Activity of salivary glands in secreting honey‐elaborating enzymes in two subspecies of honeybee (Apis mellifera L)

The activity of invertase, glucose oxidase and amylase in the cephalic (post‐cerebral) and thoracic salivary glands is determined in Egyptian and Carniolan honeybees (Apis mellifera L). For this purpose, three ages of worker bees are selected for enzyme assays. The results show that the three target enzymes are detected in the two glands during the three worker ages, except invertase, which cannot be detected in the cephalic gland of newly emerged bees of both subspecies. In both glands, the secretion of invertase is highest, followed by amylase and then glucose oxidase. In Carniolan bees, invertase secretion of the cephalic and thoracic glands increases gradually with age. In Egyptian bees, invertase increases with age only in the cephalic gland, whereas, in the thoracic gland, the highest secretion activity is detected in 10–15‐day‐old bees. The highest amounts of glucose oxidase and amylase in the cephalic gland are detected in newly emerged individuals of both Egyptian and Carniolan bees. In the thoracic gland, however, the highest activity of both enzymes is recorded only in newly emerged Egyptian bees. The results are discussed in the light of bee management and biological aspects of the two subspecies.     

Estimation of Canine Leishmania Infection Prevalence in Six Cities of the Algerian Littoral Zone Using a Bayesian Approach

A large-scale study on canine Leishmania infection (CanL) was conducted in six localities along a west-east transect in the Algerian littoral zone (Tlemcen, Mostaganem, Tipaza, Boumerdes, Bejaia, Jijel) and covering two sampling periods. In total 2,184 dogs were tested with an indirect fluorescent antibody test (IFAT) and a direct agglutination test (DAT). Combined multiple-testing and several statistical methods were compared to estimate the CanL true prevalence and tests characteristics (sensitivity and specificity). The Bayesian full model showed the best fit and yielded prevalence estimates between 11% (Mostaganem, first period) and 38% (Bejaia, second period). Sensitivity of IFAT varied (in function of locality) between 86% and 88% while its specificity varied between 65% and 87%. DAT was less sensitive than IFAT but showed a higher specificity (between 80% and 95% in function of locality or/and season). A general increasing trend of the CanL prevalence was noted from west to east. A concordance between the present results and the incidence of human cases of visceral leishmaniasis was observed, where also a maximum was recorded for Bejaia. The results of the present study highlight the dangers when using IFAT as a gold standard.     

Morphological and microsatellite diversity associated with ecological factors in natural populations of Medicago laciniata Mill. (Fabaceae)

Genetic variability in 10 natural Tunisian populations of Medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. A large degree of genetic variability within-populations and among-populations was detected for both quantitative characters and molecular markers. High genetic differentiation among populations for quantitative traits was seen, with Q _ST = 0.47, and F _ST = 0.47 for microsatellite markers. Several quantitative traits displayed no statistical difference in the levels of Q _ST and F _ST . Further, significant correlations between quantitative traits and eco-geographical factors suggest that divergence in the traits among populations may track environmental differences. There was no significant correlation between genetic variability at quantitative traits and microsatellite markers within populations. The site-of-origin of eco-geographical factors explain between 18.13% and 23.40% of genetic variance among populations at quantitative traits and microsatellite markers, respectively. The environmental factors that most influence variation in measured traits among populations are assimilated phosphorus (P₂0₅) and mean annual rainfall, followed by climate and soil texture, altitude and organic matter. Significant associations between eco-geographical factors and gene diversity, H _e , were established in five-microsatellite loci suggesting that these simple sequence repeats (SSRs) are not necessarily biologically neutral.     

Effect of Sodium Selenite and Vitamin E on the Renal Cortex in Rats: An Ultrastructure Study

This study examined the use of vitamin E to alleviate toxic effects of sodium selenite. Adult male albino rats (n = 50) was divided into five groups. Group 1 was control, Groups 2 and 4 were treated with sodium selenite (2 mg/kg) for 2 and 4 weeks, respectively, Groups 3 and 5 were treated with sodium selenite (2 mg/kg) and vitamin E (100 mg/kg) for 2 and 4 weeks, respectively. Renal tissues were studied using anti-BCL2 and examined ultrastructurally. Positive Bax immunoreactivity was detected after 2 and more positive after 4 weeks and nearly all groups improved with co-administration of vitamin E. Ultrastructural study revealed lesions in Bowman's capsule and proximal convoluted tubules. The submicroscopic study revealed damage and necrosis of cortical structures after 2 and 4 weeks, respectively. After 4 weeks, cellular changes were seen, such as vacuolation and moderate degeneration of cells, widening of the urinary space scattered through the cortex with loss of cellular details, formation of apical buds, degeneration, and cellular rupture. Present findings disclosed an ameliorative effect of adding vitamin E to sodium selenite-induced changes in cortical tissues. Clinically, it is advised to add vitamin E to avoid selenium overdose hazards.     

