Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior

PGal4 excision reveals the pleiotropic effects of Voila, a Drosophila locus that affects development and courtship behaviour

0016-6723 (Print) Journal Article Research Support, Non-U.S. Gov'tIn Drosophila melanogaster, the PGal4 transposon inserted at the chromosomal site 86E1-2 is associated with the Voila1 allele that causes multiple phenotypes. Homozygous Voila1/1 flies rarely reach adulthood and heterozygous Voila1/+ adult males display strong homosexual courtship behaviour. Both normal behavioural and developmental phenotypes were rescued by remobilizing the PGal4 element. Yet, the rescue of heterosexual courtship and of adult viability did not occur in the same strains, indicating that these defects have different genetic origins. Furthermore, many strains showed a partial rescue of both characters. Molecular analysis revealed that the PGal4 transposon is inserted upstream of the 5'UTR of the prospero gene. The excision strains with no detectable fragment of the PGal4 transposon remaining showed a rescued viability for homozygote adults. Moreover, the developmental period with the highest homozygote lethality was correlated with the size of PGal4 element that remained inserted at the Voila locus. This suggests a relationship between developmental viability and the amount of DNA inserted within the promoter of prospero

Increased dopamine level enhances male-male courtship in Drosophila

1529-2401 (Electronic) Journal Article Research Support, Non-U.S. Gov'tSexual behavior between males is observed in many species, but the biological factors involved are poorly known. In mammals, manipulation of dopamine has revealed the role of this neuromodulator on male sexual behavior. We used genetic and pharmacological approaches to manipulate the dopamine level in dopaminergic cells in Drosophila and investigated the consequence of this manipulation on male-male courtship behavior. Males with increased dopamine level showed enhanced propensity to court other males but did not change their courtship toward virgin females, general olfactory response, general gustatory response, or locomotor activity. Our results indicate that the high intensity of male-male interaction shown by these manipulated males was related to their altered sensory perception of other males

The role of cuticular pheromones in courtship conditioning of Drosophila males

Courtship conditioning is an associative learning paradigm in Drosophila melanogaster, wherein male courtship behavior is modified by experience with unreceptive, previously mated females. While the training experience with mated females involves multiple sensory and behavioral interactions, we hypothesized that female cuticular hydrocarbons function as a specific chemosensory conditioned stimulus in this learning paradigm. The effects of training with mated females were determined in courtship tests with either wild-type virgin females as courtship targets, or with target flies of different genotypes that express distinct cuticular hydrocarbon (CH) profiles. Results of tests with female targets that lacked the normal CH profile, and with male targets that expressed typically female CH profiles, indicated that components of this CH profile are both necessary and sufficient cues to elicit the effects of conditioning. Results with additional targets indicated that the female-specific 7,11-dienes, which induce naive males to court, are not essential components of the conditioned stimulus. Rather, the learned response was significantly correlated with the levels of 9-pentacosene (9-P), a compound found in both males and females of many Drosophila strains and species. Adding 9-P to target flies showed that it stimulates courting males to attempt to copulate, and confirmed its role as a component of the conditioned stimulus by demonstrating dose-dependent increases in the expression of the learned response. Thus, 9-P can contribute significantly to the conditioned suppression of male courtship toward targets that express this pheromone

Autocrine fibroblast growth factor-2 signaling contributes to altered endothelial phenotype in pulmonary hypertension.

Pulmonary vascular remodeling is key to the pathogenesis of idiopathic pulmonary arterial hypertension (IPAH). We recently reported that fibroblast growth factor (FGF)2 is markedly overproduced by pulmonary endothelial cells (P-ECs) in IPAH and contributes significantly to smooth muscle hyperplasia and disease progression. Excessive FGF2 expression in malignancy exerts pathologic effects on tumor cells by paracrine and autocrine mechanisms.We hypothesized that FGF2 overproduction contributes in an autocrine manner to the abnormal phenotype of P-ECs, characteristic of IPAH. In distal pulmonary arteries (PAs) of patients with IPAH, we found increased numbers of proliferating ECs and decreased numbers of apoptotic ECs, accompanied with stronger immunoreactivity for the antiapoptotic molecules, B-cell lymphoma (BCL)2, and BCL extra long (BCL-xL) compared with PAs from control patients. These in situ observations were replicated in vitro, with cultured P-ECs from patients IPAH exhibiting increased proliferation and diminished sensitivity to apoptotic induction with marked increases in the antiapoptotic factors BCL2 and BCL-xL and levels of phosphorylated extracellular signal-regulated (ERK)1/2 compared with control P-ECs. IPAH P-ECs also exhibited increased FGF2 expression and an accentuated proliferative and survival response to conditioned P-EC media or exogenous FGF2 treatment. Decreasing FGF2 signaling by RNA interference normalized sensitivity to apoptosis and proliferative potential in the IPAH P-ECs. Our findings suggest that excessive autocrine release of endothelial-derived FGF2 in IPAH contributes to the acquisition and maintenance of an abnormal EC phenotype, enhancing proliferation through constitutive activation of ERK1/2 and decreasing apoptosis by increasing BCL2 and BCL-xL.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Bone morphogenetic protein signalling in heritable versus idiopathic pulmonary hypertension

