O Brasil destaca-se como maior produtor de seda em escala comercial no Ocidente e o quinto maior no mundo, devido ao eficiente sistema integrado de produção, que qualifica os fios de seda brasileiros como de alta qualidade. A sericicultura é a criação do Bombyx mori L. (bicho-da-seda) para obtenção dos casulos de seda para a fiação. A atividade emprega, no Brasil, aproximadamente, 2.500 famílias no meio rural, gerando renda por cerca de 8 a 9 meses do ano, contribuindo para a fixação delas ao campo. Além disso, cerca de 2.000 funcionários trabalham nas empresas de fiação no meio urbano, e o total de empregos, contando com os empregos indiretos, associados à atividade, somam, aproximadamente, 20.000. Esta pesquisa teve como objetivo apresentar a dinâmica da inovação da sericicultura no Brasil e as medidas que vêm sendo tomadas nesse sentido. Os dados, para elaboração deste estudo, foram coletados por meio de análise bibliográfica, assim como, visitas técnicas às empresas e aos produtores ligados à sericicultura nos estados do Paraná e São Paulo. Foram realizadas entrevistas com quatro sericicultores, juntamente com representantes das empresas Fiação de Seda BRATAC S.A., Fiação de Seda Artesanal O Casulo Feliz, Instituto Vale da Seda e com Enéas Neto, estilista residente da marca Vale da Seda. As principais modernizações constatadas visam diminuir o esforço físico do trabalhador rural e aumentar a produtividade, mantendo os padrões de qualidade. Constatou-se, nas visitas e entrevistas aos produtores rurais, que a sericicultura é, na maioria dos casos, a principal fonte de renda familiar, afirmando a importância social e econômica da referida atividade e que, mesmo após anos anteriores de declínio, vem se mostrando promissora no Brasil, com aumentos gradativos nas últimas safras, tornando-se uma atividade bastante rentável. Por meio das entrevistas com os empresários e representantes do setor, relacionados com a produção de seda no Brasil, percebe-se que se sentem otimistas com relação ao futuro da seda, pois existe hoje uma maior preocupação com o uso de produtos provenientes de extração mais sustentável, duráveis e com maior valor agregado e, a seda, se enquadra nesses requisitos. Além disso, estudos preliminares indicam uma correlação positiva entre a produção de seda e a mitigação da Pegada de Carbono. Desse modo, a sericicultura, de forma sustentável, ética e socialmente responsável, poderá apresentar cada vez maior destaque e, por consequência, refletir positivamente na economia brasileira como um todo. Conclui-se que a sericicultura é uma atividade economicamente viável para o Brasil, o qual apresenta condições de solo e clima favoráveis para a criação do bicho-da-seda, em diversas regiões de seu território, com a possibilidade de gerar empregos e renda, tanto na área rural, quanto na urbana. Impulsionada pela mecanização e modernização da atividade agropecuária, a sericicultura nacional vem retomando lugar de destaque / Brazil stands out as the largest commercial scale silk producer in the West and the fifth largest in the world due to its efficient integrated production system, which qualifies Brazilian silk yarns as high quality. The sericulture is the creation of Bombyx mori L. (silkworm) to obtain silk cocoons for spinning. The activity employs approximately 2,500 rural families in Brazil, generating income for about 8 to 9 months of the year, contributing to their setting in the field. In addition, around 2,000 employees work in the spinning companies and the total amount of jobs, added to the indirect jobs by the activity, is, approximately, 20,000. This research aimed to present the dynamic of sericulture innovation in Brazil and the measures that have been taken in this direction. All the data for the preparation of this study were collected through bibliographic analysis, as well as technical visits to companies and producers linked to sericulture in the states of Parana and Sao Paulo. Interviews were conducted with four sericulturists, along with representatives of the spinning companies of Silk BRATAC S.A., spinning of handmade silk O Casulo Feliz, Silk Valley Institute and with Eneas Neto, resident designer of the Silk Valley brand. The main modernizations observed aim to reduce the physical effort of the rural worker and increase productivity, maintaining the renowned Brazilian quality standards. In the visits and interviews with rural producers, sericulture is, in most cases, the main source of income of the family, affirming the social and economic importance of this activity, and that, even after previous years of decline, showing promising in Brazil, with gradual increases in the last harvests, becoming a very profitable activity for producers of other crops. Through interviews with businessmen and industry representatives related to the production of silk in Brazil, it is perceived that they feel optimistic about the future of silk, as there is a greater concern with the use of products from more sustainable extraction, durable and with higher added value, and silk meets these requirements. Furthermore, preliminary studies indicate a positive correlation between silk production and Carbon Footprint mitigation. In this way, sericulture, in a sustainable, ethical and socially responsible manner, may be increasingly prominent, and consequently, positively reflecting on the Brazilian economy as a whole. It is concluded that sericulture is an economically viable activity for Brazil that presents favorable soil and climate conditions for the creation of silkworms, as well as generates jobs and income in the rural area, contributing to a decrease in the rural exodus. Driven by the mechanization and modernization of agricultural activity, the national sericulture has resumed a prominent place

