How do signaling and transcription factors regulate both axis elongation and Hox gene expression along the anteroposterior axis?

2020 ◽  
Vol 62 (5) ◽  
pp. 363-375 ◽  
Author(s):  
Seiji Saito ◽  
Takayuki Suzuki
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Hox Gene ◽  
Anteroposterior Axis ◽  
Axis Elongation

scholarly journals Hox gene expression during development of the phoronid Phoronopsis harmeri

2020 ◽  
Author(s):  
Ludwik Gąsiorowski ◽  
Andreas Hejnol
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Life Cycle ◽  
Hox Genes ◽  
Positional Information ◽  
Larval Body ◽  
Hox Gene ◽  
Larval Stages ◽  
Phoronopsis Harmeri ◽  
Embryonic And Larval Development

Abstract Background: Phoronida is a small group of marine worm-like suspension feeders, which together with brachiopods and bryozoans form the clade Lophophorata. Although their development is well studied on the morphological level, data regarding gene expression during this process are scarce and restricted to the analysis of relatively few transcription factors. Here we present a description of the expression patterns of Hox genes during the embryonic and larval development of the phoronid Phoronopsis harmeri. Results: We identified sequences of eight Hox genes in the transcriptome of Ph. harmeri and determined their expression pattern during embryonic and larval development using whole mount in situ hybridization. We found that none of the Hox genes is expressed during embryonic development. Instead their expression is initiated in the later developmental stages, when the larval body is already formed. In the investigated initial larval stages the Hox genes are expressed in the non-collinear manner in the posterior body of the larvae: in the telotroch and the structures that represent rudiments of the adult worm. Additionally, we found that certain head-specific transcription factors are expressed in the oral hood, apical organ, preoral coelom, anterior digestive system and developing larval tentacles, anterior to the Hox-expressing territories. Conclusions: The lack of Hox gene expression during early development of Ph. harmeri indicates that the larval body develops without positional information from the Hox patterning system. Such phenomenon might be a consequence of the evolutionary intercalation of the larval form into an ancestral life cycle of phoronids. The observed Hox gene expression can also be a consequence of the actinotrocha representing a “head larva”, which is composed of the most anterior body region that is devoid of Hox gene expression. Such interpretation is further supported by the expression of head-specific transcription factors. This implies that the Hox patterning system is used for the positional information of the trunk rudiments and is, therefore, delayed to the later larval stages. We propose that a new body form was intercalated to the phoronid life cycle by precocious development of the anterior structures or by delayed development of the trunk rudiment in the ancestral phoronid larva.

Hox gene induction in the neural tube depends on three parameters: competence, signal supply and paralogue group

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 849-859 ◽  
Author(s):  
A. Grapin-Botton ◽  
M.A. Bonnin ◽  
N.M. Douarin Le
Keyword(s):  
Gene Expression ◽  
Neural Tube ◽  
Hox Genes ◽  
Gene Induction ◽  
Paraxial Mesoderm ◽  
Environmental Cues ◽  
Hox Gene ◽  
Anteroposterior Axis ◽  
Gene Regulatory ◽  
Genomic Clusters

It has been previously shown that Hox gene expression in the rhombencephalon is controlled by environmental cues. Thus posterior transposition of anterior rhombomeres to the r7/8 level results in the activation of Hox genes of the four first paralog groups and in homeotic transformations of the neuroepithelial fate according to its position along the anteroposterior axis. We demonstrate here that although the anteroposterior levels of r2 to r6 express Hox genes they do not have inducing activity on more anterior territories. If transposed at the posterior rhombencephalon and trunk level, however, the same anterior regions are able to express Hox gene such as Hoxa-2, a-3 or b-4. We also provide evidence that these signals are transferred by two paths: one vertical, arising from the paraxial mesoderm, and one planar, travelling in the neural epithelium. The competence to express Hox genes extends up to the forebrain and midbrain but expression of Hox genes does not preclude Otx2 expression in these territories and results only in slight changes in their phenotypes. Similarly, rhombomeres transplanted to posterior truncal levels turned out to be able to express posterior genes of the first eight paralog groups to the exclusion of others located downstream in the Hox genes genomic clusters. This suggests that the neural tube is divided into large territories characterized by different Hox gene regulatory features.

Neuronal cell migration in C. elegans: regulation of Hox gene expression and cell position

Development ◽  
1996 ◽  
Vol 122 (10) ◽  
pp. 3117-3131 ◽  
Author(s):  
J. Harris ◽  
L. Honigberg ◽  
N. Robinson ◽  
C. Kenyon
Keyword(s):  
Gene Expression ◽  
Cell Migration ◽  
Neuronal Cell ◽  
Body Region ◽  
Wild Type ◽  
Hox Gene ◽  
Anteroposterior Axis ◽  
C Elegans ◽  
Cell Position ◽  
Posterior Body Region

