scholarly journals A Combined Morphological and Molecular Evolutionary Analysis of Karst-Environment Adaptation for the Genus Urophysa (Ranunculaceae)

2021 ◽  
Vol 12 ◽  
Author(s):  
Deng-Feng Xie ◽  
Rui-Yu Cheng ◽  
Xiao Fu ◽  
Xiang-Yi Zhang ◽  
Megan Price ◽  
...  

The karst environment is characterized by low soil water content, periodic water deficiency, and poor nutrient availability, which provides an ideal natural laboratory for studying the adaptive evolution of its inhabitants. However, how species adapt to such a special karst environment remains poorly understood. Here, transcriptome sequences of two Urophysa species (Urophysa rockii and Urophysa henryi), which are Chinese endemics with karst-specific distribution, and allied species in Semiaquilegia and Aquilegia (living in non-karst habitat) were collected. Single-copy genes (SCGs) were extracted to perform the phylogenetic analysis using concatenation and coalescent methods. Positively selected genes (PSGs) and clusters of paralogous genes (Mul_genes) were detected and subsequently used to conduct gene function annotation. We filtered 2,271 SCGs and the coalescent analysis revealed that 1,930 SCGs shared the same tree topology, which was consistent with the topology detected from the concatenated tree. Total of 335 PSGs and 243 Mul_genes were detected, and many were enriched in stress and stimulus resistance, transmembrane transport, cellular ion homeostasis, calcium ion transport, calcium signaling regulation, and water retention. Both molecular and morphological evidences indicated that Urophysa species evolved complex strategies for adapting to hostile karst environments. Our findings will contribute to a new understanding of genetic and phenotypic adaptive mechanisms of karst adaptation in plants.

Author(s):  
Daniella F Lato ◽  
G Brian Golding

Abstract Increasing evidence supports the notion that different regions of a genome have unique rates of molecular change. This variation is particularly evident in bacterial genomes where previous studies have reported gene expression and essentiality tend to decrease, while substitution rates usually increases with increasing distance from the origin of replication. Genomic reorganization such as rearrangements occur frequently in bacteria and allow for the introduction and restructuring of genetic content, creating gradients of molecular traits along genomes. Here, we explore the interplay of these phenomena by mapping substitutions to the genomes of Escherichia coli, Bacillus subtilis, Streptomyces, and Sinorhizobium meliloti, quantifying how many substitutions have occurred at each position in the genome. Preceding work indicates that substitution rate significantly increases with distance from the origin. Using a larger sample size and accounting for genome rearrangements through ancestral reconstruction, our analysis demonstrates that the correlation between the number of substitutions and distance from the origin of replication is often significant but small and inconsistent in direction. Some replicons had a significantly decreasing trend (E. coli and the chromosome of S. meliloti), while others showed the opposite significant trend (B. subtilis, Streptomyces, pSymA and pSymB in S. meliloti). dN, dS and ω were examined across all genes and there was no significant correlation between those values and distance from the origin. This study highlights the impact that genomic rearrangements and location have on molecular trends in some bacteria, illustrating the importance of considering spatial trends in molecular evolutionary analysis. Assuming that molecular trends are exclusively in one direction can be problematic.


1995 ◽  
Vol 36 (2-3) ◽  
pp. 201-214 ◽  
Author(s):  
Ken-ichi Ohba ◽  
Masashi Mizokami ◽  
Tomoyoshi Ohno ◽  
Kaoru Suzuki ◽  
Etsuro Orito ◽  
...  

The Nucleus ◽  
2014 ◽  
Vol 57 (1) ◽  
pp. 61-65
Author(s):  
Arpita Rakshit ◽  
Rabindra Nath Chatterjee

1994 ◽  
Vol 14 (1) ◽  
pp. 10-20
Author(s):  
M Wu ◽  
C D Allis ◽  
M T Sweet ◽  
R G Cook ◽  
T H Thatcher ◽  
...  

