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Genome and phylogenetic analyses of Trypanosoma evansi reveal extensive similarity to T. brucei and multiple independent origins for dyskinetoplasty.

Carnes J, Anupama A, Balmer O, Jackson A, Lewis M, Brown R, Cestari I, Desquesnes M, Gendrin C, Hertz-Fowler C, Imamura H, Ivens A, Kořený L, Lai DH, MacLeod A, McDermott SM, Merritt C, Monnerat S, Moon W, Myler P, Phan I, Ramasamy G, Sivam D, Lun ZR, Lukeš J, Stuart K, Schnaufer A - PLoS Negl Trop Dis (2015)

Bottom Line: Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality.Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA.Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.

View Article: PubMed Central - PubMed

Affiliation: Seattle Biomedical Research Institute, Seattle, United States of America.

ABSTRACT
Two key biological features distinguish Trypanosoma evansi from the T. brucei group: independence from the tsetse fly as obligatory vector, and independence from the need for functional mitochondrial DNA (kinetoplast or kDNA). In an effort to better understand the molecular causes and consequences of these differences, we sequenced the genome of an akinetoplastic T. evansi strain from China and compared it to the T. b. brucei reference strain. The annotated T. evansi genome shows extensive similarity to the reference, with 94.9% of the predicted T. b. brucei coding sequences (CDS) having an ortholog in T. evansi, and 94.6% of the non-repetitive orthologs having a nucleotide identity of 95% or greater. Interestingly, several procyclin-associated genes (PAGs) were disrupted or not found in this T. evansi strain, suggesting a selective loss of function in the absence of the insect life-cycle stage. Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality. Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA. Candidates for CDS that are absent from the reference genome were identified in supplementary de novo assemblies of T. evansi reads. Phylogenetic analyses show that the sequenced strain belongs to a dominant group of clonal T. evansi strains with worldwide distribution that also includes isolates classified as T. equiperdum. At least three other types of T. evansi or T. equiperdum have emerged independently. Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.

No MeSH data available.


Related in: MedlinePlus

Pulse-field gel electrophoresis comparing chromosomes of T. evansi STIB805 (Tev) and T. b. brucei TREU 927/4 (927).While the sizes of megabase chromosomes are largely similar, differences in the intermediate and minichromosomes (825 kbp and smaller) are evident between T. evansi and T. brucei. Although T. brucei chromosomes I-XI were not unambiguously identified, labels to the left of the gel indicate bands consistent with the expected T. brucei chromosome sizes [46], as well as intermediate and minichromosomes. The signal at the top of the gel is from the well, as indicated.
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pntd-0003404-g001: Pulse-field gel electrophoresis comparing chromosomes of T. evansi STIB805 (Tev) and T. b. brucei TREU 927/4 (927).While the sizes of megabase chromosomes are largely similar, differences in the intermediate and minichromosomes (825 kbp and smaller) are evident between T. evansi and T. brucei. Although T. brucei chromosomes I-XI were not unambiguously identified, labels to the left of the gel indicate bands consistent with the expected T. brucei chromosome sizes [46], as well as intermediate and minichromosomes. The signal at the top of the gel is from the well, as indicated.

Mentions: PFGE was performed to visualize the pattern of chromosomes in the akinetoplastic T. evansi STIB805 strain. Multiple bands corresponding to megabase chromosomes ranging in size from ∼1 to ∼5 Mb could be visualized (Fig. 1). The most noticeable differences in the chromosomal pattern in comparison to T. brucei are the five intermediate chromosome bands that range from ∼300 kb to ∼800 kb. Additionally, two size groups of minichromosomes (∼100 kb and ∼200 kb) were observed in T. evansi STIB805. Such a degree of variability is within the range observed among strains of T. b. brucei[46].


Genome and phylogenetic analyses of Trypanosoma evansi reveal extensive similarity to T. brucei and multiple independent origins for dyskinetoplasty.

Carnes J, Anupama A, Balmer O, Jackson A, Lewis M, Brown R, Cestari I, Desquesnes M, Gendrin C, Hertz-Fowler C, Imamura H, Ivens A, Kořený L, Lai DH, MacLeod A, McDermott SM, Merritt C, Monnerat S, Moon W, Myler P, Phan I, Ramasamy G, Sivam D, Lun ZR, Lukeš J, Stuart K, Schnaufer A - PLoS Negl Trop Dis (2015)

Pulse-field gel electrophoresis comparing chromosomes of T. evansi STIB805 (Tev) and T. b. brucei TREU 927/4 (927).While the sizes of megabase chromosomes are largely similar, differences in the intermediate and minichromosomes (825 kbp and smaller) are evident between T. evansi and T. brucei. Although T. brucei chromosomes I-XI were not unambiguously identified, labels to the left of the gel indicate bands consistent with the expected T. brucei chromosome sizes [46], as well as intermediate and minichromosomes. The signal at the top of the gel is from the well, as indicated.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4288722&req=5

pntd-0003404-g001: Pulse-field gel electrophoresis comparing chromosomes of T. evansi STIB805 (Tev) and T. b. brucei TREU 927/4 (927).While the sizes of megabase chromosomes are largely similar, differences in the intermediate and minichromosomes (825 kbp and smaller) are evident between T. evansi and T. brucei. Although T. brucei chromosomes I-XI were not unambiguously identified, labels to the left of the gel indicate bands consistent with the expected T. brucei chromosome sizes [46], as well as intermediate and minichromosomes. The signal at the top of the gel is from the well, as indicated.
Mentions: PFGE was performed to visualize the pattern of chromosomes in the akinetoplastic T. evansi STIB805 strain. Multiple bands corresponding to megabase chromosomes ranging in size from ∼1 to ∼5 Mb could be visualized (Fig. 1). The most noticeable differences in the chromosomal pattern in comparison to T. brucei are the five intermediate chromosome bands that range from ∼300 kb to ∼800 kb. Additionally, two size groups of minichromosomes (∼100 kb and ∼200 kb) were observed in T. evansi STIB805. Such a degree of variability is within the range observed among strains of T. b. brucei[46].

Bottom Line: Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality.Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA.Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.

View Article: PubMed Central - PubMed

Affiliation: Seattle Biomedical Research Institute, Seattle, United States of America.

ABSTRACT
Two key biological features distinguish Trypanosoma evansi from the T. brucei group: independence from the tsetse fly as obligatory vector, and independence from the need for functional mitochondrial DNA (kinetoplast or kDNA). In an effort to better understand the molecular causes and consequences of these differences, we sequenced the genome of an akinetoplastic T. evansi strain from China and compared it to the T. b. brucei reference strain. The annotated T. evansi genome shows extensive similarity to the reference, with 94.9% of the predicted T. b. brucei coding sequences (CDS) having an ortholog in T. evansi, and 94.6% of the non-repetitive orthologs having a nucleotide identity of 95% or greater. Interestingly, several procyclin-associated genes (PAGs) were disrupted or not found in this T. evansi strain, suggesting a selective loss of function in the absence of the insect life-cycle stage. Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality. Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA. Candidates for CDS that are absent from the reference genome were identified in supplementary de novo assemblies of T. evansi reads. Phylogenetic analyses show that the sequenced strain belongs to a dominant group of clonal T. evansi strains with worldwide distribution that also includes isolates classified as T. equiperdum. At least three other types of T. evansi or T. equiperdum have emerged independently. Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.

No MeSH data available.


Related in: MedlinePlus