scholarly journals New lineages of photobionts in Bolivian lichens expand our knowledge on habitat preferences and distribution of Asterochloris algae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Magdalena Kosecka ◽  
Beata Guzow-Krzemińska ◽  
Ivana Černajová ◽  
Pavel Škaloud ◽  
Agnieszka Jabłońska ◽  
...  

AbstractWe studied the biodiversity of Asterochloris photobionts found in Bolivian lichens to better understand their global spatial distribution and adaptation strategies in the context of a worldwide phylogeny of the genus. Based on nuclear ITS rDNA, the chloroplast rbcL gene and the actin type I gene we reconstructed a phylogenetic tree that recovered nine new Asterochloris lineages, while 32 Bolivian photobiont samples were assigned to 12 previously recognized Asterochloris lineages. We also show that some previously discovered Asterochloris photobiont species and lineages may occur in a broader spectrum of climatic conditions, and mycobiont species and photobionts may show different preferences along an altitude gradient. To reveal general patterns of of mycobiont specificity towards the photobiont in Asterochloris, we tested the influence of climate, altitude, geographical distance and effects of symbiotic partner (mycobiont) at the species level of three genera of lichen forming fungi: Stereocaulon, Cladonia and Lepraria. Further, we compared the specificity of mycobionts towards Asterochloris photobionts in cosmopolitan, Neotropical, and Pantropical lichen forming fungi. Interestingly, cosmopolitan species showed the lowest specificity to their photobionts, but also the lowest haplotype diversity. Neotropical and Paleotropical mycobionts, however, were more specific.

2020 ◽  
Author(s):  
Magdalena Kosecka ◽  
Beata Guzow-Krzemińska ◽  
Ivana Černajová ◽  
Pavel Škaloud ◽  
Agnieszka Jabłońska ◽  
...  

Abstract We studied biodiversity of Asterochloris photobionts found in lichen symbioses in Bolivian Andean vegetation and, to better understand global spatial distribution and adaptation strategies of this algae, in relation to worldwide phylogeny of the genus. Based on nuclear ITS rDNA, chloroplast rbcL gene and actin type I gene we constructed a phylogenetic tree that recovered 12 new Asterochloris lineages; and 29 Bolivian photobiont samples were assigned to 11 previously recognized Asterochloris lineages. We showed that some Asterochloris photobiont species and lineages known to date may occur in a broader spectrum of climatic conditions and mycobiont species and photobionts may show different preferences in the altitude gradient. To reveal general patterns of specificity of the mycobionts towards the photobiont in Asterochloris dependent symbiosis on global range, we tested the influence of climate, altitude, geographical distance and effects of symbiotic partner (mycobiont) at the species level of three genera of lichen forming fungi, i.e. Stereocaulon, Cladonia and Lepraria. Also, we compared specificity of mycobionts towards Asterochloris photobionts in cosmopolitan, Neotropical, and Pantropical lichen forming fungi. Interestingly, cosmopolitan species showed the lowest specificity to their photobionts’, but also the lowest haplotype diversity. While, Neotropical and Paleotropical mycobionts were more specific.


1997 ◽  
Vol 272 (7) ◽  
pp. 4458-4466 ◽  
Author(s):  
Jing Jin Gu ◽  
Jozef Spychala ◽  
Beverly S. Mitchell

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
D. Kosova-Maali ◽  
E. Bergeron ◽  
Y. Maali ◽  
T. Durand ◽  
J. Gonzalez ◽  
...  

This study aims at genetic characterization and phylogenetic relationships ofNocardia brasiliensisfocusing by using housekeepingrrs,hsp65,andsodAgenes.N. brasiliensisis the species responsible for 80% of cases of actinomycetoma, one form of cutaneous nocardiosis which occurs mainly in tropical regions reaching immunocompetent patients in which the disease can lead to amputation. We analyze 36 indigenous cases ofN. brasiliensisthat happened in France. Phylogenetic analysis targetingrrsgene showed no robustness at phylogenetic nodes level. However, the use of a concatenation ofhsp65andsodAgenes showed that the tested strains surprisingly ranked in 3 well-defined genotypes. Genotypes 2 and 3 were phylogenetically closer to each other and both diverged from genotype 1 sustained by a high bootstrap of 81%. This last genotype hosts all the cases of pulmonary forms (3), the sole cerebral form, and almost all the cases of immunocompromised patients (3 out of 4). Moreover, excepting one of them, all the strains belonging to this group present a susceptibility to imipenem which is not the case in the other genotypes that rarely count among them strains being susceptible to this drug. The haplotype diversity (Hd) ofhsp65(0.927) andsodA(0.885) genes was higher than that ofrrs(0.824). For this gene, we obtained 16 polymorphic sites whereas, forhsp65andsodAgenes, up to 27 and 29 were identified, respectively. This study reveals that these two genes have an important genetic discriminatory power for the evaluation of the intraspecies genetic variability ofN. brasiliensisand they may be useful for identification purposes at species level. This study also reveals the possible existence of a new species harbored by genotype 1.


2012 ◽  
Vol 8 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Thomas Pommier ◽  
Emmanuel J. P. Douzery ◽  
David Mouillot

Although environmental filtering has been observed to influence the biodiversity patterns of marine bacterial communities, it was restricted to the regional scale and to the species level, leaving the main drivers unknown at large biogeographic scales and higher taxonomic levels. Bacterial communities with different species compositions may nevertheless share phylogenetic lineages, and phylogenetic turnover (PT) among those communities may be surprisingly low along any biogeographic or environmental gradient. Here, we investigated the relative influence of environmental filtering and geographical distance on the PT between marine bacterial communities living more than 8000 km apart in contrasted abiotic conditions. PT was high between communities and was more structured by local environmental factors than by geographical distance, suggesting the predominance of a lineage filtering process. Strong phenotype-environment mismatches observed in the ocean may surpass high connectivity between marine microbial communities.


