Lake-depth related pattern of genetic and morphological diatom diversity in boreal Lake Bolshoe Toko, Eastern Siberia

Abstract

Large, old and heterogenous lake systems are valuable sources of biodiversity. The analysis of current spatial variability within such lakes increases our understanding of the origin and establishment of biodiversity. The environmental sensitivity and the high taxonomic richness of diatoms make them ideal organisms to investigate intra-lake variability. We investigated modern intra-lake diatom diversity in the large and old sub-arctic Lake Bolshoe Toko in Siberia. Our study uses diatom-specific metabarcoding, applying a short rbcL marker combined with next-generation sequencing and morphological identification to analyse the diatom diversity in modern sediment samples of 17 intra-lake sites. We analysed abundance-based compositional taxonomic diversity and generic phylogenetic diversity to investigate the relationship of diatom diversity changes with water depth. The two approaches show differences in taxonomic identification and alpha diversity, revealing a generally higher diversity with the genetic approach. With respect to beta diversity and ordination analyses, both approaches result in similar patterns. Water depth or related lake environmental conditions are significant factors influencing intra-lake diatom patterns, showing many significant negative correlations between alpha and beta diversity and water depth. Further, one near-shore and two lagoon lake sites characterized by low (0-10m) and medium (10-30m) water depth are unusual with unique taxonomic compositions. At deeper (>30m) water sites we identified strongest phylogenetic clustering in Aulacoseira, but generally much less in Staurosira, which supports that water depth is a strong environmental filter on the Aulacoseira communities. Our study demonstrates the utility of combining analyses of genetic and morphological as well as phylogenetic diversity to decipher compositional and generic phylogenetic patterns, which are relevant in understanding intra-lake heterogeneity as a source of biodiversity in the sub-arctic glacial Lake Bolshoe Toko.

Lake Sedimentary DNA Research on Past Terrestrial and Aquatic Biodiversity: Overview and Recommendations

“…The current view is that the DNA information in sediments degrades faster than pigments or lipids, although significant positive correlations have been observed between these different proxies [18,72,77,[137][138][139][140][141]. Studies comparing diatom diversity retrieved from sediment using morphological and genetic approaches consistently show that beta-diversity values obtained from both methods were highly comparable (i.e., the turnover is similar), whereas alpha-diversity values and taxonomic assignment datasets were not [45,[142][143][144][145][146][147]. This discrepancy in the reconstructions is at least in part attributable to very sparsely populated genetic databases available for diatoms, which can be tested in the near-future thanks to the exponential growth of genomic databases and initiatives such as the Earth Biogenome Project [148].…”

A new insight into acute lymphoblastic leukemia in children: influences of changed intestinal microfloras

“…The boxplot of α diversity can show the difference in α diversity between the groups more intuitively. The boxplot can present 5 statistics (minimum, first quartile, median, third median and maximum, as well as 5 lines from bottom to top), with outliers marked with “°” [ 12 – 14 ].…”

“…In the study on microbial composition and structure, OTU or evolutionary types are always used to represent species information. In relevant study on the intestinal flora, PCoA is widely applied to compare the composition of different intestinal floras [ 12 – 14 ].…”

Genetic and morphologic determination of diatom community composition in surface sediments from glacial and thermokarst lakes in the Siberian Arctic

“…The high within-lake diversity of Aulacoseira spp. has been identified by genetic and morphological approaches (Risberg et al 1999;Biskaborn et al 2019b;Stoof-Leichsenring et al 2020), and is mostly explained by water depth variations. Lindavia ocellata is known to be dominant in old and large lakes, and the appearance of different morphological variations over glacial/interglacial cycles has been attributed to climate changes or evolutionary selection (Edlund et al 2003;Cvetkoska et al 2018).…”

“…Glacial lakes in Russia are often characterised by deep and stratified waters, which during winter are covered by a thick ice layer (up to several metres), but do not freeze to the ground (Biskaborn et al 2019b). These large and old lakes possess a wide range of established, in-lake habitats and heterogenous catchment areas that impact intra-lake biodiversity patterns, as has been shown in sub-arctic Lake Bolshoe Toko (Biskaborn et al 2019b;Stoof-Leichsenring et al 2020). Moreover, studies on large lakes uncovered the presence of endemic species (Cvetkoska et al 2018;Genkal and Yarushina 2018) and are hotspots of biodiversity (Cvetkoska et al 2018).…”