Maternal Inheritance Pattern Research Articles

CNS involvement in myotonic dystrophy type 1: does sex play a role?

Myotonic dystrophy type 1 (DM1) is a hereditary neuromuscular disorder affecting the central nervous system (CNS). Although sex differences have been explored in other neuromuscular disorders, research on this topic in DM1 remains limited. The present study aims to analyze sex differences (both the patient's and disease-transmitting parent's sex) with a focus on CNS outcomes. Retrospective data from 146 non-congenital DM1 patients were analyzed, including clinical, molecular, neuropsychological, and neuroradiological data. Sex and inheritance pattern differences were analyzed using t-tests, and ANOVA analyses were conducted to address the interactions. Overall, no significant sex differences were observed except in certain cognitive domains. However, individuals with maternal inheritance showed larger CTG expansion size, lower estimated IQs, and poorer performance on visual memory, executive functions, and language domains than those with paternal inheritance. Notably, IQ performance was independently influenced by inheritance pattern and CTG expansion. This study is the first to delve into sex differences in DM1 with a focus on CNS outcomes. While the results revealed the absence of a sex-specific clinic-molecular profile, more substantial CNS differences were observed between patients with maternal and paternal inheritance patterns. The hypothetical existence of genomic imprinting and its potential mechanism are discussed. These findings hold potential implications for aiding clinical management by improving genetic counseling and predicting disease severity and prognosis.

Comparative Analysis of Maternal Gene Expression Patterns Unravels Evolutionary Signatures Across Reproductive Modes.

Maternal genes have a pivotal role in regulating metazoan early development. As such their functions have been extensively studied since the dawn of developmental biology. The temporal and spatial dynamics of their transcripts have been thoroughly described in model organisms and their functions have been undergoing heavy investigations. Yet, less is known about the evolutionary changes shaping their presence within diverse oocytes. Due to their unique maternal inheritance pattern, a high degree is predicted to be present when it comes to their expression. Insofar only limited and conflicting results have emerged around it. Here, we set out to elucidate which evolutionary changes could be detected in the maternal gene expression patterns using phylogenetic comparative methods on RNAseq data from 43 species. Using normalized gene expression values and fold change information throughout early development we set out to find the best-fitting evolutionary model. Through modeling, we find evidence supporting both the high degree of divergence and constraint on gene expression values, together with their temporal dynamics. Furthermore, we find that maternal gene expression alone can be used to explain the reproductive modes of different species. Together, these results suggest a highly dynamic evolutionary landscape of maternal gene expression. We also propose a possible functional dichotomy of maternal genes which is influenced by the reproductive strategy undertaken by examined species.

Unpredictable Chemical Diversity of Essential Oils in Cinnamomum burmanni (Lauraceae) Living Collections: Beyond Maternally Inherited Phylogenetic Relationships.

The genus Cinnamomum encompasses diverse species with various applications, particularly in traditional medicine and spice production. This study focuses on Cinnamomum burmanni, specifically on a high-D-borneol-content chemotype, known as the Meipian Tree, in Guangdong Province, South China. This research explores essential oil diversity, chemotypes, and chloroplast genomic diversity among 28 C. burmanni samples collected from botanical gardens. Essential oils were analyzed, and chemotypes classified using GC-MS and statistical methods. Plastome assembly and phylogenetic analysis were conducted to reveal genetic relationships. Results showed distinct chemotypes, including eucalyptol and borneol types, with notable variations in essential oil composition. The chloroplast genome exhibited conserved features, with phylogenetic analysis revealing three major clades. Borneol-rich individuals in clade II suggested a potential maternal inheritance pattern. However, phylogenetic signals revealed that the composition of essential oils is weakly correlated with plastome phylogeny. The study underscores the importance of botanical gardens in preserving genetic and chemical diversity, offering insights for sustainable resource utilization and selective breeding of high-yield mother plants of C. burmanni.

The interplay between mitochondria, the gut microbiome and metabolites and their therapeutic potential in primary mitochondrial disease.

