Tetraspanin Cd9b and Cxcl12a/Cxcr4b have a synergistic effect on the control of collective cell migration

Collective cell migration is essential for embryonic development and homeostatic processes. During zebrafish development, the posterior lateral line primordium (pLLP) navigates along the embryo flank by collective cell migration. The chemokine receptors, Cxcr4b and Cxcr7b, as well as their cognate ligand, Cxcl12a, are essential for this process. We corroborate that knockdown of the zebrafish cd9 tetraspanin orthologue, cd9b, results in mild pLL abnormalities. Through generation of CRISPR and TALEN mutants, we show that cd9a and cd9b function partially redundantly in pLLP migration, which is delayed in the cd9b single and cd9a; cd9b double mutants. This delay led to a transient reduction in neuromast numbers. Loss of both Cd9a and Cd9b sensitized embryos to reduced Cxcr4b and Cxcl12a levels. Together these results provide evidence that Cd9 modulates collective cell migration of the pLLP during zebrafish development. One interpretation of these observations is that Cd9 contributes to more effective chemokine signalling

CXCR7 influences leukocyte entry into the CNS parenchyma by controlling abluminal CXCL12 abundance during autoimmunity

During CNS autoimmunity, brain endothelial cell CXCR7 internalizes CXCL12 from the perivascular space, thereby permitting leukocyte migration into the CNS parenchyma

A median fin derived from the lateral plate mesoderm and the origin of paired fins

The development of paired appendages was a key innovation during evolution and facilitated the aquatic to terrestrial transition of vertebrates. Largely derived from the lateral plate mesoderm (LPM), one hypothesis for the evolution of paired fins invokes derivation from unpaired median fins via a pair of lateral fin folds located between pectoral and pelvic fin territories1. Whilst unpaired and paired fins exhibit similar structural and molecular characteristics, no definitive evidence exists for paired lateral fin folds in larvae or adults of any extant or extinct species. As unpaired fin core components are regarded as exclusively derived from paraxial mesoderm, any transition presumes both co-option of a fin developmental programme to the LPM and bilateral duplication2. Here, we identify that the larval zebrafish unpaired pre-anal fin fold (PAFF) is derived from the LPM and thus may represent a developmental intermediate between median and paired fins. We trace the contribution of LPM to the PAFF in both cyclostomes and gnathostomes, supporting the notion that this is an ancient trait of vertebrates. Finally, we observe that the PAFF can be bifurcated by increasing bone morphogenetic protein signalling, generating LPM-derived paired fin folds. Our work provides evidence that lateral fin folds may have existed as embryonic anlage for elaboration to paired fins

An impact of CNTs on an MHD Casson Marangoni boundary layer flow over a porous medium with suction/injection and thermal radiation

The current work employs the single wall and multiwall carbon nanotube models to investigate the effect of suction and injection over a Marangoni boundary layer flow on magnetohydrodynamics (MHD) Casson fluid and thermal radiation on a permeable surface. The nonlinear partial differential equations (PDEs) produced by the governing equations for the prescribed flow are translated using the proper similarity transformations into a system of nonlinear ordinary differential equations (ODEs). The consequential nonlinear equation is solved analytically by using incomplete Gamma function. The effects of suction and injection over velocity profile and temperature distribution are presented graphically. It was found that the heat transfer rate increased due to increases in the volume fraction. In addition, the applied magnetics energy, on the other hand, causes it to decrease. Further, single wall carbon nanoliquid has a higher temperature than multiwall nanoliquid. The problem under consideration has a wide range of commercial and scientific applications in various industries like aviation and medicine field. The impacts of MHD and suction/injection on the flow and heat transfer properties of the fluid are examined under the influence of radiation, and the solution of each profile is shown in the form of figures along with the outcomes of the interface velocity and heat transfer rate at the surface

An MHD effect on a newtonian fluid flow due to a superlinear stretching sheet

The preliminary aim of this article is to investigate the effect of magnetohydrodynamic (MHD) flows of a viscous fluid due to a superlinear stretching sheet. These boundary layer flows arise in the industrial processes such as polymer extrusion processes, metal spinning, glass blowing and heat exchangers. The representing frameworks of highly nonlinear partial differential equations are mapped to nonlinear ordinary differential equations with a constant coefficient via similarity transformation and are solved analytically. The results are analyzed by means of various plots to provide the comparison and found to be in better agreement with the classical results of Crane and Pavlov. The viscous fluid due to a superlinear stretching sheet in the presence ofMHDhas enormous amount of nonlinearity in conducting the solution area with different arrangements.27450150

Woolly hair with trichoscopic features

Woolly hair is the presence of more or less tightly coiled hair over the scalp of persons of non-African or Negroid background. A 3-year-old girl presented with woolly hair since birth. She had no other systemic abnormality. Trichoscopic examination of the scalp hairs revealed slight variation in the thickness of hair shafts, which was well visualized in an individual plucked hair. Broken hair shafts were visible. We are presenting this case due its sheer rarity and for its trichoscopy findings. Tricoscopy is better alternative than light microscopy for hair shaft abnormality as it allows visualizing multiple hairs without plucking it