Complete Mitogenome of Threespot Flounder Grammatobothus polyophthalmus (Pleuronectiformes: Bothidae) and Study on the Mechanism of Gene Rearrangement in 13 Bothids

2019 ◽  
Author(s):  
Hairong Luo ◽  
Xiaoyu Kong ◽  
Shixi Chen ◽  
Wei Shi

Abstract Background: The mitochondrial genomes (mitogenomes) of 12 bothids (Pleuronectiformes) from eight genera have been obtained. From the data, the genomic-scale and various gene rearrangements revealed the high diversity of variation in these mitogenomes. Results: A total of 18170 bp of Grammatobothus polyophthalmus mitogenome was determined including 37 genes and two control regions (CRs). Genes encoded by L-strand were grouped to an eight-genes cluster (Q-A-C-Y-S1-ND6-E-P) except for the tRNA-N, other genes encoded by H-strand were grouped together (F-12S … CytB-T) except for the tRNA-D that was translocated to inside of the eight-genes cluster. The mitogenome of G. polyophthalmus and that of 12 known bothids possessed the similar genomic-scale rearrangements with the only differences in the various combinations of CR, tRNA-D and eight-genes cluster, and the shuffling of tRNA-V. Based on the structure character of all 13 bothid mitogenomes, the Dimer-Mitogenome and Non-Random Loss (DMNR) model was fitted to account for all these rearrangements. And the translocation of tRNA-D occurring after the DMNR process in 10 of 13 bothid mitogenomes was confirmed. The striking finding was that each of degenerated genes existing in the gene rearrangement process in 13 bothids had their counterparts of intergenic spaces. Conclusions: The result of corresponding relationship between degenerated genes and intergenic spaces provided the significant evidence to support the possibility of the DMNR model, as well as, the existing of dimeric mitogenome in mitochondrion. The findings of this study were rare phenomenona in teleost fish, which not only promoted the understanding of mitogenome structural diversity, but also shed light on studying of mitochondrial rearrangement and replication.

2021 ◽  
Author(s):  
Avas Pakrashi ◽  
VIKAS KUMAR ◽  
Dhirti Banerjee ◽  
Kaomud Tyagi ◽  
C. M. Kalleshwaraswamy

Abstract Mitochondrial genome rearrangements have been used for defining historical relationships, but there have been incidences of convergences at different taxonomic levels. Here, we sequenced complete mitogenome of Aleurodicus rugioperculatus (Aleyrodidae: Aleurodicinae) to examine gene rearrangements and phylogenetic relationships within the family Aleyrodidae. We identified five gene blocks (I-V) in the whitefly ancestor that are shared plesiomorphies retained in different whitefly lineages. Gene block I is conserved in all whiteflies except three species (Tetraleurodes acaciae and two Bemisia species). Conversely, we detected 83 derived gene boundaries within the family. Mapping these gene boundaries onto a phylogenetic tree revealed that 16 were symplesiomorphies for two subfamilies; 9 were synapomorphies at different taxonomic levels, and 28 autapomorphies for individual species. Bayesian Inference (BI) and Maximum Likelihood (ML) phylogenetic analyses yielded similar topologies supporting the monophyly of Aleyrodinae and Aleurodicinae. Exclusion of PCG third codon positions from phylogenetic analyses improved both node support and consistency with prior analyses. To understand the significance of gene order convergence on phylogeny of the whiteflies, more species-level data is required.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hairong Luo ◽  
Xiaoyu Kong ◽  
Shixi Chen ◽  
Wei Shi