The various roles of the mitochondria and the microbiome in health and disease have been thoroughly investigated, though they are often examined independently and in the context of chronic disease. However, the mitochondria and microbiome are closely connected, namely, through their evolution, maternal inheritance patterns, overlapping role in many diseases and their importance in the maintenance of human health. The concept known as the "mitochondria-microbiome crosstalk" is the ongoing bidirectional crosstalk between these two entities and warrants further exploration and consideration, especially in the context of primary mitochondrial disease, where mitochondrial dysfunction can be detrimental for clinical manifestation of disease, and the role and composition of the microbiome is rarely investigated. A potential mechanism underlying this crosstalk is the role of metabolites from both the mitochondria and the microbiome. During digestion, gut microbes modulate compounds found in food, which can produce metabolites with various bioactive effects. Similarly, mitochondrial metabolites are produced from substrates that undergo biochemical processes during cellular respiration. This review aims to provide an overview of current literature examining the mitochondria-microbiome crosstalk, the role of commonly studied metabolites serve in signaling and mediating these biochemical pathways, and the impact diet has on both the mitochondria and the microbiome. As a final point, this review highlights the up-to-date implications of the mitochondria-microbiome crosstalk in mitochondrial disease and its potential as a therapeutic tool or target.

Mitochondrial heteroplasmy as a marker for premature coronary artery disease: analysis of the poly-C tract of the control region sequence

Abstract Mitochondrial DNA (mtDNA) differs from the nuclear genome in many aspects: a maternal inheritance pattern, being more prone to acquire somatic novo mutations, accumulative with age; and the possible coexistence of different mtDNA alleles (heteroplasmy). Mitochondria are key cellular organelles responsible for energy production, involved in complex mechanisms, including atherosclerosis. In this scenario, we aimed to evaluate mtDNA variants that could be associated with premature cardiovascular disease. We evaluated 188 consecutive patients presenting with premature myocardial infarction with ST elevation (STEMI) confirmed by coronary angiogram. mtDNA polymorphisms and clinical data were evaluated and compared with 271 individuals from the same population (control group). Tobacco consumption (80.85% vs 21.21%, p<0.01) and dyslipidemia (38.83% vs 28.41%, p=0.02) were significant more frequent among STEMI patients. Besides, C16223T mtDNA mutation and poly-C heteroplasmy were significantly more frequent among premature STEMI cases than in controls. The OR associated C16223T mtDNA mutation with an increased presence of cardiovascular risk factors. Our data suggest that mtDNA C16223T mutation and poly-C heteroplasmy may be associated with unstable atherosclerosis disease. Moreover, the presence of cardiovascular risk factors (CVRFs) was associated to C16223T mtDNA mutation, with a cumulative effect. Protective mitochondrial pathways are potential therapeutic targets. Thus, preventing exposure to the damaging mechanisms associated to CVRFs is of the utmost importancemtDNA sanger analysisBaseline characteristics.

Refining the Global Phylogeny of Mitochondrial N1a, X, and HV2 Haplogroups Based on Rare Mitogenomes from Croatian Isolates.

Mitochondrial DNA (mtDNA) has been used for decades as a predominant tool in population genetics and as a valuable addition to forensic genetic research, owing to its unique maternal inheritance pattern that enables the tracing of individuals along the maternal lineage across numerous generations. The dynamic interplay between evolutionary forces, primarily genetic drift, bottlenecks, and the founder effect, can exert significant influence on genetic profiles. Consequently, the Adriatic islands have accumulated a subset of lineages that exhibits remarkable absence or rarity within other European populations. This distinctive genetic composition underscores the islands' potential as a significant resource in phylogenetic research, with implications reaching beyond regional boundaries to contribute to a global understanding. In the initial attempt to expand the mitochondrial forensic database of the Croatian population with haplotypes from small isolated communities, we sequenced mitogenomes of rare haplogroups from different Croatian island and mainland populations using next-generation sequencing (NGS). In the next step and based on the obtained results, we refined the global phylogeny of haplogroup N1a, HV2, and X by analyzing rare haplotypes, which are absent from the current phylogenetic tree. The trees were based on 16 novel and 52 previously published samples, revealing completely novel branches in the X and HV2 haplogroups and a new European cluster in the ancestral N1a variant, previously believed to be an exclusively African-Asian haplogroup. The research emphasizes the importance of investigating geographically isolated populations and their unique characteristics within a global context.

