scholarly journals Draft genome of the Eutardigrade Milnesium tardigradum sheds light on ecdysozoan evolution

2017 ◽  
Author(s):  
Felix Bemm ◽  
Laura Burleigh ◽  
Frank Förster ◽  
Roland Schmucki ◽  
Martin Ebeling ◽  
...  
Keyword(s):  
Draft Genome ◽  
High Stress ◽  
Sister Group ◽  
Low Earth Orbit ◽  
Protein Domain ◽  
Phylogenetic Position ◽  
Alternative Pathways ◽  
Stress Protection ◽  
Phylogenetic Reconstructions ◽  
The Family

AbstractTardigrades are among the most stress tolerant animals and survived even unassisted exposure to space in low earth orbit. Still, the adaptations leading to these unusual physiological features remain unclear. Even the phylogenetic position of this phylum within the Ecdysozoa is unclear. Complete genome sequences might help to address these questions as genomic adaptations can be revealed and phylogenetic reconstructions can be based on new markers. Here, we present a first draft genome of a species from the family Milnesiidae, namely Milnesium tardigradum. We consistently place M. tardigradum and the two previously sequenced Hypsibiidae species, Hypsibius dujardini and Ramazzottius varieornatus, as sister group of the nematodes with the arthropods as outgroup. Based on this placement, we identify a massive gene loss thus far attributed to the nematodes which predates their split from the tardigrades. We provide a comprehensive catalog of protein domain expansions linked to stress response and show that previously identified tardigrade-unique proteins are erratically distributed across the genome of M. tardigradum. We further suggest alternative pathways to cope with high stress levels that are yet unexplored in tardigrades and further promote the phylum Tardigrada as a rich source of stress protection genes and mechanisms.

scholarly journals A fresh look at Cladarosymblema narrienense, a tetrapodomorph fish (Sarcopterygii: Megalichthyidae) from the Carboniferous of Australia, illuminated via X-ray tomography

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12597
Author(s):  
Alice M. Clement ◽  
Richard Cloutier ◽  
Jing Lu ◽  
Egon Perilli ◽  
Anton Maksimenko ◽  
...  
Keyword(s):  
Original Description ◽  
Sister Group ◽  
Axial Skeleton ◽  
Phylogenetic Position ◽  
Micro Computed Tomography ◽  
Holotype Specimen ◽  
Freshwater Swamp ◽  
The Family ◽  
First Time ◽  
Detailed Work

Background The megalichthyids are one of several clades of extinct tetrapodomorph fish that lived throughout the Devonian–Permian periods. They are advanced “osteolepidid-grade” fishes that lived in freshwater swamp and lake environments, with some taxa growing to very large sizes. They bear cosmine-covered bones and a large premaxillary tusk that lies lingually to a row of small teeth. Diagnosis of the family remains controversial with various authors revising it several times in recent works. There are fewer than 10 genera known globally, and only one member definitively identified from Gondwana. Cladarosymblema narrienense Fox et al. 1995 was described from the Lower Carboniferous Raymond Formation in Queensland, Australia, on the basis of several well-preserved specimens. Despite this detailed work, several aspects of its anatomy remain undescribed. Methods Two especially well-preserved 3D fossils of Cladarosymblema narrienense, including the holotype specimen, are scanned using synchrotron or micro-computed tomography (µCT), and 3D modelled using specialist segmentation and visualisation software. New anatomical detail, in particular internal anatomy, is revealed for the first time in this taxon. A novel phylogenetic matrix, adapted from other recent work on tetrapodomorphs, is used to clarify the interrelationships of the megalichthyids and confirm the phylogenetic position of C. narrienense. Results Never before seen morphological details of the palate, hyoid arch, basibranchial skeleton, pectoral girdle and axial skeleton are revealed and described. Several additional features are confirmed or updated from the original description. Moreover, the first full, virtual cranial endocast of any tetrapodomorph fish is presented and described, giving insight into the early neural adaptations in this group. Phylogenetic analysis confirms the monophyly of the Megalichthyidae with seven genera included (Askerichthys, Cladarosymblema, Ectosteorhachis, Mahalalepis, Megalichthys, Palatinichthys, and Sengoerichthys). The position of the megalichthyids as sister group to canowindrids, crownward of “osteolepidids” (e.g.,Osteolepis and Gogonasus), but below “tristichopterids” such as Eusthenopteron is confirmed, but our findings suggest further work is required to resolve megalichthyid interrelationships.

