Two new species of Tardigrada from moss cushions (Grimmia sp.) in a xerothermic habitat in northeast Tennessee (USA, North America), with the first identification of males in the genus Viridiscus

Background. The phylum Tardigrada consists of over 1,300 species that inhabit terrestrial, freshwater and marine environments throughout the world. In terrestrial habitats they live primarily in mosses, lichens, leaf litter and soil, whereas tardigrades in freshwater and marine environments are mainly found in sediments and on aquatic plants. More than 65 species have been previously reported in the state of Tennessee, USA. Methods. Tardigrades present in moss cushions (Grimmia sp.) collected from a xerothermic habitat on the East Tennessee State University campus, Johnson City, TN, USA, were extracted, mounted on slides, identified, and counted. Additional samples of fresh dried moss were used for integrative analyses, including morphological analysis with phase contrast (PCM) and scanning electron microscopy (SEM), as well as molecular analyses of COI, 18S rRNA, 28S rRNA, and ITS-2 of the Macrobiotus and Milnesium species. Results. Five species were found, including two species new to science: Viridiscus miraviridis sp. nov. and Macrobiotus basiatus sp. nov. Viridiscus miraviridis sp. nov. differs from other members of the genus mainly by having a different type of dorsal cuticle and some other, more subtle, morphometric characters. In addition to the two new species, Viridiscus perviridis and Viridiscus viridissimus were present, and males of Vir. viridissimus were found for the first time, the first record of males in the genus Viridiscus. Macrobiotus basiatus sp. nov. is most similar to Macrobiotus nelsonae, but it differs from Mac. nelsonae mainly by the stylet supports being situated in a more anterior position, shorter and narrower egg processes, and a smaller number of areoles around the egg processes. Moreover, the identification of Milnesium inceptum was confirmed as the first record for the USA by analysis of COI

Two New Species of Tardigrada From Moss Cushions (Grimmia sp.) in a Xerothermic Habitat in Northeast Tennessee (USA, North America), With the First Identification of Males in the genus Viridiscus

Background. The phylum Tardigrada consists of over 1,300 species that inhabit terrestrial, freshwater and marine environments throughout the world. In terrestrial habitats they live primarily in mosses, lichens, leaf litter and soil, whereas tardigrades in freshwater and marine environments are mainly found in sediments and on aquatic plants. More than 65 species have been previously reported in the state of Tennessee, USA. Methods. Tardigrades present in moss cushions (Grimmia sp.) collected from a xerothermic habitat on the East Tennessee State University campus, Johnson City, TN, USA, were extracted, mounted on slides, identified, and counted. Additional samples of fresh dried moss were used for integrative analyses, including morphological analysis with phase contrast (PCM) and scanning electron microscopy (SEM), as well as molecular analyses of COI, 18S rRNA, 28S rRNA, and ITS-2 of the Macrobiotus and Milnesium species. Results. Five species were found, including two species new to science: Viridiscus miraviridis sp. nov. and Macrobiotus basiatus sp. nov. Viridiscus miraviridis sp. nov. differs from other members of the genus mainly by having a different type of dorsal cuticle and some other, more subtle, morphometric characters. In addition to the two new species, Viridiscus perviridis and Viridiscus viridissimus were present, and males of Vir. viridissimus were found for the first time, the first record of males in the genus Viridiscus. Macrobiotus basiatus sp. nov. is most similar to Macrobiotus nelsonae, but it differs from Mac. nelsonae mainly by the stylet supports being situated in a more anterior position, shorter and narrower egg processes, and a smaller number of areoles around the egg processes. Moreover, the identification of Milnesium inceptum was confirmed as the first record for the USA by analysis of COI

VDAC contribution to pathogenesis of Huntington disease revealed by studies of the disease cell models