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Bone morphogenetic protein signaling in familial versus idiopathic pulmonary arterial hypertension

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Detailed Investigation of the Immunodominant Role of O-Antigen Stoichiometric O-Acetylation as Revealed by Chemical Synthesis, Immunochemistry, Solution Conformation and STD-NMR Spectroscopy for Shigella flexneri 3a

International audienceShigella flexneri 3a causes bacillary dysentery. Its O-antigen has the {2)-[α-d-Glcp-(1→3)]-α-l-Rhap-(1→2)-α-l-Rhap-(1→3)-[Ac→2]-α-l-Rhap-(1→3)-[Ac→6]≈40 % -β-d-GlcpNAc-(1→} ([(E)ABAc CAc D]) repeating unit, and the non-O-acetylated equivalent defines S. flexneri X. Propyl hepta-, octa-, and decasaccharides sharing the (E')A'BAc CD(E)A sequence, and their non-O-acetylated analogues were synthesized from a fully protected BAc CD(E)A allyl glycoside. The stepwise introduction of orthogonally protected mono- and disaccharide imidate donors was followed by a two-step deprotection process. Monoclonal antibody binding to twenty-six S. flexneri types 3a and X di- to decasaccharides was studied by an inhibition enzyme-linked immunosorbent assay (ELISA) and STD-NMR spectroscopy. Epitope mapping revealed that the 2C -acetate dominated the recognition by monoclonal IgG and IgM antibodies and that the BAc CD segment was essential for binding. The glucosyl side chain contributed to a lesser extent, albeit increasingly with the chain length. Moreover, tr-NOESY analysis also showed interaction but did not reveal any meaningful conformational change upon antibody binding

Aldehyde perception induces specific molecular responses in Laminaria digitata and affects algal consumption by a specialist grazer

International audienceSUMMARY In the marine environment, distance signaling based on water‐borne cues occurs during interactions between macroalgae and herbivores. In the brown alga Laminaria digitata from North‐Atlantic Brittany, oligoalginates elicitation or grazing was shown to induce chemical and transcriptomic regulations, as well as emission of a wide range of volatile aldehydes, but their biological roles as potential defense or warning signals in response to herbivores remain unknown. In this context, bioassays using the limpet Patella pellucida and L. digitata were carried out for determining the effects of algal transient incubation with 4‐hydroxyhexenal (4‐HHE), 4‐hydroxynonenal (4‐HNE) and dodecadienal on algal consumption by grazers. Simultaneously, we have developed metabolomic and transcriptomic approaches to study algal molecular responses after treatments of L. digitata with these chemical compounds. The results indicated that, unlike the treatment of the plantlets with 4‐HNE or dodecadienal, treatment with 4‐HHE decreases algal consumption by herbivores at 100 ng.ml −1 . Moreover, we showed that algal metabolome was significantly modified according to the type of aldehydes, and more specifically the metabolite pathways linked to fatty acid degradation. RNAseq analysis further showed that 4‐HHE at 100 ng.ml −1 can activate the regulation of genes related to oxylipin signaling pathways and specific responses, compared to oligoalginates elicitation. As kelp beds constitute complex ecosystems consisting of habitat and food source for marine herbivores, the algal perception of specific aldehydes leading to targeted molecular regulations could have an important biological role on kelps/grazers interactions

Cross-talk between Endothelial and Smooth Muscle Cells in Pulmonary Hypertension: Critical Role for Serotonin-Induced Smooth Muscle Hyperplasia

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