Biology subjects

Amato, E.

Publications and source records attributed to Amato, E..

5 recordsLinked to original sources

bioRxiv2025

GnRH-1 Neurons Are Not in the Goofy Group: 123cre Tracing Sets the Record Straight

The olfactory placode (OP) gives rise to a wide array of chemosensory neurons in the nasal region, including olfactory sensory neurons, vomeronasal sensory neurons, and those of the septal organ and Grueneberg ganglion. During placodal invagination, the OP also produces migratory neurons, including gonadotropin-releasing hormone-1 (GnRH-1) neurons, somatostatin-expressing neurons, Prokineticin Receptor 2 (Prokr2) pioneer/terminal nerve (TN) neurons, which are thought to initiate olfactory bulb development. Despite decades of research, the genetic lineage and molecular identity of OP-derived neuronal types remain under investigation. GnRH-1 neurons play essential roles in reproduction and chemodetection but appear genetically distinct from olfactory and vomeronasal chemosensory neurons. The Golgi-associated olfactory signaling regulator Goofy/Gfy is broadly expressed across the placode-derived nasal chemosensory neurons. To determine whether its expression is specific to nasal chemosensory neurons or it is a shared genetic feature across OP derivatives we characterized Gfy expression and lineage at embryonic and postnatal stages. Our results confirm broad Gfy expression in developing chemosensory neurons and subsets of olfactory pioneer/TN neurons. However, we found that while Gfy was not expressed in GnRH-1 neurons while migrating, analysis at late development and postnatal stages, revealed the existence of Gfy-traced neuronal populations in the basal forebrain, some of which also express GnRH. These findings uncover previously unrecognized genetic heterogeneity among migratory nasal neurons and reinforce previous studies suggesting the existence of additional neurons with nasal origin in the brain. In addition to this, analysis of Gfy expression along the developmental trajectory of vomeronasal sensory neurons at postnatal stages revealed intriguing differences in the developmental dynamics across the two main types of vomeronasal sensory neurons.

developmental biology↗

bioRxiv2025

Tracing Early Migratory Neurons in the Developing Nose Using Contactin-2 (Cntn2)CreERT2

Neuronal migration during embryonic development is a fundamental process. In the developing nose of rodents, neurons that form during early neurogenic waves in the olfactory placode leave this structure to migrate toward or into the developing brain as part of the migratory mass. This mass includes Gonadotropin-releasing hormone-1 (GnRH-1) neurons, pioneer/terminal nerve (TN) neurons, as well as neural crest-derived olfactory glial cells called olfactory ensheathing cells. There have been a limited number of molecular markers available to effectively trace and functionally manipulate the early migratory neurons that originate in the olfactory region. Contactin-2 (Cntn2), also known as transiently expressed axonal surface glycoprotein-1 (TAG-1), has been used to label various developing neuronal populations, including the commissural neurons of the spinal cord, motor neurons, and TN neurons. Previous single-cell RNA sequencing analyses of the developing olfactory system have identified Cntn2 expression in the TN, suggesting that Cntn2 is a suitable molecular marker for studying nasal migratory neurons. To trace Cntn2 expression in the developing olfactory system, we generated an inducible Cntn2CreERT2 mouse line. In this study, we outline how this mouse line can serve as an effective tool for time-controlled chimeric manipulation of specific neuronal populations of interest.

neuroscience↗

bioRxiv2025

Shared Lineage, Distinct Outcomes: Yap and Taz Loss Differentially Impact Schwann and Olfactory Ensheathing Cell Development Without Disrupting GnRH-1 Migration

Olfactory Ensheathing Cells (OECs) are glial cells originating from the neural crest, critical for bundling olfactory axons to the brain. Their development is crucial for the migration of Gonadotropin-Releasing Hormone-1 (GnRH-1) neurons, which are essential for puberty and fertility. OECs have garnered interest as potential therapeutic targets for central nervous system lesions, although their development is not fully understood. Our single-cell RNA sequencing of mouse embryonic nasal tissues suggests that OECs and Schwann cells share a common origin from Schwann cell precursors yet exhibit significant genetic differences. The transcription factors Yap and Taz have previously been shown to play a crucial role in Schwann cell development. We used Sox10-Cre mice to conditionally ablate Yap and Taz in migrating the neural crest and its derivatives. Our analyses showed reduced Sox10+ glial cells along nerves in the nasal region, altered gene expression of SCs, melanocytes, and OECs, and a significant reduction in olfactory sensory neurons and vascularization in the vomeronasal organ. However, despite these changes, GnRH-1 neuronal migration remained unaffected. Our findings highlight the importance of the Hippo pathway in OEC development and how changes in cranial neural crest derivatives indirectly impact the development of olfactory epithelia.

developmental biology↗

bioRxiv2023

Illuminating the Terminal Nerve: Uncovering the Link between GnRH-1 and Olfactory Development.

During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), Gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the olfactory placode induce olfactory bulb morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the terminal nerve axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal (HPG) axis. Kallmann syndrome is characterized by impaired olfactory system development, defective olfactory bulbs, defective secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the Prokineticin-2/Prokineticin-Receptor-2 (Prokr2) signaling pathway in olfactory bulb morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome, and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of olfactory bulb morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons that are distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum. Key Points1) Pioneer or terminal nerve neurons play a crucial role in initiating the development of the olfactory bulbs. We found that the Prokineticin Receptor-2 gene, associated with Kallmann syndrome, is expressed by the olfactory pioneer/terminal nerve neurons. 2) We genetically traced, isolated, and conducted Single-cell RNA sequencing on terminal nerve neurons of rodents. This analysis revealed a significant enrichment of gene expression related to Kallmann syndrome. 3) Our study indicates that the investigation of Pioneer/terminal nerve neurons should be a pivotal focal point for comprehending developmental defects affecting olfactory and GnRH-1 systems.

developmental biology↗

bioRxiv2020

Multiplex single-molecule kinetics of nanopore-coupled polymerases

DNA polymerases have revolutionized the biotechnology field due to their ability to precisely replicate stored genetic information. Screening variants of these enzymes for unique properties gives the opportunity to identify polymerases with novel features. We have previously developed a single-molecule DNA sequencing platform by coupling a DNA polymerase to a -hemolysin pore on a nanopore array. Here, we use this approach to demonstrate a single-molecule method that enables rapid screening of polymerase variants in a multiplex manner. In this approach, barcoded DNA strands are complexed with polymerase variants and serve as templates for nanopore sequencing. Nanopore sequencing of the barcoded DNA reveals both the barcode identity and kinetic properties of the polymerase variant associated with the cognate barcode, allowing for multiplexed investigation of many polymerase variants in parallel on a single nanopore array. Further, we develop a robust classification algorithm that discriminates kinetic characteristics of the different polymerase mutants. As a proof of concept, we demonstrate the utility of our approach by screening a library of ~100 polymerases to identify variants for potential applications of biotechnological interest. We anticipate our screening method to be broadly useful for applications that require polymerases with unique or altered physical properties.

synthetic biology↗