Wydział BiologiiCelem niniejszej pracy było sprawdzenie czy białko VDAC jest istotne dla rozwoju choroby Huntingtona i zbadanie znaczenia obecności izoform białka VDAC dla obserwowanych efektów ekspresji Htt i mHtt. W badaniach stosowano dwa modele HD: linie komórkowe PC12 i model oparty na komórkach S. cerevisiae. Oba te modele umożliwiają kontrolowaną ekspresję Htt i mHtt, przy czym drugi z nich umożliwia także badanie wpływu tej ekspresji w obecności bądź przy braku danej izoformy ludzkiego białka VDAC. Modele te wykorzystano dla zbadania wpływu ekspresji Htt i mHtt na przeżywalność komórek, funkcje bioenergetyczne mitochondriów, a także właściwości kanałowe białek VDAC. Otrzymane wyniki wskazują, że obecność białka VDAC ma znaczenie dla analizowanych efektów ekspresji Htt i mHtt. Co więcej, znaczenie ma także izoforma badanego białka VDAC. Stwierdzono na przykład, że ekspresja mHtt w komórkach PC12, w których dominuje ilościowo izoforma VDAC1, jak i w komórkach modelu drożdżowego z ekspresją VDAC1 człowieka skutkuje zmniejszeniem przeżywalności tych komórek, przy czym w przypadku komórek drożdży efekt ten wymaga obecności stresu temperaturowego (tj. 37°C). Co ciekawe, ów stres temperaturowy może mieć wpływ na poziom agregacji mHtt. Otrzymane wyniki uzyskane dla komórek modelu drożdżowego z ekspresją hVDAC1 wydają się potwierdzać kluczowe znaczenie tej izoformy VDAC dla efektu mHtt na funkcjonowanie mitochondriów. Pozostaje to w związku z wynikami uzyskanymi dla preparatów VDAC izolowanych z komórek PC12, w przypadku których wykazano, że ekspresja mHtt może prowadzić do zmian aktywności kanałowej białka VDAC1.The aim of this study was to check whether VDAC protein is important for Htt and/or mHtt effects on cells, which in turn would indicate VDAC participation in the pathogenesis of HD. The contribution of VDAC isoforms to the observed effects of Htt and mHtt expression was also evaluated. Two models of this disease were used in the study: PC12 and Saccharomyces cerevisiae cells. Both of these models allow for controlled expression of Htt and mHtt, while the second one also allows for determination of the effect of Htt/mHtt expression in the presence or absence of human VDAC isoforms. These models were used to investigate the effect of Htt and mHtt expression on cell survival, bioenergetic functions as well as channel properties of VDAC proteins. The obtained results indicate that the presence of VDAC protein is important for the analyzed effects of Htt and mHtt expression. Moreover, the isoform of VDAC protein also matters. For example, the expression of mHtt in PC12 cells (in which VDAC1 isoform is quantitatively dominant), as well as in the yeast HD model cells expressing human VDAC1 (hVDAC1) results in decreased survival of these cells. In the case of the yeast cells this effect requires the presence of temperature stress (37oC), which may affect the level of mHtt aggregation. Moreover, data obtained for hVDAC1 expressing cells of the yeast HD model appear to confirm the key importance of this VDAC isoform for mHtt effect on mitochondrial function. This is in line with results obtained for VDAC preparations isolated from PC12 cells as it was observed that mHtt expression may lead to changes in VDAC1 channel activity.Badania zrealizowano ze środków: NCN 2011/01/B/NZ3/00359 GDWB-06/2015 KNOW RNA Research Centre in Poznan No.01/KNOW2/201

VDAC contribution to pathogenesis of Huntington disease revealed by studies of the disease cell models

