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Biology subjects

Laznovsky, J.

Publications and source records attributed to Laznovsky, J..

3 recordsLinked to original sources

Unveiling Vertebrate Development Dynamics in Frog Xenopus laevis using Micro-CT Imaging

BackgroundXenopus laevis, the African clawed frog, is a versatile vertebrate model organism employed across various biological disciplines, prominently in developmental biology to elucidate the intricate processes underpinning body plan reorganization during metamorphosis. Despite its widespread utility, a notable gap exists in the availability of comprehensive datasets encompassing Xenopus late developmental stages. FindingsIn the present study, we harnessed micro-computed tomography (micro-CT), a non-invasive 3D imaging technique utilizing X-rays to examine structures at a micrometer scale, to investigate the developmental dynamics and morphological changes of this crucial vertebrate model. Our approach involved generating high-resolution images and computed 3D models of developing Xenopus specimens, spanning from premetamorphosis tadpoles to fully mature adult frogs. This extensive dataset enhances our understanding of vertebrate development and is adaptable for various analyses. For instance, we conducted a thorough examination, analyzing body size, shape, and morphological features, with a specific emphasis on skeletogenesis, teeth, and organs like the brain at different stages. Our analysis yielded valuable insights into the morphological changes and structure dynamics in 3D space during Xenopus development, some of which were not previously documented in such meticulous detail. This implies that our datasets effectively capture and thoroughly examine Xenopus specimens. Thus, these datasets hold the solid potential for additional morphological and morphometric analyses, including individual segmentation of both hard and soft tissue elements within Xenopus. ConclusionsOur repository of micro-CT scans represents a significant resource that can enhance our understanding of Xenopus development and the associated morphological changes. The widespread utility of this amphibian species, coupled with the exceptional quality of our scans, which encompass a comprehensive series of developmental stages, opens up extensive opportunities for their broader research application. Moreover, these scans have the potential for use in virtual reality, 3D printing, and educational contexts, further expanding their value and impact. Graphical abstract & lay summary3D images of selected developmental stages of X. laevis in a comparison (scale bar = 10 mm). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=67 SRC="FIGDIR/small/598452v1_ufig1.gif" ALT="Figure 1"> View larger version (14K): org.highwire.dtl.DTLVardef@1bc4664org.highwire.dtl.DTLVardef@1b1750dorg.highwire.dtl.DTLVardef@17bddaaorg.highwire.dtl.DTLVardef@115de4e_HPS_FORMAT_FIGEXP M_FIG C_FIG Lay summaryX-ray tomography was used to examine the African clawed frog (Xenopus laevis). An extensive data set of specimens from tadpoles to adult frogs provides novel insights into the changes and developmental dynamics of selected structures, which opens avenues to an improved understanding of this crucial animal model.

developmental biology↗

Bleeding in patients and mice with Alagille syndrome: sex differences and risk factors

Spontaneous lethal bleeds are major cause of death in the pediatric liver disease Alagille syndrome (ALGS), yet risk factors and screening methods have not been established. We performed a systematic review and identified significantly more female than male patients with idiopathic intracranial hemorrhage (10:1). We investigated bleeding and vasculature in patients and a mouse model for ALGS (Jag1Ndr/Ndr mice) and asked whether phenotypes identified in mice could be detected in patients non-invasively. Jag1Ndr/Ndr mice bled spontaneously, exhibiting a thin skull and vascular defects including artery-vein crossings, tortuous vessels, capillary breakdown and CADASIL-like sparse vascular smooth muscle cell coverage which was aggravated by hypertension. Retinographs from patients confirmed tortuous blood vessels and artery-vein crossings in ALGS. In conclusion, Jag1Ndr/Ndr mice could be used to develop interventions for vascular defects in ALGS, and retinography could provide a non-invasive method for vascular analysis in these pediatric patients.

developmental biology↗

DoUble resin Casting micro computed Tomography (DUCT) reveals biliary and vascular pathology in a mouse model of Alagille syndrome

BACKGROUND AND AIMSAlagille syndrome, like several other liver diseases, is characterized by malformation of lumenized structures, such as the circulatory or biliary systems. Liver architecture has typically been studied through 2D sections and, more recently, using thick tissue sections combined with immunofluorescence. We aimed to develop a robust method to image, digitalize and quantify 3D architecture of the biliary and vascular systems in tandem. METHODSThe biliary and portal vein trees of the mouse liver were injected with Microfil resin, followed by microCT scanning. Tomographic data was segmented and analyzed using a MATLAB script we wrote to investigate length, volume, tortuosity, branching, and the relation between the vascular and biliary systems. Double resin casting micro computed tomography (DUCT) was applied to a mouse model for Alagille syndrome (Jag1Ndr/Ndr mice), in which the biliary system is absent at postnatal stages, but regenerates by adulthood. Phenotypes discovered using DUCT were validated with cumbersome consecutive liver sections from mouse and human liver including patients with Alagille syndrome. RESULTSDUCT revealed tortuous bile ducts either placed further from portal veins, or ectopically traversing the parenchyma and connecting two portal areas, in Jag1Ndr/Ndr mice. Furthermore, bile ducts either ended abruptly, or branched independently of portal vein branching, with bifurcations placed hilar or peripheral to portal vein branches. The branching defects, parenchymal bile ducts, and blunt endings were confirmed in patient samples. CONCLUSIONDUCT is a powerful technique, which provides computerized 3D reconstruction of casted networks. It exposes and quantifies previously unknown vascular and biliary phenotypes in mouse models, revealing new phenotypes in patients. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/848481v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@1565121org.highwire.dtl.DTLVardef@1e86cfcorg.highwire.dtl.DTLVardef@4b4cc3org.highwire.dtl.DTLVardef@19cb20e_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