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Characterization of the bovine pregnancy-associated glycoprotein gene family--analysis of gene sequences, regulatory regions within the promoter and expression of selected genes.

Telugu BP, Walker AM, Green JA - BMC Genomics (2009)

Bottom Line: The Pregnancy-associated glycoproteins (PAGs) belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order.However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs), were found to be unique to the modern boPAG grouping, but not the ancient boPAGs.These experiments mark the crucial first step in discerning the complex transcriptional regulation operating within the boPAG gene family.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA. telugub@missouri.edu

ABSTRACT

Background: The Pregnancy-associated glycoproteins (PAGs) belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order. In cattle, the PAG gene family is comprised of at least 22 transcribed genes, as well as some variants. Phylogenetic analyses have shown that the PAG family segregates into 'ancient' and 'modern' groupings. Along with sequence differences between family members, there are clear distinctions in their spatio-temporal distribution and in their relative level of expression. In this report, 1) we performed an in silico analysis of the bovine genome to further characterize the PAG gene family, 2) we scrutinized proximal promoter sequences of the PAG genes to evaluate the evolution pressures operating on them and to identify putative regulatory regions, 3) we determined relative transcript abundance of selected PAGs during pregnancy and, 4) we performed preliminary characterization of the putative regulatory elements for one of the candidate PAGs, bovine (bo) PAG-2.

Results: From our analysis of the bovine genome, we identified 18 distinct PAG genes and 14 pseudogenes. We observed that the first 500 base pairs upstream of the translational start site contained multiple regions that are conserved among all boPAGs. However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs), were found to be unique to the modern boPAG grouping, but not the ancient boPAGs. We gathered evidence by means of Q-PCR and screening of EST databases to show that boPAG-2 is the most abundant of all boPAG transcripts. Finally, we provided preliminary evidence for the role of ETS- and DDVL-related TFs in the regulation of the boPAG-2 gene.

Conclusion: PAGs represent a relatively large gene family in the bovine genome. The proximal promoter regions of these genes display differences in putative TF binding sites, likely contributing to observed differences in spatial and temporal expression. We also discovered that boPAG-2 is the most abundant of all boPAG transcripts and provided evidence for the role of ETS and DDVL TFs in its regulation. These experiments mark the crucial first step in discerning the complex transcriptional regulation operating within the boPAG gene family.

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The relative distribution of ESTs of individual boPAGs represented in the bovine EST database. The total numbers of ESTs that matched the coding sequences with more than 98% nucleotide identity in at least 350 bp of query sequence were considered a match and were shown in the figure. Note the relative abundance of the ESTs corresponding to boPAG-2 in comparison to the other members of the PAG family.
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Figure 6: The relative distribution of ESTs of individual boPAGs represented in the bovine EST database. The total numbers of ESTs that matched the coding sequences with more than 98% nucleotide identity in at least 350 bp of query sequence were considered a match and were shown in the figure. Note the relative abundance of the ESTs corresponding to boPAG-2 in comparison to the other members of the PAG family.

Mentions: In order to verify if apparent differences observed in the promoter sequence might be associated with the relative levels of transcription of various genes, the bovine EST database was searched to define the relative distribution of various boPAG transcripts. Of all the boPAGs that were investigated, boPAG-2 had the highest occurrence, with 92 ESTs represented in the database (Figure 6). The next most abundant member was boPAG-11 with 46 ESTs (Figure 6). Of the modern boPAGs that were assessed, boPAG-1 had the highest number of EST matches with 28, followed by boPAG-17 with 25 matches (Figure 6).


Characterization of the bovine pregnancy-associated glycoprotein gene family--analysis of gene sequences, regulatory regions within the promoter and expression of selected genes.

Telugu BP, Walker AM, Green JA - BMC Genomics (2009)

The relative distribution of ESTs of individual boPAGs represented in the bovine EST database. The total numbers of ESTs that matched the coding sequences with more than 98% nucleotide identity in at least 350 bp of query sequence were considered a match and were shown in the figure. Note the relative abundance of the ESTs corresponding to boPAG-2 in comparison to the other members of the PAG family.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2682831&req=5

Figure 6: The relative distribution of ESTs of individual boPAGs represented in the bovine EST database. The total numbers of ESTs that matched the coding sequences with more than 98% nucleotide identity in at least 350 bp of query sequence were considered a match and were shown in the figure. Note the relative abundance of the ESTs corresponding to boPAG-2 in comparison to the other members of the PAG family.
Mentions: In order to verify if apparent differences observed in the promoter sequence might be associated with the relative levels of transcription of various genes, the bovine EST database was searched to define the relative distribution of various boPAG transcripts. Of all the boPAGs that were investigated, boPAG-2 had the highest occurrence, with 92 ESTs represented in the database (Figure 6). The next most abundant member was boPAG-11 with 46 ESTs (Figure 6). Of the modern boPAGs that were assessed, boPAG-1 had the highest number of EST matches with 28, followed by boPAG-17 with 25 matches (Figure 6).

Bottom Line: The Pregnancy-associated glycoproteins (PAGs) belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order.However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs), were found to be unique to the modern boPAG grouping, but not the ancient boPAGs.These experiments mark the crucial first step in discerning the complex transcriptional regulation operating within the boPAG gene family.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA. telugub@missouri.edu

ABSTRACT

Background: The Pregnancy-associated glycoproteins (PAGs) belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order. In cattle, the PAG gene family is comprised of at least 22 transcribed genes, as well as some variants. Phylogenetic analyses have shown that the PAG family segregates into 'ancient' and 'modern' groupings. Along with sequence differences between family members, there are clear distinctions in their spatio-temporal distribution and in their relative level of expression. In this report, 1) we performed an in silico analysis of the bovine genome to further characterize the PAG gene family, 2) we scrutinized proximal promoter sequences of the PAG genes to evaluate the evolution pressures operating on them and to identify putative regulatory regions, 3) we determined relative transcript abundance of selected PAGs during pregnancy and, 4) we performed preliminary characterization of the putative regulatory elements for one of the candidate PAGs, bovine (bo) PAG-2.

Results: From our analysis of the bovine genome, we identified 18 distinct PAG genes and 14 pseudogenes. We observed that the first 500 base pairs upstream of the translational start site contained multiple regions that are conserved among all boPAGs. However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs), were found to be unique to the modern boPAG grouping, but not the ancient boPAGs. We gathered evidence by means of Q-PCR and screening of EST databases to show that boPAG-2 is the most abundant of all boPAG transcripts. Finally, we provided preliminary evidence for the role of ETS- and DDVL-related TFs in the regulation of the boPAG-2 gene.

Conclusion: PAGs represent a relatively large gene family in the bovine genome. The proximal promoter regions of these genes display differences in putative TF binding sites, likely contributing to observed differences in spatial and temporal expression. We also discovered that boPAG-2 is the most abundant of all boPAG transcripts and provided evidence for the role of ETS and DDVL TFs in its regulation. These experiments mark the crucial first step in discerning the complex transcriptional regulation operating within the boPAG gene family.

Show MeSH