1996 ◽  
Vol 8 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Rina Wu ◽  
Eric Legius ◽  
Wim Robberecht ◽  
Monique Dumoulin ◽  
Jean-Jacques Cassiman ◽  
...  

1992 ◽  
Vol 12 (10) ◽  
pp. 4714-4723
Author(s):  
J L Slack ◽  
M I Parker ◽  
V R Robinson ◽  
P Bornstein

Although transformation of rodent fibroblasts can lead to dramatic changes in expression of extracellular matrix genes, the molecular basis and physiological significance of these changes remain poorly understood. In this study, we have investigated the mechanism(s) by which ras affects expression of the genes encoding type I collagen. Levels of both alpha 1(I) and alpha 2(I) collagen mRNAs were markedly reduced in Rat 1 fibroblasts overexpressing either the N-rasLys-61 or the Ha-rasVal-12 oncogene. In fibroblasts conditionally transformed with N-rasLys-61, alpha 1(I) transcript levels began to decline within 8 h of ras induction and reached 1 to 5% of control levels after 96 h. In contrast, overexpression of normal ras p21 had no effect on alpha 1(I) or alpha 2(I) mRNA levels. Nuclear run-on experiments demonstrated that the transcription rates of both the alpha 1(I) and alpha 2(I) genes were significantly reduced in ras-transformed cells compared with those in parental cells. In addition, the alpha 1(I) transcript was less stable in transformed cells. Chimeric plasmids containing up to 3.6 kb of alpha 1(I) 5'-flanking DNA and up to 2.3 kb of the 3'-flanking region were expressed at equivalent levels in both normal and ras-transformed fibroblasts. However, a cosmid clone containing the entire mouse alpha 1(I) gene, including 3.7 kb of 5'- and 4 kb of 3'-flanking DNA, was expressed at reduced levels in fibroblasts overexpressing oncogenic ras. We conclude that oncogenic ras regulates the type I collagen genes at both transcriptional and posttranscriptional levels and that this effect, at least for the alpha 1(I) gene, may be mediated by sequences located either within the body of the gene itself or in the distal 3'-flanking region.


Zootaxa ◽  
2020 ◽  
Vol 4772 (2) ◽  
pp. 253-276
Author(s):  
MIN OK SONG ◽  
CHANG-HO LEE

A taxonomic study on bdelloid rotifers collected from various terrestrial habitats at five different locations in Korea resulted in eight new Korean records and two new species-level taxa, Philodina clypeata  n. sp. and P. verrucosa  n. sp. Among the eight new Korean records, two species- and three subspecies-level taxa are new to Asia as well. These new Korean records also include seven rare species/subspecies-level taxa with poorly known distributions. Habrotrocha gracilis quadridens Schulte and Macrotrachela zickendrahti seda Donner were rediscovered in Korea 64 and 53 years, respectively, after the original descriptions. Habrotrocha ligula aligula Burger, Macrotrachela insulana Donner, M. petulans Milne, M. pinnigera (Murray), and Philodina parvicalcar De Koning have been reported from two to three countries only including their type localities before the present study. In addition, a partial sequence of mitochondrial cytochrome c oxidase subunit I gene (mtCOX1) for P. verrucosa  n. sp. as well as a taxonomic key for the Philodina species recorded from Korea to date are also provided here. 


2005 ◽  
Vol 152 (2) ◽  
pp. 242-249 ◽  
Author(s):  
A.M. deGiorgio-Miller ◽  
L.J. Treharne ◽  
R.J. McAnulty ◽  
P.D. Coleridge Smith ◽  
G.J. Laurent ◽  
...  

1992 ◽  
Vol 12 (10) ◽  
pp. 4714-4723 ◽  
Author(s):  
J L Slack ◽  
M I Parker ◽  
V R Robinson ◽  
P Bornstein

Although transformation of rodent fibroblasts can lead to dramatic changes in expression of extracellular matrix genes, the molecular basis and physiological significance of these changes remain poorly understood. In this study, we have investigated the mechanism(s) by which ras affects expression of the genes encoding type I collagen. Levels of both alpha 1(I) and alpha 2(I) collagen mRNAs were markedly reduced in Rat 1 fibroblasts overexpressing either the N-rasLys-61 or the Ha-rasVal-12 oncogene. In fibroblasts conditionally transformed with N-rasLys-61, alpha 1(I) transcript levels began to decline within 8 h of ras induction and reached 1 to 5% of control levels after 96 h. In contrast, overexpression of normal ras p21 had no effect on alpha 1(I) or alpha 2(I) mRNA levels. Nuclear run-on experiments demonstrated that the transcription rates of both the alpha 1(I) and alpha 2(I) genes were significantly reduced in ras-transformed cells compared with those in parental cells. In addition, the alpha 1(I) transcript was less stable in transformed cells. Chimeric plasmids containing up to 3.6 kb of alpha 1(I) 5'-flanking DNA and up to 2.3 kb of the 3'-flanking region were expressed at equivalent levels in both normal and ras-transformed fibroblasts. However, a cosmid clone containing the entire mouse alpha 1(I) gene, including 3.7 kb of 5'- and 4 kb of 3'-flanking DNA, was expressed at reduced levels in fibroblasts overexpressing oncogenic ras. We conclude that oncogenic ras regulates the type I collagen genes at both transcriptional and posttranscriptional levels and that this effect, at least for the alpha 1(I) gene, may be mediated by sequences located either within the body of the gene itself or in the distal 3'-flanking region.


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