Ethanol has been described as a teratogen in vertebrate development. During early stages of brain formation, ethanol affects the evagination of the optic vesicles, resulting in synophthalmia or cyclopia, phenotypes where the optic vesicles partially or totally fuse. The mechanisms by which ethanol affects the morphogenesis of the optic vesicles are however largely unknown. In this study we make...

During copulation, spermatophores produced by male coleoid cephalopods undergo the spermatophoric reaction, a complex process of evagination that culminates in the attachment of the spermatangium (everted spermatophore containing the sperm mass) on the female's body. To better understand this complicated phenomenon, the present study investigated the functional morphology of the spermatophore o...

Flagellates of Naegleria gruberi have an interconnected flagellar apparatus consisting of nucleus, rhizoplast and accessory filaments, basal bodies, and flagella. The structures of these components have been found to be similar to those in other flagellates. The development of methods for obtaining the relatively synchronous transformation of populations of Naegleria amebae into flagellates has...

The light-sensing organelle of the vertebrate rod photoreceptor, the outer segment (OS), is a modified cilium containing approximately 1,000 stacked disc membranes that are densely packed with visual pigment rhodopsin. The mammalian OS is renewed every ten days; new discs are assembled at the base of the OS by a poorly understood mechanism. Our results suggest that discs are formed and matured ...

Sperm transfer in the Japanese ponerine ant Diacamma sp. was studied by making histologicalsections through copulatingpairs.Males of this species remain attached to the female by their genitalia for several hours, during which they are killed by the gamergate and her nestmates. Our sections revealed that males clasp the female’s last sternite with two chelate appendices of the male copulatory o...

Stationary phase cultures of Candida albicans inoculated into fresh medium at 37°C synchronously form buds at pH 4.5 and mycelia at pH 6.5. During bud formation, a filament ring forms just under the plasma membrane at the mother cell-bud junction at roughly the time of evagination. A filament ring also forms in myce}ium-forming cells, but it appears later than in a budding cell and it is positi...

Stationary phase cultures of Candida albicans inoculated into fresh medium at 37°C synchronously form buds at pH 4.5 and mycelia at pH 6.5. During bud formation, a filament ring forms just under the plasma membrane at the mother cell-bud junction at roughly the time of evagination. A filament ring also forms in myce}ium-forming cells, but it appears later than in a budding cell and it is positi...

The plasticity of pluripotent stem cells provides new possibilities for studying development, degeneration, and regeneration. Protocols for the differentiation of retinal organoids from embryonic stem cells have been developed, which either recapitulate complete eyecup morphogenesis or maximize photoreceptor genesis. Here, we have developed a protocol for the efficient generation of large, 3D-s...

The formation of membrane microparticles through vesiculation of the platelet plasma membrane is known to provide catalytic surface for several enzyme complexes of the coagulation system, and to underlie the procoagulant responses elicited with platelet activation. This induced shedding of vesicles from the plasma membrane is most prominent when platelets are activated by the terminal complemen...