Licentiatavhandling (sammanfattning) Alnarp : Sveriges lantbruksuniversitet. / Härtill 2 uppsatser.

Cette thèse aborde l’écologie et l’évolution des relations qu’entretiennent les orchidées du genre Ophrys avec leurs pollinisateurs. L’approche comparative et la combinaison (i) d’analyses chimiques de phéromones sexuelles et de parfums floraux, (ii) d’analyses génétiques avec des outils moléculaires, et (ii) de tests de comportement réalisés sur les insectes in situ nous ont permis d’éclairer certains aspects méconnus de ces interactions inter-spécifiques. La pollinisation des orchidées du genre Ophrys est assurée par des mâles d'abeilles ou de guêpes solitaires qui opèrent une tentative d’accouplement (pseudocopulation) sur le labelle des fleurs. L'attraction des pollinisateurs est généralement hautement spécifique, régie par un mimétisme des signaux (chimiques, visuels, tactiles) des femelles des espèces d'insectes concernés. Malgré cette spécificité, des hybrides se forment occasionnellement en conditions naturelles, témoignant de la perméabilité partielle des barrières d'isolement reproductif entre espèces. Au cours de ce programme de recherche, nous avons entrepris l’étude des interactions Ophryspollinisateurs en mettant l’accent sur trois aspects spécifiques, à savoir (i) la sélection des caractères floraux par les pollinisateurs, (ii) l'isolement reproductif entre espèces d'Ophrys sympatriques, et enfin (iii) l'évolution des caractères floraux au sein d'un complexe d'espèces-soeurs d'Ophrys associées à différents pollinisateurs. Les principaux résultats de ce travail sont repris ci-dessous, ponctués de références aux articles qui rassemblent l’intégralité des études réalisées.

Diss. (sammanfattning). Alnarp : Sveriges lantbruksuniversitet, 2005. / Härtill 7 uppsatser.

A maioria dos Lepidoptera utiliza feromônio sexual para atração do parceiro para o acasalamento. A técnica da interrupção do acasalamento ou confusão sexual de machos é usada para interferir na comunicação entre os parceiros sexuais. Isto é obtido com a liberação de altas doses de feromônio sintético, para saturar o ambiente em que se deseja fazer o controle e, desta forma, diminuir a habilidade dos machos em localizar as fêmeas. O bicho-mineiro do café Leucoptera coffeella é considerado atualmente a principal praga desta cultura no Brasil. O controle químico tem sido o mais utilizado para impedir o ataque deste inseto, causando sérios problemas para o homem e para o meio ambiente. Para amenizar estes problemas, atualmente têm-se desenvolvido novas técnicas de manejo das pragas que atacam esta cultura. O presente trabalho testou, em campo, a viabilidade da técnica de confusão sexual de machos para a redução da população do bicho mineiro do café e com isso a diminuição do prejuízo que este inseto causa à lavoura. Foram instaladas três unidades experimentais de 20 ha. em uma lavoura de café. A eficiência desta técnica foi testada por meio da comparação de machos capturados em armadilhas iscadas com feromônio, entre a área tratada com o feromônio sexual para confundimento e outras duas áreas não tratadas com feromônio. Outra forma de avaliar a eficiência foi por meio da intensidade de injúrias que o inseto causou as folhas. Avaliando os resultados obtidos, pode-se implicar que o emprego do feromônio sexual sintético de L. coffeella não foi efetivo para reduzir os acasalamentos da espécie-praga e para diminuir o dano causado as plantas. Nesse contexto o insucesso pode ser atribuído a uma combinação de vários fatores, merecendo destaque à composição química, dose do feromônio e a formulação empregada, o momento de aplicação na lavoura, densidade populacional e a estratégia de acasalamento da praga, além do tamanho da área tratada e dos fatores climáticos._________________________________________________________________________________________ ABSTRACT: Most Lepidoptera use sex pheromones for the attraction of a mate. A technique for controlling lepidopteron pests, denominated mating disruption, aims at obstructing the communication between sexual partners. This is obtained with the release of synthetic pheromone in order to saturate the atmosphere, thereby decreasing the ability of mates to locate each other. The coffee leaf miner Leucoptera coffeella is the main pest of the coffee in Brazil. Chemical control has been used frequently to control the attack of L. coffeella, but this causes serious problems to man and environment. To avoid such problems, new techniques are being developed currently to control the attack of this pest. The present work is a field test of the viability of mating disruption to reduce coffee leaf miner populations and consequently, decrease its damage to the crop. Three experimental units of 20 ha. were installed in a coffee plantation. The intensity of mating disruption was tested through the comparison of synthetic-baited pheromone traps in areas where the sex pheromone was applied and two untreated areas. Another form to measure intensity of mating disruption was through the level of damage that the insect caused to the leaves. The results showed that the employment of the synthetic sex pheromone of L. coffeella did not reduce the mating of the insects and did not decrease the damage of plants. The failure of the mating disruption technique may be attributed to a combination of several factors, such as composition and/or dose of the pheromone and its formulation, the moment of application in the crop, the population density and the mating strategy of the pest, the size of the treated area as well as climatic factors.

