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The contribution of the genomes of a termite and a locust to our understanding of insect neuropeptides and neurohormones.

Veenstra JA - Front Physiol (2014)

Bottom Line: The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts.The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not.The relevance of these findings is discussed.

View Article: PubMed Central - PubMed

Affiliation: INCIA UMR 5287 CNRS, Université de Bordeaux Pessac, France.

ABSTRACT
The genomes of the migratory locust Locusta migratoria and the termite Zootermopsis nevadensis were mined for the presence of genes encoding neuropeptides, neurohormones, and their G-protein coupled receptors (GPCRs). Both species have retained a larger number of neuropeptide and neuropeptide GPCRs than the better known holometabolous insect species, while other genes that in holometabolous species appear to have a single transcript produce two different precursors in the locust, the termite or both. Thus, the recently discovered CNMa neuropeptide gene has two transcripts predicted to produce two structurally different CNMa peptides in the termite, while the locust produces two different myosuppressin peptides in the same fashion. Both these species also have a calcitonin gene, which is different from the gene encoding the calcitonin-like insect diuretic hormone. This gene produces two types of calcitonins, calcitonins A and B. It is also present in Lepidoptera and Coleoptera and some Diptera, but absent from mosquitoes and Drosophila. However, in holometabolous insect species, only the B transcript is produced. Their putative receptors were also identified. In contrast, Locusta has a highly unusual gene that codes for a salivation stimulatory peptide. The Locusta genes for neuroparsin and vasopressin are particularly interesting. The neuroparsin gene produces five different transcripts, of which only one codes for the neurohormone identified from the corpora cardiaca. The other four transcripts code for neuroparsin-like proteins, which lack four amino acid residues, and that for that reason we called neoneuroparsins. The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts. The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not. The relevance of these findings is discussed.

No MeSH data available.


Related in: MedlinePlus

Nucleotide sequence of the putative promoter and first coding exon of various Locusta vasopressin genes. The TATA box and a near perfect copy of the first motif of the Drosophila core promoter (Ohler, 2006) are emphasized, while the putative intron donor splice site is in bold italics. The conceptually translated protein is indicated below the DNA sequence and the predicted signal peptide is highlighted in yellow, the convertase cleavage site in red, the glycine residue transformed into the C-terminal amide in purple, the vasopressin-like sequence in light blue and the two cysteine residues that will form the disulfide bridge in orange.
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Figure 15: Nucleotide sequence of the putative promoter and first coding exon of various Locusta vasopressin genes. The TATA box and a near perfect copy of the first motif of the Drosophila core promoter (Ohler, 2006) are emphasized, while the putative intron donor splice site is in bold italics. The conceptually translated protein is indicated below the DNA sequence and the predicted signal peptide is highlighted in yellow, the convertase cleavage site in red, the glycine residue transformed into the C-terminal amide in purple, the vasopressin-like sequence in light blue and the two cysteine residues that will form the disulfide bridge in orange.

Mentions: In the Zootermopsis genome a single vasopressin gene was encountered, but the Locusta genome seems to have 6–8 such genes. This estimate is based on the number of genomic reads that encode the CLINTCPRGGKR sequence present in various Locusta genomic SRAs. Interestingly the first exon of the Locusta gene as well as the putative promoter sequence upstream of it, including a TATA box and a near perfect match of motif 1 of the Drosophila core promotor described by Ohler (2006), are very well-conserved (Figure 15). Three sequences in the genome assembly are completely identical to this consensus sequence. Of the other eight highly similar sequences in the assembly we detected one that has a single silent nucleotide substitution, another that lacks the last G in the GTAAG splice donor site, and a third one that has several nucleotide substitutions, some of which are predicted to lead to a different, but just as functional, signal peptide. In the latter sequence the amino acid immediately after the Lys-Arg convertase cleavage site is predicted to be a Asp residue rather than the Ala in the other sequences. Finally, there are four incomplete sequences and one that misses a piece in the DNA coding the prepropeptide and cannot produce a vasopressin-like peptide. Whereas the first exon and the DNA sequence immediately preceding it, are very well-conserved between the different genes, this is not the case for the other exons or the intron following the first coding exon. Although it is possible to identify some putative second exons, we were unable to identify the third. Those exons seem to be much less conserved than the first one. It is not clear whether the current genome assembly of the various vasopressin genes is correct, as the short length of the reads makes it difficult to assemble repetitive sequences or multiple copies of a similar gene.