Abstract Background The mitogenomes of 12 teleost fish of the bothid family (order Pleuronectiformes) indicated that the genomic-scale rearrangements characterized in previous work. A novel mechanism of genomic rearrangement called the Dimer-Mitogenome and Non-Random Loss (DMNL) model was used to account for the rearrangement found in one of these bothids, Crossorhombus azureus. Results The 18,170 bp mitogenome of G. polyophthalmus contains 37 genes, two control regions (CRs), and the origin of replication of the L-strand (OL). This mitogenome is characterized by genomic-scale rearrangements: genes located on the L-strand are grouped in an 8-gene cluster (Q-A-C-Y-S1-ND6-E-P) that does not include tRNA-N; genes found on the H-strand are grouped together (F-12S … CytB-T) except for tRNA-D that was translocated inside the 8-gene L-strand cluster. Compared to non-rearranged mitogenomes of teleost fishes, gene organization in the mitogenome of G. polyophthalmus and in that of the other 12 bothids characterized thus far is very similar. These rearrangements could be sorted into four types (Type I, II, III and IV), differing in the particular combination of the CR, tRNA-D gene and 8-gene cluster and the shuffling of tRNA-V. The DMNL model was used to account for all but one gene rearrangement found in all 13 bothid mitogenomes. Translocation of tRNA-D most likely occurred after the DMNL process in 10 bothid mitogenomes and could have occurred either before or after DMNL in the three other species. During the DMNL process, the tRNA-N gene was retained rather than the expected tRNA-N′ gene. tRNA-N appears to assist in or act as OL function when the OL secondary structure could not be formed from intergenic sequences. A striking finding was that each of the non-transcribed genes has degenerated to a shorter intergenic spacer during the DMNL process. These findings highlight a rare phenomenon in teleost fish. Conclusions This result provides significant evidence to support the existence of dynamic dimeric mitogenomes and the DMNL model as the mechanism of gene rearrangement in bothid mitogenomes, which not only promotes the understanding of mitogenome structural diversity, but also sheds light on mechanisms of mitochondrial genome rearrangement and replication.


2002 ◽  
Vol 16 (3) ◽  
pp. 345 ◽  
Author(s):  
M. Dowton ◽  
L. R. Castro ◽  
A. D. Austin

Mitochondrial gene rearrangements are the latest tool in the arsenal of phylogeneticists for investigating historical relationships. They are complex molecular characters that may provide more reliable evidence of ancestry than comparative molecular data. Here we review the phylogenetic utility of mitochondrial gene rearrangements, and find that despite isolated incidences of convergence, derived gene order appears highly congruent with phylogenies produced from other sources of data. We calculate that the chance of two mitochondrial genomes sharing the same derived genome organisation is only 1/2664, but caution that this ignores the possibility that the (as yet uncharacterised) gene rearrangement mechanism may greatly increase the chance of convergence. Broader taxonomic surveys of mitochondrial genome organisation will lead to a more realistic indication of the historical incidence of convergence in genome organisation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kun Zhang ◽  
Kehua Zhu ◽  
Yifan Liu ◽  
Hua Zhang ◽  
Li Gong ◽  
...  

AbstractThe structure and gene sequence of the fish mitochondrial genome are generally considered to be conservative. However, two types of gene arrangements are found in the mitochondrial genome of Anguilliformes. In this paper, we report a complete mitogenome of Muraenesox cinereus (Anguilliformes: Muraenesocidae) with rearrangement phenomenon. The total length of the M. cinereus mitogenome was 17,673 bp, and it contained 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNA genes, and two identical control regions (CRs). The mitochondrial genome of M. cinereus was obviously rearranged compared with the mitochondria of typical vertebrates. The genes ND6 and the conjoint trnE were translocated to the location between trnT and trnP, and one of the duplicated CR was translocated to the upstream of the ND6. The tandem duplication and random loss is most suitable for explaining this mitochondrial gene rearrangement. The Anguilliformes phylogenetic tree constructed based on the whole mitochondrial genome well supports Congridae non-monophyly. These results provide a basis for the future Anguilliformes mitochondrial gene arrangement characteristics and further phylogenetic research.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1134
Author(s):  
Fei Ye ◽  
Hu Li ◽  
Qiang Xie

Reduviidae, a hyper-diverse family, comprise 25 subfamilies with nearly 7000 species and include many natural enemies of crop pests and vectors of human disease. To date, 75 mitochondrial genomes (mitogenomes) of assassin bugs from only 11 subfamilies have been reported. The limited sampling of mitogenome at higher categories hinders a deep understanding of mitogenome evolution and reduviid phylogeny. In this study, the first mitogenomes of Holoptilinae (Ptilocnemus lemur) and Emesinae (Ischnobaenella hainana) were sequenced. Two novel gene orders were detected in the newly sequenced mitogenomes. Combined 421 heteropteran mitogenomes, we identified 21 different gene orders and six gene rearrangement units located in three gene blocks. Comparative analyses of the diversity of gene order for each unit reveal that the tRNA gene cluster trnI-trnQ-trnM is the hotspot of heteropteran gene rearrangement. Furthermore, combined analyses of the gene rearrangement richness of each unit and the whole mitogenome among heteropteran lineages confirm Reduviidae as a ‘hot-spot group’ of gene rearrangement in Heteroptera. The phylogenetic analyses corroborate the current view of phylogenetic relationships between basal groups of Reduviidae with high support values. Our study provides deeper insights into the evolution of mitochondrial gene arrangement in Heteroptera and the early divergence of reduviids.