Wydział BiologiiCelem niniejszej pracy było sprawdzenie czy białko VDAC jest istotne dla rozwoju choroby Huntingtona i zbadanie znaczenia obecności izoform białka VDAC dla obserwowanych efektów ekspresji Htt i mHtt. W badaniach stosowano dwa modele HD: linie komórkowe PC12 i model oparty na komórkach S. cerevisiae. Oba te modele umożliwiają kontrolowaną ekspresję Htt i mHtt, przy czym drugi z nich umożliwia także badanie wpływu tej ekspresji w obecności bądź przy braku danej izoformy ludzkiego białka VDAC. Modele te wykorzystano dla zbadania wpływu ekspresji Htt i mHtt na przeżywalność komórek, funkcje bioenergetyczne mitochondriów, a także właściwości kanałowe białek VDAC. Otrzymane wyniki wskazują, że obecność białka VDAC ma znaczenie dla analizowanych efektów ekspresji Htt i mHtt. Co więcej, znaczenie ma także izoforma badanego białka VDAC. Stwierdzono na przykład, że ekspresja mHtt w komórkach PC12, w których dominuje ilościowo izoforma VDAC1, jak i w komórkach modelu drożdżowego z ekspresją VDAC1 człowieka skutkuje zmniejszeniem przeżywalności tych komórek, przy czym w przypadku komórek drożdży efekt ten wymaga obecności stresu temperaturowego (tj. 37°C). Co ciekawe, ów stres temperaturowy może mieć wpływ na poziom agregacji mHtt. Otrzymane wyniki uzyskane dla komórek modelu drożdżowego z ekspresją hVDAC1 wydają się potwierdzać kluczowe znaczenie tej izoformy VDAC dla efektu mHtt na funkcjonowanie mitochondriów. Pozostaje to w związku z wynikami uzyskanymi dla preparatów VDAC izolowanych z komórek PC12, w przypadku których wykazano, że ekspresja mHtt może prowadzić do zmian aktywności kanałowej białka VDAC1.The aim of this study was to check whether VDAC protein is important for Htt and/or mHtt effects on cells, which in turn would indicate VDAC participation in the pathogenesis of HD. The contribution of VDAC isoforms to the observed effects of Htt and mHtt expression was also evaluated. Two models of this disease were used in the study: PC12 and Saccharomyces cerevisiae cells. Both of these models allow for controlled expression of Htt and mHtt, while the second one also allows for determination of the effect of Htt/mHtt expression in the presence or absence of human VDAC isoforms. These models were used to investigate the effect of Htt and mHtt expression on cell survival, bioenergetic functions as well as channel properties of VDAC proteins. The obtained results indicate that the presence of VDAC protein is important for the analyzed effects of Htt and mHtt expression. Moreover, the isoform of VDAC protein also matters. For example, the expression of mHtt in PC12 cells (in which VDAC1 isoform is quantitatively dominant), as well as in the yeast HD model cells expressing human VDAC1 (hVDAC1) results in decreased survival of these cells. In the case of the yeast cells this effect requires the presence of temperature stress (37oC), which may affect the level of mHtt aggregation. Moreover, data obtained for hVDAC1 expressing cells of the yeast HD model appear to confirm the key importance of this VDAC isoform for mHtt effect on mitochondrial function. This is in line with results obtained for VDAC preparations isolated from PC12 cells as it was observed that mHtt expression may lead to changes in VDAC1 channel activity.Badania zrealizowano ze środków: NCN 2011/01/B/NZ3/00359 GDWB-06/2015 KNOW RNA Research Centre in Poznan No.01/KNOW2/201

The association of VDAC with cell viability of PC12 model of Huntington’s disease

It is becoming increasingly apparent that mitochondria dysfunction plays an important role in pathogenesis of Huntington’s disease (HD) but the underlying mechanism is still elusive. Thus, there is a still need for further studies concerning the upstream events in the mitochondria dysfunction that could contribute to cell death observed in HD. Taking into account the fundamental role of the voltage-dependent anion-selective channel (VDAC) in mitochondria functioning it is reasonable to consider the channel as a crucial element in HD etiology. Therefore, we applied inducible PC12 cell model of HD to determine the relationship between the effect of expression of wild type and mutant huntingtin (Htt and mHtt, respectively) on cell survival and mitochondria functioning in intact cells under conditions of undergoing cell divisions. Because after 48h of Htt and mHtt expression differences in mitochondria functioning co-occurred with differences in the cell viability we decided to estimate the effect of Htt and mHtt expression lasted for 48h on VDAC functioning. Therefore we isolated VDAC from the cells and tested the preparations by black lipid membrane (BLM) system. We observed that the expression of mHtt, but not Htt, resulted in changes of the open state conductance and voltage-dependence when compared to control cells cultured in the absence of the expression. Importantly, for all the VDAC preparations we observed a dominant quantitative content of VDAC1 and the quantitative relationships between VDAC isoforms were not changed by Htt and mHtt expression. Thus, Htt and mHtt-mediated functional changes of VDAC, being predominantly VDAC1, which occur shortly after these protein appearance in cells may result in differences concerning mitochondria functioning and viability of cells expressing Htt and mHtt. The assumption is important for better understanding of cytotoxicity as well as cytoprotection mechanisms of potential clinical application

Towards understanding of plant mitochondrial VDAC proteins: An overview of bean (Phaseolus) VDAC proteins

As the main grain legume consumed worldwide, the common bean (Phaseolus vulgaris) is generally considered as a model for food legumes. The mitochondrial voltage-dependent anion-selective channel (VDAC) is the major transport pathway for inorganic ions, metabolites, and tRNA, and consequently it controls the exchange of these compounds between the cytoplasm and the mitochondrion. Two VDAC isoforms of Phaseolus coccineus have been investigated experimentally. However, plant VDACs are known to belong to a small multigenic family of variable size. Here, we combine available experimental as well as genomic and transcriptomic data to identify and characterize the VDAC family of Phaseolus vulgaris. To this aim, we review the current state of our knowledge of Phaseolus VDAC functional and structural properties. The genomic and transcriptomic data available for the putative VDACs of Phaseolus vulgaris are studied using bioinformatics approach including homology modelling. The obtained results indicate that five out of the seven putative VDAC encoding sequences (named PvVDAC1-5) share strongly conserved motifs and structural homology with known VDACs. Notably, PvVDAC4 and PvVDAC5 are very close to the two abundant and characterized experimentally VDAC isoforms purified from Phaseolus coccineus mitochondria.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Two new species of the genus Milnesium Doyère, 1840 (Tardigrada, Apochela, Milnesiidae) from Madagascar

