweight. Determinants of relevant cord blood mitochondrial heteroplasmies were identified using multiple linear regression models. One % increase in VAF of cord blood MT-D-Loop16362T > C heteroplasmy was associated with rapid growth at 6 months (OR = 1.03; 95% CI: 1.01-1.05; p = 0.001) and 12 months (OR = 1.02; 95% CI: 1.00-1.03; p = 0.02). Furthermore, this variant was associated with childhood overweight at 4-6 years (OR = 1.01; 95% CI 1.00-1.02; p = 0.05). Additionally, rapid growth at 6 months (OR = 3.00; 95% CI: 1.49-6.14; p = 0.002) and 12 months (OR = 4.05; 95% CI: 2.06-8.49; p < 0.001) was also associated with childhood overweight at 4-6 years. Furthermore, we identified maternal age, pre-pregnancy BMI, maternal education, parity, and gestational age as determinants of cord blood MT-D-Loop16362T > C heteroplasmy. Our findings, based on mitochondrial DNA genotyping, offer insights into the molecular machinery leading to rapid growth in early life, potentially explaining a working mechanism of the development toward childhood overweight.

Indel variation in the mitochondrial ND5 region supports monophyly of the tribe Hippoglossoidini (sensu Vinnikov et al. 2018) within the family Pleuronectidae

AbstractIndel (insertion–deletion) events observed in the genome represent irreversible mutational processes, making indel regions crucial characteristics for discussing phylogenetic relationships. The tribe Hippoglossoidini is a recently proposed taxonomic group based on the molecular phylogenetic analyses of both mitochondrial (mt) and nuclear DNA sequences. However, no synapomorphic characteristics have been identified within this tribe, either morphologically or molecularly. In the present study, we sequenced the ND5 region of mtDNA in the righteye flounder species and conducted interspecific comparisons. We found a 12 bp indel immediately upstream of the stop codon in the ND5 region. A comparative analysis of this region with outgroup species from the Paralichthyidae revealed that the indel was a unique insertion shared by the common ancestor of the Hippoglossoidini species, providing irreversible evidence to support the monophyly of this taxonomic group (synapomorphic characters).