Virgin females compete for mates in the male lekking species Ceratitis capitata

Abstract. Aggressive behaviour occurring in intrasexual competition is an important trait for animal fitness. Although female intrasexual aggression is reported in several insect species, little is known about female competition and aggressive interactions in polygynous male lekking species. The interactions of female Mediterranean fruit flies, Ceratitis capitata (a male lekking species), with other females and mating pairs under laboratory conditions are investigated. Mature, unmated (virgin) females are aggressive against each other and against mating pairs, whereas immature females are not. Female aggression against other females decreases dramatically after mating; however, mated females maintain aggression against mating pairs. In addition, higher intrasexual aggression rates are observed for mature, virgin females than for virgin males of the same age. The results show that female aggressiveness is virginity related, suggesting female competition for mates. These findings have important implications for understanding the physiological aspects of a complex social behaviour such as aggression and should stimulate further research on female agonistic behaviour in male lekking mating systems.     

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) receptor specific peptide analogues for PET imaging of breast cancer: In vitro/in vivo evaluation

Vasoactive intestinal peptide and pituitary adenylate cyclase activating peptide have high affinity for VPAC1, VPAC2 and PAC1 receptors overexpressed on human cancer cells. Four potent analogues of these peptides, TP3939, TP3982, TP4200 and TP3805 were labeled with (64)Cu and evaluated ex vivo and in vivo to asses their biological activity and receptor specificity. The ultimate goal is to utilize (64)Cu analogues for positron emission tomography (PET) imaging of breast cancers in humans. Radiochemical purity of each analogue was >92%. The muscle relaxivity assay revealed IC(50) to be 5.3x10(-8) M, 4.4x10(-8) M, 8.1x10(-8) M, 8.1x10(-9) M and Kd values determined by receptor specific cell binding assays were 3.3 nM, 0.33 nM, 0.2 nM and 0.72 nM for TP3805, TP3939, TP3982, and TP4200 respectively. The receptor affinity, using human breast cancer tissues, was 10.93 times greater than normal breast tissues. RT-PCR confirmed increased VPAC1 receptor expression on human breast tumor cells over normal cells and corroborated with autoradiography data. The blood clearance was rapid and in vivo translocation of (64)Cu to plasma protein was <15%. Data demonstrate that these analogues are potent, have uncompromised biological activity and are worthy of further evaluation for accurate PET imaging of human breast cancers and in determining malignant and benign lesions.     

Synthesis and SAR of novel oxazolidinones: discovery of ranbezolid

Novel oxazolidinones were synthesized containing a number of substituted five-membered heterocycles attached to the 'piperazinyl-phenyl-oxazolidinone' core of eperezolid. Further, the piperazine ring of the core was replaced by other diamino-heterocycles. These modifications led to several compounds with potent activity against a spectrum of resistant and susceptible gram-positive organisms, along with the identification of ranbezolid (RBx 7644) as a clinical candidate.     

Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 ± 1.7 years) and middle-aged (mean age = 56.3 ± 4.7 years) subjects after 1 hour of heat shock at 42°C. Genotype-specific HSR was measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible and inducible forms of Hsp70 decreased 1.3-fold (P < 0.001) and 1.4-fold (P < 0.001), respectively, in the monocytes with age. In the young subjects, a positive association was found between HSPA1L(T2437C) polymorphism and HSR. CC carriers had a significantly lower induction than TT carriers in both monocytes (P = 0.015) and lymphocytes (P = 0.044). This polymorphism, which is present in the coding region of HSPA1L gene, can affect the chaperoning function of Hsp70. These data consolidate our other observations that the CC genotype is unfavorable for human longevity and provide a functional explanation in terms of variations in HSR.     

Heat shock response and ageing: mechanisms and applications

Ageing is associated with a decrease in the ability of cells to cope with environmental challenges. This is due partly to the attenuation of a primordial stress response, the so-called heat shock (HS) response, which induces the expression of heat shock proteins (HSPs), composed of chaperones and proteases. The attenuation of the HS response during ageing may be responsible for the accumulation of damaged proteins as well as abnormal regulation of cell death. Maintenance of the HS response by repeated mild heat stress causes anti-ageing hormetic effects on cells and organisms. Here, we describe the molecular mechanism and the state of the HS response as well as the role of specific HSPs during ageing, and discuss the possibility of hormetic modulation of ageing and longevity by repeated mild stress.     

