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Marc Herbin - One of the best experts on this subject based on the ideXlab platform.
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Development and growth of the pelvic fin in the extant coelacanth Latimeria chalumnae.
Anatomical record (Hoboken N.J. : 2007), 2020Co-Authors: Rohan Mansuit, Gael Clement, Anthony Herrel, Hugo Dutel, Paul Tafforeau, Mathieu Santin, Marc HerbinAbstract:The ontogeny of the paired appendages has been extensively studied in lungfishes and tetrapods, but remains poorly known in coelacanths. Recent work has shed light on the anatomy and development of the pectoral fin in Latimeria chalumnae. Yet, information on the development of the pelvic fin and girdle is still lacking. Here, we described the development of the pelvic fin and girdle in Latimeria chalumnae based on 3D reconstructions generated from conventional and X-ray synchrotron microtomography, as well as MRI acquisitions. As in other jawed vertebrates, the development of the pelvic fin occurs later than that of the pectoral fin in Latimeria. Many elements of the endoskeleton are not yet formed at the earliest stage sampled. The four mesomeres are already formed in the fetus, but only the most proximal radial elements (preaxial radial 0-1) are formed and individualized at this stage. We suggest that all the preaxial radial elements in the pelvic and pectoral fin of Latimeria are formed through the fragmentation of the mesomeres. We document the progressive ossification of the pelvic girdle, and the presence of a trabecular system in the adult. This trabecular system likely reinforces the cartilaginous girdle to resist the muscle forces exerted during locomotion. Finally, the presence of a preaxial element in contact with the pelvic girdle from the earliest stage of development onward questions the mono-basal condition of the pelvic fin in Latimeria. However, the particular shape of the mesomeres may explain the presence of this element in contact with the girdle.
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Neurocranial development of the coelacanth and the evolution of the sarcopterygian head
Nature, 2019Co-Authors: Hugo Dutel, Philippe Janvier, Gael Clement, Anthony Herrel, Paul Tafforeau, Manon Galland, John A. Long, Michael J. Fagan, Mathieu D. Santin, Marc HerbinAbstract:The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods^ 1 . Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint^ 2 , 3 . Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray micro-computed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria , as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria , and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes. Micro-computed tomography and magnetic resonance imaging of a growth series of the coelacanth Latimeria chalumnae traces the ontogeny of the brain and neurocranium, which sheds light on neurocranial evolution in sarcopterygian fishes.
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neurocranial development of the coelacanth and the evolution of the sarcopterygian head
Nature, 2019Co-Authors: Hugo Dutel, Philippe Janvier, Gael Clement, Anthony Herrel, Paul Tafforeau, Mathieu Santin, Manon Galland, John A. Long, Michael J. Fagan, Marc HerbinAbstract:The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods1. Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint2,3. Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray micro-computed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria, as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria, and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes.
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The homology and function of the lung plates in extant and fossil coelacanths
Scientific reports, 2017Co-Authors: Camila Cupello, Philippe Janvier, Gael Clement, Marc Herbin, François J. Meunier, Paulo M. BritoAbstract:The presence of a pulmonary organ that is entirely covered by true bone tissue and fills most of the abdominal cavity is hitherto unique to fossil actinistians. Although small hard plates have been recently reported in the lung of the extant coelacanth Latimeria chalumnae, the homology between these hard structures in fossil and extant forms remained to be demonstrated. Here, we resolve this question by reporting the presence of a similar histological pattern–true cellular bone with star-shaped osteocytes, and a globular mineralisation with radiating arrangement–in the lung plates of two fossil coelacanths (Swenzia latimerae and Axelrodichthys araripensis) and the plates that surround the lung of the most extensively studied extant coelacanth species, L. chalumnae. The point-for-point structural similarity of the plates in extant and fossil coelacanths supports their probable homology and, consequently, that of the organ they surround. Thus, this evidence questions the previous interpretations of the fatty organ as a component of the pulmonary complex of Latimeria.
