Gene Arrangement and Sequence of str Operon of Phytoplasma Resemble Those of Bacillus More Than Those of Mycoplasma

2002 ◽  
Vol 68 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Shin-ichi MIYATA ◽  
Ken-ichiro FURUKI ◽  
Toshimi SAWAYANAGI ◽  
Kenro OSHIMA ◽  
Tsutomu KUBOYAMA ◽  
...  
Keyword(s):  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vikas Kumar ◽  
Kaomud Tyagi ◽  
Rajasree Chakraborty ◽  
Priya Prasad ◽  
Shantanu Kundu ◽  
...  

AbstractThe complete mitochondrial genome of Lyrognathus crotalus is sequenced, annotated and compared with other spider mitogenomes. It is 13,865 bp long and featured by 22 transfer RNA genes (tRNAs), and two ribosomal RNA genes (rRNAs), 13 protein-coding genes (PCGs), and a control region (CR). Most of the PCGs used ATN start codon except cox3, and nad4 with TTG. Comparative studies indicated the use of TTG, TTA, TTT, GTG, CTG, CTA as start codons by few PCGs. Most of the tRNAs were truncated and do not fold into the typical cloverleaf structure. Further, the motif (CATATA) was detected in CR of nine species including L. crotalus. The gene arrangement of L. crotalus compared with ancestral arthropod showed the transposition of five tRNAs and one tandem duplication random loss (TDRL) event. Five plesiomophic gene blocks (A-E) were identified, of which, four (A, B, D, E) retained in all taxa except family Salticidae. However, block C was retained in Mygalomorphae and two families of Araneomorphae (Hypochilidae and Pholcidae). Out of 146 derived gene boundaries in all taxa, 15 synapomorphic gene boundaries were identified. TreeREx analysis also revealed the transposition of trnI, which makes three derived boundaries and congruent with the result of the gene boundary mapping. Maximum likelihood and Bayesian inference showed similar topologies and congruent with morphology, and previously reported multi-gene phylogeny. However, the Gene-Order based phylogeny showed sister relationship of L. crotalus with two Araneomorphae family members (Hypochilidae and Pholcidae) and other Mygalomorphae species.


Genetics ◽  
1996 ◽  
Vol 142 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Jianzhi Zhang ◽  
Masatoshi Nei

Antennapedia (Antp)-class homeobox genes are involved in the determination of pattern formation along the anterior-posterior axis of the animal embryo. A phylogenetic analysis of Antp-class homeodomains of the nematode, Drosophila, amphioxus, mouse, and human indicates that the 13 cognate group genes of this gene family can be divided into two major groups, i.e., groups I and II. Group I genes can further be divided into subgroups A (cognate groups 1–2), B (cognate group 3), and C (cognate groups 4–8), and group II genes can be divided into subgroups D (cognate groups 9–10) and E (cognate groups 11–13), though this classification is somewhat ambiguous. Evolutionary distances among different amino acid sequences suggest that the divergence between group I and group II genes occurred ∼1000 million years (MY) ago, and the five different subgroups were formed by ∼600 MY ago, probably before the divergence of Pseudocoelomates (e.g., nematodes) and Coelomates (e.g., insects and chordates). Our results show that the genes that are phylogenetically close are also closely located in the chromosome, suggesting that the colinearity between the gene expression and gene arrangement was generated by successive tandem gene duplications and that the gene arrangement has been maintained by some sort of selection.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 668
Author(s):  
Tinghao Yu ◽  
Yalin Zhang

More studies are using mitochondrial genomes of insects to explore the sequence variability, evolutionary traits, monophyly of groups and phylogenetic relationships. Controversies remain on the classification of the Mileewinae and the phylogenetic relationships between Mileewinae and other subfamilies remain ambiguous. In this study, we present two newly completed mitogenomes of Mileewinae (Mileewa rufivena Cai and Kuoh 1997 and Ujna puerana Yang and Meng 2010) and conduct comparative mitogenomic analyses based on several different factors. These species have quite similar features, including their nucleotide content, codon usage of protein genes and the secondary structure of tRNA. Gene arrangement is identical and conserved, the same as the putative ancestral pattern of insects. All protein-coding genes of U. puerana began with the start codon ATN, while 5 Mileewa species had the abnormal initiation codon TTG in ND5 and ATP8. Moreover, M. rufivena had an intergenic spacer of 17 bp that could not be found in other mileewine species. Phylogenetic analysis based on three datasets (PCG123, PCG12 and AA) with two methods (maximum likelihood and Bayesian inference) recovered the Mileewinae as a monophyletic group with strong support values. All results in our study indicate that Mileewinae has a closer phylogenetic relationship to Typhlocybinae compared to Cicadellinae. Additionally, six species within Mileewini revealed the relationship (U. puerana + (M. ponta + (M. rufivena + M. alara) + (M. albovittata + M. margheritae))) in most of our phylogenetic trees. These results contribute to the study of the taxonomic status and phylogenetic relationships of Mileewinae.


