The Futalosine Pathway Played an Important Role in Menaquinone Biosynthesis during Early Prokaryote Evolution

ABSTRACT A quarter of a century ago, it was pointed out that evolution can act in an important conservative way, in addition to its normal progresssive mode. Evolution to a fitte form via changes at one locus means that the descendants of an individual with an improved locus or set of loci will supplant the previous population and carry with them the ulk of the total genotype of that original individual in asexual populations. Inasmuch as that individual is most likely to be wild type at most other loci, neutral and even other positively selected mutations will be reduced or eliminated from the population, if they are rare at the time of the evolutionary advance. In the present paper this problem has been set up for a computer simulation. The computations show the limits within which this effect functions and the conditions under which it does not. The conclusion is that it is likely tliat evoluticn at a locus proceeds in the course of many population re lacements or revolutions, mostly via the rare occasions when the revolution carries a previously infrequent mutational type into abundance.

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Genome sequencing and functional genes comparison between Sphingopyxis USTB-05 and Sphingomonas morindae NBD5

10.1101/2021.03.29.437629 ◽

2021 ◽

Author(s):

Chao Liu ◽

Qianqian Xu ◽

Zhenzhen Zhao ◽

Shahbaz Ahmad ◽

Haiyang Zhang ◽

...

Keyword(s):

Environmental Pollutants ◽

Nuclear Genome ◽

Environmental Pollutant ◽

Whole Genome Sequence ◽

Functional Genes ◽

Whole Genome ◽

Protein Coding ◽

Protein Coding Genes ◽

New Genes ◽

Prokaryote Evolution

Sphingomonadaceae has a large number of strains that can biodegrade hepatotoxins or environmental pollutants. The latest research reported that certain strains can also produce lutein. Based on the third-generation sequencing technology, we analyzed the whole genome sequence and compared related functional genes of two strains of Sphingomonadaceae isolated from different habitats. The genome of Sphingopyxis USTB-05 was 4,679,489 bp and contained 4312 protein coding genes. The 4,239,716 bp nuclear genome of Sphingomonas morindae NBD5, harboring 3882 protein coding genes, has two sets of chromosomes. Both strains had lutein synthesis metabolism pathway sharing identical synthetic genes of crtB, crtE, crtI, crtQ, crtL, crtR, atoB, dxs, dxr, ispD, ispE, ispDF, gcpE, ispG, ispH, ispA, ispB and ispU. Sphingopyxis USTB-05 had hepatotoxins microcystins and nodularin metabolic pathways related to 16 genes (ald, ansA, gdhA, crnA, phy, ocd, hypdh, spuC, nspC, speE, murI, murD, murC, hmgL, bioAand glsA), while these genes were not found in Sphingomonas morindae NBD5. The unique protein sequences of strain NBD5 and strain USTB-05 were 155 and 199, respectively. The analysis of whole genome of the two Sphingomonadaceae strains provides insights into prokaryote evolution, the new pathway for lutein production and the new genes for environmental pollutant biodegradation.

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Evolution of the Circadian Clock Mechanism in Prokaryotes

Israel Journal of Ecology and Evolution ◽

10.1560/ijee_52_3-4_343 ◽

2006 ◽

Vol 52 (3-4) ◽

pp. 343-357 ◽

Cited By ~ 5

Author(s):

Volodymyr Dvornyk

Keyword(s):

Driving Forces ◽

Sequence Data ◽

Biological Evolution ◽

Circadian System ◽

Oxygenic Photosynthesis ◽

Global Changes ◽

Gene Duplications ◽

Living Organisms ◽

Prokaryote Evolution ◽

Clock Mechanism

The circadian system of prokaryotes is probably the oldest among the circadian systems of living organisms. The genes comprising the system are very different in their evolutionary histories. The reconstruction of macroevolution of the circadian genes in cyanobacteria suggests that there are probably at least two types of circadian systems, based either on the threekaigenes (kaiA, kaiB, andkaiC) or onkaiBandkaiC.When referred to the recently published results about a genomic timescale of prokaryote evolution, the origin ofkaiBandsasAcorresponds to the appearance of anoxygenic photosynthesis, while the origin of thekaiBCoperon corresponds to the time when oxygenic photosynthesis evolved.The results of the studies performed so far suggest that major steps in macroevolution of the circadian system in cyanobacteria have been related to global changes in the environment and to keystone advances in biological evolution. This macroevolution has involved selection, multiple lateral transfers, gene duplications, and fusions as its primary driving forces. The proposed scenario of the circadian system's macroevolution is far from complete and will be updated as new genomic and sequence data are accumulated.

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