Mariette Bedhomme, C. Mathieu, A. Pulido, Y. Henry, C. Bergounioux
In Schizosaccharomyces pombe, septum formation is intricately controlled by proteins which constitute the SIN (Septum Initiation Network) signalling cascade. The SIN ensures the coordination between mitotic exit and cytokinesis. Yeast spg1p is a core component of the SIN pathway and we have previously characterized the two orthologs of this G-protein in Arabidopsis thaliana (named AtSGP1 and 2). In this work, the cell and tissue expression of AtSGP genes during plant development has been analysed using AtSGP promoter::GUS fusions in stably transformed A. thaliana lines. AtSGP1 promoter activity was restricted to the quiescent centre, collumella cells, stomata guard cells and the stele while AtSGP2 promoter activity was detected in atrichoblasts, trichomes and pollen. The observed promoter activities are in accordance with publicly available pollen, stomata guard cell and root transcriptome data. Two-hybrid experiments previously evidenced an interaction between AtMAP3Kepsilon1 and AtSGP1. The AtMAP3Kepsilon1 promoter activity was detected in root apices, trichomes and ovule integuments. A genetic approach involving both markers of these specialized cells and mutant backgrounds was used to reinforce our hypothesis. It appears that, although highly conserved between plants and fungi, the spg1p G-protein has evolved in plants to perform a function different from the SIN pathway. Interestingly, cells expressing AtSGPs possessed limited or null mitotic activity. Our data suggests that AtSGP are crucial signalling components involved either in early cell fate specification, or in the final steps of cell differentiation. This is an interesting starting point for a wider study devoted to functional experiments designed to test these hypotheses.
{"title":"Arabidopsis monomeric G-proteins, markers of early and late events in cell differentiation.","authors":"Mariette Bedhomme, C. Mathieu, A. Pulido, Y. Henry, C. Bergounioux","doi":"10.1387/ijdb.072488mb","DOIUrl":"https://doi.org/10.1387/ijdb.072488mb","url":null,"abstract":"In Schizosaccharomyces pombe, septum formation is intricately controlled by proteins which constitute the SIN (Septum Initiation Network) signalling cascade. The SIN ensures the coordination between mitotic exit and cytokinesis. Yeast spg1p is a core component of the SIN pathway and we have previously characterized the two orthologs of this G-protein in Arabidopsis thaliana (named AtSGP1 and 2). In this work, the cell and tissue expression of AtSGP genes during plant development has been analysed using AtSGP promoter::GUS fusions in stably transformed A. thaliana lines. AtSGP1 promoter activity was restricted to the quiescent centre, collumella cells, stomata guard cells and the stele while AtSGP2 promoter activity was detected in atrichoblasts, trichomes and pollen. The observed promoter activities are in accordance with publicly available pollen, stomata guard cell and root transcriptome data. Two-hybrid experiments previously evidenced an interaction between AtMAP3Kepsilon1 and AtSGP1. The AtMAP3Kepsilon1 promoter activity was detected in root apices, trichomes and ovule integuments. A genetic approach involving both markers of these specialized cells and mutant backgrounds was used to reinforce our hypothesis. It appears that, although highly conserved between plants and fungi, the spg1p G-protein has evolved in plants to perform a function different from the SIN pathway. Interestingly, cells expressing AtSGPs possessed limited or null mitotic activity. Our data suggests that AtSGP are crucial signalling components involved either in early cell fate specification, or in the final steps of cell differentiation. This is an interesting starting point for a wider study devoted to functional experiments designed to test these hypotheses.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76146150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marisabel Fernández-Mongil, Celia J Venza, Amelia Rivera, J. Lasalde-Dominicci, Warren Burggren, L. Rojas
Thyroid hormones--particularly triiodothyronine, T3--play a critical role in the morphological transformations comprising metamorphosis in larval bullfrogs (Rana catesbeiana). Traditional staging criteria for anuran larvae incompletely distinguish physiological and behavioral changes during growth. We therefore first developed a new parameter to describe larval growth, the developmental index (DI), which is simply the ratio between the tail length of the larva and its head diameter. Using the DI we were able to identify two distinct populations classifying the larvae during growth along a continuous linear scale with a cutoff value of DI at 2.8. Classification based on the DI, used in this study, proved an effective complement to existing classifications based on developmental staging into pre- or pro-metamorphic stages. Exposure to T3 in the water induced a rapid (beginning within 5 min) and significant decrease (approximately 20-40%) in locomotor activity, measured as total distance traversed and velocity. The largest decrease occurred in more developed larvae (DI<2.8). To determine correlated changes in the neuromuscular junctions during metamorphosis and apoptotic tail loss, miniature endplate currents from tail muscle were recorded during acute exposure to a hypertonic solution, which simulates an apoptotic volume decrease. Our results support a role for T3 in regulating larval locomotor activity during development, and suggest an enhanced response to volume depletion at the neuromuscular junction of older larvae (DI<2.8) compared to younger animals (DI> or =2.8). We discuss the significance of the possible role of an apoptotic volume decrease at the level of the neuromuscular junction.
