Tarentola Annularis Research Articles

Cloning and expression of human IFN-γ in Leishmania tarentolae

Increasing therapeutic applications for recombinant human interferon-gamma (rhIFN-γ), an antiviral pro-inflammatory cytokine, has broadened interest in optimizing methods for its production. We herein describe a unicellular eukaryotic system, Leishmania tarentolae, a Trypanosomatidae protozoan parasite of gecko Tarentola annularis, which has recently been introduced as a candidate for heterologous gene expression. In this study, the hIFN-γ cDNA was amplified from phyto-hemagglutinin-stimulated peripheral blood mononuclear cells of a healthy blood donor using RT–PCR. In order to express, the rhIFN-γ protein, the resulting cDNA was cloned in two expression cassettes (each containing one copy of hIFN-γ cDNA) and integrated into the small subunit of ribosomal RNA gene of L. tarentolae genome by electroporation. Transformed clones were selected in the presence of appropriate antibiotics. Western blotting of rhIFN-γ and ELISA confirmed the expression and production of 9.5 mg of rhIFN-γ protein/l respectively.

Recombinant Protein Expression in Leishmania tarentolae

A variety of recombinant protein expression systems have been developed for heterologous genes in both prokaryotic and eukaryotic systems such as bacteria, yeast, mammals, insects, transgenic animals, and plants. Recently Leishmania tarentolae, a trypanosomatid protozoan parasite of the white-spotted wall gecko (Tarentola annularis), has been suggested as candidate for heterologous genes expression. Trypanosomatidae are rich in glycoproteins, which can account for more than 10% of total protein; the oligosaccharide structures are similar to those of mammals with N-linked galactose, and fucose residues. To date several heterologous proteins have been expressed in L. tarentolae including both cytoplasmic enzymes and membrane receptors. Significant advances in the development of new strains and vectors, improved techniques, and the commercial availability of those tools coupled with a better understanding of the biology of Leishmania species will lead to value and power in commercial and research labs alike.

Expression of human tissue plasminogen activator in the trypanosomatid protozoan Leishmania tarentolae

A variety of recombinant protein expression systems have been developed for heterologous genes in both prokaryotic and eukaryotic systems such as bacteria, yeast, mammals, insects, transgenic animals and transgenic plants. Also, it has been reported that Leishmania tarentolae, a trypanosomatid protozoan parasite of the white-spotted wall gecko (Tarentola annularis), has the capability of expressing heterologous genes. Trypanosomatidae are rich in glycoproteins, which can account for more than 10% of total protein. The oligosaccharide structures of their glycoproteins are similar to those of mammals with N-linked galactose, and sialic acid residues. For a variety of reasons, including the glycosylation patterns and the secondary structures of some of these proteins, synthesis in eukaryotic system is highly preferable. In addition, formation of native disulfide bonds in complex eukaryotic proteins is tremendously important. In the present study, we tried to express the tPA (tissue plasminogen activator) gene in L. tarentolae. This protein is a thrombolytic agent with 527 amino acid residues. tPA possesses serine-protease activity, with 35 cysteine residues that participate in the formation of 17 disulfide bonds. We have used an expression cassette, including the alpha intergenic regions of Leishmania major and two sites at the 3'- and 5'-ends, for homologous recombination in L. tarentolae, in addition to antibiotic-resistant genes. Southern-blot analysis showed that the human tPA gene had been inserted into the genome of the parasite. The expression of the tPA at the mRNA and protein levels was confirmed. It was shown that the expressed tPA in this system was 70 i.u. (international units)/ml of culture media, which is much higher than levels reported previously in other systems.

Retinal Photoreceptor Fine Structure in some reptiles

The structure of the photoreceptors of four different reptiles: the homed viper Cerastes cerastes (diurnal and nocturnal), the European Chameleo chameleon (diurnal), the gold skink Eumeces schneidrii (diurnal) and the Egyptian gecko, Tarentola annularis (nocturnal) has been investigated by light and electron microscopy. The photoreceptors of diurnal reptiles were mainly of the cone type and those of nocturnal were mainly rods. The ellipsoid region of both double rods in the nocturnals and large single cones in the species having both nocturnals and diurnal activity, consist of several mitochondria arranged in a remarkable radially gradient architecture which accommodates with the specific function of this region as a focusing device helping to condense light onto the outer segments. Moreover the principle cone of double cone and single cone of diurnal reptiles possessed a large oil droplet in the region between the inner segment and outer segment. This droplet is thought to play a role in filtering light and so doing enhanced contrast reduce glare and lessen chromatic aberration. It is worth to mention that the outer segment of rods in nocturnal reptiles approaches a length of approximately four folds the length of the inner segments of the same photoreceptors cells. This character is of a particular interest, since the outer segment is the site of photopigments and the increase in its length magnifies its ability of light and consequently accommodate with the night vision.