Mitochondrial genome study in blood of maternally inherited ALS cases

BackgroundALS is a heterogeneous disease in which different factors such as mitochondrial phenotypes act in combination with a genetic predisposition. This study addresses the question of whether homoplasmic (total mitochondrial genome of a sample is affected) and/or heteroplasmic mutations (wildtype and mutant mitochondrial DNA molecules coexist) might play a role in familial ALS. Blood was drawn from familial ALS patients with a possible maternal pattern of inheritance according to their pedigrees, which was compared to blood of ALS patients without maternal association as well as age-matched controls. In two cohorts, we analyzed the mitochondrial genome from whole blood or isolated white blood cells and platelets using a resequencing microarray (Affymetrix MitoChip v2.0) that is able to detect homoplasmic and heteroplasmic mitochondrial DNA mutations and allows the assessment of low-level heteroplasmy.ResultsWe identified an increase in homoplasmic ND5 mutations, a subunit of respiratory chain complex I, in whole blood of ALS patients that allowed maternal inheritance. This effect was more pronounced in patients with bulbar onset. Heteroplasmic mutations were significantly increased in different mitochondrial genes in platelets of patients with possible maternal inheritance. No increase of low-level heteroplasmy was found in maternal ALS patients.ConclusionOur results indicate a contribution of homoplasmic ND5 mutations to maternally associated ALS with bulbar onset. Therefore, it might be conceivable that specific maternally transmitted rather than randomly acquired mitochondrial DNA mutations might contribute to the disease process. This stands in contrast with observations from Alzheimer’s and Parkinson’s diseases showing an age-dependent accumulation of unspecific mutations in mitochondrial DNA.

Presumptive First Record of Myotis aurascens (Chiroptera, Vespertilionidae) from China with a Phylogenetic Analysis.

Bat groups have a high degree of species diversity, and the taxonomic status and phylogenetic relationships among bat species have always been research hotspots. Due to the fact that morphological characteristics do not always reflect the evolutionary relationships among species, mitochondrial DNA has been widely used in the study of species relationships due to its maternal inheritance pattern. Myotis aurascens has been suggested as a possible synonym for M. davidii. However, the status of this classification has been controversial. In this study, the morphological and molecular characteristics of a M. aurascens captured from Inner Mongolia, China, were analyzed to determine its taxonomic status. In terms of morphological features, the body weight was 6.33 g, the head and body length were 45.10 mm, the forearm length was 35.87 mm, and the tragus length was 7.51 mm. These values all fell within the species signature data range. Nucleotide skew analysis of the protein-coding genes (PCGs) suggested that only five PCGs (ND1, ND2, COX2, ATP8, and ND4) showed AT-skew value within the mitogenome of M. aurascens. Except for ND6, the GC-skew values of the other PCGs were negative, reflecting the preference for C and T bases compared to G and A bases. Molecular phylogenetic analyses based on mitochondrial PCGs indicated that M. aurascens was a distinct species from M. davidii and phylogenetically closer to M. ikonnikovi, M. alcathoe, and M. mystacinus. Genetic distance analysis also showed that M. aurascens and M. davidii were distantly related. Therefore, the integrated analysis demonstrated that M. aurascens should be considered a distinct species rather than a synonym of M. davidii. Our study could provide a reference for enriching species diversity and research on conservation in China.

A novel DEAH-box helicase 37 mutation associated with differences of sex development.

To determine the genetic etiology of a family pedigree with two patients affected by differences of sex development (DSD). Assess the clinical characteristics of the patients and achieve exome sequencing results and in vitro functional studies. The 15-year-old proband, raised as female, presented with delayed puberty and short stature associated with atypical genitalia. Hormonal profile showed hypergonadotrophic hypogonadism. Imaging studies revealed the absence of a uterus and ovaries. The karyotype confirmed a 46, XY pattern. Her younger brother presented with a micropenis and hypoplastic scrotum with non-palpable testis and hypospadias. Laparoscopic exploration was performed on the younger brother. Streak gonads were found and removed due to the risk of neoplastic transformation. Post-operative histopathology showed the co-existence of Wolffian and Müllerian derivatives. Whole-exome sequencing identified a novel mutation (c.1223C>T, p. Ser408Leu) in the Asp-Glu-Ala-His-box helicase 37 gene, which was found to be deleterious by in silico analysis. Segregation analysis of the variant displayed a sex-limited, autosomal dominant, maternal inheritance pattern. In vitro experiments revealed that the substitution of 408Ser by Leu caused decreased DHX37 expression both at the mRNA and protein levels. Moreover, the β-catenin protein was upregulated, and the p53 protein was unaltered by mutant DHX37. We described a novel mutation (c.1223C>T, p. Ser408Leu) of the DHX37 gene associated with a Chinese pedigree consisting of two 46, XY DSD patients. We speculated that the underlying molecular mechanism might involve upregulation of the β-catenin protein.

