Journal of Basic and Applied Zoology最新文献

Reciprocal cross effects with respect to larval salivary secretory protein levels were studied in the interspecific fertile reciprocal hybrids by crossing Drosophila nasuta nasuta, and Drosophila nasuta albomicans. These proteins are produced copiously during the third larval instar stage and are believed to play a role in the attachment of pupa to the substratum prior to pupariation as well as in insect immunity. Quantitative variations were encountered among the reciprocal hybrids. Significant heterosis was observed between D. n. nasuta and the F₁ hybrid female of a cross between D. n. albomicans female and D. n. nasuta male (21.39%) while the F₁ hybrids of a cross between D. n. nasuta female and D. n. albomicans male showed a marginal increase (4.24%) from the mid parent level. The glue secretions were correlated to total cell number but independent of gland size. SDS PAGE revealed a considerable heterosis with respect to X-linked protein fractions. Here we report sex specific biochemical heterosis. However the X-linked fractions undergo dosage compensation in both parents and hybrids indicating strict regulatory control.

Cotton seed based artificial diet has been standardized for continuous rearing of pink bollworm Pectinophora gossypiella (Saunders) at the Central Institute for Cotton Research, Regional Station, Coimbatore. The ingredients of the diet are easily available and are cost effective. Basic ingredients of the diet are cotton seed flour (processed) and chick pea flour, Carbohydrate, Protein, Fat sources, multi vitamin, antimicrobial agents and agar as thickening agent are used as other ingredients. Micro centrifuge tubes with lid were used as rearing containers. Individual neonate larvae were released on each piece of the diet inside the micro centrifuge tube and the lids were closed. This prevented larval escape, retaining them inside the tubes and also prevented diet dehydration. The recovery of insect reared on diet was recorded as 95.56%. Egg hatchability and adult emergence were 100% while pupal malformation was nil. Eggs, larval and pupal periods were recorded as 4.8 ± 0.632, 25.10 ± 0.994 and 7.9 ± 0.88 days, respectively. Larval and pupal weights were recorded as 21.40 mg ± 3.63, 18.00 mg ± 2.73, respectively.

Scorpion venom is a complex mixture of components with various pharmacological and toxicological effects. It is characterized by the presence of a large number of toxins that specifically interact with ion channels of excitable cells. The Egyptian scorpion Androctonus bicolor belongs to the family of Buthidae and until now no information is available about the effect of its venom on cardiac muscles. Using an in vitro approach, cardiotoxicity and mode of action of A. bicolor venom on isolated toad’s heart were investigated. Direct application of scorpion venom (0.5 μg/ml) into isolated toad’s heart induced a remarkable bradycardia concomitant with a protraction in the conduction time (P–R interval). In the meantime, a significant increase in the R-wave amplitude (ventricular contraction) was noticed after 5 min of venom perfusion. Various cases of cardiac disorders were recorded such as sinus arrhythmias, ectopic beats and different degrees of heart block. Through using different autonomic and ion channel blockers, the possible mechanism of action of A. bicolor venom on isolated toad’s heart was revealed. The application of both atropine (4 μg/ml) and verapamil (5 μg/ml) could not alleviate the pronounced negative chronotropic and positive inotropic effects. Meanwhile, a significant decrease in the R-wave amplitude was observed after propranolol (5 μg/ml) application. In conclusion, our findings indicate that the venom of A. bicolor directly influenced the cardiac electrical activity of toads through β-adrenergic receptors. The direct effect of this venom on cardiac tissues may significantly contribute in the development of several cardiotoxic effects following scorpion sting.