Retinal Photoreceptor Fine Structure in some reptiles

The structure of the photoreceptors of four different reptiles: the homed viper Cerastes cerastes (diurnal and nocturnal), the European Chameleo chameleon (diurnal), the gold skink Eumeces schneidrii (diurnal) and the Egyptian gecko, Tarentola annularis (nocturnal) has been investigated by light and electron microscopy. The photoreceptors of diurnal reptiles were mainly of the cone type and those of nocturnal were mainly rods. The ellipsoid region of both double rods in the nocturnals and large single cones in the species having both nocturnals and diurnal activity, consist of several mitochondria arranged in a remarkable radially gradient architecture which accommodates with the specific function of this region as a focusing device helping to condense light onto the outer segments. Moreover the principle cone of double cone and single cone of diurnal reptiles possessed a large oil droplet in the region between the inner segment and outer segment. This droplet is thought to play a role in filtering light and so doing enhanced contrast reduce glare and lessen chromatic aberration. It is worth to mention that the outer segment of rods in nocturnal reptiles approaches a length of approximately four folds the length of the inner segments of the same photoreceptors cells. This character is of a particular interest, since the outer segment is the site of photopigments and the increase in its length magnifies its ability of light and consequently accommodate with the night vision.

Behavioural ecology of the White-spotted Gecko, Tarentola annularis (Reptilia: Gekkonidae), in Ismailia City, Egypt

Aspects of the ecology of Tarentola annularis were studied in Ismailia City from August 1999 through July 2002. T. annularis is nocturnal, active throughout the year, with maximum activity in autumn. In hot months, T. annularis showed an irregular activity pattern, but in other months a unimodal pattern. T. annularis is a sit-and-wait predator, opportunistic, feeding upon a wide variety of prey with cockroaches and grasshoppers being the predominant prey. Food also included plant materials and spiders. T. annularis occasionally showed an active foraging behaviour and a tendency to cannibalism. T. annularis used different microhabitat types but, as a scansorial gecko, it was mainly found on walls and fences. Some individual geckos occupied the same place for weeks or months. The breeding season mainly extended from March through July. In the breeding season, the smallest gravid female measured 69 mm SVL and the smallest adult male with enlarged testes measured 60 mm SVL.

Glyceraldehyde 3-Phosphate Dehydrogenase Is an Enzyme-Crystallin in Diurnal Geckos of the Genus Phelsuma

Lenses from diurnal geckos, Phelsuma barbouri, Phelsuma madagascariensis grandis and Phelsuma serraticauda contain a prominent 37 kDa polypeptide (π-crystallin) that is not present in lenses from the nocturnal geckos, Gekko gekko, Hemidactylus garnoti, Tarentola annularis, and Uroplatus henkeli. This protein was partially purified from P. serraticauda and was identified as glyceraldehyde 3-phosphate dehydrogenase (GAPD). The GAPDs, which constitute 14-24% of the lens soluble protein in the diurnal species, were highly active. The presence of this enzyme in the lenses of diurnal, but not nocturnal, geckos supports the hypothesis that the oxido-reductases found as enzyme-crystallins may function in providing protection against the increased oxidative stress to which diurnal species are exposed. These findings strongly support the concept that the recruitment of enzyme-crystallins is a selective response to changes in the visual environment.

Chromosomes of Three Egyptian Lizards of the Family Gekkonidae (Squamata: Reptilia).

Chromosomal analysis of the three Egyptian species of the family Gekkonidae (Hemidac-tylus turcicus, Ptychodactylus hasselquisti and Tarentola annularis) have been studied. The diploid chromosome number of the three species is 2n=44, 2n=40 and 2n=42 respectively. All the chromosomes of the former species are acrocentrics while the latter two species have acrocentrics and microchromosomes. No differences were observed in the sex chromosomes of both sexes. Comparison of the karyotypic data of these species had been discussed.

Physalopteroides tarentolae n. sp. (Nematoda: Physalopteridae) from the gecko Tarentola annularis in the Sudan

Physalopteroides tarentolae n. sp. is described from the gecko Tarentola annularis in the area around Khartoum, Sudan. Light and scanning electron micrographs showed that P. tarentolae belongs to the group of Physalopteroides species with pronounced dentition on the right pseudolabium. P. tarentolae is also distinguished by the absence of spicules, the presence of 11 pairs of symmetrically arranged pedunculate caudal papillae, and the presence of the vulva, with a characteristic rectangular field of cuticular ridges, at the level of the oesophageo-intestinal junction.