Mitochondrial Heteroplasmy as a Marker for Premature Coronary Artery Disease: Analysis of the Poly-C Tract of the Control Region Sequence

Mitochondrial DNA (mtDNA) differs from the nuclear genome in many aspects: a maternal inheritance pattern; being more prone to acquire somatic de novo mutations, accumulative with age; and the possible coexistence of different mtDNA alleles (heteroplasmy). Mitochondria are key cellular organelles responsible for energy production and involved in complex mechanisms, including atherosclerosis. In this scenario, we aimed to evaluate mtDNA variants that could be associated with premature cardiovascular disease. We evaluated 188 consecutive patients presenting with premature myocardial infarction with ST elevation (STEMI) confirmed by coronary angiogram. mtDNA polymorphisms and clinical data were evaluated and compared with 271 individuals from the same population (control group). Tobacco consumption (80.85% vs. 21.21%, p < 0.01) and dyslipidemia (38.83% vs. 28.41%, p = 0.02) were significantly more frequent among STEMI patients. Moreover, C16223T mtDNA mutation and poly-C heteroplasmy were significantly more frequent among premature STEMI male patients than in controls. The OR associated C16223T mtDNA with the increased presence of cardiovascular risk factors. Our data suggest that mtDNA 16223T and heteroplasmy may be associated with unstable premature atherosclerosis disease in men. Moreover, the presence of cardiovascular risk factors (CVRFs) was associated with C16223T mtDNA, with a cumulative effect. Protective mitochondrial pathways are potential therapeutic targets. Preventing exposure to the damaging mechanisms associated with CVRFs is of utmost importance.

The complete mitochondrial genome of the hybrid snow crab Chionoecetes opilio (♀) × C. japonicus (♂) (Crustacea: Decapoda: Majoidea) and its phylogenetic analysis

We report the complete mitochondrial genome of a hybrid snow crab between a femaleChionoecetes opilioand maleC.japonicus. The circular genome was 16,065 bp in length, and consisted of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a control region. The composition and arrangement of its complete mitochondrial genome were very similar to that reported for the maternal species,C.opilio. The close genetic relationship is reflected in the phylogenetic tree and supports maternal inheritance patterns.

The relevance of migraine in the clinical spectrum of mitochondrial disorders

Recent scientific evidence suggests a link between migraine and brain energy metabolism. In fact, migraine is frequently observed in mitochondrial disorders. We studied 46 patients affected by mitochondrial disorders, through a headache-focused semi-structured interview, to evaluate the prevalence of migraine among patients affected by mitochondrial disorders, the possible correlations between migraine and neuromuscular genotype or phenotype, comorbidities, lactate acid levels and brain magnetic resonance spectroscopy. We explored migraine-related disability, analgesic and prophylactic treatments. Diagnoses were achieved according to International Classification of Headache Disorders, 3rd edition. Lifetime prevalence of migraine was 61% (28/46), with high values in both sexes (68% in females, 52% in males) and higher than the values found in both the general population and previous literature. A maternal inheritance pattern was reported in 57% of cases. MIDAS and HIT6 scores revealed a mild migraine-related disability. The high prevalence of migraine across different neuromuscular phenotypes and genotypes suggests that migraine itself may be a common clinical manifestation of brain energy dysfunction. Our results provide new relevant indications in favour of migraine as the result of brain energy unbalance.

Mutation profile of neurodegenerative mitochondriopathy – LHON in Southern India

BackgroundLeber’s Hereditary Optic Neuropathy (LHON) is a rare mitochondriopathy causing retinal ganglion cell degeneration resulting in central vision loss. It is caused by mitochondrial DNA (mtDNA) mutations and thus follows maternal inheritance pattern. MethodsWe analysed the whole mitochondrial genome in 100 South Indian LHON patients by utilizing Sanger and Next Generation Sequencing approaches. Haplogroup analysis was performed using HaploGrep2 to predict the risk group. Methylation changes in the mtDNA D-loop region were investigated by performing methylation-specific polymerase chain reaction (MSP). ResultsLHON associated mutations were detected in 55% of the patients of which 42% harboured the primary mutations and 13% harboured potentially pathogenic variants that were previously reported to cause LHON. The candidate mutations identified with confirmed pathogenicity are: m.11778G > A (38%), m.14484 T > C (3%), m.4171C > A (1%) and m.11696G > A (1%). MSP results demonstrated that the D-loop region was unmethylated in all the study subjects including mutation-positive patients, mutation-negative patients, asymptomatic carriers, and controls. Haplogroup-M was prevalent (69%) in the study cohort followed by R (14%), U (9%), N (3%), HV (2%), G (2%), and W (1%). The frequency of the predominant mutation m.11778G > A was found lower (̴ 11%) in haplogroup-U. ConclusionsSouth Indian LHON cohort shows a unique profile of mtDNA mutations and haplogroup association presumably with no role of D-loop methylation. MT-ND4, MT-ND5, and MT-ND1 serve as the hotspot genes in this cohort. The presence of LHON associated mutations in patients lacking the common primary mutations insists on the necessity of mitochondrial genome sequencing in individuals suspected with LHON.