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Interactive 3D PDF model of Latimeria chalumnae oesophagus and vestigial lung. Three-dimensional reconstruction of the lung and oesophagus of the adult specimen CCC 28. Yellow, oesophagus; red, vestigial lung. from Lung anatomy and histology of the e
2017Co-Authors: Camila Cupello, Gael Clement, Marc Herbin, François J. Meunier, Paulo M. BritoAbstract:Lungs are specialized organs that originated from the posterior pharyngeal cavity and considered as plesiomorphic for osteichthyans, as they are found in extant basal actinopterygians (i.e. Polypterus) and in all major groups of extant sarcopterygians. The presence of a vestigial lung in adult stages of the extant coelacanth Latimeria chalumnae is the result of allometric growth during ontogeny, in relation with deep times adaptation to deep water. Here, we present the first detailed histological and anatomical description of the lung of Latimeria chalumnae, providing new insights into its arrested differentiation in an air-breathing complex, mainly represented by the absence of pneumocytes and of compartmentalization in the latest ontogenetic stages
Gael Clement - One of the best experts on this subject based on the ideXlab platform.
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Development and growth of the pelvic fin in the extant coelacanth Latimeria chalumnae.
Anatomical record (Hoboken N.J. : 2007), 2020Co-Authors: Rohan Mansuit, Gael Clement, Anthony Herrel, Hugo Dutel, Paul Tafforeau, Mathieu Santin, Marc HerbinAbstract:The ontogeny of the paired appendages has been extensively studied in lungfishes and tetrapods, but remains poorly known in coelacanths. Recent work has shed light on the anatomy and development of the pectoral fin in Latimeria chalumnae. Yet, information on the development of the pelvic fin and girdle is still lacking. Here, we described the development of the pelvic fin and girdle in Latimeria chalumnae based on 3D reconstructions generated from conventional and X-ray synchrotron microtomography, as well as MRI acquisitions. As in other jawed vertebrates, the development of the pelvic fin occurs later than that of the pectoral fin in Latimeria. Many elements of the endoskeleton are not yet formed at the earliest stage sampled. The four mesomeres are already formed in the fetus, but only the most proximal radial elements (preaxial radial 0-1) are formed and individualized at this stage. We suggest that all the preaxial radial elements in the pelvic and pectoral fin of Latimeria are formed through the fragmentation of the mesomeres. We document the progressive ossification of the pelvic girdle, and the presence of a trabecular system in the adult. This trabecular system likely reinforces the cartilaginous girdle to resist the muscle forces exerted during locomotion. Finally, the presence of a preaxial element in contact with the pelvic girdle from the earliest stage of development onward questions the mono-basal condition of the pelvic fin in Latimeria. However, the particular shape of the mesomeres may explain the presence of this element in contact with the girdle.
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Neurocranial development of the coelacanth and the evolution of the sarcopterygian head
Nature, 2019Co-Authors: Hugo Dutel, Philippe Janvier, Gael Clement, Anthony Herrel, Paul Tafforeau, Manon Galland, John A. Long, Michael J. Fagan, Mathieu D. Santin, Marc HerbinAbstract:The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods^ 1 . Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint^ 2 , 3 . Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray micro-computed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria , as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria , and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes. Micro-computed tomography and magnetic resonance imaging of a growth series of the coelacanth Latimeria chalumnae traces the ontogeny of the brain and neurocranium, which sheds light on neurocranial evolution in sarcopterygian fishes.
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neurocranial development of the coelacanth and the evolution of the sarcopterygian head
Nature, 2019Co-Authors: Hugo Dutel, Philippe Janvier, Gael Clement, Anthony Herrel, Paul Tafforeau, Mathieu Santin, Manon Galland, John A. Long, Michael J. Fagan, Marc HerbinAbstract:The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods1. Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint2,3. Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray micro-computed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria, as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria, and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes.
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The homology and function of the lung plates in extant and fossil coelacanths
Scientific reports, 2017Co-Authors: Camila Cupello, Philippe Janvier, Gael Clement, Marc Herbin, François J. Meunier, Paulo M. BritoAbstract:The presence of a pulmonary organ that is entirely covered by true bone tissue and fills most of the abdominal cavity is hitherto unique to fossil actinistians. Although small hard plates have been recently reported in the lung of the extant coelacanth Latimeria chalumnae, the homology between these hard structures in fossil and extant forms remained to be demonstrated. Here, we resolve this question by reporting the presence of a similar histological pattern–true cellular bone with star-shaped osteocytes, and a globular mineralisation with radiating arrangement–in the lung plates of two fossil coelacanths (Swenzia latimerae and Axelrodichthys araripensis) and the plates that surround the lung of the most extensively studied extant coelacanth species, L. chalumnae. The point-for-point structural similarity of the plates in extant and fossil coelacanths supports their probable homology and, consequently, that of the organ they surround. Thus, this evidence questions the previous interpretations of the fatty organ as a component of the pulmonary complex of Latimeria.
