Pleurostomatid ciliates,as a highly diverse and widely distributed unicellular eukaryote group,play a crucial role in the cycling of nutrients and energy in microbial food webs.However,research on pleurostomatids remains insufficient,resulting in a paucity of molecular information and substantial gaps in knowledge of their phylogenetic relationships.In recent years,we investigated pleurostomatid diversity in various Chinese habitats,including their systematic relationships and taxonomic circumscriptions,which were comprehensively analyzed using an integrative morphomolecular approach.Results revealed that:(1)pleurostomatids can be categorized into two suborders,Protolitonotina subord.nov.and Amphileptina Jankowski,1967;(2)Protolitonotina subord.nov.represents the ancestral pleurostomatid group and includes two genera,Protolitonotus and Heterolitonotus gen.nov.,characterized by right kineties progressively shortened along rightmost full kineties and absence of a left dorsolateral kinety;(3)Heterolitonotus gen.nov.represents an orphan lineage and is defined by an oral slit extending to its dorsal margin;(4)“Protolitonotus clampi”does not group with congeners but instead represents an orphan lineage,thus Novilitonotus gen.nov.is established to which P.clampi is transferred as Novilitonotus clampi comb.nov.;(5)three new species,Apoamphileptus paraclaparedii sp.nov.,Heterolitonotus rex gen.nov.,sp.nov.,and Loxophyllum apohelus sp.nov.,are described;and(6)helices 21es6a to 21es6d within the V4 region of small subunit ribosomal RNA(SSU rRNA)may serve as a useful tool for discriminating pleurostomatids.The evolutionary relationships among all main lineages of pleurostomatids are discussed and a key to the identification of pleurostomatid genera is provided.
Orchidaceae are one of the largest families of angiosperms in terms of species richness.In the last decade,numerous studies have delved into reconstructing the phylogenetic framework of Orchidaceae,leveraging data from plastid,mitochondrial and nuclear sources.These studies have provided new insights into the systematics,diversification and biogeography of Orchidaceae,establishing a robust foundation for future research.Nevertheless,pronounced controversies persist regarding the precise placement of certain lineages within these phylogenetic frameworks.To address these discrepancies and deepen our understanding of the phylogenetic structure of Orchidaceae,we provide a comprehensive overview and analysis of phylogenetic studies focusing on contentious groups within Orchidaceae since 2015,delving into discussions on the underlying reasons for observed topological conflicts.We also provide a novel phylogenetic framework at the subtribal level.Furthermore,we examine the tempo and mode underlying orchid species diversity from the perspective of historical biogeography,highlighting factors contributing to extensive speciation.Ultimately,we delineate avenues for future research aimed at enhancing our understanding of Orchidaceae phylogeny and diversity.
Yajun WangHanchen WangChao YeZhiping WangChongbo MaDongliang LinXiaohua Jin
Dear Editor,Bamboos(Bambusoideae,Poaceae)are of significant economic and ecological importance,supporting billions of people and contributing to international trade(Wu et al.,2023).They play a crucial role in carbon fixation and support a multitude of other species including the giant panda(Clark et al.,2015).Since the release of the first draft genome of moso bamboo(Phyllostachys edulis)(Peng et al.,2013),there has been a notable increase in the sequencing,assembly,and annotation of diverse bamboo genomes(Guo et al.,2019;Zheng et al.,2022;Ma et al.,2024).An existing resource for bamboo genomics,BambooGDB(Zhao et al.,2014),provides information based on the individual draft reference genome of moso bamboo.What is needed,however,is a resource reinforcing multiple genome assemblies in Bambusoideae to enable researchers to unravel the evolutionary history of chromosomes and genes through cladespecific comparative genomic investigations.Here,we present BambooBase(https://bamboo.genobank.org/),a newly developed web-based database designed to provide a seamless user experience for bamboo omics and systematics.
In this paper,we study the systematics of the 2_(1)^(+)states in the N=82 even-even isotones with proton numbers between 52 and 72.We calculate the level energies of the 0_(1)^(+),2_(1)^(+)states and the electric quadrupole reduced transition probabilities B(E2;2_(1)^(+)→0_(1)^(+)),in the framework of the nuclear shell model with a monopole-and multipole-optimized realistic interaction.Our calculations yield good agreement with the experimental data and show a 2.5 MeV gap at Z=64 subshell closure in^(146)Gd.We predict that the B(E2;2_(1)^(+)→0_(1)^(+))value for^(146)Gd is close to those for^(142)Nd and^(144)Sm,and the values increase rapidly from^(148)Dy to^(152)Yb.
