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21.
Perlińska-Lenart U Orlowski J Laudy AE Zdebska E Palamarczyk G Kruszewska JS 《Applied and environmental microbiology》2006,72(12):7778-7784
Expression of the Saccharomyces cerevisiae DPM1 gene (coding for dolichylphosphate mannose synthase) in Trichoderma reesei (Hypocrea jecorina) increases the intensity of protein glycosylation and secretion and causes ultrastructural changes in the fungal cell wall. In the present work, we undertook further biochemical and morphological characterization of the DPM1-expressing T. reesei strains. We established that the carbohydrate composition of the fungal cell wall was altered with an increased amount of N-acetylglucosamine, suggesting an increase in chitin content. Calcofluor white staining followed by fluorescence microscopy indicated changes in chitin distribution. Moreover, we also observed a decreased concentration of mannose and alkali-soluble beta-(1,6) glucan. A comparison of protein secretion from protoplasts with that from mycelia showed that the cell wall created a barrier for secretion in the DPM1 transformants. We also discuss the relationships between the observed changes in the cell wall, increased protein glycosylation, and the greater secretory capacity of T. reesei strains expressing the yeast DPM1 gene. 相似文献
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半翅目鞘喙亚目是一类具有重要演化意义的昆虫。该亚目包括三个科:鞘喙蝽科(Peloridiidae)和卡拉蝽科(Karabasiidae)同属于鞘喙蝽总科;原臭虫科(Progonocimicidae)属于原臭虫总科。鞘喙蝽科是唯一的现生类群,孑遗于南半球。卡拉蝽科化石较丰富,但只发现于中亚、西伯利亚和蒙古中生代地层。本文... 相似文献
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The venom that Chelonus sp. near curvimaculatus injects into each parasitized Trichoplusia ni egg is entirely injected within the first 8 s of the 19-s oviposition period, before deposition of the parasitoid egg that is injected during the final 1-2 s of the oviposition. The parasitization factor, causing precocious metamorphosis of the host, is injected after the venom, but before the parasite egg. The venom by itself does not cause developmental redirection of the host. Chelonus venom proteins are very stable in the host egg during the first 2 days of egg development. Then, on the last day before hatching, they are rapidly degraded by the proteolytic enzymes appearing in 3-day-old T. ni eggs. Among those that degrade the venom proteins are serine-type proteinases, and at least one seems to be a trypsin-like enzyme. 相似文献
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Max A B Haase Jacek Kominek Dana A Opulente Xing-Xing Shen Abigail L LaBella Xiaofan Zhou Jeremy DeVirgilio Amanda Beth Hulfachor Cletus P Kurtzman Antonis Rokas Chris Todd Hittinger 《Genetics》2021,217(2)
Dollo’s law posits that evolutionary losses are irreversible, thereby narrowing the potential paths of evolutionary change. While phenotypic reversals to ancestral states have been observed, little is known about their underlying genetic causes. The genomes of budding yeasts have been shaped by extensive reductive evolution, such as reduced genome sizes and the losses of metabolic capabilities. However, the extent and mechanisms of trait reacquisition after gene loss in yeasts have not been thoroughly studied. Here, through phylogenomic analyses, we reconstructed the evolutionary history of the yeast galactose utilization pathway and observed widespread and repeated losses of the ability to utilize galactose, which occurred concurrently with the losses of GALactose (GAL) utilization genes. Unexpectedly, we detected multiple galactose-utilizing lineages that were deeply embedded within clades that underwent ancient losses of galactose utilization. We show that at least two, and possibly three, lineages reacquired the GAL pathway via yeast-to-yeast horizontal gene transfer. Our results show how trait reacquisition can occur tens of millions of years after an initial loss via horizontal gene transfer from distant relatives. These findings demonstrate that the losses of complex traits and even whole pathways are not always evolutionary dead-ends, highlighting how reversals to ancestral states can occur. 相似文献
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Marzena Wieczorkowska Jacek Zielonka Joanna Celińska Jan Adamus Ewa Ciesielska Andrzej Marcinek 《Free radical research》2013,47(11):1157-1162
It is shown that NADH can be effectively oxidized by 1-methyl-3-nitropyridine in non-enzymatic and enzyme-mediated processes. Mechanistic issues of these reactions are discussed. These processes seem to contribute to the observed cytotoxicity of 1-methyl-3-nitropyridine. A key role of 1-methyl-3-nitropyridinyl radical formed in the enzyme-mediated processes is emphasized. 相似文献