The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs
<p>Abstract</p> <p>Background</p> <p>The Hawaiian endemic genus <it>Clermonti</it>a (Campanulaceae) includes 22 species, 15 of which, the double-corolla species, are characterized by an extra whorl of organs that appear to be true petals occupying what is no...
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2012-11-01
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| Series: | EvoDevo |
| Subjects: | |
| Online Access: | http://www.evodevojournal.com/content/3/1/26 |
| _version_ | 1811266257762123776 |
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| author | Hofer Katherine A Ruonala Raili Albert Victor A |
| author_facet | Hofer Katherine A Ruonala Raili Albert Victor A |
| author_sort | Hofer Katherine A |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>The Hawaiian endemic genus <it>Clermonti</it>a (Campanulaceae) includes 22 species, 15 of which, the double-corolla species, are characterized by an extra whorl of organs that appear to be true petals occupying what is normally the sepal whorl. Previous research has shown that the presence of homeotic petaloid organs in some other plant groups correlates with ectopic expression of B-function MADS box genes, but similar core eudicot examples of apparent groundplan divergence remain unstudied. B-function genes, which are not normally expressed in the sepal whorl, are required for determination and maintenance of petal identity. Here, we investigate the potential role of altered B-function gene expression contributing to the morphological diversity of this island genus.</p> <p>Results</p> <p>We examined the morphology and developmental genetics of two different species of <it>Clermontia</it>, one of which, <it>C. arborescens</it>, has normal sepals while the other, <it>C. parviflora</it>, has two whorls of petal-like organs. Scanning electron microscopy of cell surface morphologies of first and second whorl organs in the double-corolla species <it>C. parviflora</it> revealed conical epidermal cells on the adaxial surfaces of both first and second whorl petaloid organs, strongly suggesting a homeotic conversion in the former. Phylogenetic analysis of <it>Clermontia</it> species based on 5S ribosomal DNA non-transcribed spacer sequences indicated a probable single and geologically recent origin of the double-corolla trait within the genus, with numerous potential reversals to the standard sepal-petal format. Quantitative polymerase chain reaction analysis of homologs of the B-function genes <it>PISTILLATA</it> (<it>PI</it>), <it>APETALA3</it> and <it>TOMATO MADS 6</it> indicated ectopic expression of two <it>PI</it> paralogs in the first whorl of <it>C. parviflora</it>; no such homeotic expression was observed for the other two genes, nor for several other MADS box genes involved in various floral and non-floral functions. In the standard sepal-petal species <it>C. arborescens</it>, ectopic expression of PI homologs was not observed. In <it>C. parviflora</it>, the upregulation of <it>PI</it> homologs was precisely restricted to the perianth and stamen whorls, excluding a simple overexpression phenotype. <it>In situ</it> hybridization analysis of <it>C. parviflora</it> material similarly showed first and second whorl PI homolog expression in developing flower buds.</p> <p>Conclusions</p> <p>Our morphological and gene expression data strongly suggest that a drastic and heritable phenotypic change, at the level of floral groundplan, can originate from a homeotic mutation that is likely regulatory, being under precise spatiotemporal control as opposed to having pleiotropic characteristics. The uniqueness of this trait among core eudicots could be linked to increased ecological viability in an unstable island environment, a chance event which need not have posed any immediate adaptive benefit. We argue that the evolutionarily young morphological radiation of <it>Clermontia</it> may form a model system for general understanding of mechanisms of larger-scale angiosperm diversification in past, similarly unstable environments, in which small regulatory changes may have been responsible for modern-day groundplan differences.</p> <p>Trial registration</p> <p>Clinical Trials.gov- NCT01710735</p> <p>Significance and Innovations</p> <p>The present investigation is one of the first to examine the hypothesis of grossmuscle contractile inhibition due to the presence of diagnostically relevant MFTrPs.Individuals suffering from clinically relevant levels of self-reported pain are able to tolerate maximum voluntary contraction testing, but delayed onset muscle soreness (DOMS) is a likely side-effect irrespective of symptom status. As a consequence, its confounding effect during subsequent testing must be taken into account.</p> |
| first_indexed | 2024-04-12T20:38:49Z |
| format | Article |
| id | doaj.art-e7d2c9b1fdd54b12b0dda0937af43989 |
| institution | Directory Open Access Journal |
| issn | 2041-9139 |
| language | English |
| last_indexed | 2024-04-12T20:38:49Z |
| publishDate | 2012-11-01 |
| publisher | BMC |
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| series | EvoDevo |
