Morphometric study of the testis in sheep embryos using unbiased design-based stereology

Sheep have been used as translational models of human postnatal testicular development. However, the morphometric features of the normal developing testis in sheep embryos have not been previously investigated using stereology. The objective of the present work was to establish normal quantitative parameters for fetal testicular tissue components in sheep, using unbiased design-based stereological methods. Twenty-four sheep embryos were divided into four gestational age groups (9–11, 12–14, 15–17 and 18–20 weeks of gestation) on the basis of the embryos’ crown-rump length. Isotropic, systematic uniform random sections of the left testes were obtained by employing the orientator method. Testicular total volume, the absolute and proportional volumes occupied by the seminiferous tubules and interstitial tissue, as well as the seminiferous tubule length, were estimated using the point-counting system and the unbiased counting frame principle. All the parameters, with the exception of the interstitial tissue's fractional volume, gradually increased along with gestational age, with the maximum increase especially seen in the late fetal stages. The proportional volume of the interstitial tissue, on the other hand, showed a decreasing trend along with increasing gestational age. The absolute volume of the testes, of the seminiferous tubules and of the interstitial tissue, and the length of the seminiferous tubules showed a significant (p< 0.05) positive linear correlation with gestational age. Several similarities were observed with human testicular embryogenesis. The stereological data emerging from the present study might prove useful as basic contribution to the fields of andrology and embryology and stimulate further research in these areas.     

Seasonal morphology and immunoreactivity of cytokeratin and atrial natriuretic peptide in dromedary camel poll glands

Poll glands are characteristic feature of dromedary camels; although they yield a yellowish offensive secretion, especially during rutting (breeding) season, their function is not yet exactly specified. The present study shows the seasonal morphology and immunoreactivity of cytokeratin (CK) and atrial natriuretic peptide (ANP) in the camel poll gland; the result could clearly specify the role of the gland in camel reproduction. Poll glands are compound tubulo-alveolar in structure. During rutting season, the secretory units showed wide lumina and simple squamous epithelium surrounded by myoepithelial cells; the lumina became narrower and the epithelium changed to simple cuboidal during non-rutting season. Many glandular lobules showed abundant interlobular connective tissue with fewer and smaller secretory units during non-rutting season compared to rutting season. Positive CK and ANP immunoreactivity was detected in the cytoplasm of epithelial cells of secretory units and ducts together with the myoepithelial cells and blood vessels. Although CK immunoreactivity was more intense during rutting season in comparison to non-rutting season, there was no seasonal variation in ANP immunoreactivity. During both seasons, while the glandular capsule, connective tissue septa, interstitium showed negative CK immunoreactions, they reacted moderately to ANP. In conclusion, the poll gland undergoes annual structural and functional changes which are suggested to correlate with the male seasonal sexual behaviour. Further, the biological role of CK and ANP proteins together with their immunohistochemical expression in the camel poll gland suggests a stimulatory effect in the glandular secretory cells, and hence, they might modify camel sexual activity.     

Does timing of daily feeding affect growth rates of juvenile three‐spined sticklebacks,Gasterosteus aculeatus L?

Abstract – To assess the consequences of unpredictability in the availability of food, this study measured the effect of timing of the daily feeding on food consumption and growth rates of juvenile Gasterosteus aculeatus. The experiment lasted 21 days at 14 °C and a photoperiod of 10 hours of light and 14 hours of dark. Fish were housed individually and allocated at random to three treatments. The mean initial weight of fish was 0.402 g. Group 1 were fed live enchytraeid worms for 2 h after lights came on ("morning"), group 2 was offered food for 2 h randomly at any time of the day ("random") during the light period and group 3 received food for 2 h before the lights went off ("evening"). There was no significant effect of timing of feeding on mean daily food consumption, which was 0.052 g day⁻¹. Daily consumption on the random schedule was more irregular than on the two fixed schedules. Timing of feeding had no significant effect on mean specific growth rate (G) (2.42% day⁻¹), gross growth efficiency (23.3%), white muscle RNA:DNA ratio (5.6), carcase lipid content (31.7% dry wt) and carcase dry matter content (27.4% wet wt). Thus, a lack of predictability in the availability of food during the light period of the day did not impose a detectable cost on the growth performance of the stickleback.     