The contribution of the genomes of a termite and a locust to our understanding of insect neuropeptides and neurohormones.

Veenstra JA - Front Physiol (2014)

Nucleotide sequence of the putative promoter and first coding exon of various Locusta vasopressin genes. The TATA box and a near perfect copy of the first motif of the Drosophila core promoter (Ohler, 2006) are emphasized, while the putative intron donor splice site is in bold italics. The conceptually translated protein is indicated below the DNA sequence and the predicted signal peptide is highlighted in yellow, the convertase cleavage site in red, the glycine residue transformed into the C-terminal amide in purple, the vasopressin-like sequence in light blue and the two cysteine residues that will form the disulfide bridge in orange.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4237046&req=5

Figure 15: Nucleotide sequence of the putative promoter and first coding exon of various Locusta vasopressin genes. The TATA box and a near perfect copy of the first motif of the Drosophila core promoter (Ohler, 2006) are emphasized, while the putative intron donor splice site is in bold italics. The conceptually translated protein is indicated below the DNA sequence and the predicted signal peptide is highlighted in yellow, the convertase cleavage site in red, the glycine residue transformed into the C-terminal amide in purple, the vasopressin-like sequence in light blue and the two cysteine residues that will form the disulfide bridge in orange.
Mentions: In the Zootermopsis genome a single vasopressin gene was encountered, but the Locusta genome seems to have 6–8 such genes. This estimate is based on the number of genomic reads that encode the CLINTCPRGGKR sequence present in various Locusta genomic SRAs. Interestingly the first exon of the Locusta gene as well as the putative promoter sequence upstream of it, including a TATA box and a near perfect match of motif 1 of the Drosophila core promotor described by Ohler (2006), are very well-conserved (Figure 15). Three sequences in the genome assembly are completely identical to this consensus sequence. Of the other eight highly similar sequences in the assembly we detected one that has a single silent nucleotide substitution, another that lacks the last G in the GTAAG splice donor site, and a third one that has several nucleotide substitutions, some of which are predicted to lead to a different, but just as functional, signal peptide. In the latter sequence the amino acid immediately after the Lys-Arg convertase cleavage site is predicted to be a Asp residue rather than the Ala in the other sequences. Finally, there are four incomplete sequences and one that misses a piece in the DNA coding the prepropeptide and cannot produce a vasopressin-like peptide. Whereas the first exon and the DNA sequence immediately preceding it, are very well-conserved between the different genes, this is not the case for the other exons or the intron following the first coding exon. Although it is possible to identify some putative second exons, we were unable to identify the third. Those exons seem to be much less conserved than the first one. It is not clear whether the current genome assembly of the various vasopressin genes is correct, as the short length of the reads makes it difficult to assemble repetitive sequences or multiple copies of a similar gene.

Bottom Line: The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts.The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not.The relevance of these findings is discussed.

View Article: PubMed Central - PubMed

Affiliation: INCIA UMR 5287 CNRS, Université de Bordeaux Pessac, France.

ABSTRACT
The genomes of the migratory locust Locusta migratoria and the termite Zootermopsis nevadensis were mined for the presence of genes encoding neuropeptides, neurohormones, and their G-protein coupled receptors (GPCRs). Both species have retained a larger number of neuropeptide and neuropeptide GPCRs than the better known holometabolous insect species, while other genes that in holometabolous species appear to have a single transcript produce two different precursors in the locust, the termite or both. Thus, the recently discovered CNMa neuropeptide gene has two transcripts predicted to produce two structurally different CNMa peptides in the termite, while the locust produces two different myosuppressin peptides in the same fashion. Both these species also have a calcitonin gene, which is different from the gene encoding the calcitonin-like insect diuretic hormone. This gene produces two types of calcitonins, calcitonins A and B. It is also present in Lepidoptera and Coleoptera and some Diptera, but absent from mosquitoes and Drosophila. However, in holometabolous insect species, only the B transcript is produced. Their putative receptors were also identified. In contrast, Locusta has a highly unusual gene that codes for a salivation stimulatory peptide. The Locusta genes for neuroparsin and vasopressin are particularly interesting. The neuroparsin gene produces five different transcripts, of which only one codes for the neurohormone identified from the corpora cardiaca. The other four transcripts code for neuroparsin-like proteins, which lack four amino acid residues, and that for that reason we called neoneuroparsins. The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts. The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not. The relevance of these findings is discussed.

No MeSH data available.


Related in: MedlinePlus