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Interactive 3D PDF model of Latimeria chalumnae oesophagus and vestigial lung. Three-dimensional reconstruction of the lung and oesophagus of the adult specimen CCC 28. Yellow, oesophagus; red, vestigial lung. from Lung anatomy and histology of the e
2017Co-Authors: Camila Cupello, Gael Clement, Marc Herbin, François J. Meunier, Paulo M. BritoAbstract:Lungs are specialized organs that originated from the posterior pharyngeal cavity and considered as plesiomorphic for osteichthyans, as they are found in extant basal actinopterygians (i.e. Polypterus) and in all major groups of extant sarcopterygians. The presence of a vestigial lung in adult stages of the extant coelacanth Latimeria chalumnae is the result of allometric growth during ontogeny, in relation with deep times adaptation to deep water. Here, we present the first detailed histological and anatomical description of the lung of Latimeria chalumnae, providing new insights into its arrested differentiation in an air-breathing complex, mainly represented by the absence of pneumocytes and of compartmentalization in the latest ontogenetic stages
Marco Gerdol - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Sex Determination and Sex Differentiation Genes in Latimeria
2016Co-Authors: Mariko Forconi, Marco Barucca, Maria Assunta Biscotti, Alberto Pallavicini, Francesco Buonocore, Adriana Canapa, Teresa Capriglione, Daisy Monica Makapedua, Anna M. Fausto, Marco GerdolAbstract:Genes involved in sex determination and differentiation have been identified in mice, humans, chickens, reptiles, amphibians and teleost fishes. However, little is known of their functional conservation, and it is unclear whether there is a common set of genes shared by all vertebrates. Coelacanths, basal Sarcopterygians and unique ‘‘living fossils’’, could help establish an inventory of the ancestral genes involved in these important developmental processes and provide insights into their components. In this study 33 genes from the genome of Latimeria chalumnae and from the liver and testis transcriptomes of Latimeria menadoensis, implicated in sex determination and differentiation, were identified and characterized and their expression levels measured. Interesting findings were obtained for GSDF, previously identified only in teleosts and now characterized for the first time in the sarcopterygian lineage; FGF9, which is not found in teleosts; and DMRT1, whose expression in adult gonads has recently been related to maintenance of sexual identity. The gene repertoire and testis-specific gene expression documented in coelacanths demonstrate a greater similarity to modern fishes and poin
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transcriptional activity of transposable elements in coelacanth
Journal of Experimental Zoology, 2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Marco Gerdol, Alberto Pallavicini, Domitille Chalopin, Delphine Galiana, Adriana CanapaAbstract:The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in “living fossil” species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 379–389, 2014. © 2013 Wiley Periodicals, Inc.
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Characterization of Purine Catabolic Pathway Genes in Coelacanths
2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Anna Maria Fausto, Marco Gerdol, Alberto Pallavicini, Francesco Buonocore, Giuseppe Scapigliati, Manfred SchartlAbstract:Coelacanths are a critically valuable species to explore the gene changes that took place in the transition from aquatic to terrestrial life. One interesting and biologically relevant feature of the genus Latimeria is ureotelism. However not all urea is excreted from the body; in fact high concentrations are retained in plasma and seem to be involved in osmoregulation. The purine catabolic pathway, which leads to urea production in Latimeria, has progressively lost some steps, reflecting an enzyme loss during diversification of terrestrial species. We report the results of analyses of the liver and testis transcriptomes of the Indonesian coelacanth Latimeria menadoensis and of the genome of Latimeria chalumnae, which has recently been fully sequenced in the framework of the coelacanth genome project. We describe five genes, uricase, 5-hydroxyisourate hydrolase, parahox neighbor B, allantoinase, and allantoicase, each coding for one of the five enzymes involved in urate degradation to urea, and report the identification of a putative second form of 5-hydroxyisourate hydrolase that is characteristic of the genus Latimeria. The present data also highlight the activity of the complete purine pathway in the coelacanth liver and suggest its involvement in the maintenance of high plasma urea concentrations. J. Exp. Zool. © 2013 Wiley Periodicals, Inc
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Transcriptional activity of transposable elements in coelacanth
2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Marco Gerdol, Alberto Pallavicini, Domitille Chalopin, Adriana Canapa, Delphine Galiana, Ettore OlmoAbstract:The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in "living fossil" species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity. © 2013 Wiley Periodicals, Inc