In C. elegans, the Hox gene mab-5, which specifies the fates of cells in the posterior body region, has been shown to direct the migrations of certain cells within its domain of function. mab-5 expression switches on in the neuroblast QL as it migrates into the posterior body region. mab-5 activity is then required for the descendants of QL to migrate to posterior rather than anterior positions. What information activates Hox gene expression during this cell migration? How are these cells subsequently guided to their final positions? We address these questions by describing four genes, egl-20, mig-14, mig-1 and lin-17, that are required to activate expression of mab-5 during migration of the QL neuroblast. We find that two of these genes, egl-20 and mig-14, also act in a mab-5-independent way to determine the final stopping points of the migrating Q descendants. The Q descendants do not migrate toward any obvious physical targets in wild-type or mutant animals. Therefore, these genes appear to be part of a system that positions the migrating Q descendants along the anteroposterior axis.

scholarly journals Hox gene expression during development of the phoronid Phoronopsis harmeri

2019 ◽  
Author(s):  
Ludwik Gąsiorowski ◽  
Andreas Hejnol
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Life Cycle ◽  
Larval Development ◽  
Hox Genes ◽  
Positional Information ◽  
Larval Body ◽  
Hox Gene ◽  
Phoronopsis Harmeri ◽  
Embryonic And Larval Development

Abstract Background: Phoronida is a small group of marine worm-like suspension feeders, which together with brachiopods and bryozoans form the clade Lophophorata. Although their development is well studied on the morphological level, data regarding gene expression during this process are scarce and restricted to the analysis of relatively few transcription factors. Here we present a description of the expression patterns of Hox genes during the embryonic and larval development of the phoronid Phoronopsis harmeri.Results: We identified sequences of 8 Hox genes in the transcriptome of Ph. harmeri and determined their expression pattern during embryonic and larval development using whole mount in situ hybridization. We found that none of the Hox genes is expressed during embryonic development. Instead their expression is initiated in the later developmental stages, when the larval body is already formed. The Hox genes are expressed in the non-collinear manner in the posterior body of the larvae: in the telotroch and the structures that represent rudiments of the adult worm, which emerges through the process of drastic metamorphosis. Additionally, we found that certain head-specific transcription factors are expressed in the oral hood, apical organ, anterior digestive system and developing larval tentacles, anterior to the Hox-expressing territories.Conclusions: The lack of Hox gene expression during early development of Ph. harmeri indicates that the larval body develops without positional information of the Hox patterning system. Such phenomenon might be a consequence of the evolutionary intercalation of the larval form into an ancestral life cycle of phoronids. The observed Hox gene expression can also be a consequence of the actinotrocha representing a “head larva”, which is composed of the most anterior body region that is devoid of Hox gene expression, which is supported by the expression of head-specific transcription factors. This implies that the Hox patterning system is used for the positional information of the trunk rudiments and is, therefore, delayed to the later larval stages. We propose that a new body form was intercalated to the phoronid life cycle by precocious development of the anterior structures or by delayed development of the trunk rudiment in the ancestral phoronid larva.

Hox gene expression reveals regionalization along the anteroposterior axis of the zebrafish notochord

1998 ◽  
Vol 208 (9) ◽  
pp. 517-522 ◽  
Author(s):  
V. E. Prince ◽  
Alivia L. Price ◽  
Robert K. Ho
Keyword(s):  
Gene Expression ◽  
Hox Gene ◽  
Anteroposterior Axis

DES exposure alters hox gene expression in the developing mouse miillerian system

1998 ◽  
Vol 5 (1) ◽  
pp. 39A-39A ◽  
Author(s):  
H TAYLOR ◽  
K BLOCK ◽  
A KARDANA ◽  
P IGARASHI
Keyword(s):  
Gene Expression ◽  
Hox Gene

scholarly journals Transcriptome Analysis of Hypertrophic Heart Tissues from Murine Transverse Aortic Constriction and Human Aortic Stenosis Reveals Key Genes and Transcription Factors Involved in Cardiac Remodeling Induced by Mechanical Stress

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Peng Yu ◽  
Baoli Zhang ◽  
Ming Liu ◽  
Ying Yu ◽  
Ji Zhao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Aortic Stenosis ◽  
Mechanical Stress ◽  
Cardiac Remodeling ◽  
Interaction Network ◽  
Cytokine Signaling ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Genomic Changes

Background. Mechanical stress-induced cardiac remodeling that results in heart failure is characterized by transcriptional reprogramming of gene expression. However, a systematic study of genomic changes involved in this process has not been performed to date. To investigate the genomic changes and underlying mechanism of cardiac remodeling, we collected and analyzed DNA microarray data for murine transverse aortic constriction (TAC) and human aortic stenosis (AS) from the Gene Expression Omnibus database and the European Bioinformatics Institute. Methods and Results. The differential expression genes (DEGs) across the datasets were merged. The Venn diagrams showed that the number of intersections for early and late cardiac remodeling was 74 and 16, respectively. Gene ontology and protein–protein interaction network analysis showed that metabolic changes, cell differentiation and growth, cell cycling, and collagen fibril organization accounted for a great portion of the DEGs in the TAC model, while in AS patients’ immune system signaling and cytokine signaling displayed the most significant changes. The intersections between the TAC model and AS patients were few. Nevertheless, the DEGs of the two species shared some common regulatory transcription factors (TFs), including SP1, CEBPB, PPARG, and NFKB1, when the heart was challenged by applied mechanical stress. Conclusions. This study unravels the complex transcriptome profiles of the heart tissues and highlighting the candidate genes involved in cardiac remodeling induced by mechanical stress may usher in a new era of precision diagnostics and treatment in patients with cardiac remodeling.

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