The Chayong Cu-polymetallic deposit is a recently discovered Cu-polymetallic deposit hosted in the Sanjiang Metallogenic Belt within the Tibetan Plateau of China to the northeast of the North Qiangtang terrane.The ore body occurs in siltstone and is controlled by a northwest-trending fault structure.According to the associations,assemblages,and cutting relationships between ore veins,the hydrothermal mineralization period can be divided into three mineralization stages:(1)a molybdenite mineralization stage,(2)a Cu-polymetallic sulfide stage,and(3)a quartzcarbonate stage.Two types of fluid inclusions(FIs),namely,liquid and vapor-rich inclusions,are present in quartz as so ciated with sulfide minerals.Early-stage FIs are both iquid and vapor-rich,homogenized at temperatures ranging from 364.1 to 384.2℃,and have salinities ranging from0.70%to 9.60%NaCl equivalent(eqv).The middle-stage FIs are also both liquid-and vapor-rich,homogenized at temperatures ranging from 272.4 to 355.6℃,and have salinities ranging from 0.53%-17.10%NaCl eqv.The late-stage FIs are liquid,homogenized at temperatures ranging from 209.4to 255.3℃,and have salinities ranging from 0.35%-6.87%NaCl eqv.The samples from the deposit haveδ^(34)S values of-21.8‰to-19.2‰and-5.5‰to-6.0‰,suggesting that sulfur was derived from the host sediments and magmatic fluids,respectively.The metallic minerals within the deposit have^(206)Pb/^(204)Pb,^(207)Pb/^(204)Pb,and^(208)Pb/^(204)Pb values of 18.439-18.458,15.656-15.679,and 38.772-38.863,respectively,suggesting that the metals were derived from the upper crust and orogenic belts.The samples from the deposit haveδ^(18)O_(W)values of 2.99‰-7.99‰andδD_(W) values ranging from-84.4‰to-73.9‰,indicating that the pre-forming fluids were magmatic and mixed with minor amounts of meteoric water.The ore-forming fluid of the Chayong copper polymetallic deposit was a high-temperature,medium-to low-salinity H_(2)O-NaCl-CH_(4)-N_(2)±CO_(2)fluid system.The early high-temperature magmatic fluid,due to b
The Mg isotopic compositions of siliciclastic components(δ^(26)Mg_(sili))of sediments and sedimentary rocks have been commonly used to constrain the intensity of continental weathering,based on observations of,(1)an upward enrichment of26Mg in modern weathering profiles,(2)preferential uptake of26Mg in soil clays,and(3)general positive correlations between weathering intensities andδ^(26)Mg_(sili)values.However,not all weathering profiles display an upward increase ofδ^(26)Mg_(sili),and not all soil clays enrich in26Mg,complicating the interpretations ofδ^(26)Mg_(sili)data of sediments and sedimentary rocks.To further explore the controls ofδ^(26)Mg_(sili)of sediments and sedimentary rocks,here we measuredδ^(26)Mg_(sili),mineralogical compositions and major element compositions of deep sea sediments from South China Sea(SCS)and carbonate rock samples from two late Paleozoic sections in South China.Carbonate samples show decreasing trends of both normalized Mg concentration(Mgnorm)andδ^(26)Mg_(sili)values with the increase of weathering intensity,while SCS sediments samples do not show any correlation between Mgnormorδ^(26)Mg_(sili)values and weathering intensity.A three-stages weathering model is developed to explain the observed Mgnorm andδ^(26)Mg_(sili)data.In the new model,weathering can be divided into three stages,(1)the preliminary weathering stage characterized by dissolution of primary minerals and formation of secondary clay minerals in saprolite,(2)the transitional stage with massive vermiculite and chlorite formation on the bottom of soil,and(3)the advanced stage showing dissolution of vermiculite and chlorite in the top of soil.The new model explains anδ^(26)Mg_(sili)increase and Mgnormdecrease with an increase weathering intensity in preliminary weathering stage and decrease of Mgnormandδ^(26)Mg_(sili)with increase weathering intensity in advanced weathering stage.The revised weathering model warrants the application of Mg isotope in the study of continental weathering in deep time.