The knowledge of the diversity and distribution of tardigrades on Madagascar is rather poor. To date, only 13 tardigrade taxa have been reported from this region (including one Milnesium species). We examined 46 specimens belonging to two new-to-science species of the genus Milnesium described herein using an integrative approach, including classical morphology and molecular marker (COI, ITS-2 and 28S rRNA) analysis. The species were found in two moss and lichen samples collected in the Ivohibory forest in Fianarantsoa Province. Milnesium matheusi sp. nov., with claw configuration [3-3]–[3-3] and rather wide buccal tube, morphologically is most similar to: Mil. beatae Roszkowska, Ostrowska & Kaczmarek, 2015, Mil. bohleberi Bartels, Nelson, Kaczmarek & Michalczyk, 2014, Mil. eurystomum Maucci, 1991, Mil. shilohae Meyer, 2015 and Mil. tumanovi Pilato, Sabella & Lisi, 2016; however, it differs from these by morphometric characteristics. Milnesium wrightae sp. nov., by the presence of four points on secondary branches of claws IV, is most similar to Mil. quadrifidum Nederström, 1919. However, Mil. wrightae sp. nov. differs from Mil. quadrifidum by claw configuration ([4-4]–[4-4] in Mil. quadrifidum vs. [3-3]–[4-4] in Mil. wrightae sp. nov.), but also by the position of the fourth points on secondary branches of claws IV, which are located near the base of the claw in the new species and near the top of the claw in Mil. quadrifidum. Genotypic analysis showed that Mil. matheusi sp. nov. is most similar to Milnesium sp. (28S rRNA), Mil. variefidum (COI) and Mil. t. tardigradum (ITS-2) while Mil. wrightae sp. nov. is most similar to Milnesium sp. (28S rRNA), Mil. variefidum (COI) and Mil. matheusi (ITS-2). Five Milnesium taxa are recorded from the African region, including the two new species from Madagascar reported in this study

Two new species of the genus Milnesium Doyère, 1840 (Tardigrada, Apochela, Milnesiidae) from Madagascar

The knowledge of the diversity and distribution of tardigrades on Madagascar is rather poor. To date, only 13 tardigrade taxa have been reported from this region (including one Milnesium species). We examined 46 specimens belonging to two new-to-science species of the genus Milnesium described herein using an integrative approach, including classical morphology and molecular marker (COI, ITS-2 and 28S rRNA) analysis. The species were found in two moss and lichen samples collected in the Ivohibory forest in Fianarantsoa Province. Milnesium matheusi sp. nov., with claw configuration [3-3]–[3-3] and rather wide buccal tube, morphologically is most similar to: Mil. beatae Roszkowska, Ostrowska & Kaczmarek, 2015, Mil. bohleberi Bartels, Nelson, Kaczmarek & Michalczyk, 2014, Mil. eurystomum Maucci, 1991, Mil. shilohae Meyer, 2015 and Mil. tumanovi Pilato, Sabella & Lisi, 2016; however, it differs from these by morphometric characteristics. Milnesium wrightae sp. nov., by the presence of four points on secondary branches of claws IV, is most similar to Mil. quadrifidum Nederström, 1919. However, Mil. wrightae sp. nov. differs from Mil. quadrifidum by claw configuration ([4-4]–[4-4] in Mil. quadrifidum vs. [3-3]–[4-4] in Mil. wrightae sp. nov.), but also by the position of the fourth points on secondary branches of claws IV, which are located near the base of the claw in the new species and near the top of the claw in Mil. quadrifidum. Genotypic analysis showed that Mil. matheusi sp. nov. is most similar to Milnesium sp. (28S rRNA), Mil. variefidum (COI) and Mil. t. tardigradum (ITS-2) while Mil. wrightae sp. nov. is most similar to Milnesium sp. (28S rRNA), Mil. variefidum (COI) and Mil. matheusi (ITS-2). Five Milnesium taxa are recorded from the African region, including the two new species from Madagascar reported in this study