Ultrastructural differentiation of sperm tail region in Diplometopon zarudnyi (an amphisbaenian reptile).

Diplometopon zarudnyi, a worm lizard belongs to amphisbaenia under trogonophidae family. This species exists in limited areas of the Arabian Peninsula and is an oscillating digger found in sub-surface soils. The present study aimed to investigate the sperm tail differentiation in D. zarudnyi. Ten male adults of D. zarudnyi were collected from Riyadh during April-May 2011. To study the sperm tail at the ultrastructural level the testes were fixed in 3% glutaraldehyde, than post fixed in 1% osmium tetaroxide followed by dehydration in ethanol grades; samples were cleared in propylene oxide and embedded in resin. Tail formation begins by the moving of centrioles and mitochondria towards the posterior pole of sperm head. Simultaneously many microtubules of the midpiece axoneme were enclosed by a thick layer of granular material. Mitochondria of midpiece lie alongside the proximal centriole which forms a very short neck region and possess tubular cristae internally and concentric layers of cristae superficially. During this course a fibrous sheath surrounds the axoneme of mid and principal piece. At the end dissolution of longitudinal manchette takes place. The mitochondria then rearrange themselves around the proximal and distal centrioles to form a neck region. Later, the fibrous sheath surrounds the proximal portion of the flagella. This part along with sperm head of D. zarudnyi provides a classical model that could be used in future for evolutionary and phylogenetic purposes of class reptilia.

Reproductive biology of the horned viper, Cerastes cerastes gasperettii in the central region of Saudi Arabia.

The reproductive biology of the horned viper, Cerastes cerastes gasperettii, in Riyadh region of Saudi Arabia was investigated over a period of one year. Study of reproductive cycle of male and female C. c. gasperettii revealed that the breeding season is relatively short (April and May). Thereafter females laid eggs by mid of July and hatching probably had taken place by the end of September. No activity was observed during winter, this may indicate just a single clutch per year. Relative testis weight to body weight was drastically increased ([Formula: see text] = 0.88%) during the peak of reproductive activity (May) where maximal expansion of seminiferous tubules was also attained during April and May ([Formula: see text] = 209 µm and 191 µm, respectively). Likewise, the ovarian activity was the highest during May where ovarian parameters were greater in terms of relative ovarian weight to body weight and ova diameter being 0.46% and 2.29 mm, respectively. Fat body weight was increased drastically just before the peak of reproductive activity then started to decline during June. It could be concluded that the harsh desert conditions and similar environments certainly affect reproductive activity of Saudi Arabian reptiles including snakes.

Increased Antioxidant Potential and Decreased Free Radical Production in Response to Mild Injection of Crude Venom, Cerastes cerastes gasperetti.

ABSTRACT The purpose of this study was to examine the effects of Cerastes cerastes gasperetti crude venom (CCV) on free radical (FR) production and biological antioxidant potential (BAP). Thirty male rats, matched with age and weight, were divided randomly into three groups: control (C), negative control (NC), and experimental (E). Animals in the control group served as control for needlestick and venom injection. Animals in the negative control group, which served as control for venom-induced effects, were injected intraperitoneally (IP) with saline for 8 days, whereas animals of the experimental group were injected IP with crude CCV, at a dose of 1/4 LD(50), for the same period. All animals of the three groups remained under normal laboratory and dietary conditions. Blood samples were collected by heart puncture technique and were analyzed immediately for FRs and BAP. ANOVA analysis indicated a significant difference (p < 0.05) among group means. Tukey-Kramer multiple comparisons showed that FRs increased significantly (p < 0.05) in the NC group, implying that needlestick during injection of saline for 8 days caused internal organ injury sufficient enough to induce reactive oxygen species (ROS) generation. Surprisingly, there were no significant (p > 0.05) changes in FRs in the E group as compared with the C group, which indicates that CCV counteracted the effects induced by ROS. BAP increased significantly (p < 0.05) in the E group as compared with the NC group, reflecting the activation of some antioxidant enzymes. Linear regression of FRs on BAP was significant (p < 0.05) in both the C and E groups. Based on the results of this study, it can be concluded that the CCV contains biochemical factors that activate antioxidant enzymes, as evident by elevation in the BAP that depresses ROS formation.

Blood parasites of five species of lizards trapped in Abha Province, Saudi Arabia.