No description available.

O processo reprodutivo é de extrema importância para os organismos vivos, é através dele que os indivíduos transmitem as informações contidas em seus genes para as próximas gerações. Para que qualquer indivíduo seja bem-sucedido nesse processo, o primeiro desafio a ser superado é encontrar um parceiro sexual. Para cumprir essa tarefa, machos e fêmeas comunicam sua presença utilizando uma variedade de canais sensoriais. Nas abelhas sociais,o encontro entre machos e fêmeas é um processo complexo e resultado de um refinado sistema de comunicação, mediado principalmente por sinais químicos. Embora Meliponini seja o maior e mais diverso grupo de abelhas sociais, existem poucas informações sobre a comunicação sexual desses insetos. Um fenômeno comum nesse grupo de abelhas é a formação de grandes agregados de machos nas proximidades de colônias que possuem uma rainha virgem. No entanto, os sinais envolvidos na atração dos machos e na formação desses agregados são pouco conhecidos. Desse modo, este trabalho objetivou investigar os fatores envolvidos na comunicação sexual de Meliponini. Para explorar esse problema, nós realizamos uma revisão sobre a biologia reprodutiva dessas abelhas (cap. 1), testamos o papel das forrageiras na atração de machos (cap.2), identificamos os compostos presentes nas marcas depositadas por machos nas agregações (cap.3) e investigamos os fatores relacionados à escolha dos machos por uma determinada colônia (cap. 4). Os resultados obtidos apontam que as forrageiras têm um papel central na atração dos machos e que os machos depositam ativamente seus hidrocarbonetos cuticulares nos locais de agregação. Além disso, foi possível identificar que a atratividade de uma colônia está relacionada com a sua biomassa. Assim, esses resultados contribuem para ampliar nosso conhecimento sobre o processo reprodutivo em abelhas sem ferrão e mostram que a comunicação sexual desse grupo de insetos é um processo tão complexo quanto fascinante que envolve machos, rainhas e operárias / Reproduction is the utmost important process for living organisms since it is through this process that individuals can transmit their genetic information to the next generation. To be successful in this process, the first challenge individuals need to overcome is finding a sexual partner. To accomplish this task, males and females communicate their presence using several sensorial modalities. In highly eusocial bees, this complex process is the outcome of a precise chemical communication system. Stingless bees (Meliponini) represents the most species-rich group of eusocial bees and although a lot of information related to the group can be found in the literature, very little is known about their mating communication. A common phenomenon in this group of social bees is the formation of large male aggregations in front of nests during reproductive events. However, the factors involved in the formation of such male aggregation are poorly understood. Therefore, the aim of this study was to investigate the mating communication of stingless bees. To explore this problem, we reviewed the mating biology of the bees (chapter 1), tested the role of foragers in the attraction of males (chapter 2), identified the compounds that drones deposit at the aggregation site (chapter 3) and investigated the factors related to the differential attraction of males to colonies (chapter 4). Our results suggest that foragers have a central role in the long-range attraction of males and that males actively deposit their cuticular hydrocarbons at the aggregation site. Furthermore, we observed that the number of attracted males increased with the weight of colonies, showing that the attractiveness of colonies is related to their biomass. Thus, these results contribute to improve our knowledge about the reproductive process of stingless bees and show that the sexual communication of these bees is as complex as fascinating and involves males, queens and workers