Effect of low level of dietary aflatoxins on baladi rabbits

Aflatoxins B1, B2, G1 & G2 were administered in a low concentration (100 ppb of each aflatoxin (AN] in a mash offered to Baladi rabbits. An other group of rabbits were fed on the same contaminated mash in addition to 0.25% charcoal (CC). The two groups were compared to control animals fed on AN-free mash. Inclusion of AN in the diet decreased feed and water consumption, body weight and survival rate. Charcoal improved somewhat feed and water consumption and growth rate than AN-group. However, CC-group affected digestibility of organic matter more than AN-group. Relative weights of liver, kidneys, heart and adrenal glands were significantly higher in AN and CC groups than the control group. Blood haemoglobin content, packed cell volume percentage and sedimentation rate were lower in AN group. Although there were an increase in each of serum, calcium, inorganic phosphorus, cholesterol, phospholipids and glutamic-pyruvic transaminase in AN group, yet the serum nitrogen and glutamic-oxalacetic transaminase were reduced. Charcoal had alleviated AN-effects concerning N, GPT and phospholipids. Chemical analysis revealed elevation of water, ash and silica contents of liver and water content of muscles from AN-animals. On the other hand, fat content, GOT and vitamin A in the liver as well as muscles ash were reduced. Addition of CC to the diet reduced AN-effects on liver fat, ash and silica but resulted in a rise of the water content of liver and muscles and liver GPT activity. Charcoal also resulted in a sharp decrease in vitamin A content of the liver. Aflatoxin treatments (in AN and CC groups) reduced bone ash, silica and magnesium as well as bone volume. Charcoal administration increased Ca-content of bones. Aflatoxin feeding (in AN group) resulted in a high residual percentage of AN in muscles, serum, liver, heart and kidneys with relationships of 51 :24 : 3 :2 : 1, respectively. Only 1.42% of the fed AN was excreted in the faeces. Charcoal usage had a good effect as it prevented AN to accumulate in the organs. Aflatoxin contaminated diets (in AN and CC groups) resulted in paralysis, disorder of fat deposition, discolouration and haemorrhages of some organs. Scanning electron microscopic examination revealed no ill effect on the surface structure of the small intestine due to either AN or AN + CC. Pathological examination showed that the main affected organs were liver, heart and spleen, respectively. The changes include hepatic round cell infiltration, irregularities of lobular plats, focal necrosis and periportal fibrosis.(ABSTRACT TRUNCATED AT 400 WORDS)     

A cluster of metabolic defects caused by mutation in a mitochondrial tRNA

Hypertension and dyslipidemia are risk factors for atherosclerosis and occur together more often than expected by chance. Although this clustering suggests shared causation, unifying factors remain unknown. We describe a large kindred with a syndrome including hypertension, hypercholesterolemia, and hypomagnesemia. Each phenotype is transmitted on the maternal lineage with a pattern indicating mitochondrial inheritance. Analysis of the mitochondrial genome of the maternal lineage identified a homoplasmic mutation substituting cytidine for uridine immediately 5' to the mitochondrial transfer RNA(Ile) anticodon. Uridine at this position is nearly invariate among transfer RNAs because of its role in stabilizing the anticodon loop. Given the known loss of mitochondrial function with aging, these findings may have implications for the common clustering of these metabolic disorders.     

Pharmacokinetics of levamisole after intramuscular and oral administrations to Caspian salmon (Salmo trutta caspius)

The pharmacokinetic parameters of levamisole were determined in the Caspian salmon after intramuscular (IM), oral by gavage, and oral by feed administrations. Eighty-one healthy fish in three different groups received levamisole at the dose of 25 mg/fish by each route. Blood samples were collected at time points of 0, 0.5, 1, 2, 4, 6, 12, 14, and 24 hr after administrations. Plasma levamisole concentrations were measured by a validated high-performance liquid chromatography (HPLC) assay and were analyzed using a noncompartmental approach. The mean terminal half-life was 4.56, 3.95, and 2.91 hr for IM, gavage and feed routes, respectively. The peak plasma concentration for IM, gavage, and feed routes of levamisole were 35.53, 4.63, and 8.36 µg/ml, respectively, at the time of 0.25 for IM, and 1 hr for gavage and feed. The relative bioavailability for gavage and feed routes was 54.80 and 69.30. The similar bioavailability for gavage and feed might be indicative of similar efficacy for these routes of administrations. Further studies are warranted to evaluate the absolute oral bioavailability and the effective dose in Caspian salmon.     

Estimation of additive and non-additive genetic variance component for growth traits in Adani goats

Tropical Animal Health and Production - Non-additive genetic effects are important to increase the accuracy of estimating genetic parameters for growth traits. The aim of this study was to estimate...     

Genetic structure of Iranian indigenous sheep breeds: insights for conservation

Tropical Animal Health and Production - Genetic structure and genetic diversity levels of indigenous Iranian sheep breeds are not clear, despite the interest this region has in itself as an...     

灌溉模式与种植方式对河西地区青贮玉米生长、产量和经济效益的影响

为探究灌溉模式与种植方式对青贮玉米（Zea mays L.）生长、产量和经济效益的影响,本研究在河西地区设置3个种植方式（S：青贮玉米单播;SM：青贮玉米与秣食豆（Glycine max L.Merr）混播;SL：青贮玉米与拉巴豆（Lablab purpureus L.Sweet）混播）和6种灌溉模式（W1：6叶期灌溉;W2：6叶期和12叶期灌溉;W3：6叶期和散粉期灌溉;W4：6叶期、12叶期和散粉期灌溉;W5：6叶期、散粉期和灌浆期灌溉;W6：6叶期、12叶期、散粉期和灌浆期灌溉）进行田间试验。结果表明：SM、SL和S种植下玉米的株高、茎粗和相叶绿素含量差异不显著,但SM和SL较S显著提高了叶面积指数;SM和SL的鲜干草产量和净收益显著高于S;在灌浆期和收获期,W5和W6的株高、茎粗、相对叶绿素含量和叶面积指数显著高于W1;W5、W6的鲜干草产量和净收益显著高于W1,W2和W3。所有处理中,SM-W5获得了最高的干草产量和净收益,是河西地区青贮玉米适宜的栽培模式。