Genetic differentiation across a behavioural boundary in a primitively eusocial bee, <Emphasis Type="Italic">Halictus poeyi</Emphasis> Lepeletier (Hymenoptera,Halictidae)

Summary. In Florida, the primitively eusocial bee, Halictus poeyi Lepeletier exhibits two different colony cycles: populations in northern and central Florida are univoltine with an annually brooded colony cycle, while populations in southern Florida, including the Florida Keys, are multivoltine with a continuously brooded colony cycle. In this study, we test the hypothesis of reduced gene flow between the colony types by comparing levels of genetic differentiation among populations having similar colony phenologies with that among populations having different colony phenologies. We use allozyme markers to estimate F_ST, a robust measure of genetic differentiation. We found that genetic differentiation is not significantly higher between populations having different colony phenologies than between populations having similar colony phenologies. Environmental conditions thus may play an important role in influencing the expression of the alternative colony types of H. poeyi populations in Florida.     

Nucleic Acid Related Compounds: A Convenient Synthesis of 3-Deazauridine Analogues

Abstract

A novel synthesis of 3-deazapyrimidine glycosides utilizing pyridine-2(1H)-ones or their sodium salts and α-halomonosugars namely D-glucose or D-galactose as starting components is described.     

Low levels of quantitative and molecular genetic differentiation among natural populations of Medicago ciliaris Kroch. (Fabaceae) of different Tunisian eco-geographical origin

In this paper, we analyze the genetic variability in four Tunisian natural populations of Medicago ciliaris using 19 quantitative traits and six polymorphic microsatellite loci. We investigated the amplification transferability of 30 microsatellites developed in the model legume M. truncatula to M. ciliaris. Results revealed that about 56.66% of analyzed markers are valuable genetic markers for M. ciliaris. The most genetic diversity at quantitative traits and microsatellite loci was found to occur within populations (>80%). Low differentiations among populations at quantitative traits Q _ST  = 0.146 and molecular markers F _ST  = 0.18 were found. The majority of measured traits exhibited no significant difference in the level of Q _ST and F _ST . Furthermore, significant correlations established between these traits and eco-geographical factors suggested that natural selection should be invoked to explain the level of phenotypic divergence among populations rather than drift. There was no significant correlation between population differentiation at quantitative traits and molecular markers. Significant spatial genetic structure consistent with models of isolation by distance was detected within all studied populations. The site-of-origin environmental factors explain about 9.07% of total phenotypic genetic variation among populations. The eco-geographical factors that influence more the variation of measured traits among populations are the soil texture and altitude. Nevertheless, there were no consistent pattern of associations between gene diversity (He) and environmental factors.     

Induction and genetic identification of a callus‐like growth developed in the brown alga Fucus vesiculosus

Induction of an axenic filamentous‐like callus growth from the brown algae Fucus vesiculosus is described. Different treatments were investigated in various combinations to develop axenic cultures based on identification of surface symbionts via 18S ribosomal RNA. Moreover, viability was confirmed after such processes by 2,3,5‐triphenyl tetrazolium chloride assay that demonstrated an average viability of 29%, relative to nonsterilized explants. After six weeks of a phototrophic cultivation on artificial sea water‐12‐nitrilotriacetic acid (0.5% w/v agar), a filamentous‐like callus growth was observed, which was identified genetically through its mitochondrial DNA after subculturing. Achievement of confirmed marine callus cultures might enrich old previously established blue biotechnology techniques and open new chances for cultivation of brown algae for production of good manufacturing practice‐compliant bioproducts.     

Pharmacokinetic stability of macrocyclic peptide triazole HIV‐1 inactivators alone and in liposomes

Previously, we reported the discovery of macrocyclic peptide triazoles (cPTs) that bind to HIV‐1 Env gp120, inhibit virus cell infection with nanomolar potencies, and cause irreversible virion inactivation. Given the appealing virus‐killing activity of cPTs and resistance to protease cleavage observed in vitro, we here investigated in vivo pharmacokinetics of the cPT AAR029b. AAR029b was investigated both alone and encapsulated in a PEGylated liposome formulation that was designed to slowly release inhibitor. Pharmacokinetic analysis in rats showed that the half‐life of FITC‐AAR029b was substantial both alone and liposome‐encapsulated, 2.92 and 8.87 hours, respectively. Importantly, liposome‐encapsulated FITC‐AAR029b exhibited a 15‐fold reduced clearance rate from serum compared with the free FITC‐cPT. This work thus demonstrated both the in vivo stability of cPT alone and the extent of pharmacokinetic enhancement via liposome encapsulation. The results obtained open the way to further develop cPTs as long‐acting HIV‐1 inactivators against HIV‐1 infection.