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.


2020 ◽  
Vol 13 (3) ◽  
pp. 1393-1396
Author(s):  
Maggie Zhou ◽  
Yen Chen Kevin Ko ◽  
Gregory W. Charville ◽  
Kristen N. Ganjoo

Ewing’s sarcoma is a rare and aggressive tumor that typically arises in the long bones of the extremities. It belongs in the family of small round blue cell tumors and is characterized immunohistochemically by diffuse CD99 expression and molecularly by one of several oncogenic translocations, most commonly t(11;22)(q24;q12) between the <i>EWSR1</i> gene and the <i>FLI1</i> gene. Here we present a rare case of Ewing’s sarcoma in the sinonasal tract with <i>FUS-ERG</i> gene arrangement that was regarded for almost a decade as a sinonasal-type hemangiopericytoma (glomangiopericytoma). This case illustrates the surprisingly prolonged natural history of Ewing’s sarcoma that did not receive therapy for many years and the importance of considering alternative genetic translocations. Our experience suggests that the presence of diffuse CD99 membranous staining pattern in a small blue round cell tumor with morphology typical for Ewing’s sarcoma but FISH negative for <i>EWSR1</i> rearrangement should prompt consideration of <i>FUS-ERG</i> fusion.


Recent advances in nucleic acid technology have facilitated the detection and detailed structural analysis of a wide variety of genes in higher organisms, including those in man. This in turn has opened the way to an examination of the evolution of structural genes and their surrounding and intervening sequences. In a study of the evolution of haemoglobin genes and neighbouring sequences in man and the primates, we have investigated gene arrangement and DNA sequence divergence both within and between species ranging from Old World monkeys to man. This analysis is beginning to reveal the evolutionary constraints that have acted on this region of the genome during primate evolution. Furthermore, DNA sequence variation, both within and between species, provides, in principle, a novel and powerful method for determining inter-specific phylogenetic distances and also for analysing the structure of present-day human populations. Application of this new branch of molecular biology to other areas of the human genome should prove important in unravelling the history of genetic changes that have occurred during the evolution of man.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ann-Katrin Llarena ◽  
Marina Aspholm ◽  
Kristin O’Sullivan ◽  
Grzegorz Wêgrzyn ◽  
Toril Lindbäck

Shiga toxin is the major virulence factor of enterohemorrhagic Escherichia coli (EHEC), and the gene encoding it is carried within the genome of Shiga toxin-converting phages (Stx phages). Numerous Stx phages have been sequenced to gain a better understanding of their contribution to the virulence potential of EHEC. The Stx phages are classified into the lambdoid phage family based on similarities in lifestyle, gene arrangement, and nucleotide sequence to the lambda phages. This study explores the replication regions of non-lambdoid Stx phages that completely lack the O and P genes encoding the proteins involved in initiating replication in the lambdoid phage genome. Instead, they carry sequences encoding replication proteins that have not been described earlier, here referred to as eru genes (after EHEC phage replication unit genes). This study identified three different types of Eru-phages, where the Eru1-type is carried by the highly pathogenic EHEC strains that caused the Norwegian O103:H25 outbreak in 2006 and the O104:H4 strain that caused the large outbreak in Europe in 2011. We show that Eru1-phages exhibit a less stable lysogenic state than the classical lambdoid Stx phages. As production of phage particles is accompanied by production of Stx toxin, the Eru1-phage could be associated with a high-virulence phenotype of the host EHEC strain. This finding emphasizes the importance of classifying Stx phages according to their replication regions in addition to their Stx-type and could be used to develop a novel strategy to identify highly virulent EHEC strains for improved risk assessment and management.


Sign in / Sign up

Export Citation Format

Share Document