Tetrahymena thermophila micronuclei contain four linker-associated proteins, alpha, beta, gamma, and delta. Synthetic oligonucleotides based on N-terminal protein sequences of beta and gamma were used to clone the micronuclear linker histone (MLH) gene. The MLH gene is single copy and is transcribed into a 2.4-kb message encoding all four linker-associated proteins. The message is translated into a polypeptide (Mic LH) that is processed at the sequence decreases RTK to give proteins whose amino acid sequences differ markedly from each other, from the sequence of macronuclear H1, and from sequences of typical H1s of other organisms. This represents the first example of multiple chromatin proteins derived from a single polyprotein. The delta protein consists largely of two high-mobility-group (HMG) boxes. An evolutionary analysis of HMG boxes indicates that the delta HMG boxes are similar to the HMG boxes of tsHMG, a protein that appears in elongating mouse spermatids when they condense and cease transcription, suggesting that delta could play a similar role in the micronucleus. The micronucleus divides mitotically, while the macronucleus divides amitotically. Surprisingly, macronuclear H1 but not Mic LH contains sequences resembling p34cdc2 kinase phosphorylation sites, while each of the Mic LH-derived proteins contains a typical protein kinase A phosphorylation site in its carboxy terminus.


Bionatura ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2251-2255
Author(s):  
Arwa Mujahid Al-Shuwaikh ◽  
Ealaf Abbas khudair ◽  
Dalya Basil Hanna

SEN Virus (SENV) is a newly discovered group of transmissible, hepatotropic, single-stranded, circular, non-enveloped DNA viruses that are distantly linked to the widely distributed Torque Teno Virus (TTV) family. This research aimed to use nucleotide sequencing to identify the genetic alterations of SEN-V and to investigate the similarities between isolates. Seven DNA samples of SENV, which were previously extracted from blood of post transfusion hepatitis, were used to identify the genetic variation of SEN-V by nucleotide sequencing. According to the current analysis results, specific primer pairs were used to detect SENV DNA sequences isolated from Iraqi patients with hepatitis; however, those specific primers can also detect two new variants of SENV that are closely related to the Torque Teno Virus. In addition, four SENV isolates showed several substitution mutations, and one of them revealed the replacement of Proline (P) at position 11 with Serine (S). Only one local isolate of SENV was 100% identical to the Iranian isolate (GenBank acc. no. GQ452051.1) from thalassemia.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8450 ◽  
Author(s):  
Sunan Huang ◽  
Xuejun Ge ◽  
Asunción Cano ◽  
Betty Gaby Millán Salazar ◽  
Yunfei Deng

The genus Dicliptera (Justicieae, Acanthaceae) consists of approximately 150 species distributed throughout the tropical and subtropical regions of the world. Newly obtained chloroplast genomes (cp genomes) are reported for five species of Dilciptera (D. acuminata, D. peruviana, D. montana, D. ruiziana and D. mucronata) in this study. These cp genomes have circular structures of 150,689–150,811 bp and exhibit quadripartite organizations made up of a large single copy region (LSC, 82,796–82,919 bp), a small single copy region (SSC, 17,084–17,092 bp), and a pair of inverted repeat regions (IRs, 25,401–25,408 bp). Guanine-Cytosine (GC) content makes up 37.9%–38.0% of the total content. The complete cp genomes contain 114 unique genes, including 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analyses of nucleotide variability (Pi) reveal the five most variable regions (trnY-GUA-trnE-UUC, trnG-GCC, psbZ-trnG-GCC, petN-psbM, and rps4-trnL-UUA), which may be used as molecular markers in future taxonomic identification and phylogenetic analyses of Dicliptera. A total of 55-58 simple sequence repeats (SSRs) and 229 long repeats were identified in the cp genomes of the five Dicliptera species. Phylogenetic analysis identified a close relationship between D. ruiziana and D. montana, followed by D. acuminata, D. peruviana, and D. mucronata. Evolutionary analysis of orthologous protein-coding genes within the family Acanthaceae revealed only one gene, ycf15, to be under positive selection, which may contribute to future studies of its adaptive evolution. The completed genomes are useful for future research on species identification, phylogenetic relationships, and the adaptive evolution of the Dicliptera species.


2003 ◽  
Vol 270 (2) ◽  
pp. 173-180 ◽  
Author(s):  
A. Sarkar ◽  
C. Sim ◽  
Y. S. Hong ◽  
J. R. Hogan ◽  
M. J. Fraser ◽  
...  

2019 ◽  
Vol 10 ◽  
Author(s):  
Yanzhi Mao ◽  
Xuhong Sun ◽  
Jianguo Shen ◽  
Fangluan Gao ◽  
Guangwei Qiu ◽  
...  

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