A conserved regulatory program drives emergence of the lateral plate mesoderm

Cardiovascular cell lineages emerge with kidney, smooth muscle, and limb skeleton progenitors from the lateral plate mesoderm (LPM). How the LPM emerges during development and how it has evolved to form key lineages of the vertebrate body plan remain unknown. Here, we captured LPM formation by transgenic in toto imaging and lineage tracing using the first pan-LPM enhancer element from the zebrafish gene draculin (drl). drl LPM enhancer-based reporters are specifically active in LPM-corresponding territories of several chordate species, uncovering a universal LPM-specific gene program. Distinct from other mesoderm, we identified EomesA, FoxH1, and MixL1 with BMP/Nodal-controlled Smad activity as minimally required factors to drive drl-marked LPM formation. Altogether, our work provides a developmental and mechanistic framework for LPM emergence and the in vitro differentiation of cardiovascular cell types. Our findings suggest that the LPM may represent an ancient cell fate domain that predates ancestral vertebrates

A conserved regulatory program drives emergence of the lateral plate mesoderm

Cardiovascular cell lineages emerge with kidney, smooth muscle, and limb skeleton progenitors from the lateral plate mesoderm (LPM). How the LPM emerges during development and how it has evolved to form key lineages of the vertebrate body plan remain unknown. Here, we captured LPM formation by transgenic in toto imaging and lineage tracing using the first pan-LPM enhancer element from the zebrafish gene draculin (drl). drl LPM enhancer-based reporters are specifically active in LPM-corresponding territories of several chordate species, uncovering a universal LPM-specific gene program. Distinct from other mesoderm, we identified EomesA, FoxH1, and MixL1 with BMP/Nodal-controlled Smad activity as minimally required factors to drive drl-marked LPM formation. Altogether, our work provides a developmental and mechanistic framework for LPM emergence and the in vitro differentiation of cardiovascular cell types. Our findings suggest that the LPM may represent an ancient cell fate domain that predates ancestral vertebrates

A conserved regulatory program initiates lateral plate mesoderm emergence across chordates

Cardiovascular lineages develop together with kidney, smooth muscle, and limb connective tissue progenitors from the lateral plate mesoderm (LPM). How the LPM initially emerges and how its downstream fates are molecularly interconnected remain unknown. Here, we isolate a pan-LPM enhancer in the zebrafish-specific draculin (drl) gene that provides specific LPM reporter activity from early gastrulation. In toto live imaging and lineage tracing of drl-based reporters captures the dynamic LPM emergence as lineage-restricted mesendoderm field. The drl pan-LPM enhancer responds to the transcription factors EomesoderminA, FoxH1, and MixL1 that combined with Smad activity drive LPM emergence. We uncover specific activity of zebrafish-derived drl reporters in LPM-corresponding territories of several chordates including chicken, axolotl, lamprey, Ciona, and amphioxus, revealing a universal upstream LPM program. Altogether, our work provides a mechanistic framework for LPM emergence as defined progenitor field, possibly representing an ancient mesodermal cell state that predates the primordial vertebrate embryo

Diagnosis of prostate cancer with magnetic resonance imaging in men treated with 5-alpha-reductase inhibitors

Purpose The primary aim of this study was to evaluate if exposure to 5-alpha-reductase inhibitors (5-ARIs) modifies the effect of MRI for the diagnosis of clinically significant Prostate Cancer (csPCa) (ISUP Gleason grade >= 2).Methods This study is a multicenter cohort study including patients undergoing prostate biopsy and MRI at 24 institutions between 2013 and 2022. Multivariable analysis predicting csPCa with an interaction term between 5-ARIs and PIRADS score was performed. Sensitivity, specificity, and negative (NPV) and positive (PPV) predictive values of MRI were compared in treated and untreated patients.Results 705 patients (9%) were treated with 5-ARIs [median age 69 years, Interquartile range (IQR): 65, 73; median PSA 6.3 ng/ml, IQR 4.0, 9.0; median prostate volume 53 ml, IQR 40, 72] and 6913 were 5-ARIs naive (age 66 years, IQR 60, 71; PSA 6.5 ng/ml, IQR 4.8, 9.0; prostate volume 50 ml, IQR 37, 65). MRI showed PIRADS 1-2, 3, 4, and 5 lesions in 141 (20%), 158 (22%), 258 (37%), and 148 (21%) patients treated with 5-ARIs, and 878 (13%), 1764 (25%), 2948 (43%), and 1323 (19%) of untreated patients (p < 0.0001). No difference was found in csPCa detection rates, but diagnosis of high-grade PCa (ISUP GG >= 3) was higher in treated patients (23% vs 19%, p = 0.013). We did not find any evidence of interaction between PIRADS score and 5-ARIs exposure in predicting csPCa. Sensitivity, specificity, PPV, and NPV of PIRADS >= 3 were 94%, 29%, 46%, and 88% in treated patients and 96%, 18%, 43%, and 88% in untreated patients, respectively.Conclusions Exposure to 5-ARIs does not affect the association of PIRADS score with csPCa. Higher rates of high-grade PCa were detected in treated patients, but most were clearly visible on MRI as PIRADS 4 and 5 lesions.Trial registration The present study was registered at ClinicalTrials.gov number: NCT05078359

Gene regulatory Network controlling anterior-posterior patterning of Central Nervous System and melanosomal logistics in Ciona intestinalis: a transcriptomic approach.