Phylogenetic relationships of the subfamily Pyrgulinae (Gastropoda: Caenogastropoda: Hydrobiidae) with emphasis on the genus Dianella Gude, 1913

Zootaxa ◽  
2005 ◽  
Vol 891 (1) ◽  
pp. 1 ◽  
Author(s):  
Magdalena Szarowska ◽  
Andrzej Falniowski ◽  
FRANK Riedel ◽  
Thomas Wilke
Keyword(s):  
Type Species ◽  
Sister Group ◽  
Molecular Data ◽  
Character Evolution ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Data Sets ◽  
Sequencing Data ◽  
The Family ◽  
Anatomical Characters

The phylogenetic position of the subfamily Pyrgulinae within the superfamily Rissooidea has been discussed very controversially. Different data sets not only led to different evolutionary scenarios but also to different systematic classifications of the taxon. The present study uses detailed anatomical data for two pyrgulinid taxa, the type species of the subfamily, Pyrgula annulata (Linnaeus, 1767), and the type species of the little known genus Dianella, D. thiesseana (Kobelt, 1878), as well as DNA sequencing data of three gene fragments from representatives of eight rissooidean families to A) infer the phylogenetic position of Pyrgulinae with emphasis on its relationships within the family Hydrobiidae, B) to study the degree of concordance between anatomyand DNAbased phylogenies and C) to trace the evolution of anatomical characters along a multi-gene molecular phylogeny to find the anatomical characters that might be informative for future cladistic analyses. Both anatomical and molecular data sets indicate either a very close or even sister-group relationship of Pyrgulinae and Hydrobiinae. However, there are major conflicts between the two data sets on and above the family level. Notably, Hydrobiidae is not monophyletic in the anatomical analysis. The reconstruction of anatomical character evolution indicates that many of the characters on which the European hydrobioid taxonomy is primarily based upon are problematic. The inability to clearly separate some hydrobiids from other distinct families based on those characters might explain why until only a few years ago, "Hydrobiidae" was a collecting box for numerous rissooidean taxa (mostly species with shells small and lacking any characteristic features). The present study not only stresses the need for comprehensive molecular studies of rissooidean taxa, it also demonstrates that much of the problems surrounding anatomical analyses in rissooidean taxa are due to the lack of comprehensive data for many representatives. In order to aid future comparativeanatomical studies and a better understanding of character evolution in the species-rich family Hydrobiidae, detailed anatomical descriptions for P. annulata and D. thiesseana are provided.Key words: Pyrgulinae, Pyrgula, Dianella, Hydrobiidae, phylogeny, DNA, anatomy, Greece

scholarly journals Molecular phylogeny and shell microstructure of Fungiacava eilatensis Goreau et al. 1968, boring into mushroom corals (Scleractinia: Fungiidae), in relation to other mussels (Bivalvia: Mytilidae)

2011 ◽  
Vol 80 (3) ◽  
pp. 169-178 ◽  
Author(s):  
Masato Owada ◽  
Bert W. Hoeksema
Keyword(s):  
Sister Group ◽  
Shell Shape ◽  
Phylogenetic Position ◽  
Shell Layer ◽  
Shell Microstructure ◽  
Phylogenetic Reconstructions ◽  
Molecular Phylogenetic ◽  
Coral Reef Ecosystems ◽  
Mushroom Coral ◽  
Rrna Sequences

Research on the evolution of the symbiosis between the boring mussel Fungiacava eilatensis (Bivalvia: Mytilidae) and its mushroom coral hosts (Scleractinia: Fungiidae), which requires phylogenetic reconstructions of both the Mytilidae and the Fungiidae, contributes to the understanding of the complexity of coral reef ecosystems. Previously, Fungiacava was regarded as a genus that had descended from Leiosolenus or as belonging to the subfamily Crenellinae, but no phylogenetic support has been obtained for this hypothesis. In the present study, the 18s rRNA sequences of ten mytilid species and the shell microstructures of 12 mytilids were investigated. The phylogenetic position of F. eilatensis is discussed in relation to its associations with its host species. The results of the molecular phylogenetic analysis indicate that F. eilatensis forms a sister group with Leiosolenus simplex, a livecoral- boring species within the Leiosolenus clade. Scanning electron microscope observations indicate that the shell of F. eilatensis is constructed of 3 layers: the outer shell layer with a homogeneous structure, the middle shell layer as a sheet nacreous structure, and the inner shell layer with an irregular simple prism structure. This shell microstructure of F. eilatensis is similar to that of Leiosolenus malaccanus and L. simplex. These findings show that F. eilatensis has descended from a coral-boring Leiosolenus species and that it would be adequate for Fungiacava to be treated as Leiosolenus. However, because of its extraordinary shell shape it has been kept as a separate genus.

