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. 2024 Mar 2;16(3):evae058.
doi: 10.1093/gbe/evae058.

A Small Genome amidst the Giants: Evidence of Genome Reduction in a Small Tubulinid Free-Living Amoeba

Yonas I Tekle  1 , Hanna Tefera  1
Affiliations

A Small Genome amidst the Giants: Evidence of Genome Reduction in a Small Tubulinid Free-Living Amoeba

Yonas I Tekle et al. Genome Biol Evol. .

Abstract

This study investigates the genomic characteristics of Echinamoeba silvestris, a small-sized amoeba within the Tubulinea clade of the Amoebozoa supergroup. Despite Tubulinea's significance in various fields, genomic data for this clade have been scarce. E. silvestris presents the smallest free-living amoeba genome within Tubulinea and Amoebozoa to date. Comparative analysis reveals intriguing parallels with parasitic lineages in terms of genome size and predicted gene numbers, emphasizing the need to understand the consequences of reduced genomes in free-living amoebae. Functional categorization of predicted genes in E. silvestris shows similar percentages of ortholog groups to other amoebae in various categories, but a distinctive feature is the extensive gene contraction in orphan (ORFan) genes and those involved in biological processes. Notably, among the few genes that underwent expansion, none are related to cellular components, suggesting adaptive processes that streamline biological processes and cellular components for efficiency and energy conservation. Additionally, our investigation into noncoding and repetitive elements sheds light on the evolution of genome size in amoebae, with E. silvestris distinguished by low percentage of repetitive elements. Furthermore, the analysis reveals that E. silvestris has the lowest mean number of introns per gene among the species studied, providing further support for its observed compact genome. Overall, this research underscores the diversity within Tubulinea, highlights knowledge gaps in Amoebozoa genomics, and positions E. silvestris as a valuable addition to genomic data sets, prompting further exploration of complexities in Amoebozoa diversity and genome evolution.

Keywords: Amoebozoa; C-value paradox; Tubulinea; evolution; genome size; horizontal gene transfer.

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Figures

Fig. 1.
Fig. 1.
Taxonomic classification of predicted proteins deduced from E. silvestris draft genome.
Fig. 2.
Fig. 2.
Correlation between genome size and number of predicted genes in Amoebozoans.
See this image and copyright information in PMC

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References

    1. Bajrai LH, Benamar S, Azhar E, Robert C, Levasseur A, Raoult D, La Scola B. Kaumoebavirus, a new virus that clusters with faustoviruses and Asfarviridae. Viruses 2016:8(11):278. 10.3390/v8110278. - DOI - PMC - PubMed
    1. Bakre AA, Rawal K, Ramaswamy R, Bhattacharya A, Bhattacharya S. The LINEs and SINEs of Entamoeba histolytica: comparative analysis and genomic distribution. Exp Parasitol. 2005:110(3):207–213. 10.1016/j.exppara.2005.02.009. - DOI - PubMed
    1. Baumgartner M, Yapi A, Grobner-Ferreira R, Stetter KO. Cultivation and properties of Echinamoeba thermarum n. sp., an extremely thermophilic amoeba thriving in hot springs. Extremophiles 2003:7(4):267–274. 10.1007/s00792-003-0319-6. - DOI - PubMed
    1. Bennett MD, Leitch IJ. Genome size evolution in plants. San Diego (CA): Elsevier; 2005.
    1. Cavalier-Smith T, Chao EEY, Oates B. Molecular phylogeny of Amoebozoa and the evolutionary significance of the unikont Phalansterium. Eur J Protistol. 2004:40(1):21–48. 10.1016/j.ejop.2003.10.001. - DOI

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