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Analysis of Schistosoma mansoni genes shared with Deuterostomia and with possible roles in host interactions.

Venancio TM, DeMarco R, Almeida GT, Oliveira KC, Setubal JC, Verjovski-Almeida S - BMC Genomics (2007)

Bottom Line: In this work we found 427 genes conserved in the Deuterostomia group that have orthologs in S. mansoni and no members in any nematodes and insects so far sequenced.Using S. mansoni homologs, we have employed a parsimonious rationale to compute the total gene losses/gains in nematodes, arthropods and deuterostomes under either the Coelomata or the Ecdysozoa evolutionary hypotheses; our results show a lower losses/gains number under the latter hypothesis.Given their known functions in Deuterostomia, it is possible that some of them have been co-opted to perform functions related (directly or indirectly) to host adaptation or interaction with host signaling processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Bioinformatics; Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900 São Paulo, SP, Brazil. venancio@iq.usp.br

ABSTRACT

Background: Schistosoma mansoni is a blood helminth parasite that causes schistosomiasis, a disease that affects 200 million people in the world. Many orthologs of known mammalian genes have been discovered in this parasite and evidence is accumulating that some of these genes encode proteins linked to signaling pathways in the parasite that appear to be involved with growth or development, suggesting a complex co-evolutionary process.

Results: In this work we found 427 genes conserved in the Deuterostomia group that have orthologs in S. mansoni and no members in any nematodes and insects so far sequenced. Among these genes we have identified Insulin Induced Gene (INSIG), Interferon Regulatory Factor (IRF) and vasohibin orthologs, known to be involved in mammals in mevalonate metabolism, immune response and angiogenesis control, respectively. We have chosen these three genes for a more detailed characterization, which included extension of their cloned messages to obtain full-length sequences. Interestingly, SmINSIG showed a 10-fold higher expression in adult females as opposed to males, in accordance with its possible role in regulating egg production. SmIRF has a DNA binding domain, a tryptophan-rich N-terminal region and several predicted phosphorylation sites, usually important for IRF activity. Fourteen different alternatively spliced forms of the S. mansoni vasohibin (SmVASL) gene were detected that encode seven different protein isoforms including one with a complete C-terminal end, and other isoforms with shorter C-terminal portions. Using S. mansoni homologs, we have employed a parsimonious rationale to compute the total gene losses/gains in nematodes, arthropods and deuterostomes under either the Coelomata or the Ecdysozoa evolutionary hypotheses; our results show a lower losses/gains number under the latter hypothesis.

Conclusion: The genes discussed which are conserved between S. mansoni and deuterostomes, probably have an ancient origin and were lost in Ecdysozoa, being still present in Lophotrochozoa. Given their known functions in Deuterostomia, it is possible that some of them have been co-opted to perform functions related (directly or indirectly) to host adaptation or interaction with host signaling processes.

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S. mansoni Insulin Induced Gene (SmINSIG) and its orthologs. A: Multiple sequence alignment (MSA) of SmINSIG and several orthologs. Two distantly related yeast INSIG homologs were included in the MSA. SmINSIG transmembrane regions predicted by TMHMM and MINNOU are indicated by red and green bars, respectively. A consensus sequence and conservation bars are also represented; B: Maximum Likelihood tree constructed from the alignment of SmINSIG and several INSIGs found in public databases. The S. mansoni branch is represented in red. Numbers next to the branches represent bootstrap values (in 1000 samplings).
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Figure 2: S. mansoni Insulin Induced Gene (SmINSIG) and its orthologs. A: Multiple sequence alignment (MSA) of SmINSIG and several orthologs. Two distantly related yeast INSIG homologs were included in the MSA. SmINSIG transmembrane regions predicted by TMHMM and MINNOU are indicated by red and green bars, respectively. A consensus sequence and conservation bars are also represented; B: Maximum Likelihood tree constructed from the alignment of SmINSIG and several INSIGs found in public databases. The S. mansoni branch is represented in red. Numbers next to the branches represent bootstrap values (in 1000 samplings).

Mentions: Figure 2A illustrates a multiple alignment of INSIGs from different deuterostomes and SmINSIG, where the conserved domain is shown and the six transmembrane regions are marked. BLASTP search against the nr database at GenBank using SmINSIG as query resulted in a best match to the zebrafish (Danio rerio) INSIG-1 ortholog ([GenBank: AAH45341.1]) with 49% identity and 68% similarity over 144 amino acids. A Maximum Likelihood tree was constructed (refer to the Methods section for details) (Figure 2B), and suggests that SmINSIG diverged before the gene duplication event responsible for emergence of the two vertebrate paralogs in zebrafish.