{"title":"Triiodothyronine (T3) action on aquatic locomotor behavior during metamorphosis of the bullfrog Rana catesbeiana.","authors":"Marisabel Fernández-Mongil, Celia J Venza, Amelia Rivera, J. Lasalde-Dominicci, Warren Burggren, L. Rojas","doi":"10.1387/ijdb.072307mf","DOIUrl":"https://doi.org/10.1387/ijdb.072307mf","url":null,"abstract":"Thyroid hormones--particularly triiodothyronine, T3--play a critical role in the morphological transformations comprising metamorphosis in larval bullfrogs (Rana catesbeiana). Traditional staging criteria for anuran larvae incompletely distinguish physiological and behavioral changes during growth. We therefore first developed a new parameter to describe larval growth, the developmental index (DI), which is simply the ratio between the tail length of the larva and its head diameter. Using the DI we were able to identify two distinct populations classifying the larvae during growth along a continuous linear scale with a cutoff value of DI at 2.8. Classification based on the DI, used in this study, proved an effective complement to existing classifications based on developmental staging into pre- or pro-metamorphic stages. Exposure to T3 in the water induced a rapid (beginning within 5 min) and significant decrease (approximately 20-40%) in locomotor activity, measured as total distance traversed and velocity. The largest decrease occurred in more developed larvae (DI<2.8). To determine correlated changes in the neuromuscular junctions during metamorphosis and apoptotic tail loss, miniature endplate currents from tail muscle were recorded during acute exposure to a hypertonic solution, which simulates an apoptotic volume decrease. Our results support a role for T3 in regulating larval locomotor activity during development, and suggest an enhanced response to volume depletion at the neuromuscular junction of older larvae (DI<2.8) compared to younger animals (DI> or =2.8). We discuss the significance of the possible role of an apoptotic volume decrease at the level of the neuromuscular junction.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83639659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Onecut genes belong to a family of transcription factors that are known to be important in embryonic development. In the present study, we analyzed the pattern of expression of Onecut-1/HNF6 in Xenopus tropicalis using RT-PCR and whole mount in situ hybridization. Expression of the Xenopus tropicalis Onecut-1/HNF6 gene was found to be conserved in the neural tube, the sensory placodes and in the anterior ventral endoderm in a domain consistent with the developing liver primordium.
