Development

Adrenal cortex and gonads represent the two major steroidogenic organs in mammals. Both tissues are considered to share a common developmental origin characterized by the expression of Nr5a1/Sf1. The precise origin of adrenogonadal progenitors and the processes driving differentiation toward the adrenal or gonadal fate remain, however, elusive. Here, we provide a comprehensive single-cell transcriptomic atlas of early mouse adrenogonadal development including 52 cell types belonging to twelve major cell lineages.

The biological characteristics of the temporomandibular joint disc involve complex cellular network in cell identity and extracellular matrix composition to modulate jaw function. The lack of a detailed characterization of the network severely limits the development of targeted therapies for temporomandibular joint-related diseases. Here we profiled single-cell transcriptomes of disc cells from mice at different postnatal stages, finding that the fibroblast population could be divided into chondrogenic and non-chondrogenic clusters.

Fingerprints are complex and individually unique patterns in the skin. Established prenatally, the molecular and cellular mechanisms that guide fingerprint ridge formation and their intricate arrangements are unknown. Here we show that fingerprint ridges are epithelial structures that undergo a truncated hair follicle developmental program and fail to recruit a mesenchymal condensate. Their spatial pattern is established by a Turing reaction-diffusion system, based on signaling between EDAR, WNT, and antagonistic BMP pathways.

A mesiodens is a supernumerary tooth located in the midline of the premaxilla. To investigate the genetic cause of mesiodens, clinical and radiographic examination were performed on 23 family members of a two-generation Hmong family. Whole exome sequencing (WES) or Sanger sequencing were performed in 22 family members and two unrelated Thai patients with mesiodens. WES in the Hmong family revealed a missense mutation (c.1807G>A;p.Glu603Lys) in PTPN23 in seven affected members and six unaffected members. The mode of inheritance was autosomal dominance with incomplete penetrance (53.84%).

Sound stimulus is encoded in mice by three molecularly and physiologically diverse subtypes of sensory neurons, called Ia, Ib, and Ic spiral ganglion neurons (SGNs). Here, we show that the transcription factor Runx1 controls SGN subtype composition in the murine cochlea. Runx1 is enriched in Ib/Ic precursors by late embryogenesis. Upon the loss of Runx1 from embryonic SGNs, more SGNs take on Ia rather than Ib or Ic identities. This conversion was more complete for genes linked to neuronal function than to connectivity. Accordingly, synapses in the Ib/Ic location acquired Ia properties.

It has been proposed that smooth muscle differentiation may physically sculpt airway epithelial branches in mammalian lungs. Serum response factor (SRF) acts with its co-factor myocardin to activate the expression of contractile smooth muscle markers. In the adult, however, smooth muscle exhibits a variety of phenotypes beyond contractile, and these are independent of SRF/myocardin-induced transcription. To determine whether a similar phenotypic plasticity is exhibited during development, we deleted Srf from the mouse embryonic pulmonary mesenchyme.

Ureteric bud induction and branching morphogenesis is fundamental to the establishment of the renal architecture and is a key determinant of nephron number. Defective ureteric bud morphogenesis could give rise to a spectrum of malformations associated with congenital anomalies of the kidney and urinary tract (CAKUT). Signaling involving glial cell line-derived neurotrophic factor and its receptor RET and coreceptor GFRA1 appears to be particularly important in ureteric bud development.

The molecular identification of neural progenitor cell populations that connect to establish the sympathetic nervous system (SNS) remains unclear. This is due to technical limitations in the acquisition and spatial mapping of molecular information to tissue architecture.To address this, we applied Slide-seq spatial transcriptomics to intact fresh frozen chick trunk tissue transversely cryo-sectioned at the developmental stage prior to SNS formation. In parallel, we performed age- and location-matched single cell (sc) RNA-seq and 10× Genomics Visium to inform our analysis.

Type 1 alveolar epithelial cells (AT1s) and type 2 alveolar epithelial cells (AT2s) regulate the structural integrity and function of alveoli. AT1s mediate gas exchange, whereas AT2s serve multiple functions, including surfactant secretion and alveolar repair through proliferation and differentiation into AT1s as progenitors. However, mechanisms regulating AT2 proliferation and differentiation remain unclear. Here we demonstrate that Gremlin, an intrinsic inhibitor of bone morphogenetic protein (BMP), induces AT2 proliferation and differentiation.

Estrogen receptor (ER) α-expressing neurons in the ventrolateral area of the ventromedial hypothalamus (VMHvl) are implicated in the control of many behaviors and physiological processes, some of which are sex-specific. Recently, three sex-differentiated ERα subpopulations have been discovered in the VMHvl marked by co-expression with tachikinin1 (Tac1), reprimo (Rprm), or prodynorphin (Pdyn), that may subserve specific functions. These markers show sex differences in adulthood: females have many more Tac1/Esr1 and Rprm/Esr1 co-expressing cells, while males have more Pdyn/Esr1 cells.