Established interspecific metabolic allometric relationships do not adequately describe the complexity and variable physiological states of developing animals. Consequently, intraspecific allometric relationships of oxygen consumption and carbon dioxide production as a function of body mass; the respiratory quotient; the function of the silk cocoon; and body composition were investigated for each distinct developmental stage of the silkworm, Bombyx mori. Whole animal O2 consumption in Bombyx ranged from 0.00064 + 0.000047 ml O2 .hr-1 at larval instar I to 0.77 + 0.06 ml O2 .hr-1 in pre-pupal, falling to 0.21+ 0.01 ml O2 .hr-1 in the pupae. Those instars having a significant relationship between O2 consumption as a function of body mass, the slope of the line relating O2 consumption to body mass varied between 0.99 and 1.02, while across all instars the slope was 0.82. Developmental allometry should be presented for individual developmental stages because the individual allometric exponents of the stages can be significantly different from the overall allometric exponent throughout development and in some cases, the overall allometric exponent can be a statistical artifact. The first larval instar of Bombyx mori has the lowest cross sectional area of high metabolic tissue of the midgut (27%) and had one of the highest percentages of some metabolically inert tissues (i.e. lipid, 7.5%). Body composition of the first instar does not support the idea that smaller mass animals having the highest O2 consumption are composed of a greater percentage of metabolically active organs when compared to larger animals. However, this developmental stage has the highest percentage of the mitochondrial marker cytochrome oxidase, which correlates well with the high O2 consumption rate of the smaller mass. Therefore, established interspecific principles should not be assumed to function as valid models for intraspecific developmental relationships of metabolism as a function of body mass. Developmental allometry should include an analysis of individual stages of development as well as an analysis of development as a whole to gain a comprehensive understanding of the complexity of allometry of the developing animal such as the silkworm.

La communication phéromonale chez les lépidoptères, si sensible et spécifique, constitue un modèle de choix pour l'étude des bases moléculaires de la réception olfactive. La spécificité de ce système serait assurée dès le niveau périphérique, dans l'antenne, par l'intervention d'une diversité de protéines impliquées dans la chimioréception des odorants. Le ver à soie, Bombyx mori, est une espèce particulièrement appréciée pour l'étude des mécanismes olfactifs : la réponse des mâles à la phéromone est connue, l'espèce est manipulable génétiquement et les séquences génomiques sont accessibles sur Internet. Au cours de mon travail de thèse, j'ai pu identifier et caractériser au niveau moléculaire une diversité de gènes olfactifs appartenant à différentes familles par des techniques bioinformatiques d'analyse du génome et de biologie moléculaire. Leurs patrons d'expression ont notamment été analysés afin de vérifier si leur localisation tissulaire était compatible avec une fonction chimiosensorielle. Certains de ces gènes (BmPBP2, BmPBP3, BmAOX2) pourraient coder pour des protéines spécifiquement impliquées dans la réception phéromonale alors que d'autres (BmAOX1, BmSNMP2) pourraient intervenir aussi dans la réception de molécules moins spécifiques. Par leurs interactions combinées et séquentielles avec les molécules odorantes, ces différentes familles de protéines permettraient d'assurer leur reconnaissance spécifique au cours des différentes étapes périphériques de la réception olfactive. Par ailleurs, j'ai pu participer à la mise au point chez le ver à soie d'un outil novateur d'analyse fonctionnelle in vivo basé sur l'expression par transgenèse de RO dans les antennes du ver à soie. Ce système a été développé avec un récepteur phéromonal mâle-spécifique, BmOR1. Les femelles des lignées transgéniques exprimaient fortement le récepteur dans leurs antennes, mais se sont révélées incapables de répondre au composé phéromonal (Bol) au cours d'enregistrements électrophysiologiques. L'utilisation future d'un nouveau promoteur spécifique des neurones olfactifs, pOR2, pourrait permettre de développer le premier système stable d'analyse fonctionnelle in vivo chez un lépidoptère.

