Variation, Evolution, and Correlation Analysis of C+G Content and Genome or Chromosome Size in Different Kingdoms and Phyla

Abstract

C+G content (GC content or G+C content) is known to be correlated with genome/chromosome size in bacteria but the relationship for other kingdoms remains unclear. This study analyzed genome size, chromosome size, and base composition in most of the available sequenced genomes in various kingdoms. Genome size tends to increase during evolution in plants and animals, and the same is likely true for bacteria. The genomic C+G contents were found to vary greatly in microorganisms but were quite similar within each animal or plant subkingdom. In animals and plants, the C+G contents are ranked as follows: monocot plants>mammals>non-mammalian animals>dicot plants. The variation in C+G content between chromosomes within species is greater in animals than in plants. The correlation between average chromosome C+G content and chromosome length was found to be positive in Proteobacteria, Actinobacteria (but not in other analyzed bacterial phyla), Ascomycota fungi, and likely also in some plants; negative in some animals, insignificant in two protist phyla, and likely very weak in Archaea. Clearly, correlations between C+G content and chromosome size can be positive, negative, or not significant depending on the kingdoms/groups or species. Different phyla or species exhibit different patterns of correlation between chromosome-size and C+G content. Most chromosomes within a species have a similar pattern of variation in C+G content but outliers are common. The data presented in this study suggest that the C+G content is under genetic control by both trans- and cis- factors and that the correlation between C+G content and chromosome length can be positive, negative, or not significant in different phyla.

Sequence analysis of Maturase K (matK): A chloroplast-encoding gene in some selected pulses

“…Analysis of the GC content of the nucleotide sequences of matK gene in the selected legumes ranged from 27.29% to 30.71%. This confirms the earlier report of Li and Du (2014).Poly (A) tail is a common modification of eukaryotic mRNA and plays many fundamental roles in mRNA stability (Mangus et al, 2003;Coller and Parker, 2004). It is a long chain of adenine nucleotides that is added to the 3' end mRNA during RNA process as it increases the stability of the molecule.…”

“…Important to mention is the fact that genomic adaptations associated with changing GC content might have played a significant role in the evolution of plants. Base composition is a fundamental property of genomes and a strong influence on gene function and regulation (Li and Du, 2014). In higher organisms, the GC content was lower in dicot plants and highest in monocot plants (Li and Du, 2014).…”

“…Base composition is a fundamental property of genomes and a strong influence on gene function and regulation (Li and Du, 2014). In higher organisms, the GC content was lower in dicot plants and highest in monocot plants (Li and Du, 2014). GC content of monocots varied between 33.6-48.9% (Smarda et al, 2014).…”

Steps in Metagenomics: Let’s Avoid Garbage in and Garbage Out

“…Figure 1.3 provides an overview of expected genome size in prokaryotes that can be complemented by other resources providing the exact information on specific genomes. [13][14][15][16] The correlation between G+C content and chromosome size can be positive, negative, or not significant depending on the clade from kingdom to species. 15 To our advantage, most chromosomes within a species have a similar pattern of correlation between G+C content and chromosome size; however, outliers are common.…”

“…[13][14][15][16] The correlation between G+C content and chromosome size can be positive, negative, or not significant depending on the clade from kingdom to species. 15 To our advantage, most chromosomes within a species have a similar pattern of correlation between G+C content and chromosome size; however, outliers are common. 15 Longitudinal studies present their own challenges and can be independently analyzed at each time point, along the timeline as well as across body sites 17,18 (see chapter 7 in this book).…”