| spelling | doaj.art-e7d2c9b1fdd54b12b0dda0937af439892022-12-22T03:17:30ZengBMCEvoDevo2041-91392012-11-01312610.1186/2041-9139-3-26The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologsHofer Katherine ARuonala RailiAlbert Victor A<p>Abstract</p> <p>Background</p> <p>The Hawaiian endemic genus <it>Clermonti</it>a (Campanulaceae) includes 22 species, 15 of which, the double-corolla species, are characterized by an extra whorl of organs that appear to be true petals occupying what is normally the sepal whorl. Previous research has shown that the presence of homeotic petaloid organs in some other plant groups correlates with ectopic expression of B-function MADS box genes, but similar core eudicot examples of apparent groundplan divergence remain unstudied. B-function genes, which are not normally expressed in the sepal whorl, are required for determination and maintenance of petal identity. Here, we investigate the potential role of altered B-function gene expression contributing to the morphological diversity of this island genus.</p> <p>Results</p> <p>We examined the morphology and developmental genetics of two different species of <it>Clermontia</it>, one of which, <it>C. arborescens</it>, has normal sepals while the other, <it>C. parviflora</it>, has two whorls of petal-like organs. Scanning electron microscopy of cell surface morphologies of first and second whorl organs in the double-corolla species <it>C. parviflora</it> revealed conical epidermal cells on the adaxial surfaces of both first and second whorl petaloid organs, strongly suggesting a homeotic conversion in the former. Phylogenetic analysis of <it>Clermontia</it> species based on 5S ribosomal DNA non-transcribed spacer sequences indicated a probable single and geologically recent origin of the double-corolla trait within the genus, with numerous potential reversals to the standard sepal-petal format. Quantitative polymerase chain reaction analysis of homologs of the B-function genes <it>PISTILLATA</it> (<it>PI</it>), <it>APETALA3</it> and <it>TOMATO MADS 6</it> indicated ectopic expression of two <it>PI</it> paralogs in the first whorl of <it>C. parviflora</it>; no such homeotic expression was observed for the other two genes, nor for several other MADS box genes involved in various floral and non-floral functions. In the standard sepal-petal species <it>C. arborescens</it>, ectopic expression of PI homologs was not observed. In <it>C. parviflora</it>, the upregulation of <it>PI</it> homologs was precisely restricted to the perianth and stamen whorls, excluding a simple overexpression phenotype. <it>In situ</it> hybridization analysis of <it>C. parviflora</it> material similarly showed first and second whorl PI homolog expression in developing flower buds.</p> <p>Conclusions</p> <p>Our morphological and gene expression data strongly suggest that a drastic and heritable phenotypic change, at the level of floral groundplan, can originate from a homeotic mutation that is likely regulatory, being under precise spatiotemporal control as opposed to having pleiotropic characteristics. The uniqueness of this trait among core eudicots could be linked to increased ecological viability in an unstable island environment, a chance event which need not have posed any immediate adaptive benefit. We argue that the evolutionarily young morphological radiation of <it>Clermontia</it> may form a model system for general understanding of mechanisms of larger-scale angiosperm diversification in past, similarly unstable environments, in which small regulatory changes may have been responsible for modern-day groundplan differences.</p> <p>Trial registration</p> <p>Clinical Trials.gov- NCT01710735</p> <p>Significance and Innovations</p> <p>The present investigation is one of the first to examine the hypothesis of grossmuscle contractile inhibition due to the presence of diagnostically relevant MFTrPs.Individuals suffering from clinically relevant levels of self-reported pain are able to tolerate maximum voluntary contraction testing, but delayed onset muscle soreness (DOMS) is a likely side-effect irrespective of symptom status. As a consequence, its confounding effect during subsequent testing must be taken into account.</p>http://www.evodevojournal.com/content/3/1/26Myofascial painTrigger pointsNeck/shoulder painHealth status |
| spellingShingle | Hofer Katherine A Ruonala Raili Albert Victor A The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs EvoDevo Myofascial pain Trigger points Neck/shoulder pain Health status |
| title | The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs |
| title_full | The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs |
| title_fullStr | The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs |
| title_full_unstemmed | The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs |
| title_short | The double-corolla phenotype in the Hawaiian lobelioid genus <it>Clermontia</it> involves ectopic expression of <it>PISTILLATA</it> B-function MADS box gene homologs |
| title_sort | double corolla phenotype in the hawaiian lobelioid genus it clermontia it involves ectopic expression of it pistillata it b function mads box gene homologs |
| topic | Myofascial pain Trigger points Neck/shoulder pain Health status |
| url | http://www.evodevojournal.com/content/3/1/26 |
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