Probes for PRL

RESULTS : PR-specific expression of _PRLΔE1_ was observed in the following canine models of progressive inherited retinal degeneration (IRD): _RPGR_-XLPRA1 and _NPHP5_-LCA. In _RPGR_-XLPRA2 carrier retinas that undergo random X-inactivation, patches of_ PRLΔE1 _expression correlated with patches of PR degeneration. However, we did not observe expression of _PRLΔE1_ 24 hrs and 2 wks after light exposure that triggers acute rod loss in the canine RHO-T4R model of adRP. No _PRLΔE1 _expression was seen either in the _CNGB3_-ACHM3 retina that undergoes extremely slow cone degeneration. In _RPGR-_XLPRA1 and _RPGR-_XLPRA2 dogs subretinally-injected with an AAV-_RPGR_ vector, _PRLΔE1 _was completely absent in treated PRs while robust expression was seen in diseased/untreated areas.

Single-cell technologies capture cellular heterogeneity to focus on previously poorly described subpopulations of cells. While work by our lab and many others have metagenomically characterized a low biomass intrauterine microbial community, alongside microbial transcripts, antigens, and metabolites, the functional importance of low biomass microbial communities in placental immuno-microenvironments are still being elucidated. Given their hypothesized role in modulating inflammation and immune ontogeny to enable tolerance to beneficial microbes while warding off pathogens, there is a need for single-cell resolution. Herein, we summarize the potential for mechanistic understandings of these and other key fundamental early developmental processes by applying single-cell approaches.This article is protected by

In fish, prolactin-producing cells (lactotropes) are located in the anterior part of the pituitary and play an essential role in osmoregulation. However, small satellite lactotrope populations have been described in other parts of the pituitary in several species. The functional and developmental backgrounds of these extra populations are not known. We recently described two distinct prolactin-expressing cell types in Japanese medaka, a salinity tolerant fish, using single cell transcriptomics. In this study, we thus characterize the two transcriptomically distinct lactotrope cell types and explore the hypothesis that they represent the spatially distinct cell populations found in other species. Single cell RNA sequencing shows that one of the two lactotrope cell types exhibits an expression profile similar to that of stem cell populations. Using in situ hybridization, we show that the medaka pituitary often develops additional small satellite lactotrope cell groups, like in other teleost species. These satellite clusters arise early during development and grow in cell number throughout life regardless of the animal’s sex. Surprisingly, there seems to be no correspondence between the stem cell-like lactotropes and these newly emerging lactotrope populations. Instead, our data support a scenario in which the stem cell-like lactotropes are an intrinsic stage in the development of every spatially distinct lactotrope cluster. In addition, lactotrope activity in the medaka pituitary decreases when environmental salinity increases in the two spatially distinct lactotrope clusters, supporting their role in osmoregulation. However, this decrease appears weaker in the satellite lactotrope cell groups, suggesting that these lactotropes are differentially regulated.

Dexamethasone-induced Ras-related protein 1 (Rasd1) is a member of the Ras superfamily of monomeric G proteins that have a regulatory function in signal transduction. Rasd1, also known as Dexras1 or AGS1, is rapidly induced by dexamethasone (Dex). While prior data indicates that Rasd1 is highly expressed in the pituitary and that the gene may function in regulation of corticotroph activity, its exact cellular localization in this tissue has not been delineated. Nor has it been determined which endocrine pituitary cell type(s) are responsive to Dex-induced expression of Rasd1. We hypothesized that Rasd1 is primarily localized in corticotrophs and furthermore, that its expression in these cells would be upregulated in response to exogenous Dex administration. Rasd1 expression in each pituitary cell type both under basal conditions and 1-hour post Dex treatment were examined in adult male mice. While a proportion of all endocrine pituitary cell types expressed Rasd1, a majority of corticotrophs and thyrotrophs expressed Rasd1 under basal condition. In vehicle treated animals, approximately 50-60% of corticotrophs and thyrotrophs cells expressed Rasd1 while the gene was detected in only 15-30% of lactotrophs, somatotrophs, and gonadotrophs. In Dex treated animals, Rasd1 expression was significantly increased in corticotrophs, somatotrophs, lactotrophs, and gonadotrophs but not thyrotrophs. In Dex treated animals, Rasd1 was detected in 80-95% of gonadotrophs and corticotrophs. In contrast, Dex treatment increased Rasd1 expression to a lesser extent (55-60%) in somatotrophs and lactotrophs. Corticotrophs of the pars intermedia, which lack glucocorticoid receptors, failed to display increased Rasd1 expression in Dex treated animals. Rasd1 is highly expressed in corticotrophs under basal conditions and is further increased after Dex treatment, further supporting its role in glucocorticoid negative feedback. In addition, the presence and Dex-induced expression of Rasd1 in endocrine pituitary cell types, other than corticotrophs, may implicate Rasd1 in novel pituitary functions.