Abstract
The lengths of intergenic regions between neighboring genes that are convergent, divergent, or unidirectional were calculated for plastids of the rhodophytic branch and complete archaeal and bacterial genomes. Statistically significant linear relationships between any pair of the medians of these three length types have been revealed in each genomic group. Exponential relationships between the optimal growth temperature and each of the three medians have been revealed as well. The leading coefficients of the regression equations relating all pairs of the medians as well as temperature and any of the medians have the same sign and order of magnitude. The results obtained for plastids, archaea, and bacteria are also similar at the qualitative level. For instance, the medians are always low at high temperatures. At low temperatures, the medians tend to statistically significant greater values and scattering. The original model was used to test our hypothesis that the intergenic distances are optimized in particular to decrease the competition of RNA polymerases within the locus that results in transcribing shortened RNAs. Overall, this points to an effect of temperature for both remote and close genomes.
Highlights
Plastids are semiautonomous organelles originating from cyanobacteria; in the rhodophytic branch, they are represented in red algae (Rhodophyta) as well as in species with plastids of secondary or tertiary origin from Rhodophyta plastids
E considered bacteria (810 genomes) can be clustered into four parts by OGT with the following intervals: 5–30°C (305), 30–40°C (406), 40–65°C (45), and 65–85°C (54). e corresponding Fisher indices Fcalc equal 18, 12, and 31, which are much higher than the tabular value F0.05(3, 806) 2.6. e proposed clustering of species by temperature T is in a good agreement with the traditional classification into hyperthermophiles thermophiles, mesophiles, and psychrophiles. ey are approximately as follows: above 60°C, above 45°C, in 20–45°C, and below 10°C, respectively
A linear relationship between the medians is beyond question; the corresponding linear regressions are unconditionally confirmed by the statistical test for plastids, archaea, and bacteria
Summary
1. Introduction e dependence of intergenic distances between each other and on the species’ optimal growth temperature was considered in three large groups: plastids of the rhodophytic branch, archaea, and bacteria. A significant correlation between intergenic distances in convergent and divergent neighboring gene pairs was observed in several archaea and bacteria [1]. E considered OGTs range from 2 to 52.5°C in plastid species, from 22.5 to 114°C in archaea, and from 7 to 85°C in bacteria Plastids are semiautonomous organelles originating from cyanobacteria; in the rhodophytic branch, they are represented in red algae (Rhodophyta) as well as in species with plastids of secondary or tertiary origin from Rhodophyta plastids. Eir optimal growth temperature varies in a wide range, from 20°C to 116°C. ermophilic archaea include representatives of early diverged phylogenetic groups Crenarchaeota and Euryarchaeota. Methanoculleus marisnigri (20–25°C) and Methanococcoides burtonii (23.4°C) are the exceptions among the considered species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