The tilapia Oreochromis mossambicus shows a series of short ovarian cycles throughout the year. The present study examined the impact of low intensity ambient natural light (ANL) in indoor environment on the follicular developmental status and the spawning cycle of O. mossambicus. The stripped fish (eggs removed manually, day 1) held outdoors in direct natural light (DNL) successfully spawned between 24 and 28 days, whereas those reared in ANL failed to spawn despite the presence of a significantly higher number of stage V (vitellogenic) follicles in the ovary compared to that of DNL during the prespawning phase (day 23). These fish did not spawn even up to day 50. The profile of serum levels of cortisol did not show a significant difference between the two experimental conditions. On the other hand, the serum levels of estradiol (E₂) were significantly higher during vitellogenic phase (day 18) compared to previtellogenic phase (day 12) in both experimental fish. In fish exposed to DNL, the serum levels of E₂ decreased prior to spawning, but remained significantly higher in fish exposed to ANL, suggesting the possible absence of a steroidogenic shift prior to spawning. The results reveal that lack of a critical environmental cue such as the light signal might affect the spawning cycle by causing alterations in the ovarian steroidogenic activity, for the first time in a continuously breeding fish such as O. mossambicus.

The present study was undertaken to evaluate the median lethal concentration (LC₅₀), morphological deformities and changes in behavioural responses caused by commercial formulations of malathion on Duttaphrynus melanostictus tadpoles. The LC₅₀ value was found to be 7.5 mg/l and ability of malathion to cause morphological anomalies and changes in behavioural responses in tadpoles were studied at sublethal concentrations of 0.5 mg/l (1/15th), 0.75 mg/l (1/10th) and 1.5 mg/l (1/5th) for a duration of 5 days. The morphological defects and changes in behavioural responses like notochord curvature and loss of fright response respectively were witnessed as an important conduct; in addition, other symptoms under both the parameters were known to be time (i.e. developmental stage) and concentration dependent thereby acknowledging the direct cause of damage due to malathion. Thus, based on the present study, care must be taken when this chemical is in use at agricultural sites especially nearby aquatic ecosystems.

Nile tilapia; Oreochromis niloticus was used as a bio-indicator to evaluate the impact of zinc metal. The potential impacts of zinc nanoparticles (Zn NPs) on aquatic ecosystems have attracted special attention due to their unique properties. The present investigation was designed to evaluate and compare between the possible ecotoxicological effects of zinc bulk particles (BPs) and Zn NPs on O. niloticus. LC50/96 h of Zn (BPs & NPs) were (1.36 & 0.18 g/l), respectively. The concentration equivalent to 1/2 LC50/96 h of Zn BPs (0.68 g/l) and Zn NPs (0.09 g/l) was selected for 7, 14 & 28 days. Exposure of the studied fish to 1/2 LC50/96 h of Zn BPs & Zn NPs elicited a significant decrease in total lipids, total protein and globulin contents, coinciding with an enhancement in serum glucose, albumin, creatinine and uric acid concentrations, as well as activities of liver enzymes named AST, ALT, and ALP after the experimental periods. Moreover, Zn NPs significantly induced an increase in liver and gills glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels and with concomitant decreases in the liver and gill (GSH) level in the studied fish. The adverse effects of NPs were observed to be time dependent with increasing extent during the studied time intervals, while fish groups treated with BPs showed more or less time dependent effects. In conclusion, Zn NPs have stronger toxic impacts than that of the Zn BPs, and increased with prolonged exposure time.

The use of steroid-treated feeds as 17 α-methyltestosterone for the production of all-male populations is widespread in tilapia aquaculture. The aim of the present study was to investigate the misuse effects of methyltestosterone on monosex farmed Nile tilapia, Oreochromis niloticus by evaluation of hematological and biochemical values. The fishes were obtained from four localities (Assiut as a control, Beheira, Alexandria and Kafr el-Sheikh: three farms from each governorate as farmed monosex produced using methyltestosterone). The total erythrocyte count, hemoglobin rate, hematocrit percentage, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), white blood cell count, blood platelets, lymphocyte, monocyte, neutrophils and basophils were determined. The results showed that there were changes in the erythrocytic series and in the defense white blood cells. Activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), glucose, cholesterol, total protein, uric acid and creatinine were determined for biochemical study. These alterations are considered an indication for performance and health of fish in the monosex culture medium indicating the side effects of overdose induction of MT.

The present study was undertaken to examine the relative contribution of the SR-Ca²⁺ release and sarcolemmal Ca²⁺ channels in developing the cardiac force at two different temperatures (20 and 30 °C) in the catfish (Clarias gariepinus).

