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Embryonic development of the unfertilized silkworm eggs
VRCHOTOVÁ, Markéta
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.
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Molekulární podmíněnost rezistence lnu vůči těžkým kovům a možnost jejího ovlivnění transgenozí
Vrbová, Miroslava
This work is focused on the molecular conditionality of flax resistance to heavy metals. Attention was therefore devoted to the identification of proteins whose role in stress response to heavy metals have not been discovered yet in flax. Two contrasting flax varieties displayed differences in steady state levels of short thiol peptides (GSH and PC) and heavy-metal binding proteins (ferritin and lipocalin) which can detoxify cadmium via chelation. These results are the first published analysis of the proteomic response to cadmium exposure in commercially important annual crop with potential use in phytoremediation. Another of the objectives was to verify the possibilities of influencing the flax resistance to heavy metal using transgenosis. There were obtained a multiplied flax plants, in which the presence of a transgene was verified, and these lines were tested for tolerance and accumulation of cadmium in both in vitro and in the field conditions.
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Risk assessment and perspectives of GMO cultivation in the Czech Republic
ŠANDEROVÁ, Šárka
The bachelor thesis provides an overview of the issue of genetically modified organisms (GMOs). I chose this topic because its importance is currently increasing as GMOs and their products are becoming inherent part of our lives. The areas sown with GM crops increase in the world every year and GM products are also imported to the Czech Republic. In the literature research are described methods used to insert foreign DNA into plant cells. Especially common is transformation via bacteria strain Agrobacterium using so called microprojectiles. Most often used transgenes cause the plant to gain new properties, such as tolerance to herbicides, resistance to insect pests, tolerance to stress etc. There follows a summary of the legislative conditions and the concept of coexistence in the Czech Republic, which every grower, who decides to grow GM crops, should follow. In Europe only two GM crops are allowed for commercial cultivation, Bt corn and GM potatoes. In 2010 The Czech Republic became the only European country where both the allowed crops were grown. In the thesis is also summarised existing knowledge of GM crops cultivation in the world. Finally, we evaluate potential risks associated with GM crops cultivation. Significant role in the risk assessment plays also the impact of GMO cultivation on target and nontarget organisms. We also discuss the possibilities and prospects of their cultivation in our country and in the world. The aim of the thesis is to help the readers, professional or not, understand the issue so they can form their own opinion.
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Isolation, characterization and localization of orthologous sequence of the \kur{Drosophila Notch} gene in codling moth, \kur{Cydia pomonella}
KŮTA, Václav
The codling moth, Cydia pomonella (Tortricidae) is a significant pest in apple orchards. In the 1990ies, a control programme using the Sterile Insect Technique (SIT) has been established, based on bisexual releases of sterile insects into wild populations of this pest. Male-only releases are not possible due to the lack of an efficient system to produce male-only progeny. Recently, a new approach has been proposed for the development of genetic sexing strains in Lepidoptera. It is based on insertion of a dominant conditional lethal mutation of the Notch gene, derived from the N60g11 allele of Drosophila, into the female W chromosome by means of transgenesis. This study deals with isolation, characterization, and chromosomal localization of a codling moth orthologue of the Drosophila Notch gene with the aim to prepare a mutant sequence of the orthologue to be used in plasmid constructs for germline transformation of this pest.
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