Haemogregarina sp. (Apicomplexa: Adeleorina) from the geckoTarentola annularis in the Sudan: fine structure and life-cycle trials

The ubiquitous gecko Tarentola annularis in the area around Khartoum, Sudan, was found to be infected with Haemogregarina sp., with merogonic stages in its pulmonary endothelial cells and gamonts in its erythrocytes. The fine structure of Haemogregarina meronts, merozoites and gamonts revealed great conformity with the micromorphology of similar stages of other apicomplexan parasites. The unsuccessful transmission of Haemogregarina gamonts to the mosquitoes Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi is also reported.

Cristallisation de l'he´moglobine d'un reptile au cours de sa digestion chez un pentastomide

The hemoglobin of the lizard Tarentola annularis has been studied within erythrocytes being digested in the gut of a parasitic pentastomide, Raillietiella sp. The hemoglobin is crystallized in the form of bundles comprised of numerous tubules (up to 2000). These tubules are simple or complex. Simple tubules are 50 nm in diameter; their wall is made up of two electron-opaque rings, separated by a clear ring. Complex tubules are up to 100 nm in diameter and show as many as 13 concentric walls. High magnification of transverse sections of simple tubules show 96 granules; each opaque ring is made up of 48 granules. Human hemoglobin is known to crystallize as 18-nm tubules, the wall of which is made up of six molecules; comparison of these data with our observations indicates that transverse sections of tubules of crystallized lizard hemoglobin should contain 24 molecules. Thus, each molecule of crystallized lizard hemoglobin consists of four granules; these granules may be considered as globin molecules. Erythrocytes in fresh lizard blood do not show crystallized hemoglobin; however, in blood treated with sodium bisulfite, they show tubules similar to that found in the parasite.

Rhythmic activity, temperature‐tolerance, water‐relations and mechanism of heat death in a tropical skink and gecko

A comparison is made of the temperature‐ and water‐relations of the day‐active skink Mabuya quinquetaeniatus and nocturnal gecko Tarentola annularis. In darkness with regularly fluctuating temperatures M. Quinquetaeniatus is active during hot periods, T. annularis when the temperature falls. The lethal temperatures of both species for 24 hours exposure are around 40°C, but T. annularis can withstand a considerably higher degree of desiccation which may be correlated with its comparative lack of mobility. High sand temperatures are not avoided by either species until body temperatures rise. It is postulated that if heat‐death results from physiological oxygen deficiency, as previously suggested, some other cause, such as protein coagulation, must operate simulataneously.

Amoebae found in the intestine of lizards from the Sudan

1. The morphology of an Entamoeba from the Sudanese lizards Mabuya quinquetaeniata, M. striata and Tarentola annularis is described. It was similar to Entamoeba coli of man.2. It is referred to the species E. flaviviridis, Knowles & Das Gupta (1935).3. An ‘Amoeba’ was observed in Tarentola annularis which was similar in size to the Entamoeba. The nuclear structure, however, was distinctive, with a very large karyosome and no peripheral chromatin. The cysts were uninucleate.4. It is very similar to the organism described as Vahlkampfia reynoldsi by McFall (1926).

Caudal ribs in geckos.

DURING a comparative study of the osteology of some Egyptian geckos, including Stenodactylus stenodactylus, Tropiocolotes tripolitanus, T. steudneri, Ptyodactylus hasselquistii, Hemidactylus turcica, Tarentola mauritanica and T. annularis, a rather interesting detail concerning the caudal region of the vertebral column was observed, which has not previously been recorded in living Lacertilia, so far as we are aware. It concerns the presence of caudal ribs in geckos. Among the above-mentioned species, such ribs were found in both Tarentola annularis and Ptyodactylus hasselquistii.

H˦moproteus of Tarentola annularis

Journal Article Hæmoproteus of Tarentola Annularis Get access D. Riding, M.D., M.R.C.S., L.R.C.P. D. Riding, M.D., M.R.C.S., L.R.C.P. Government Bacteriologist, Wellcome Tropical Research Laboratories, Khartoum, Sudan Search for other works by this author on: Oxford Academic PubMed Google Scholar Transactions of The Royal Society of Tropical Medicine and Hygiene, Volume 23, Issue 6, April 1930, Pages 635–636, https://doi.org/10.1016/S0035-9203(30)80029-4 Published: 01 April 1930