{"title":"Expression of Xenopus tropicalis HNF6/Onecut-1.","authors":"K. Haworth, B. Latinkić","doi":"10.1387/ijdb.072472ke","DOIUrl":"https://doi.org/10.1387/ijdb.072472ke","url":null,"abstract":"Onecut genes belong to a family of transcription factors that are known to be important in embryonic development. In the present study, we analyzed the pattern of expression of Onecut-1/HNF6 in Xenopus tropicalis using RT-PCR and whole mount in situ hybridization. Expression of the Xenopus tropicalis Onecut-1/HNF6 gene was found to be conserved in the neural tube, the sensory placodes and in the anterior ventral endoderm in a domain consistent with the developing liver primordium.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81791409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joanna Argasinska, Amer A. Rana, M. Gilchrist, Kim Lachani, Alice Young, James C. Smith
Members of the REEP (Receptor expression enhancing protein) family contain a TB2/DP1, HVA22 domain that is involved in intracellular trafficking and secretion. Consistent with the presence of this domain, REEP1 and REEP3 enhance the expression of odorant and taste receptors in mammals, while mutation of these genes causes defects in neural development. REEP4 was identified in the course of a functional antisense morpholino oligonucleotide screen searching for genes involved in the early development of Xenopus tropicalis: although over-expression of the gene causes no phenotype, embryos lacking REEP4 develop a slightly kinked body axis and are paralysed. At tailbud stages of development, REEP4 is expressed in the somites and neural tube. The paralysis observed in embryos lacking REEP4 might therefore be caused by defects in the nervous system or in muscle. To address this point, we examined the expression of various neural and muscle markers and found that although all are expressed normally at early stages of development, many are down regulated by the tailbud stage. This suggests that REEP4 plays a role in the maintenance of both the nervous system and the musculature.
{"title":"Loss of REEP4 causes paralysis of the Xenopus embryo.","authors":"Joanna Argasinska, Amer A. Rana, M. Gilchrist, Kim Lachani, Alice Young, James C. Smith","doi":"10.1387/ijdb.072542ja","DOIUrl":"https://doi.org/10.1387/ijdb.072542ja","url":null,"abstract":"Members of the REEP (Receptor expression enhancing protein) family contain a TB2/DP1, HVA22 domain that is involved in intracellular trafficking and secretion. Consistent with the presence of this domain, REEP1 and REEP3 enhance the expression of odorant and taste receptors in mammals, while mutation of these genes causes defects in neural development. REEP4 was identified in the course of a functional antisense morpholino oligonucleotide screen searching for genes involved in the early development of Xenopus tropicalis: although over-expression of the gene causes no phenotype, embryos lacking REEP4 develop a slightly kinked body axis and are paralysed. At tailbud stages of development, REEP4 is expressed in the somites and neural tube. The paralysis observed in embryos lacking REEP4 might therefore be caused by defects in the nervous system or in muscle. To address this point, we examined the expression of various neural and muscle markers and found that although all are expressed normally at early stages of development, many are down regulated by the tailbud stage. This suggests that REEP4 plays a role in the maintenance of both the nervous system and the musculature.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78874237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A culture of Nicotiana tabacum leaf protoplasts, regenerating in vitro, was used to study light-induced plastid translocations. Experiments were carried out for 5 months starting with protoplasts, through single cells, microcolonies and callus to the differentiated mesophyll of regenerated plants. Although the actin cytoskeleton was fully developed at every stage of culture, blue light-mediated directional movements of chloroplasts were observed only after the full differentiation of callus into leaf tissues. These chloroplast rearrangements were similar to those observed in control plants grown from seeds. Under strong blue light, chloroplasts gathered at the cell walls parallel to the light direction (profile position); under weak blue light, they gathered at the walls perpendicular to the light direction (face position). No light-dependent plastid arrangements were found in undifferentiated cell cultures even after cell wall recovery. A characteristic pattern of plastids in the dividing cells was independent of light signals. Only trace chloroplast responses to strong blue light were detected in the first leaves regenerating from callus. We hypothesize that factors which control the developmental status of a cell, i.e. division and differentiation, take over the control of plastid redistribution from light signals.