The goal of the thesis is to incorporate materials with either fluorescent or conductive properties in silk fibers, by feeding silkworms with a diet containing these materials. To achieve this, one would have to breed (rear) silkworm from eggs into larvaes, then to feed the silkworms with this special diet containing fluorescent or conductive materials. Samples of silk were then collected either from spun cocoons or via removing the silk producing organs (silk glands) from the silkworms via dissection. The samples were then analyzed with absorbance spectrometer, spectrofluorometer or via photoluminesecent measurement to determine if any materials had been incorporated into the silk fibers.   Silkworms were successfully reared from eggs up to moths, once the silkworm larvae had grown enough in size their diet were switches from their regular food (silkworm chow) to food containing conjugated molecules or polymers with fluorescent or conductive properties. A total of 14 materials were tested. One material gave a clear positive result and that was from the fluorescent compound Rhodamine B. Other fluorescent materials, Nile red and POWT yielded some results indicating their presence in the silk but the results were not conclusive. The rest of the materials all failed with being incorporated within the silk fibers; this was due to their lethality, size, lack of zwitterionic properties and such.  The properties of the materials are of great importance for the uptake process, where a small zwitterionic molecule has a great change of being taken up and incorporated in the silk fibers. Whereas a big materials such as a polymer without any zwitterionic will in most cases just follow through the food in the digestive track without any uptake.

Transgenesis of silkworms has great potential for the development of silk with new properties as well as for the preparation of recombinant proteins for the use in biomedicine. Zabelina et al. (2015a) showed that transgenesis of parthenogenetic silkworms facilitates the selection and maintenance of transgenic homozygotes with stabile transgene insertions. However, the efficiency of transgenesis was less than 2 % compared to 60 % in the standard, non-parthenogenetic silkworms. The purpose of the present research was to explore the cause of this difference. Since transgenesis is normally performed at 25 °C but in the parthenogenetic silkworms at 15 °C (3 days incubation at this temperature is part of the protocol for the induction of parthenogenetic development), we assumed that the eggs incubated at 15 °C might have been injected with the DNA construct at unsuitable time. The work was therefore focused on the rate of embryogenesis at 15 °C in the eggs treated in different ways. Intensive cleavage of the control eggs (strain K23) was observed at 12 h after oviposition at 25 °C and between 24 and 36 h at 15 °C. The transgenesis of parthenogenetic silkworms is also complicated by the embryonic diapause. In the current work, diapause was suppressed by implanting PK1 ovaries into the non-parthenogenetic male hosts K23. Parthenogenetic development was activated by the heat shock in the chorionated eggs dissected from the implants. No cleavage was detected at 12 h after the acti-vation and nearly complete blastoderm was found at 48 h. In respect to the course of cleavage at 15 °C, transgene injection 24 h after the activating heat shock can be recommended. The eggs from endogenous ovaries of the K23 females, which also contained the implants of the PK1 ovaries, acquired partial capacity of parthenogenesis. Low rate of embryogenesis was also found in the transgenic clone VTG1. Current results suggest that more research is needed to understand and possibly explore differences in the rate of silkworms exposed to different treatments.

The spun-out silk fiber consists of two fibroin filaments that are cemented together by sericin coating. The serine-rich sericins, which make 20-30% of the cocoon silk proteins in Bombyx mori, are dissolved in hot water during silk fiber reeling from the cocoon. The sericin extract is usually discarded. Only small amounts are currently used in cosmetics and lately also as replacement of bovine serum products in the cell culture media. The use in culture media is hindered by poor standardization of the extracts. To overcome this problem, we attempted preparation of several recombinant proteins based on partial sequences of one out of the three sericin genes of Bombyx mori, sericin 3. Translation product of the Ser3 gene is extremely serine-rich with a relatively high representation of the aspartate, asparagin, glutamate, and glutamine. Using specific primers we have prepared a cDNAs of 267, 279, 525, 672, and 528 bp, respectively, derived from the Ser3 gene. The cDNAs were cloned and expressed as fusion proteins with hexahistidine in Escherichia coli. The proteins were purified by affinity chromatography and analyzed by acrylamide electrophoresis. Ser3 gene contain repetitive motifs rich in serine and including some charged amino acids.

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This diploma thesis is focused on the silk production of invertebrates. The aim of the work is to systematically introduce important species and describe the purpose of their silk production. The ability to produce silk is widespread in many insect families. The production of proteinaceous fibers also occurs in arachnids and (in the form of byssus threads) also in mollusks. The Domestic Silk Moth (Bombyx mori) is an economically important insect, being a primary producer of silk. Hence, an integral part of the thesis focuses on Domestic Silk Moth. In this thesis all developmental stages of Silk Moth (from an egg to an adult) are described. In the past, efforts to breed silkworms also appeared in the Czech lands. Therefore, a short chapter of the thesis is devoted to the history of sericulture. Furthermore, this thesis describes methods of rearing silkworm larvae. For students of Natural Sciences and Biology, it is crucial to be in touch with live objects. Because the silkworm rearing is quite simple, it is possible to incorporate this topic to the school projects about holometabolous insects. The practical part of this thesis contains schedule of practical exercise about silk moths. And in final section of practical part, worksheets for lower-secondary students are presented. Keywords: silkworm...