Fibroblast growth factor (FGF) signaling plays an important role in neural induction and subsequent development throughout the vertebrates. Likewise, the FGF signaling pathway also functions in neural development in ascidians, that are considered as basal chordate sharing conserved molecular developmental mechanisms with vertebrates. FGF and Wnt signaling are involved in development of the pigment cells in the sensory organs of C. intestinalis. Nevertheless the FGF downstream targets, involved in pigment cell precursors formation, are not yet characterized and less is known about the patterning mechanisms in specification of the anteriormost nervous system in Ciona. Here, I employed a cell sorting, microarrays, and targeted manipulations to analyse the FGF signaling gene regulatory network controlling Central Nervous System (CNS) differentiation and pigmented cell formation in C. intestinalis. Microarray data analysis revealed that FGF signaling is required for setting the anterior-posterior CNS patterning in Ciona. My results indicate that when FGF signaling is blocked in Pigment Cell Precursors (PCPs), the most anterior cells change their fate, behaving like cells of the anterior CNS. Microarray data analysis produced hundreds genes differentially expressed when FGF signaling is pertubated in pigment cell lineage. A 'reverse engineered' approach has been employed to create a pigment cell lineage-specific transcriptional network from my microarray data set and neighbors analysis permitted to identify new potential candidates involved in FGF signaling regulatory architecture. Clustering algorithms permitted to group genes according to similar expression pattern; a bioinformatic tool was used to identify statistically the over-representation of conserved transcription factor binding sites on co-expressed gene promoter regions. This analysis allowed to computationally recover putative transcription factors involved in the FGF signaling regulatory network. Furthermore from microarray data analysis, I identified new specific markers of Ciona pigmented cell lineage and several genes that may function as key factors to prime the melanosomal logistic, including biogenesis and transport. Among these, I focused on Ci-Rab38/32/rab-rp1/ltd, the only orthologue of two highly conserved small Rab GTPase, RAB38 nad RAB32. These proteins play a crucial role in the transport of melanogenic enzymes during melanosome maturation in vertebrate melanocytes. Targeted expression of the double mutant in the GTP binding pocket of Ci-Rab38/32/rab-rp1/ltd protein in Ciona pigment cell lineage, leads to the formation of larvae with defects or completely lacking of pigment cells in the sensory vesicle

Divergent mechanisms regulate conserved cardiopharyngeal development and gene expression in distantly related ascidians

Ascidians present a striking dichotomy between conserved phenotypes and divergent genomes: embryonic cell lineages and gene expression patterns are conserved between distantly related species. Much research has focused on Ciona or Halocynthia spp. but development in other ascidians remains poorly characterized. In this study, we surveyed the multipotent myogenic B7.5 lineage in Molgula spp. Comparisons to the homologous lineage in Ciona revealed identical cell division and fate specification events that result in segregation of larval, cardiac, and pharyngeal muscle progenitors. Moreover, the expression patterns of key regulators are conserved, but cross-species transgenic assays uncovered incompatibility, or 'unintelligibility', of orthologous cis-regulatory sequences between Molgula and Ciona. These sequences drive identical expression patterns that are not recapitulated in cross-species assays. We show that this unintelligibility is likely due to changes in both cis- and trans-acting elements, hinting at widespread and frequent turnover of regulatory mechanisms underlying otherwise conserved aspects of ascidian embryogenesis

Evolutionary loss of melanogenesis in the tunicate Molgula occulta

Abstract Background Analyzing close species with diverse developmental modes is instrumental for investigating the evolutionary significance of physiological, anatomical and behavioral features at a molecular level. Many examples of trait loss are known in metazoan populations living in dark environments. Tunicates are the closest living relatives of vertebrates and typically present a lifecycle with distinct motile larval and sessile adult stages. The nervous system of the motile larva contains melanized cells associated with geotactic and light-sensing organs. It has been suggested that these are homologous to vertebrate neural crest-derived melanocytes. Probably due to ecological adaptation to distinct habitats, several species of tunicates in the Molgulidae family have tailless (anural) larvae that fail to develop sensory organ-associated melanocytes. Here we studied the evolution of Tyrosinase family genes, indispensible for melanogenesis, in the anural, unpigmented Molgula occulta and in the tailed, pigmented Molgula oculata by using phylogenetic, developmental and molecular approaches. Results We performed an evolutionary reconstruction of the tunicate Tyrosinase gene family: in particular, we found that M. oculata possesses genes predicted to encode one Tyrosinase (Tyr) and three Tyrosinase-related proteins (Tyrps) while M. occulta has only Tyr and Tyrp.a pseudogenes that are not likely to encode functional proteins. Analysis of Tyr sequences from various M. occulta individuals indicates that different alleles independently acquired frameshifting short indels and/or larger mobile genetic element insertions, resulting in pseudogenization of the Tyr locus. In M. oculata, Tyr is expressed in presumptive pigment cell precursors as in the model tunicate Ciona robusta. Furthermore, a M. oculata Tyr reporter gene construct was active in the pigment cell precursors of C. robusta embryos, hinting at conservation of the regulatory network underlying Tyr expression in tunicates. In contrast, we did not observe any expression of the Tyr pseudogene in M. occulta embryos. Similarly, M. occulta Tyr allele expression was not rescued in pigmented interspecific M. occulta × M. oculata hybrid embryos, suggesting deleterious mutations also to its cis-regulatory sequences. However, in situ hybridization for transcripts from the M. occulta Tyrp.a pseudogene revealed its expression in vestigial pigment cell precursors in this species. Conclusions We reveal a complex evolutionary history of the melanogenesis pathway in tunicates, characterized by distinct gene duplication and loss events. Our expression and molecular data support a tight correlation between pseudogenization of Tyrosinase family members and the absence of pigmentation in the immotile larvae of M. occulta. These results suggest that relaxation of purifying selection has resulted in the loss of sensory organ-associated melanocytes and core genes in the melanogenesis biosynthetic pathway in M. occulta