Analysis of Schistosoma mansoni genes shared with Deuterostomia and with possible roles in host interactions.

Venancio TM, DeMarco R, Almeida GT, Oliveira KC, Setubal JC, Verjovski-Almeida S - BMC Genomics (2007)

S. mansoni Insulin Induced Gene (SmINSIG) and its orthologs. A: Multiple sequence alignment (MSA) of SmINSIG and several orthologs. Two distantly related yeast INSIG homologs were included in the MSA. SmINSIG transmembrane regions predicted by TMHMM and MINNOU are indicated by red and green bars, respectively. A consensus sequence and conservation bars are also represented; B: Maximum Likelihood tree constructed from the alignment of SmINSIG and several INSIGs found in public databases. The S. mansoni branch is represented in red. Numbers next to the branches represent bootstrap values (in 1000 samplings).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2194728&req=5

Figure 2: S. mansoni Insulin Induced Gene (SmINSIG) and its orthologs. A: Multiple sequence alignment (MSA) of SmINSIG and several orthologs. Two distantly related yeast INSIG homologs were included in the MSA. SmINSIG transmembrane regions predicted by TMHMM and MINNOU are indicated by red and green bars, respectively. A consensus sequence and conservation bars are also represented; B: Maximum Likelihood tree constructed from the alignment of SmINSIG and several INSIGs found in public databases. The S. mansoni branch is represented in red. Numbers next to the branches represent bootstrap values (in 1000 samplings).
Mentions: Figure 2A illustrates a multiple alignment of INSIGs from different deuterostomes and SmINSIG, where the conserved domain is shown and the six transmembrane regions are marked. BLASTP search against the nr database at GenBank using SmINSIG as query resulted in a best match to the zebrafish (Danio rerio) INSIG-1 ortholog ([GenBank: AAH45341.1]) with 49% identity and 68% similarity over 144 amino acids. A Maximum Likelihood tree was constructed (refer to the Methods section for details) (Figure 2B), and suggests that SmINSIG diverged before the gene duplication event responsible for emergence of the two vertebrate paralogs in zebrafish.

Bottom Line: In this work we found 427 genes conserved in the Deuterostomia group that have orthologs in S. mansoni and no members in any nematodes and insects so far sequenced.Using S. mansoni homologs, we have employed a parsimonious rationale to compute the total gene losses/gains in nematodes, arthropods and deuterostomes under either the Coelomata or the Ecdysozoa evolutionary hypotheses; our results show a lower losses/gains number under the latter hypothesis.Given their known functions in Deuterostomia, it is possible that some of them have been co-opted to perform functions related (directly or indirectly) to host adaptation or interaction with host signaling processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Bioinformatics; Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900 São Paulo, SP, Brazil. venancio@iq.usp.br

ABSTRACT

Background: Schistosoma mansoni is a blood helminth parasite that causes schistosomiasis, a disease that affects 200 million people in the world. Many orthologs of known mammalian genes have been discovered in this parasite and evidence is accumulating that some of these genes encode proteins linked to signaling pathways in the parasite that appear to be involved with growth or development, suggesting a complex co-evolutionary process.

Results: In this work we found 427 genes conserved in the Deuterostomia group that have orthologs in S. mansoni and no members in any nematodes and insects so far sequenced. Among these genes we have identified Insulin Induced Gene (INSIG), Interferon Regulatory Factor (IRF) and vasohibin orthologs, known to be involved in mammals in mevalonate metabolism, immune response and angiogenesis control, respectively. We have chosen these three genes for a more detailed characterization, which included extension of their cloned messages to obtain full-length sequences. Interestingly, SmINSIG showed a 10-fold higher expression in adult females as opposed to males, in accordance with its possible role in regulating egg production. SmIRF has a DNA binding domain, a tryptophan-rich N-terminal region and several predicted phosphorylation sites, usually important for IRF activity. Fourteen different alternatively spliced forms of the S. mansoni vasohibin (SmVASL) gene were detected that encode seven different protein isoforms including one with a complete C-terminal end, and other isoforms with shorter C-terminal portions. Using S. mansoni homologs, we have employed a parsimonious rationale to compute the total gene losses/gains in nematodes, arthropods and deuterostomes under either the Coelomata or the Ecdysozoa evolutionary hypotheses; our results show a lower losses/gains number under the latter hypothesis.

Conclusion: The genes discussed which are conserved between S. mansoni and deuterostomes, probably have an ancient origin and were lost in Ecdysozoa, being still present in Lophotrochozoa. Given their known functions in Deuterostomia, it is possible that some of them have been co-opted to perform functions related (directly or indirectly) to host adaptation or interaction with host signaling processes.

Show MeSH
Related in: MedlinePlus