Paternal leakage inheritance and a fitness cost are associated with the chloroplastic psbA gene controlled metribuzin tolerance in lentil (Lens culinaris)

Reciprocal F1, F2 and F3 populations of lentil (Lens culinaris Medik.) were developed by crossing between lines, with a chloroplastic psbA gene mutation conferring tolerance to the photosystem II inhibitor herbicide metribuzin, and sensitive parent PBA Flash, to understand the genetic control of the herbicide tolerance. Additionally, reciprocal BC1F2 populations were developed to identify any fitness penalty associated with the metribuzin tolerance. Phenotyping and genotyping results of the F1, F2, and F3 populations identified a predominantly maternal inheritance pattern, but with a level of paternal leakage. Paternal leakage occurred in approximately 20% of F1 phenotypes, when including lines showing heteroplasmy (the existence of maternal and paternal chloroplasts within an individual). Field experiments with BC1F2 and BC1F3 lines confirmed this biparental inheritance pattern. Grain yield was reduced by 20–40% in metribuzin tolerant backcrossed lines compared with sensitive lines. Net assimilation rate at the onset of anthesis and plant dry weight at mid anthesis and maturity were also reduced in the tolerant lines suggesting reduced photosynthetic efficiency associated with the metribuzin tolerance results in lower dry weight and grain yield in the tolerant lines. The mode of inheritance and associated yield penalty of the tolerance trait will complicate its introgression in lentil breeding programs. However, the high level of tolerance and unique weed control benefits of this trait suggest that this form of metribuzin tolerance in lentil, which is similar to triazine tolerant canola (Brassica napus L.), could be adopted.

Molecular characteristics of mitochondrial DNA and phylogenetic analysis of the hybrid loach of Oxygymnocypris stewartii (female) and Schizopygopsis younghusbandi (male)

The complete mitochondrial genome of the hybrid of O. stewartii (female) and S. younghusbandi (male) was sequenced and characterized in this study. The complete hybrid mitochondrial genome is 16,649 bp in length, including 2 rRNAs, 13 protein-coding genes, 22 tRNAs and 2 non-coding regions (OL and D-loop region). The results discovered that 99.89% sequence identity between the hybrid and its female parent, which confirmed the maternal inheritance pattern followed by the mitochondrial genome of the hybrid. The phylogenetic tree showed that the hybrid was relatively closer to O. stewartii. Our data would provide a valuable resource for further studies on mitochondrial inheritance mechanism of Schizothoracinae fishes and provide new insights for better conservation plans for fishery resources.

Juvenile rank acquisition is associated with fitness independent of adult rank.

Social rank is a significant determinant of fitness in a variety of species. The importance of social rank suggests that the process by which juveniles come to establish their position in the social hierarchy is a critical component of development. Here, we use the highly predictable process of rank acquisition in spotted hyenas to study the consequences of variation in rank acquisition in early life. In spotted hyenas, rank is 'inherited' through a learning process called 'maternal rank inheritance.' This pattern is very consistent: approximately 80% of juveniles acquire the exact rank expected under the rules of maternal rank inheritance. The predictable nature of rank acquisition in these societies allows the process of rank acquisition to be studied independently from the ultimate rank that each juvenile attains. In this study, we use Elo-deviance scores, a novel application of the Elo-rating method, to calculate each juvenile's deviation from the expected pattern of maternal rank inheritance during development. Despite variability in rank acquisition among juveniles, most of these juveniles come to attain the exact rank expected of them according to the rules of maternal rank inheritance. Nevertheless, we find that transient variation in rank acquisition in early life is associated with long-term fitness consequences for these individuals: juveniles 'underperforming' their expected ranks show reduced survival and lower lifetime reproductive success than better-performing peers, and this relationship is independent of both maternal rank and rank achieved in adulthood. We also find that multiple sources of early life adversity have cumulative, but not compounding, effects on fitness. Future work is needed to determine if variation in rank acquisition directly affects fitness, or if some other variable, such as maternal investment or juvenile condition, causes variation in both of these outcomes.

