Thermal adaptation of Japanese sand lance (Ammodytes personatus) in different ocean currents revealed by the cytochrome-b gene

2019 ◽  
Vol 70 (10) ◽  
pp. 1484 ◽  
Author(s):  
Zhaochao Deng ◽  
Shengyong Xu ◽  
Tianxiang Gao ◽  
Zhiqiang Han

To assess the possible thermal selection on mitochondrial coding genes in cold water species, we explored the population structure of Japanese sand lance (Ammodytes personatus) and performed selection tests on the mitochondrial cytochrome-b gene of species, using 174 individuals from eight different sea temperature populations in different ocean currents. Two distinct haplotype lineages were present in this species, and the lineage frequencies varied with changes in sea temperature. The selection tests showed that A. personatus was subject to purifying selection. Populations living in cold climates had a considerably smaller non-synonymous substitution rate/synonymous substitution rate (dN/dS) than those in temperate areas. The efficiency of the electron transfer chain system may be affected by amino acid changes at codons 353 and 371. These findings provide new evidence that temperature may affect the contemporary distribution of mitochondrial DNA clade frequencies in A. personatus.

2019 ◽  
Vol 99 (06) ◽  
pp. 1409-1416
Author(s):  
Zhaochao Deng ◽  
Xiuliang Wang ◽  
Shengyong Xu ◽  
Tianxiang Gao ◽  
Zhiqiang Han

AbstractThermoregulation has been suggested to influence mitochondrial DNA (mtDNA) evolution. Previous studies revealed that the mitochondrial protein-coding genes of fish living in temperate climates have smaller dN/dS (Non-synonymous substitution rate/Synonymous substitution rate) than tropical species. However, it is unknown whether different geographic populations of one fish species experience stronger selective pressures between cold and warm climates. The biological characteristics of the Japanese sand lance, Ammodytes personatus in the North-western Pacific is well-suited for assessing the performance of mtDNA evolution among separate geographic populations. In this study, we focused on the mitochondrial ATP6 gene of A. personatus using 174 individuals from eight different sea temperature populations. Two distinct haplotype lineages and a significant population structure (P = 0.016) were found in this species. The frequencies of the two lineages varied with the changes of annual sea temperature. The southern lineage (lineage A, dN/dS = 0.0384) showed a larger dN/dS value than the northern lineage (lineage B, dN/dS = 0.0167), suggesting that sea temperature greatly influences the evolution of the two lineages. The result provides robust evidence of local adaptation between populations in A. personatus.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Teame Gereziher MEHARI ◽  
Yanchao XU ◽  
Richard Odongo MAGWANGA ◽  
Muhammad Jawad UMER ◽  
Joy Nyangasi KIRUNGU ◽  
...  

Abstract Background Cotton is an important commercial crop for being a valuable source of natural fiber. Its production has undergone a sharp decline because of abiotic stresses, etc. Drought is one of the major abiotic stress causing significant yield losses in cotton. However, plants have evolved self-defense mechanisms to cope abiotic factors like drought, salt, cold, etc. The evolution of stress responsive transcription factors such as the trihelix, a nodule-inception-like protein (NLP), and the late embryogenesis abundant proteins have shown positive response in the resistance improvement to several abiotic stresses. Results Genome wide identification and characterization of the effects of Light-Harvesting Chloro a/b binding (LHC) genes were carried out in cotton under drought stress conditions. A hundred and nine proteins encoded by the LHC genes were found in the cotton genome, with 55, 27, and 27 genes found to be distributed in Gossypium hirsutum, G. arboreum, and G. raimondii, respectively. The proteins encoded by the genes were unevenly distributed on various chromosomes. The Ka/Ks (Non-synonymous substitution rate/Synonymous substitution rate) values were less than one, an indication of negative selection of the gene family. Differential expressions of genes showed that majority of the genes are being highly upregulated in the roots as compared with leaves and stem tissues. Most genes were found to be highly expressed in MR-85, a relative drought tolerant germplasm. Conclusion The results provide proofs of the possible role of the LHC genes in improving drought stress tolerance, and can be explored by cotton breeders in releasing a more drought tolerant cotton varieties.


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