bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/574202

A pivotal genetic program controlled by thyroid hormone during the maturation of GABAergic neurons in mice

Richard, S.·Guyot, R.·Rey-Millet, M.·Prieux, M.·Markossian, S.·Aubert, D.·Flamant, F.
View original source ↗Export metadata ↓

Abstract

In mammals, brain development is critically dependent on proper thyroid hormone signaling, via the TR1 nuclear receptor. However, the downstream mechanisms by which TR1 impacts brain development are currently unknown, notably because this receptor is expressed ubiquitously from early stages of development. In order to better define the function of TR1 in the developing brain, we used mouse genetics to induce the expression of a dominant-negative mutation of the receptor specifically in GABAergic neurons, the main inhibitory neurons in the brain, which were previously identified as sensitive to hypothyroidism. This triggered post-natal epileptic seizures, reflecting a profound impairment of GABAergic neuron maturation in different brain areas. Analysis of transcriptome and TR1 cistrome also allowed us to identify a small set of genes, the transcription of which is upregulated by TR1 in GABAergic neurons during post-natal maturation of the striatum and which probably play an important role during neurodevelopment. Thus, our results point to GABAergic neurons as direct targets of thyroid hormone during brain development and suggest that many defects seen in hypothyroid brains may be secondary to GABAergic neuron malfunction.

Source connections

Explore related subjects

developmental biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Richard, S., Guyot, R., Rey-Millet, M., Prieux, M., Markossian, S., Aubert, D., Flamant, F.. 2019-03-12. A pivotal genetic program controlled by thyroid hormone during the maturation of GABAergic neurons in mice. https://doi.org/10.1101/574202

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Prenatal THC exposure alters metabolic gene expression and KEAP1 regulation in the mouse placental labyrinth

Introduction: Prenatal cannabinoid exposure may influence fetal development through changes in placental biology, yet its effects on metabolic gene regulation remain poorly understood. We examined the effects of {Delta}9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on the mouse placental labyrinth zone. Methods: Pregnant C57BL/6JRj mice received THC (5 mg/kg), CBD (5 mg/kg), or vehicle daily by intraperitoneal injection from gestational day 5 to 17.5. Targeted NanoString profiling and pathway analysis were combined with RT-qPCR and protein measurements. Results: THC exposure reduced glutaminase (Gls), Kelch-like ECH-associated protein 1 (Keap1), and FMS-like tyrosine kinase 3 (Flt3) expression (false discovery rate = 0.0904 for each). Pathway analysis identified transcriptional changes in the nine-gene arginine-metabolism set (false discovery rate = 0.0527). No genes or pathways met the significance criteria following CBD exposure. RT-qPCR confirmed lower Keap1 expression with sexes pooled and identified lower Gls and Flt3 expression in male samples. KEAP1 protein abundance increased despite lower Keap1 mRNA, while nuclear factor erythroid 2-related factor 2 localization and heme oxygenase 1 (Hmox1) expression showed no significant differences. Discussion: These findings identify amino acid metabolic gene expression and KEAP1 regulation as complementary components of the placental response to prenatal THC exposure, connecting transcriptional changes with protein regulation within the placental exchange region.

developmental biology↗
bioRxiv2026

Mutually Repressive Transcription Factors Drive Intestinal Maturation for Weaning

In mammals, rapid neonatal growth depends on specialized intestinal enterocytes that absorb nutrients from milk. These cells exhibit distinct functions, morphologies, and gene expression programs that support neonatal nutrition before transitioning to an adult state at weaning. However, the transcriptional mechanisms that establish neonatal enterocyte identity and coordinate their maturation remain poorly understood. Here we show that the transcription factors BLIMP1 and CASZ1 form a central switch in the timing of enterocyte maturation. While BLIMP1 marks and promotes neonatal enterocytes, CASZ1 is expressed in adult enterocytes and is required for the proper timing of their emergence. Genetic analysis indicates that these neonatal and adult factors are mutually repressive, forming a genetic switch underlying weaning. This regulatory mechanism also controls glucocorticoid-induced maturation, a process relevant to both normal weaning and the clinical use of corticosteroids to promote epithelial maturation in preterm infants. We show that corticosteroids act directly on the intestinal epithelium and require CASZ1 to induce maturation. Together, these findings reveal a transcriptional mechanism that coordinates intestinal epithelial identity with the changing nutritional demands of early life and mediates the response to maturation-promoting hormones.

developmental biology↗
bioRxiv2026

Functional Data Clustering of Filopodia Dynamics

Notch signaling plays a significant role in tissue patterning. During patterning of the fruit fly dorsal thorax peripheral nervous system, basal filopodia extend the spatial range of cell-cell communication, yet it is still unclear how Notch is activated in long range signaling via filopodia interaction. Filopodia undergo dynamic length changes during their lifetime, which could supply the mechanical pulling force required for notch activation. However, their dynamics are often characterized using individual scalar values such as maximum length and extension rate which could obscure more intricate dynamics. Our hypothesis is that signaling filopodia exhibit distinct and recurrent temporal patterns which can be identified by a consideration of their complete lifetime trajectories. Our work analyzes 60 filopodia trajectories at the basal surface of the fly dorsal thorax during patterning. Length profiles were smoothed using cubic B-splines and clustered by first reducing them to their dominant functional principal component followed by the application of various clustering algorithms. We found that 94.29% of the overall trajectory variation is explained by the first four functional principal components which account for variations in maximal length, extension and retraction rate, duration of stationary phase and length fluctuation frequency. Five recurrent temporal profiles (dynamic extension modes) with varying trajectory shapes and physical attributes, were identified using trimmed K-means. These findings demonstrate that whereas the major source of structural variation in filopodia profiles remains the length, extension rate and retraction rate, nontrivial combinations of these create distinct dynamic modes of extension which provide new insight into their length profiles. Our work thus offers a quantitative framework for future research connecting filopodia dynamic extension modes to productive Notch activation.

developmental biology↗