Maternal and paternal genetic variation in Estonian local horse breeds in the context of geographically adjacent and distant Eurasian breeds.

SummaryThe maternal and paternal genetic variation of horse breeds from the Baltic Sea region, including three local Estonian breeds, was assessed and compared with that of Altai and Yakutian horses. In the mtDNA D‐loop region, 72 haplotypes assigned to 20 haplogroups in the nine breeds were detected. In Estonian local breeds, 38 mtDNA haplotypes were found, and five of them were shared by the three breeds. More than 60% of all identified haplotypes were rare. Compared with the Estonian Native and Estonian Heavy Draught breeds, a higher haplotypic diversity was found in the Tori breed (h = 0.969). Moreover, four haplotypes shared among Finnish and Estonian local horse breeds indicated ancient ancestry, and of these, H30 (haplogroup D3) showed global sharing and genetic links between modern Baltic Sea region and Siberian horses, specifically. The studied breed set showed high variability in maternal inheritance and mixed patterns of the international and native breeds of the Siberian and Baltic regions. No variation was found in paternally inherited markers among horse breeds in the Baltic Sea region.

The complete mitochondrial genome of the hybrid of Schizothorax oconnori (♀) × Schizothorax waltoni (♂)

Using Illumina next-generation sequencing (NGS), the complete mitochondrial genome sequence of the hybrid species of Schizothorax oconnori (♀) × Schizothorax waltoni (♂) was described in this study. 16,592bp long circular molecule consisted of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region. This study discovered the 99.8% sequence identity between the hybrid and its female parent, which confirmed the maternal inheritance pattern followed. The phylogenetic tree showed the hybrid was closer relationships with Schizothorax oconnori. The results would be a useful basis for conservation and phylogenetics of this hybrid.

The population genomics of multiple tsetse fly (Glossina fuscipes fuscipes) admixture zones in Uganda.

Understanding the mechanisms that enforce, maintain or reverse the process of speciation is an important challenge in evolutionary biology. This study investigates the patterns of divergence and discusses the processes that form and maintain divergent lineages of the tsetse fly Glossina fuscipes fuscipes in Uganda. We sampled 251 flies from 18 sites spanning known genetic lineages and the four admixture zones between them. We apply population genomics, hybrid zone and approximate Bayesian computation to the analysis of three types of genetic markers: 55,267 double-digest restriction site-associated DNA (ddRAD) SNPs to assess genome-wide admixture, 16 microsatellites to provide continuity with published data and accurate biogeographic modelling, and a 491-bp fragment of mitochondrial cytochrome oxidase I and II to infer maternal inheritance patterns. Admixture zones correspond with regions impacted by the reorganization of Uganda's river networks that occurred during the formation of the West African Rift system over the last several hundred thousand years. Because tsetse fly population distributions are defined by rivers, admixture zones likely represent both old and new regions of secondary contact. Our results indicate that older hybrid zones contain mostly parental types, while younger zones contain variable hybrid types resulting from multiple generations of interbreeding. These findings suggest that reproductive barriers are nearly complete in the older admixture zones, while nearly absent in the younger admixture zones. Findings are consistent with predictions of hybrid zone theory: Populations in zones of secondary contact transition rapidly from early to late stages of speciation or collapse all together.

The complete mitochondrial genome of the hybrid of Acanthopagrus schlegelii (♀) × Pagrus major (♂) with phylogenetic analysis

In this study, we firstly determined the complete mitochondrial DNA sequence of the hybrid of Acanthopagrus schlegelii (♀)×Pagrus major (♂) using the next-generation sequencing and Polymerase Chain Reaction-based method (PCR). The total length of the hybrid mitochondrial genome was identical to the female parent as 16,649 bp in length, which contained 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, and one displacement loop locus (a control region). The overall nucleotide composition is: 28.0%A, 27.9%T, 27.9%C, and 16.2%G, with a total A + T content of 45.9%. This study discovered the 99.8% sequence identity between the hybrid and its female parent, which confirmed the maternal inheritance pattern followed by the mitochondrial genome of the hybrid. The complete mitochondrial genome sequence of this hybrid sea bream may provide a valuable and useful resource for population genetic study and monitoring, and as well as for further conservation effort on this species.