The clockwork of development: interaction of Hes7 with Fgf4 and
Lfng in the mechanism of the segmentation clock.
Chatpdf was used to quickly interpret the dense information and to give an
overview of the papers utilized for this mini review.
Word count - 2526
Abstract
This mini review examines the role of Hes7 as a key regulator of the
segmentation clock during somitogenesis, while focusing on its interactions with
Fgf4 and Lfng. There will be a discussion about how Fgf4 influences the
oscillatory expression of Hes7 in the presomitic mesoderm (PSM) and thus
highlighting its importance in maintaining organized somitogenesis and vertebral
segmentation. Furthermore, the feedback mechanisms involving Notch signaling
and Lfng will be examined, which further enhances the timing of somite
formation. By taking in all the findings from different studies such as those by
Anderson et al. (2020), Williams et al. (2016) and Fujimuro et al. (2014) together,
this review will give an overview of the dynamics surrounding somite formation.
This will be done while highlighting the significance of Hes7 as key regulator
within the regulatory process of somitogenesis and thus vertebrate
development.
Introduction
Somitogenesis, the process of forming somites from the presomitic mesoderm
(PSM), is a fundamental component of vertebrate development. The
segmentation clock, a molecular oscillator that regulates the patterning and
timing of somite formation, is essential for this process. The aim of this review is
to gain a better understanding of Hes7, one of the key players in the regulatory
network involved in the segmentation clock, which functions as a core regulator.
Under the influence of various signaling pathways, including the Fibroblast
Growth Factor (FGF) signaling pathway, the expression of Hes7 oscillates. These
interactions are essential for maintaining the oscillatory dynamics needed for
somitogenesis. Furthermore, the Notch signaling pathway, modulated by Hes7
and its downstream effectors such as Lfng, plays an important role in refining the
timing of somite formation. Reviewing the interactions between these
components and their roles in somitogenesis, alongside the potential effects of
their disruption on birth defects, allows for answering the main question: How
does Hes7 function as the core regulator of the segmentation clock, and how do
interactions with Fgf4 and Lfng refine the oscillatory timing of somitogenesis?
Hes7 as a key regulator of the segmentation clock
The segmentation clock is an essential mechanism in vertebrate development,
coordinating the rhythmic formation of somites from the PSM. Multiple factors are
involved in this process, such as negative feedback loops, transcriptional and
translational regulation and oscillatory gene expression (Pourquié, 2003). While
the variety of genes with an oscillatory pattern differs among species, Hes7,
belonging to the class of Notch-responsive HES/HER transcription factors, is
widely conserved (Krol et al., 2011). This suggests that Hes7 plays a crucial role
in regulating the segmentation clock (Anderson et al., 2020).
HES7 is a basic helix-loop-helix (bHLH) transcription factor that plays an
important role in the Notch signaling pathway (Bessho et al., 2001). Its oscillatory
expression in the PSM is crucial for establishing the timing and pattern of somite
formation. Hes7 functions through a negative feedback loop, where it inhibits its
Lfng in the mechanism of the segmentation clock.
Chatpdf was used to quickly interpret the dense information and to give an
overview of the papers utilized for this mini review.
Word count - 2526
Abstract
This mini review examines the role of Hes7 as a key regulator of the
segmentation clock during somitogenesis, while focusing on its interactions with
Fgf4 and Lfng. There will be a discussion about how Fgf4 influences the
oscillatory expression of Hes7 in the presomitic mesoderm (PSM) and thus
highlighting its importance in maintaining organized somitogenesis and vertebral
segmentation. Furthermore, the feedback mechanisms involving Notch signaling
and Lfng will be examined, which further enhances the timing of somite
formation. By taking in all the findings from different studies such as those by
Anderson et al. (2020), Williams et al. (2016) and Fujimuro et al. (2014) together,
this review will give an overview of the dynamics surrounding somite formation.
This will be done while highlighting the significance of Hes7 as key regulator
within the regulatory process of somitogenesis and thus vertebrate
development.
Introduction
Somitogenesis, the process of forming somites from the presomitic mesoderm
(PSM), is a fundamental component of vertebrate development. The
segmentation clock, a molecular oscillator that regulates the patterning and
timing of somite formation, is essential for this process. The aim of this review is
to gain a better understanding of Hes7, one of the key players in the regulatory
network involved in the segmentation clock, which functions as a core regulator.
Under the influence of various signaling pathways, including the Fibroblast
Growth Factor (FGF) signaling pathway, the expression of Hes7 oscillates. These
interactions are essential for maintaining the oscillatory dynamics needed for
somitogenesis. Furthermore, the Notch signaling pathway, modulated by Hes7
and its downstream effectors such as Lfng, plays an important role in refining the
timing of somite formation. Reviewing the interactions between these
components and their roles in somitogenesis, alongside the potential effects of
their disruption on birth defects, allows for answering the main question: How
does Hes7 function as the core regulator of the segmentation clock, and how do
interactions with Fgf4 and Lfng refine the oscillatory timing of somitogenesis?
Hes7 as a key regulator of the segmentation clock
The segmentation clock is an essential mechanism in vertebrate development,
coordinating the rhythmic formation of somites from the PSM. Multiple factors are
involved in this process, such as negative feedback loops, transcriptional and
translational regulation and oscillatory gene expression (Pourquié, 2003). While
the variety of genes with an oscillatory pattern differs among species, Hes7,
belonging to the class of Notch-responsive HES/HER transcription factors, is
widely conserved (Krol et al., 2011). This suggests that Hes7 plays a crucial role
in regulating the segmentation clock (Anderson et al., 2020).
HES7 is a basic helix-loop-helix (bHLH) transcription factor that plays an
important role in the Notch signaling pathway (Bessho et al., 2001). Its oscillatory
expression in the PSM is crucial for establishing the timing and pattern of somite
formation. Hes7 functions through a negative feedback loop, where it inhibits its