Dabar vis daugiau mokslininkų bando identifikuotus gyvūnų feromonus sintetinti ir panaudoti praktinėms reikmėms, pavyzdžiui, vabzdžių sintetinių feromonų analogus naudoti kovai su žemės ūkio kenkėjais. Tačiau tik XX amžiaus pabaigoje pradėta domėtis ir žinduolių feromonais. Viena iš naujų tiriamų sričių yra: lytinių feromonų įtaka gyvūnų lytinei elgsenai. Lytinė elgsena yra vienas iš svarbiausių šunų kaip ir, bet kurios kitos gyvosios sistemos egzistavimo garantas, todėl tai paskatino mus išsamiau paanalizuoti šunų lytinės elgsenos modelį (asistavimą). Taip pat mūsų tikslas buvo sumodeliuoti tokį biotestavimo modelį kaip materiali informacija paveikia individo (šuns) elgesį ir nustatyti bei apibūdinti kas tai yra ta informacija, šiuo atveju – cheminė medžiaga. Tyrimai buvo atlikti 2005 – 2007 metais. Buvo surinkti šlapimo ėminiai iš skirtingų šunų veislių devynių kalių nerujos ir rujos metu. Ėminių rinkimo metodika buvo specialiai sukurta įgyvendinti mūsų užduotis ir yra originali. Viena dalis rinkimo metu surinktos medžiagos buvo išsiusta į Karališkąjį Technologijų Institutą Stokholme (Royal Institute of Technologies). Atlikus pirminius ėminių tyrimus, nustatyta jog tik rujojančių kalių šlapime yra TC medžiaga. Antra dalis rinkimo metu surinktos medžiagos buvo naudota biotestui. Po to buvo atlikti du biotestavimai lauko sąlygomis Pietų Rusijos aviganių veislyne „Balandis“. Šiuose tyrimuose buvo atlikti testavimai su šios veislės patinais pagal 7 mūsų sukurtus testavimo... [toliau žr. visą tekstą] / More and more scientists nowadays are trying to syntetic animals‘ pheromones and use them for practical purposes. Analogues of syntetic pheromones, for instance, are used in agriculture against pests. It was only in the end of the 20th century, however, that mammals‘ pheromones, too, started arousing interest. One of the new fields of resaerch is the animals‘ sexual behaviour. Sexual behaviour is one of the guarantees of dogs‘, as well as any other living systems‘ existence. Then an idea suggested itself to us to analyze more deeply the model of this type of behaviour amoung dogs. Our aim was also to set up a model of biotesting in what way material information is reflected on an individual‘s (dog‘s) behaviour and to establish what that information is. In this case – a chemical substance. The research was carried out between 2005 and 2007. Urine samples were gathered from bitches of different dogs‘ breeds then they were on the heat and when they were not on the heat. The method of taking the samples was specially created to satisfy our requirements and is original. One part of the samples gathered was sent to the Royal Institute of Technologies in Stockholm. The research conducted on the primary samples showed that the substance TC was to be found only in the urinie of bitches (females) that were on the heat. The rest of material gathered was used for examination. Then two biotests (in outside)was conducted at the South Russian Sheep – dog kennel “Balandis“. Researched... [to full text]