{"title":"Acquisition of plastid movement responsiveness to light during mesophyll cell differentiation.","authors":"Joanna Augustynowicz, Weronika Krzeszowiec, Halina Gabrys","doi":"10.1387/ijdb.062140ja","DOIUrl":"10.1387/ijdb.062140ja","url":null,"abstract":"<p><p>A culture of Nicotiana tabacum leaf protoplasts, regenerating in vitro, was used to study light-induced plastid translocations. Experiments were carried out for 5 months starting with protoplasts, through single cells, microcolonies and callus to the differentiated mesophyll of regenerated plants. Although the actin cytoskeleton was fully developed at every stage of culture, blue light-mediated directional movements of chloroplasts were observed only after the full differentiation of callus into leaf tissues. These chloroplast rearrangements were similar to those observed in control plants grown from seeds. Under strong blue light, chloroplasts gathered at the cell walls parallel to the light direction (profile position); under weak blue light, they gathered at the walls perpendicular to the light direction (face position). No light-dependent plastid arrangements were found in undifferentiated cell cultures even after cell wall recovery. A characteristic pattern of plastids in the dividing cells was independent of light signals. Only trace chloroplast responses to strong blue light were detected in the first leaves regenerating from callus. We hypothesize that factors which control the developmental status of a cell, i.e. division and differentiation, take over the control of plastid redistribution from light signals.</p>","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88267047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Roël, Y. Gent, J. Peterson-Maduro, F. Verbeek, O. Destrée
Tcf/Lef HMG box transcription factors are nuclear effectors of the canonical Wnt signaling pathway, which function in cell fate specification. Lef1 is required for the development of tissues and organs that depend on epithelial mesenchymal interactions. Here, we report the effects of lef1 loss of function on early development in X. tropicalis. Depletion of lef1 affects gene expression already during gastrulation and results in abnormal differentiation of cells derived from ectoderm and mesoderm. At tail bud stages, the epidermis was devoid of ciliated cells and derivatives of the neural crest, e.g. melanocytes and cephalic ganglia were absent. In the Central Nervous System, nerve fibers were absent or underdeveloped. The development of the paraxial mesoderm was affected; intersomitic boundaries were not distinct and development of the hypaxial musculature was impaired. The development of the pronephros and pronephric ducts was disturbed. Most striking was the absence of blood flow in lef1 depleted embryos. Analysis of blood vessel marker genes demonstrated that lef1 is required for the development of the major blood vessels and the heart.
{"title":"Lef1 plays a role in patterning the mesoderm and ectoderm in Xenopus tropicalis.","authors":"G. Roël, Y. Gent, J. Peterson-Maduro, F. Verbeek, O. Destrée","doi":"10.1387/ijdb.072395gr","DOIUrl":"https://doi.org/10.1387/ijdb.072395gr","url":null,"abstract":"Tcf/Lef HMG box transcription factors are nuclear effectors of the canonical Wnt signaling pathway, which function in cell fate specification. Lef1 is required for the development of tissues and organs that depend on epithelial mesenchymal interactions. Here, we report the effects of lef1 loss of function on early development in X. tropicalis. Depletion of lef1 affects gene expression already during gastrulation and results in abnormal differentiation of cells derived from ectoderm and mesoderm. At tail bud stages, the epidermis was devoid of ciliated cells and derivatives of the neural crest, e.g. melanocytes and cephalic ganglia were absent. In the Central Nervous System, nerve fibers were absent or underdeveloped. The development of the paraxial mesoderm was affected; intersomitic boundaries were not distinct and development of the hypaxial musculature was impaired. The development of the pronephros and pronephric ducts was disturbed. Most striking was the absence of blood flow in lef1 depleted embryos. Analysis of blood vessel marker genes demonstrated that lef1 is required for the development of the major blood vessels and the heart.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86171422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Src family tyrosine kinases (SFKs) play important roles in cell morphology, differentiation, motility and proliferation. Elevated expression and/or specific activity of Src kinases are characteristic for several types of human cancer. However, little information is available about the role and spatio-temporal expression of SFKs in early embryonic development. In this study we characterized, in Xenopus laevis, the expression patterns of five SFK genes src, fyn, yes, lyn and laloo as well as of the csk gene, a negative regulator of SFKs, using RT-qPCR and in situ hybridisation. We found that transcripts of all SFKs and csk were already detectable in one-cell embryos and their levels similarly oscillated during subsequent development. First, after stage 8, the levels of SFK and csk mRNAs began to decrease, reached a minimum between stages 10 and 28 and increased again. In the later stages (33-45), the levels of fyn, yes and csk mRNAs returned to approximately maternal ones, whereas the src, laloo and lyn mRNA transcripts exceeded, up to about 3.5-6-fold, their maternal levels. In situ hybridisation analysis located the SFK and csk transcripts in the animal hemisphere of Xenopus embryos. Subsequent gastrula stages showed signals in ectodermal cells, mid-neurula stage embryos at neural folds, and the tailbud stages showed strong signals in the brain and neural tube. RT-qPCR concentration profiling along the animal-vegetal axis proved in blastula and gastrula the preferential localisation of yes, src, lyn and csk transcripts towards the animal pole in a gradient-like manner. In contrast, laloo and fyn displayed a vegetal pole preference.
