We found that amoeboid cells of Dictyostelium are induced by a millimolar concentration of quinine to form a rapidly elongating, cylindrical protrusion, which often led to sustained locomotion of the cells. Formation of the protrusion was initiated by fusion of a contractile vacuole with the cell membrane. During protrusion extension, a patch of the contractile vacuole membrane stayed undiffuse...

Sexual dimorphism is common in nature and has the potential to increase intraspecific variation in performance and patterns of resource use. We sought to determine whether anadromous threespine stickleback, Gasterosteus aculeatus, exhibit sexual dimorphism in feeding kinematics. We filmed four males and four females consuming live prey in a total of 51 sequences filmed at 500 Hz, then tested fo...

Premaxillary protrusion in cypriniform fishes involves rotation of the kinethmoid, an unpaired skeletal element in the dorsal midline of the rostrum. No muscles insert directly onto the kinethmoid, so its rotation must be caused by the movement of other bones. In turn, the kinethmoid is thought to push on the ascending processes of the premaxillae, effecting protrusion. To determine the causes ...

Introduction Morgagni hernia is defined as the intrathoracic protrusion of abdominal viscera through a defect in the anterior diaphragm. It represents an uncommon type of diaphragmatic congenital hernia. Case presentation A 68-year-old female patient was admitted in our department due to progressive epigastric discomfort for the past four months. A preoperative diagnosis of a paraesophageal h...

The membranous labyrinth of the inner ear, with its three semicircular canals, originates from a simple spheroidal otic vesicle. The process is easily observed in Xenopus. The vesicle develops three dorsal outpocketings; from the two opposite faces of each outpocketing pillars of tissue are protruded into the lumen; and these paired 'axial protrusions' eventually meet and fuse, to form a column...

Cellular protrusion formation capacity is a key feature of developing neurons and many eukaryotic cells. However, the mechanisms underlying membrane growth in protrusion formation are largely unclear. In this study, photo-reactive unnatural amino acid 3-(3-methyl-3H-diazirin-3-yl)-propamino-carbonyl-Nε-l-lysine was incorporated by a genetic code expansion strategy into protrudin, a protein loca...

The protrusion of filopodia and lamellipodia from the surface of neurons is fundamental to axon extension, guidance, the formation of axon branches, and synaptic structures. Protrusion is driven by the polymerization and controlled organization of actin filament arrays. This chapter provides an overview of the basic mechanisms operative during protrusion. Mechanisms underlying the suppression o...

BACKGROUND We present two patients who developed severe protrusion of the conjunctiva and chemosis secondary to Harlequin ichthyosis (HI). CASE REPORTS Case 1 was a male infant diagnosed with HI who had parchment-like appearance and conjunctival protrusion with severe chemosis. Case 2 was a female infant on whom HI had been suspected before birth through ultrasonography. She showed thickened ...

Protrusion formation is an essential step during cell migration. Cells migrating in three-dimensional environments and in vivo can form a wide variety of protrusion types, including actin polymerization-driven lamellipodia, and contractility-driven blebs. The ability to switch between different protrusions has been proposed to facilitate motility in complex environments and to promote cancer di...

We model the regulatory role of proteins bound to looped DNA using a simulation in which dsDNA is represented as a self-avoiding chain, and proteins as spherical protrusions. We simulate long self-avoiding chains using a sequential importance sampling Monte-Carlo algorithm, and compute the probabilities for chain looping with and without a protrusion. We find that a protrusion near one of the c...