Five species of lizards, Agama yemenensis, A. adramitana, Chamaeleo chamaeleon, C. calyptratus and Acanthodactylus baskinaus were trapped alive from Abha Province. Serological and parasitological examinations of blood revealed antibodies against toxoplasmosis and leishmaniasis. Blood films showed Hepatozoon spp. The results were discussed with reference to their role as reservoir hosts.

Eimeria schmidti n. sp. (Apicomplexa: Eimeriidae) from the sandy fringe-toed lizard (Acanthodactylus schmidti) in Saudi Arabia.

Eimeria schmidti n.sp. is described from the gall bladder of Acanthodactylus schmidti from Al-Thomama area in the central region of Saudi Arabia. Sporulated oocysts are ellipsoid 31.2 x 23.3 (26.9-36.4 x 21.2-26.0). Oocyst wall is smooth, greenish yellow, 1.31 (1.16-1.41) um thick and two-layered. Micropyle, polar granule and oocyst residuum are absent. Sporocysts are ellipsoid 12.6 x 9.3 (10.9-14.1 x 7.6-10.0) um. Sporocyst residuum is present. The sporocysts lack a stieda body. Sporozoites are banana shaped blunt at one end and tapered at the second end. Eimeria species from Lacertidae are compared.

The effect of crude Cerastes cerastes gasperetti venom on the activity of key metabolic enzymes in cultured human fibroblasts.

Cultured human fibroblasts were used to study the effect of a crude extract of Cerastes cerastes gasperetti venom on the activity of a profile of key enzymes of metabolism. A single concentration of the crude venom was incubated with confluent fibroblasts established from six normal subjects for a period of three hours. A dramatic reduction in the specific activities of glucose and glycogen degradative enzymes was observed (23.7 +/- 3.9%, 36.3 +/- 8.7% and 71.1 +/- 5.7% of control for citrate synthase, glucose-6-phosphate and phosphofructokinase respectively). Furthermore, the specific activity of creatine kinase was doubled. No significant change in activity of three transaminases was noticed. Incubation of the same concentration of venom for the same period of time with serum did not result in any change in the activity of the enzymes studied. It is suggested that the cells mobilize stored phosphocreatine for the production of adenosine triphosphate (ATP) to compensate for the reduced rate of sugar catabolism. Furthermore, it is hereby suggested that the effects noticed on the enzyme activities are not directed at the enzyme protein itself, but are of mediated nature.

Effect of gonadal steroid hormones on the metabolic rate of the cold-acclimated gonadectomized male and female Chalcides ocellatus (Forskal).

Male and female Chalcides ocellatus were gonadectomized and cold acclimated at 15 degrees for 1 week. Lizards were injected with testosterone and estradiol, and their oxygen consumption was determined at 15 degrees. Testosterone and estradiol caused a significant increase in the whole body rate of oxygen consumption in male and female lizards, respectively.

The effect of thyroxine on the oxygen consumption of the ocellated skink, Chalcides ocellatus (Forskal).

Acutely administered thyroxine caused significant increase in the whole body rate of oxygen consumption of C. ocellatus at temperatures between 4 and 25 degrees C. No significant increase in the oxygen consumption was observed over the voluntary body temperature range of 30-40 degrees C.

Influence of a broad temperature range on the oxygen consumption rates of three desert lizard species.

Oxygen consumption rates of three desert lizard species: (Acanthodactylus boskianus, Lacertidae; Scincus mitranus, Scincidae; Diplometopon zarudnyi, Amphisbaenidae) were determined in relation to ambient temperatures ranging from 10 to 35 degrees C using a double-chamber, volumetric closed system. The interspecific differences in the oxygen consumption rates were found to have a close relationship between the characteristics of the M-T curves, the thermoregulatory behaviour and the ecology of the respective species. The M-T curves of the studied lizards were specifically modified and adjusted to their climatic region.

Comparison of thermal acclimation effects on the metabolism of Chalcides ocellatus (desert lizard) and Lacerta vivipara (cool-temperate lizard).

The ocellated lizard, Chalcides ocellatus, and the common lizard, Lacerta vivipara, were acclimated to two temperature regimes (10 and 30 degrees C with 12L:12D photoperiod) for 2 weeks. The oxygen consumption rates were measured for both species at temperatures between 5 and 35 degrees C. Cold acclimation was observed in L. vivipara and was in the form of an upward translation of the metabolic rate-temperature curve in comparison to the warm-acclimated lizards (30 degrees C). Chalcides ocellatus showed a response to cold acclimation by decreasing its metabolism only at 10 degrees C.