{"title":"Expression patterns of Src-family tyrosine kinases during Xenopus laevis development.","authors":"Zoltán Ferjentsik, Radek Sindelka, J. Jonák","doi":"10.1387/ijdb.072311zf","DOIUrl":"https://doi.org/10.1387/ijdb.072311zf","url":null,"abstract":"Src family tyrosine kinases (SFKs) play important roles in cell morphology, differentiation, motility and proliferation. Elevated expression and/or specific activity of Src kinases are characteristic for several types of human cancer. However, little information is available about the role and spatio-temporal expression of SFKs in early embryonic development. In this study we characterized, in Xenopus laevis, the expression patterns of five SFK genes src, fyn, yes, lyn and laloo as well as of the csk gene, a negative regulator of SFKs, using RT-qPCR and in situ hybridisation. We found that transcripts of all SFKs and csk were already detectable in one-cell embryos and their levels similarly oscillated during subsequent development. First, after stage 8, the levels of SFK and csk mRNAs began to decrease, reached a minimum between stages 10 and 28 and increased again. In the later stages (33-45), the levels of fyn, yes and csk mRNAs returned to approximately maternal ones, whereas the src, laloo and lyn mRNA transcripts exceeded, up to about 3.5-6-fold, their maternal levels. In situ hybridisation analysis located the SFK and csk transcripts in the animal hemisphere of Xenopus embryos. Subsequent gastrula stages showed signals in ectodermal cells, mid-neurula stage embryos at neural folds, and the tailbud stages showed strong signals in the brain and neural tube. RT-qPCR concentration profiling along the animal-vegetal axis proved in blastula and gastrula the preferential localisation of yes, src, lyn and csk transcripts towards the animal pole in a gradient-like manner. In contrast, laloo and fyn displayed a vegetal pole preference.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72749483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Drosophila Single minded (Sim) transcription factor is a master regulator of cell fate during midline development. The homolog mouse Sim1 and Sim2 genes are important for central nervous system development. Loss of mSim1 activity leads to an absence of specific neuroendocrine lineages within the hypothalamus, while overexpression of mSim2 leads to behavioural defects. We now provide evidence that vertebrate Sim genes might be important for limb muscle formation. We have examined by in situ hybridisation the expression of the Sim1 and Sim2 genes during limb development in chick and mouse embryos. The expression of both Sim genes is mainly associated with limb muscle formation. We found that each Sim gene has a similar temporal and spatial expression pattern in chick and mouse embryonic limbs, although with some differences for the Sim2 gene between species. In chick or mouse embryonic limbs, Sim1 and Sim2 display non-overlapping expression domains, suggesting an involvement for Sim1 and Sim2 proteins at different steps of limb muscle formation. Sim1 gene expression is associated with the early step of muscle progenitor cell migration in chick and mouse, while the Sim2 gene is expressed just after the migration process. In addition, chick and mouse Sim2 gene expression is enhanced in limb ventral muscle masses versus dorsal ventral muscle masses. Our results provide a basis for further functional analysis of the Sim genes in limb muscle formation.