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Characterization of purine catabolic pathway genes in coelacanths
Journal of Experimental Zoology, 2013Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Anna Maria Fausto, Marco Gerdol, Alberto Pallavicini, Francesco Buonocore, Giuseppe Scapigliati, Manfred SchartlAbstract:Coelacanths are a critically valuable species to explore the gene changes that took place in the transition from aquatic to terrestrial life. One interesting and biologically relevant feature of the genus Latimeria is ureotelism. However not all urea is excreted from the body; in fact high concentrations are retained in plasma and seem to be involved in osmoregulation. The purine catabolic pathway, which leads to urea production in Latimeria, has progressively lost some steps, reflecting an enzyme loss during diversification of terrestrial species. We report the results of analyses of the liver and testis transcriptomes of the Indonesian coelacanth Latimeria menadoensis and of the genome of Latimeria chalumnae, which has recently been fully sequenced in the framework of the coelacanth genome project. We describe five genes, uricase, 5-hydroxyisourate hydrolase, parahox neighbor B, allantoinase, and allantoicase, each coding for one of the five enzymes involved in urate degradation to urea, and report the identification of a putative second form of 5-hydroxyisourate hydrolase that is characteristic of the genus Latimeria. The present data also highlight the activity of the complete purine pathway in the coelacanth liver and suggest its involvement in the maintenance of high plasma urea concentrations. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 334–341, 2014. © 2013 Wiley Periodicals, Inc.
Mariko Forconi - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Sex Determination and Sex Differentiation Genes in Latimeria
2016Co-Authors: Mariko Forconi, Marco Barucca, Maria Assunta Biscotti, Alberto Pallavicini, Francesco Buonocore, Adriana Canapa, Teresa Capriglione, Daisy Monica Makapedua, Anna M. Fausto, Marco GerdolAbstract:Genes involved in sex determination and differentiation have been identified in mice, humans, chickens, reptiles, amphibians and teleost fishes. However, little is known of their functional conservation, and it is unclear whether there is a common set of genes shared by all vertebrates. Coelacanths, basal Sarcopterygians and unique ‘‘living fossils’’, could help establish an inventory of the ancestral genes involved in these important developmental processes and provide insights into their components. In this study 33 genes from the genome of Latimeria chalumnae and from the liver and testis transcriptomes of Latimeria menadoensis, implicated in sex determination and differentiation, were identified and characterized and their expression levels measured. Interesting findings were obtained for GSDF, previously identified only in teleosts and now characterized for the first time in the sarcopterygian lineage; FGF9, which is not found in teleosts; and DMRT1, whose expression in adult gonads has recently been related to maintenance of sexual identity. The gene repertoire and testis-specific gene expression documented in coelacanths demonstrate a greater similarity to modern fishes and poin
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transcriptional activity of transposable elements in coelacanth
Journal of Experimental Zoology, 2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Marco Gerdol, Alberto Pallavicini, Domitille Chalopin, Delphine Galiana, Adriana CanapaAbstract:The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in “living fossil” species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 379–389, 2014. © 2013 Wiley Periodicals, Inc.
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Characterization of Purine Catabolic Pathway Genes in Coelacanths
2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Anna Maria Fausto, Marco Gerdol, Alberto Pallavicini, Francesco Buonocore, Giuseppe Scapigliati, Manfred SchartlAbstract:Coelacanths are a critically valuable species to explore the gene changes that took place in the transition from aquatic to terrestrial life. One interesting and biologically relevant feature of the genus Latimeria is ureotelism. However not all urea is excreted from the body; in fact high concentrations are retained in plasma and seem to be involved in osmoregulation. The purine catabolic pathway, which leads to urea production in Latimeria, has progressively lost some steps, reflecting an enzyme loss during diversification of terrestrial species. We report the results of analyses of the liver and testis transcriptomes of the Indonesian coelacanth Latimeria menadoensis and of the genome of Latimeria chalumnae, which has recently been fully sequenced in the framework of the coelacanth genome project. We describe five genes, uricase, 5-hydroxyisourate hydrolase, parahox neighbor B, allantoinase, and allantoicase, each coding for one of the five enzymes involved in urate degradation to urea, and report the identification of a putative second form of 5-hydroxyisourate hydrolase that is characteristic of the genus Latimeria. The present data also highlight the activity of the complete purine pathway in the coelacanth liver and suggest its involvement in the maintenance of high plasma urea concentrations. J. Exp. Zool. © 2013 Wiley Periodicals, Inc