O processo reprodutivo é de extrema importância para os organismos vivos, é através dele que os indivíduos transmitem as informações contidas em seus genes para as próximas gerações. Para que qualquer indivíduo seja bem-sucedido nesse processo, o primeiro desafio a ser superado é encontrar um parceiro sexual. Para cumprir essa tarefa, machos e fêmeas comunicam sua presença utilizando uma variedade de canais sensoriais. Nas abelhas sociais,o encontro entre machos e fêmeas é um processo complexo e resultado de um refinado sistema de comunicação, mediado principalmente por sinais químicos. Embora Meliponini seja o maior e mais diverso grupo de abelhas sociais, existem poucas informações sobre a comunicação sexual desses insetos. Um fenômeno comum nesse grupo de abelhas é a formação de grandes agregados de machos nas proximidades de colônias que possuem uma rainha virgem. No entanto, os sinais envolvidos na atração dos machos e na formação desses agregados são pouco conhecidos. Desse modo, este trabalho objetivou investigar os fatores envolvidos na comunicação sexual de Meliponini. Para explorar esse problema, nós realizamos uma revisão sobre a biologia reprodutiva dessas abelhas (cap. 1), testamos o papel das forrageiras na atração de machos (cap.2), identificamos os compostos presentes nas marcas depositadas por machos nas agregações (cap.3) e investigamos os fatores relacionados à escolha dos machos por uma determinada colônia (cap. 4). Os resultados obtidos apontam que as forrageiras têm um papel central na atração dos machos e que os machos depositam ativamente seus hidrocarbonetos cuticulares nos locais de agregação. Além disso, foi possível identificar que a atratividade de uma colônia está relacionada com a sua biomassa. Assim, esses resultados contribuem para ampliar nosso conhecimento sobre o processo reprodutivo em abelhas sem ferrão e mostram que a comunicação sexual desse grupo de insetos é um processo tão complexo quanto fascinante que envolve machos, rainhas e operárias / Reproduction is the utmost important process for living organisms since it is through this process that individuals can transmit their genetic information to the next generation. To be successful in this process, the first challenge individuals need to overcome is finding a sexual partner. To accomplish this task, males and females communicate their presence using several sensorial modalities. In highly eusocial bees, this complex process is the outcome of a precise chemical communication system. Stingless bees (Meliponini) represents the most species-rich group of eusocial bees and although a lot of information related to the group can be found in the literature, very little is known about their mating communication. A common phenomenon in this group of social bees is the formation of large male aggregations in front of nests during reproductive events. However, the factors involved in the formation of such male aggregation are poorly understood. Therefore, the aim of this study was to investigate the mating communication of stingless bees. To explore this problem, we reviewed the mating biology of the bees (chapter 1), tested the role of foragers in the attraction of males (chapter 2), identified the compounds that drones deposit at the aggregation site (chapter 3) and investigated the factors related to the differential attraction of males to colonies (chapter 4). Our results suggest that foragers have a central role in the long-range attraction of males and that males actively deposit their cuticular hydrocarbons at the aggregation site. Furthermore, we observed that the number of attracted males increased with the weight of colonies, showing that the attractiveness of colonies is related to their biomass. Thus, these results contribute to improve our knowledge about the reproductive process of stingless bees and show that the sexual communication of these bees is as complex as fascinating and involves males, queens and workers

