Search results for "LIZARD"

Colour variation between different lineages of a colour polymorphic lizard

2019

First Data on the Molecular Phylogeography of Scincid Lizards of the Genus Mabuya

2000

A 487-bp fragment of the mitochondrial 16S rRNA gene was sequenced in 26 species of the circumtropical lizard genus Mabuya and used to analyze phylogenetic relationships within the genus. The species from Africa and Madagascar formed a monophyletic group relative to the included Asian and South American taxa. The Malagasy species included (M. elegans, M. cf. dumasi, and M. comorensis) did not appear as a monophylum. Combined and separate analysis of the 16S data and additional sequences of the mitochondrial 12S rRNA, ND4, and cytochrome b genes (a total of 2255 bp) in one Asian, two Malagasy, and two African species also did not result consistently in a monophyletic grouping of the Malagasy…

Retinal ganglion cells projecting to the optic tectum and visual thalamus of lizards.

2002

Retinal ganglion cells projecting to the optic tectum and visual thalamus have been investigated in the lizard, Podarcis hispanica. Injections of biotinylated dextran-amine in the optic tectum reveal seven morphological cell varieties including one displaced ganglion cell type. Injections in the visual thalamus yield similar ganglion cell classes plus four giant ganglion cells, including two displaced ganglion cell types. The present study constitutes the first comparison of tectal versus thalamic ganglion cell types in reptiles. The situation found in lizards is similar to that reported in mammals and birds where some cell types projecting to the thalamus are larger than those projecting t…

Serotoninergic innervation of nonprincipal cells in the cerebral cortex of the lizard Podarcis hispanica.

2004

The mechanism of serotoninergic transmission in the neo- and archicortex of mammals kis complex, including both synaptic and nonsynaptic components, direct actions on principal cells, and indirect effects mediated by GABAergic interneurons. Here we studied the termination pattern and synaptic organization of the serotoninergic afferents in the cerebral cortex of the lizard, Podarcis hispanica, which is considered to correspond in part to the mammalian hippocampal formation, with the aim of unraveling basic, phylogenetically preserved rules in the connectivity of this pathway. We demonstrate that serotoninergic afferents, visualized by immunostaining for serotonin itself, establish multiple …

Unusual change in activity pattern at cool temperature in a reptile (Sphenodon punctatus).

2014

Abstract Animals that can be active both during day and night offer unique opportunities to identify factors that influence activity pattern. By experimental manipulations of temperatures under constant photoperiod, we aimed to determine if emergence, activity and thermoregulatory behaviour of juvenile tuatara ( Sphenodon punctatus ) varied at different temperatures (20 °C, 12 °C and 5 °C). To help clarify its activity pattern, we compared tuatara with two lizard species endemic of the South Island of New Zealand for which activity pattern is known and clearly defined: the nocturnal common gecko Woodworthia “Otago/Southland” and the diurnal McCann׳s skink Oligosoma maccanni . Tuatara showed…

Ultraviolet reflectance and cryptic sexual dichromatism in the ocellated lizard, Lacerta (Timon) lepida (Squamata: Lacertidae)

2009

Ultraviolet (UV) colorations have garnered extensive theoretical and empirical treatment in recent years, although the majority of studies have concerned themselves with avian taxa. However, many lizards have acute visual systems with retinal photoreceptors that are sensitive to UV wavelengths, and also display UV-reflecting colour patches. In the present study, we used UV photography and full-spectrum reflectance spectrophotometry to describe intra- and intersexual colour variation in adult ocellated lizards Lacerta (Timon) lepida and to obtain evidence of UV-based ornamentation. We also investigated whether any colour traits correlate with morphological traits potentially related to indiv…

Osteology and relationships ofEolacerta robusta, a lizard from the Middle Eocene of Germany (Reptilia, Squamata)

2001

The osteology of the Eocene lizard Eolacerta robusta from Messel and Geiseltal is redescribed. Contrary to former opinions, Eolacerta does not possess body osteoderms, the pubis is typically lizard-like, the astragalus and calcaneum are fused, and the first cervical rib is distinctly curved posterolaterally. The suggestion that Eolacerta belongs to the modern family Lacertidae cannot be corroborated due to its many plesiomorphies and character incongruences, a view which is also supported by phylogenetic analysis. At present, Eolacerta cannot be assigned to any modern lizard family and is classified as Scleroglossa incertae sedis.

Zinc accumulation in the telencephalon of lizards.

1987

The zinc concentration in the brains of two species of lizard was determined by atomic-absorption spectrophotometry. The zinc concentration was found to be highest in the telencephalon of Lacerta galloti (21.1 micrograms/g fresh weight) and Podarcis hispanica (16.77 +/- 0.8 micrograms/g) while the mesencephalon and brain stem exhibited lower zinc concentrations, i.e., 7.0 micrograms/g in Lacerta galloti and 6.08 +/- 0.4 micrograms/g in Podarcis hispanica. This high telencephalic concentration of zinc is paralleled by intense and well-defined Timm reactivity used for demonstrating the presence of zinc-containing boutons at the light-microscope level. Volumetric-densitometric studies of these…

Imaging synaptic zinc release in living nervous tissue

2001

Zinc enriched neurons have a pool of synaptic vesicles which contain free or loosely-bound zinc ions. The movement of the vesicular zinc ions into the synaptic clefts has been previously studied by microdialysis, fluorescence postmortem staining for zinc and radioactive zinc isotope. In this study the zinc fluorescence probe N-6-metoxy-p-toluensulfonamide quinoline (TSQ) has been applied as a tracer of synaptic release of zinc ions. This fluorochrome permeates cell membranes and when exposed to living brain slices gives rise to a staining pattern similar to that seen with autometallography. In the living brain slices, fluorescence emission persists after exposure to calcium saturated ethyle…

CRMP-4 expression in the adult cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica.

2002

The control of neuritogenesis is crucial for the development, maturation and regeneration of the nervous system. The collapsin response-mediated protein 4 (CRMP-4) is a member of a family of proteins that are involved in neuronal differentiation and axonal outgrowth. In rodents, this protein is expressed in recently generated neurons such as some granule neurons of the dentate gyrus, as well as in certain differentiated neurons undergoing neurite outgrowth or synaptogenesis during adulthood. Since CRMP-4 protein appears to be highly conserved throughout the evolutionary scale, we have used immunocytochemistry to study its distribution in the lizard cerebral cortex. We have found pronounced …