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Transcriptional activity of transposable elements in coelacanth
2014Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Marco Gerdol, Alberto Pallavicini, Domitille Chalopin, Adriana Canapa, Delphine Galiana, Ettore OlmoAbstract:The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in "living fossil" species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity. © 2013 Wiley Periodicals, Inc
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Characterization of purine catabolic pathway genes in coelacanths
Journal of Experimental Zoology, 2013Co-Authors: Mariko Forconi, Gianluca De Moro, Marco Barucca, Maria Assunta Biscotti, Anna Maria Fausto, Marco Gerdol, Alberto Pallavicini, Francesco Buonocore, Giuseppe Scapigliati, Manfred SchartlAbstract:Coelacanths are a critically valuable species to explore the gene changes that took place in the transition from aquatic to terrestrial life. One interesting and biologically relevant feature of the genus Latimeria is ureotelism. However not all urea is excreted from the body; in fact high concentrations are retained in plasma and seem to be involved in osmoregulation. The purine catabolic pathway, which leads to urea production in Latimeria, has progressively lost some steps, reflecting an enzyme loss during diversification of terrestrial species. We report the results of analyses of the liver and testis transcriptomes of the Indonesian coelacanth Latimeria menadoensis and of the genome of Latimeria chalumnae, which has recently been fully sequenced in the framework of the coelacanth genome project. We describe five genes, uricase, 5-hydroxyisourate hydrolase, parahox neighbor B, allantoinase, and allantoicase, each coding for one of the five enzymes involved in urate degradation to urea, and report the identification of a putative second form of 5-hydroxyisourate hydrolase that is characteristic of the genus Latimeria. The present data also highlight the activity of the complete purine pathway in the coelacanth liver and suggest its involvement in the maintenance of high plasma urea concentrations. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 334–341, 2014. © 2013 Wiley Periodicals, Inc.
Ferenc Muller - One of the best experts on this subject based on the ideXlab platform.
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conservation of shh cis regulatory architecture of the coelacanth is consistent with its ancestral phylogenetic position
Evodevo, 2010Co-Authors: Michael Lang, Chris T Amemiya, Yavor Hadzhiev, Nicol Siegel, Carolina Parada, Uwe Strahle, Maybritt Becker, Ferenc MullerAbstract:Background The modern coelacanth (Latimeria) is the extant taxon of a basal sarcopterygian lineage and sister group to tetrapods. Apart from certain apomorphic traits, its morphology is characterized by a high degree of retention of ancestral vertebrate structures and little morphological change. An insight into the molecular evolution that may explain the unchanged character of Latimeria morphology requires the analysis of the expression patterns of developmental regulator genes and their cis-regulatory modules (CRMs).
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Conservation of shh cis-regulatory architecture of the coelacanth is consistent with its ancestral phylogenetic position
EvoDevo, 2010Co-Authors: Michael Lang, Chris T Amemiya, Yavor Hadzhiev, Nicol Siegel, Carolina Parada, Uwe Strahle, Maybritt Becker, Ferenc Muller, Axel MeyerAbstract:Background The modern coelacanth ( Latimeria ) is the extant taxon of a basal sarcopterygian lineage and sister group to tetrapods. Apart from certain apomorphic traits, its morphology is characterized by a high degree of retention of ancestral vertebrate structures and little morphological change. An insight into the molecular evolution that may explain the unchanged character of Latimeria morphology requires the analysis of the expression patterns of developmental regulator genes and their cis -regulatory modules (CRMs). Results We describe the comparative and functional analysis of the sonic hedgehog ( shh ) genomic region of Latimeria menadoensis . Several putative enhancers in the Latimeria shh locus have been identified by comparisons to sarcopterygian and actinopterygian extant species. Specific sequence conservation with all known actinopterygian enhancer elements has been detected. However, these elements are selectively missing in more recently diverged actinopterygian and sarcopterygian species. The functionality of the putative Latimeria enhancers was confirmed by reporter gene expression analysis in transient transgenic zebrafish and chick embryos. Conclusions Latimeria shh CRMs represent the ancestral set of enhancers that have emerged before the split of lobe-finned and ray-finned fishes. In contrast to lineage-specific losses and differentiations in more derived lineages, Latimeria shh enhancers reveal low levels of sequence diversification. High overall sequence conservation of shh conserved noncoding elements (CNE) is consistent with the general trend of high levels of conservation of noncoding DNA in the slowly evolving Latimeria genome.