{"title":"Sim1 and Sim2 expression during chick and mouse limb development.","authors":"P. Coumailleau, D. Duprez","doi":"10.1387/ijdb.082659pc","DOIUrl":"https://doi.org/10.1387/ijdb.082659pc","url":null,"abstract":"The Drosophila Single minded (Sim) transcription factor is a master regulator of cell fate during midline development. The homolog mouse Sim1 and Sim2 genes are important for central nervous system development. Loss of mSim1 activity leads to an absence of specific neuroendocrine lineages within the hypothalamus, while overexpression of mSim2 leads to behavioural defects. We now provide evidence that vertebrate Sim genes might be important for limb muscle formation. We have examined by in situ hybridisation the expression of the Sim1 and Sim2 genes during limb development in chick and mouse embryos. The expression of both Sim genes is mainly associated with limb muscle formation. We found that each Sim gene has a similar temporal and spatial expression pattern in chick and mouse embryonic limbs, although with some differences for the Sim2 gene between species. In chick or mouse embryonic limbs, Sim1 and Sim2 display non-overlapping expression domains, suggesting an involvement for Sim1 and Sim2 proteins at different steps of limb muscle formation. Sim1 gene expression is associated with the early step of muscle progenitor cell migration in chick and mouse, while the Sim2 gene is expressed just after the migration process. In addition, chick and mouse Sim2 gene expression is enhanced in limb ventral muscle masses versus dorsal ventral muscle masses. Our results provide a basis for further functional analysis of the Sim genes in limb muscle formation.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83561940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chun‐che Chang, Ting-yu Huang, C. E. Cook, Gee-Way Lin, Chun-Liang Shih, R. Chen
Among genes that are preferentially expressed in germ cells, nanos and vasa are the two most conserved germline markers in animals. Both genes are usually expressed in germ cells in the adult gonads, and often also during embryogenesis. Both nanos-first or vasa-first expression patterns have been observed in embryos, implying that the molecular networks governing germline development vary among species. Previously we identified Apvasa, a vasa homologue expressed in germ cells throughout all developmental stages in the parthenogenetic and viviparous pea aphid Acyrthosiphon pisum. In asexual A. pisum, oogenesis is followed by embryogenesis, and both occur within the ovarioles. In order to understand the temporal and spatial distribution of nanos versus vasa during oogenesis and embryogenesis, we isolated a nanos homologue, Apnanos, and studied its expression. In adults, Apnanos is preferentially expressed in the ovaries. In early embryos, Apnanos transcripts are localized to the cytoplasm of cellularizing germ cells, and soon thereafter are restricted to the newly segregated germ cells in the posterior region of the cellularized blastoderm. These results strongly suggest that the Apnanos gene is a germline marker and is involved in germline specification in asexual A. pisum. However, during the middle stages of development, when germline migration occurs, Apnanos is not expressed in the migrating germ cells expressing Apvasa, suggesting that Apnanos is not directly associated with germline migration.