Blood ◽  
1987 ◽  
Vol 70 (6) ◽  
pp. 1933-1939
Author(s):  
A Tawa ◽  
SH Benedict ◽  
J Hara ◽  
N Hozumi ◽  
EW Gelfand

We analyzed rearrangements of the T cell receptor gamma-chain (T gamma) gene as well as rearrangements of the T cell receptor beta-chain (T beta) gene and immunoglobulin heavy-chain (IgH) gene in 68 children with acute lymphoblastic leukemia (ALL). All 15 patients with T cell ALL showed rearrangements of both T beta and T gamma genes. Twenty-four of 53 non-T, non-B ALL patients (45%) showed T gamma gene rearrangements and only 14 of these also showed T beta gene rearrangements. Only a single patient rearranged the T beta gene in the absence of T gamma gene rearrangement. The rearrangement patterns of the T gamma gene in non-T, non-B ALL were quite different from those observed in T cell ALL, as 20 of 23 patients retained at least one germline band of the T gamma gene. In contrast, all T cell ALL patients showed no retention of germline bands. These data indicate that rearrangement of the T gamma gene is not specific for T cell ALL. Further, the results also suggest that T gamma gene rearrangement precedes T beta gene rearrangement. The combined analysis of rearrangement patterns of IgH, T beta, and T gamma genes provides new criteria for defining the cellular origin of leukemic cells and for further delineation of leukemia cell heterogeneity.


Blood ◽  
1989 ◽  
Vol 74 (7) ◽  
pp. 2508-2518 ◽  
Author(s):  
JP de Villartay ◽  
AB Pullman ◽  
R Andrade ◽  
E Tschachler ◽  
O Colamenici ◽  
...  

Abstract We analyzed the gene rearrangements associated with the newly described delta T-cell receptor (TCR) gene from a series of 19 consecutive precursor T-cell (lymphoblastic) neoplasms that represent discrete stages surrounding the TCR gene rearrangement process. Significantly, the delta TCR gene showed rearrangement in most (13 of 19) of these T cells, and in addition it was rearranged in two cells displaying no rearrangement for any other TCR gene. Our survey showed three types of delta gene rearrangements associated with cell-surface TCR expression that presumably represent usage of three V delta genes. This analysis demonstrates (1) a major subclass of human precursor T-cell neoplasms belonging to the gamma/delta T-cell receptor-rearranging subtype; (2) a narrow repertoire of human V delta gene usage; and (3) the utility of delta gene rearrangements as a diagnostic clonal marker in precursor T lymphoblastic neoplasms.


Blood ◽  
1987 ◽  
Vol 69 (3) ◽  
pp. 968-970 ◽  
Author(s):  
N Asou ◽  
M Matsuoka ◽  
T Hattori ◽  
F Kawano ◽  
S Maeda ◽  
...  

Abstract Rearrangements of the T cell gamma (T gamma) gene were studied in primary neoplastic cells from 75 patients with leukemia or lymphoma. T gamma gene rearrangements were observed in 19 of 21 T cell neoplasms; 14 of 21 immature B cell leukemias, including 4 out of 5 patients with rearrangements of both immunoglobulin heavy-chain (JH) and T cell receptor beta chain (T beta) genes; none out of 16 nonlymphoid leukemias. Thus, T gamma gene rearrangement is frequently found in immature B cells and is not always found in T cells showing T beta gene rearrangement, but it is not detected in nonlymphoid cells. Furthermore, T gamma gene rearrangement in cells with the germline configuration of the JH and T beta genes was observed. These results indicate that the detection of T gamma gene rearrangement does not allow a clear assignment to a particular lineage. However, an analysis of T gamma gene rearrangement provides a further potential tool to establish the lymphoid cellular origin and clonality of hematologic neoplasms and identify the normal stages of lymphocyte differentiation.


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