Bioengineered human IAS reconstructs with functional and molecular properties similar to intact IAS

Because of its critical importance in rectoanal incontinence, we determined the feasibility to reconstruct internal anal sphincter (IAS) from human IAS smooth muscle cells (SMCs) with functional and molecular attributes similar to the intact sphincter. The reconstructs were developed using SMCs from the circular smooth muscle layer of the human IAS, grown in smooth muscle differentiation media under sterile conditions in Sylgard-coated tissue culture plates with central Sylgard posts. The basal tone in the reconstructs and its changes were recorded following 0 Ca(2+), KCl, bethanechol, isoproterenol, protein kinase C (PKC) activator phorbol 12,13-dibutyrate, and Rho kinase (ROCK) and PKC inhibitors Y-27632 and G?-6850, respectively. Western blot (WB), immunofluorescence (IF), and immunocytochemical (IC) analyses were also performed. The reconstructs developed spontaneous tone (0.68 ± 0.26 mN). Bethanechol (a muscarinic agonist) and K(+) depolarization produced contraction, whereas isoproterenol (β-adrenoceptor agonist) and Y-27632 produced a concentration-dependent decrease in the tone. Maximal decrease in basal tone with Y-27632 and G?-6850 (each 10(-5) M) was 80.45 ± 3.29 and 17.76 ± 3.50%, respectively. WB data with the IAS constructs' SMCs revealed higher levels of RhoA/ROCK, protein kinase C-potentiated inhibitor or inhibitory phosphoprotein for myosin phosphatase (CPI-17), phospho-CPI-17, MYPT1, and 20-kDa myosin light chain vs. rectal smooth muscle. WB, IF, and IC studies of original SMCs and redispersed from the reconstructs for the relative distribution of different signal transduction proteins confirmed the feasibility of reconstruction of IAS with functional properties similar to intact IAS and demonstrated the development of myogenic tone with critical dependence on RhoA/ROCK. We conclude that it is feasible to bioengineer IAS constructs using human IAS SMCs that behave like intact IAS.     

Avian predation on a parasitic fly of cervids during winter: can host‐related cues increase the predation risk?

The deer ked (Lipoptena cervi) is an ectoparasitic fly on cervids that has expanded its distribution rapidly in Northern Europe. However, the regulating biotic factors such as predation remain unknown. The host‐independent pupal stage of the fly lasts for several months. Blackish pupae are visible against snow, especially on the bedding sites of hosts, and are thus exposed to predators. To evaluate the role of predation on the invasion dynamics and evolution of L. cervi, we monitored pupal predation on artificial bedding sites in three geographical areas in Finland during winter. We explored: (1) possible predators; (2) magnitude of predation; and (3) whether predation risk is affected by host‐derived cues. We demonstrate that pupae are predated by a number of tit species. Any reddish brown snow discoloration on bedding sites, indicating heavy infestation of the host, serves as an exploitable cue for avian predators, thereby increasing the risk of pupal predation. The ability of tits to use this host‐derived cue seems to be dependent on the prevalence of L. cervi and the period of invasion history, which suggests that it may be a learned behavioural response. Predation by tits may potentially affect the L. cervi population dynamics locally. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 275–286.     

Water saving traits co-map with a major terminal drought tolerance quantitative trait locus in pearl millet [Pennisetum glaucum (L.) R. Br.]

Low transpiration rates in pearl millet under fully irrigated conditions decrease plant water use at vegetative stage and then increase the water availability during grain filling and finally the terminal drought tolerance. Hundred and thirteen recombinant inbred lines developed from a cross between H77/833-2 and PRLT2/89-33 (terminal drought-sensitive?×?tolerant genotype) were evaluated to map transpiration rate (Tr, a proxy for canopy conductance), organ weights, leaf area and thickness and to study their interactions. Transpiration rate was increased by two H77/833-2 and two PRLT2/89-33 alleles on linkage group (LG) 2, whose importance depended on the vapor pressure deficit. The two H77/833-2 and one PRLT2/89-33 alleles co-mapped to a previously identified major terminal drought tolerance quantitative trait locus (QTL), although in a much smaller genetic interval. The other Tr allele from H77/833-2 also enhanced biomass dry weight and co-located with a formerly identified stover and tillering QTL. Leaf characteristics were linked to two loci on LG7. Plant water use was increased and decreased by different loci combinations for Tr, tillering and leaf characteristics, whose respective importance depended on the environmental conditions. Therefore, different alleles influence plant water use and have close interactions with one another and with the environment, so that different ideotypes for plant water use exist or could be designed from specific allele combinations conferring particular physiological characteristics for specific adaptation to a range of terminal drought conditions.