{"title":"Developmental expression of Apnanos during oogenesis and embryogenesis in the parthenogenetic pea aphid Acyrthosiphon pisum.","authors":"Chun‐che Chang, Ting-yu Huang, C. E. Cook, Gee-Way Lin, Chun-Liang Shih, R. Chen","doi":"10.1387/ijdb.082570cc","DOIUrl":"https://doi.org/10.1387/ijdb.082570cc","url":null,"abstract":"Among genes that are preferentially expressed in germ cells, nanos and vasa are the two most conserved germline markers in animals. Both genes are usually expressed in germ cells in the adult gonads, and often also during embryogenesis. Both nanos-first or vasa-first expression patterns have been observed in embryos, implying that the molecular networks governing germline development vary among species. Previously we identified Apvasa, a vasa homologue expressed in germ cells throughout all developmental stages in the parthenogenetic and viviparous pea aphid Acyrthosiphon pisum. In asexual A. pisum, oogenesis is followed by embryogenesis, and both occur within the ovarioles. In order to understand the temporal and spatial distribution of nanos versus vasa during oogenesis and embryogenesis, we isolated a nanos homologue, Apnanos, and studied its expression. In adults, Apnanos is preferentially expressed in the ovaries. In early embryos, Apnanos transcripts are localized to the cytoplasm of cellularizing germ cells, and soon thereafter are restricted to the newly segregated germ cells in the posterior region of the cellularized blastoderm. These results strongly suggest that the Apnanos gene is a germline marker and is involved in germline specification in asexual A. pisum. However, during the middle stages of development, when germline migration occurs, Apnanos is not expressed in the migrating germ cells expressing Apvasa, suggesting that Apnanos is not directly associated with germline migration.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78430030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In early chick embryo, the precardiac cells reside within distinct groups of mesodermal cells known as presumptive heart forming regions (HFRs). HFRs are located on the lateral sides of the Hensens node. In an effort to study fate of HFRs in isolation, HFRs were excised from early gastrulating chick embryos and cultured in vitro. A very small proportion of HFRs from 18 h incubated embryos differentiated into beating cardiomyocytes whereas about 43% of HFRs from embryos incubated for longer durations (20, 23 and 28 h) showed beating activity. The potential of HFRs, from 18 h incubated embryos, to differentiate into cardiomyocytes increased significantly in presence of Hensens node. About one third of the HFR cells underwent spontaneous differentiation into adipocytes in culture. Simultaneously, some of the cells derived from HFRs exhibited alkaline phosphatase (AP) activity indicating presence of stem cells in the culture. HFR cells were positive for vimentin indicating their mesenchymal origin. FGF supplement increased the proportion of AP-positive cells in a dose dependent manner. The present study demonstrates that HFRs can serve as a source of mesenchymal stem cells which can be gainfully employed for various purposes. The results also suggest that even though the in vitro cultured HFRs from 18 h incubated HH stage 4 chick embryo retain the potential to undergo cardiac differentiation, certain instructive signals from Hensens node may reinforce the fate.
{"title":"The heart forming region of early chick embryo is an alternative source of embryonic stem cells.","authors":"S. Borgave, Kirti Ghodke, S. Ghaskadbi","doi":"10.1387/ijdb.082677sb","DOIUrl":"https://doi.org/10.1387/ijdb.082677sb","url":null,"abstract":"In early chick embryo, the precardiac cells reside within distinct groups of mesodermal cells known as presumptive heart forming regions (HFRs). HFRs are located on the lateral sides of the Hensens node. In an effort to study fate of HFRs in isolation, HFRs were excised from early gastrulating chick embryos and cultured in vitro. A very small proportion of HFRs from 18 h incubated embryos differentiated into beating cardiomyocytes whereas about 43% of HFRs from embryos incubated for longer durations (20, 23 and 28 h) showed beating activity. The potential of HFRs, from 18 h incubated embryos, to differentiate into cardiomyocytes increased significantly in presence of Hensens node. About one third of the HFR cells underwent spontaneous differentiation into adipocytes in culture. Simultaneously, some of the cells derived from HFRs exhibited alkaline phosphatase (AP) activity indicating presence of stem cells in the culture. HFR cells were positive for vimentin indicating their mesenchymal origin. FGF supplement increased the proportion of AP-positive cells in a dose dependent manner. The present study demonstrates that HFRs can serve as a source of mesenchymal stem cells which can be gainfully employed for various purposes. The results also suggest that even though the in vitro cultured HFRs from 18 h incubated HH stage 4 chick embryo retain the potential to undergo cardiac differentiation, certain instructive signals from Hensens node may reinforce the fate.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87210263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：