The sarcolemmal Ca²⁺ contribution of activator Ca²⁺ was greater at a test temperature of 30 °C as assessed by verapamil. Whereas the SR-Ca²⁺ contribution was higher at 20 and 30 °C and a frequency rate of 0.2 and 0.4 Hz as assessed by caffeine and adrenaline, respectively. Bradykinin potentiating factor (BPF₇) which was isolated from jelly fish (Cassiopea andromeda) decreased the cardiac force developed at a frequency rate of 0.2 Hz and a temperature of 20 °C, whereas it increased the force developed at frequency rates of 0.2 and 0.4 Hz at 30 °C. These results indicate that BPF₇ may act like verapamil in reducing the cardiac force through blocking the sarcolemmal Ca²⁺ channels at low temperature and like adrenaline in an increase of the cardiac force developed at warm temperature and the high frequency rate through stimulation of SR-Ca²⁺ activator. Therefore, this study indicates that the sarcolemmal Ca²⁺ influx and the SR-Ca²⁺ release contributors of activator Ca²⁺ for cardiac force development in the catfish heart were significantly greater at warm temperature and at the pacing frequency rates of 0.2 and 0.4 Hz as assessed by verapamil, adrenaline, caffeine and BPF₇. However, the relative contribution of the sarcolemmal Ca²⁺ influx in the development of cardiac force in the catfish heart was greater than that of SR-Ca²⁺ release.

The present study aims to evaluate the possible protective role of polysaccharides extracted from the Egyptian mango Mangifera indica L. (MPS) and silymarin against cyclophosphamide (CP) nephrotoxicity in male albino rats. Male rats were randomly divided into, control group (administered distilled water orally for 10 days) and MPS (500, 1000 mg/kg, p.o.) and/or silymarin (150 mg/kg, p.o.) treated groups for 10 days. In the last 5 days of treatment rats were administered CP (150 mg/kg, i.p). The MPS revealed significant prophylactic effect against kidney injury induced by CP as demonstrated by enhancement of the kidney function via decreasing serum creatinine, urea and uric acid. Treatment of rats with MPS extract and/or silymarin significantly increased the level of reduced glutathione (GSH) and superoxide dismutase (SOD) activity while decreased the level of total malondialdehyde (MDA) and glutathione-S-transferase (GST). Also, histopathological examinations confirmed the protective efficacy of MPS and/or silymarin against CP nephrotoxicity. In conclusion, the obtained results of the present study support the protective antioxidant role of MPS and/or silymarin against CP-induced kidney disorder in rats.

Many traditional plants have been used to fight life-threatening diseases such as diabetes. These plants have been shown to possess antioxidant activities, improving the diabetes inconveniences. Wister albino rats became diabetic by streptozotocin (STZ) induction. The effect of 200 mg/kg ethanolic extracts of either Cinnamomum zeylanicum bark (CZ) or Syzygium cumini seeds (SC) was investigated on STZ-induced diabetic rats. The impact of CZ or SC administration was observed. Blood glucose, insulin level, hemoglobin content, lipid profile, liver and kidney functions, and antioxidant enzymes in plasma were evaluated. Diabetic rats exhibited an increase in the levels of blood glucose, total cholesterol, triglycerides and low density lipoprotein cholesterol (LDL-cholesterol). In contrast, the levels of insulin and high density lipoprotein cholesterol (HDL-cholesterol) were diminished.

The oral administration of CZ and SC showed a decrease in glucose level, total cholesterol, triglycerides, and LDL-cholesterol, whereas an increase in insulin level and HDL-cholesterol were recorded. What’s more, the antioxidant enzymes in diabetic control rats showed significantly abnormal activities of low superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPx) activities and reduced glutathione (GSH) compared to treated diabetic rats. Also, in the extent of lipid peroxidation (LPO).

Both CZ and SC possessed antioxidant activity as shown by elevated SOD and GPx activities and reduction in LPO. CZ and SC are functioning to improve the level of insulin, hyperglycemia, hyperlipidemia, oxidative stress and kidney and liver dysfunctions in STZ-induced diabetic rats.