The transmission of sex pheromone-mediated signals is essential for goldfish reproduction. However, the neural pathways underlying this reproductive signalling pathway in the goldfish brain is not well described. Lesioning experiments have shown previously that two brain areas, the preoptic area (POA) and the ventral telencephali pars ventralis (Vv) in particular, are important for reproduction. We used patch clamp electrophysiology to study the electrical activities of POA and Vv neurons. Based on the intrinsic properties of these neurons, we suggest there are five different functional classes of POA neurons and a single class of Vv neurons. In addition, by electrically stimulating the olfactory bulb (OB), we were able to show that this primary sensory structure makes monosynaptic glutamatergic connections with both POA and Vv neurons. While electrophysiology measures signalling events occurring at short time scales on the order of milliseconds to minutes, we were also interested in studying sex pheromone signalling in the goldfish brain over a long time scale. Thus, we describe changes in gene expression in male goldfish exposed to waterborne sex pheromones (17alpha,20beta dihydroxy-4-pregene-3-one and Prostaglandin-F2alpha) over 6 hours. We perform cDNA microarrays on Prostaglandin-F2alpha-treated fish to study the rapid modulation of transcription and define the signalling pathways affected. Our microarrays showed that 71 genes were differentially regulated (67 up and 4 down). Through gene ontology enrichment analysis, we found that these genes were involved in various biological processes such as RNA processing, neurotransmission, neuronal development, apoptosis, cellular metabolism and sexual reproduction. RT-PCRs were performed to validate our microarrays and to facilitate direct comparisons of the effects of the two sex pheromones, 17alpha,20beta dihydroxy-4-pregene-3-one and Prostaglandin-F2alpha. By combining electrophysiology and gene expression analyses, we were able to study sex-pheromone signalling on two different time scales. One short, occurring on the order of milliseconds to minutes, that involves electrical activities in the brain through the glutamatergic amino-3-hydroxy-5-methylisoxazole-4-propionate and N-methyl-D-aspartate receptors; and the other long occurring several hours later that involves changes in the gene expression levels of calmodulin and ependymin among other genes underlying neuroplasticity. Reproductive neuroplasticity in the goldfish may therefore require the activation of glutamatergic receptors which then activate downstream signals like calmodulin and ependymin to transform the sex pheromones-mediate signal into gene expression.

The transmission of sex pheromone-mediated signals is essential for goldfish reproduction. However, the neural pathways underlying this reproductive signalling pathway in the goldfish brain is not well described. Lesioning experiments have shown previously that two brain areas, the preoptic area (POA) and the ventral telencephali pars ventralis (Vv) in particular, are important for reproduction. We used patch clamp electrophysiology to study the electrical activities of POA and Vv neurons. Based on the intrinsic properties of these neurons, we suggest there are five different functional classes of POA neurons and a single class of Vv neurons. In addition, by electrically stimulating the olfactory bulb (OB), we were able to show that this primary sensory structure makes monosynaptic glutamatergic connections with both POA and Vv neurons. While electrophysiology measures signalling events occurring at short time scales on the order of milliseconds to minutes, we were also interested in studying sex pheromone signalling in the goldfish brain over a long time scale. Thus, we describe changes in gene expression in male goldfish exposed to waterborne sex pheromones (17alpha,20beta dihydroxy-4-pregene-3-one and Prostaglandin-F2alpha) over 6 hours. We perform cDNA microarrays on Prostaglandin-F2alpha-treated fish to study the rapid modulation of transcription and define the signalling pathways affected. Our microarrays showed that 71 genes were differentially regulated (67 up and 4 down). Through gene ontology enrichment analysis, we found that these genes were involved in various biological processes such as RNA processing, neurotransmission, neuronal development, apoptosis, cellular metabolism and sexual reproduction. RT-PCRs were performed to validate our microarrays and to facilitate direct comparisons of the effects of the two sex pheromones, 17alpha,20beta dihydroxy-4-pregene-3-one and Prostaglandin-F2alpha. By combining electrophysiology and gene expression analyses, we were able to study sex-pheromone signalling on two different time scales. One short, occurring on the order of milliseconds to minutes, that involves electrical activities in the brain through the glutamatergic amino-3-hydroxy-5-methylisoxazole-4-propionate and N-methyl-D-aspartate receptors; and the other long occurring several hours later that involves changes in the gene expression levels of calmodulin and ependymin among other genes underlying neuroplasticity. Reproductive neuroplasticity in the goldfish may therefore require the activation of glutamatergic receptors which then activate downstream signals like calmodulin and ependymin to transform the sex pheromones-mediate signal into gene expression.