Early embryology of Vochysiaceae and some insights into its phylogeny and intrafamilial taxonomy

Phytotaxa ◽  
2020 ◽  
Vol 443 (3) ◽  
pp. 211-257
Author(s):  
RENATA CARMO-OLIVEIRA ◽  
LUCIANA NASCIMENTO CUSTÓDIO ◽  
BERTA LANGE DE MORRETES ◽  
PAULO EUGÊNIO OLIVEIRA
Keyword(s):  
Developmental Stages ◽  
Embryo Sac ◽  
Sister Group ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Its Phylogeny ◽  
The Family

Embryological data provides insights into the taxonomy and evolution of angiosperms.  Vochysiaceae is a mostly Neotropical family whose phylogenetic position was greatly influenced by reconstructions based on molecular data, and despite its monosymmetric and oligostemonous flowers, was included as a sister group of polysymmetric and polystemonous Myrtaceae. However, molecular data has yet to resolve the relationships between the genera inside the family. We analysed the early embryology of some species of five out of the six generally accepted Neotropical genera using sequential histological analyses to compare the microsporogenesis and gametogenesis and megasporogenesis and gametogenesis between clades and with the embryology of the well-studied Myrtales. We observed some marked differences in timing and developmental stages, which somewhat corroborate the clades defined from molecular data. Multiple archesporium and embryo sacs, as well as megagametophyte maturation and fertilization long after anthesis, characterized the Qualea-Ruizteranea-Callisthene (QRC) clade, while single embryo sac mature at anthesis characterized the Vochysia-Salvertia (VS) clade. Tri-cellular pollen only occurred in Salvertia convallariodora. Seven of the eight main embryological features supported the Myrtales as present in Vochysiaceae and the remaining one, inner integument with two layers of cells, was observed in some Qualea. Thus, the studied Vochysiaceae embryology conforms very well within the order and only their strongly monosymmetric and oligostemonous flowers are less common among Myrtales.

An opisthorchiid concept of the genus Liliatrema (Trematoda: Plagiorchiida: Opisthorchioidea): an unexpected systematic position

2020 ◽  
Author(s):  
Sergey Sokolov ◽  
Evgeniy Frolov ◽  
Semen Novokreshchennykh ◽  
Dmitry Atopkin
Keyword(s):  
Phylogenetic Analyses ◽  
Sister Group ◽  
Systematic Position ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
28S Rrna ◽  
The Family ◽  
Using Data ◽  
Terminal Genitalia ◽  
Rdna Analysis

Abstract Liliatrema is a small genus of trematodes consisting of two species. Its systematic position has long been debated, partly because of the confusing reports about the structure of male terminal genitalia. Here we test the phylogenetic position of the genus Liliatrema using data on complete 18S rRNA and partial 28S rRNA gene sequences obtained for Liliatrema skrjabini. We also provide a detailed description of terminal genitalia in adult specimens of L. sobolevi and metacercariae of both Liliatrema species. The results of the 28S rDNA-based phylogenetic analysis indicate that Liliatrema falls within a well-supported clade, which also includes Apophallus and traditional opisthorchiids. This clade, in turn, is nested within a well-supported clade, containing Euryhelmis, Cryptocotyle and Scaphanocephalus. In the 18S+8S rDNA analysis, Liliatrema appears as a sister-taxon to the Cryptocotyle + Euryhelmis group. The Liliatrema + (Cryptocotyle + Euryhelmis) clade is a well-supported sister-group to the traditional opisthorchiids. The morphology of the terminal genitalia of the liliatrematids also corresponds to that of the opisthorchioids. Thus, the results of our morphological and phylogenetic analyses favour an unexpected conclusion that the genus Liliatrema belongs to the Opisthorchioidea. We propose that the genera Liliatrema, Apophallus, Euryhelmis, Cryptocotyle and Scaphanocephalus belong, respectively, within the subfamilies Liliatrematinae, Apophallinae, Euryhelminthinae and Cryptocotylinae of the family Opisthorchiidae.

scholarly journals Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ralf Britz ◽  
Neelesh Dahanukar ◽  
V. K. Anoop ◽  
Siby Philip ◽  
Brett Clark ◽  
...  
Keyword(s):  
Morphological Analysis ◽  
South India ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Fossil Calibration ◽  
New Family ◽  
Living Fossils ◽  
Morphological Stasis ◽  
The Family ◽  
Subterranean Waters

Abstract Pronounced organism-wide morphological stasis in evolution has resulted in taxa with unusually high numbers of primitive characters. These ‘living fossils’ hold a prominent role for our understanding of the diversification of the group in question. Here we provide the first detailed osteological analysis of Aenigmachanna gollum based on high-resolution nano-CT scans and one cleared and stained specimen of this recently described snakehead fish from subterranean waters of Kerala in South India. In addition to a number of derived and unique features, Aenigmachanna has several characters that exhibit putatively primitive conditions not encountered in the family Channidae. Our morphological analysis provides evidence for the phylogenetic position of Aenigmachanna as the sister group to Channidae. Molecular analyses further emphasize the uniqueness of Aenigmachanna and indicate that it is a separate lineage of snakeheads, estimated to have split from its sister group at least 34 or 109 million years ago depending on the fossil calibration employed. This may indicate that Aenigmachanna is a Gondwanan lineage, which has survived break-up of the supercontinent, with India separating from Africa at around 120 mya. The surprising morphological disparity of Aenigmachanna from members of the Channidae lead us to erect a new family of snakehead fishes, Aenigmachannidae, sister group to Channidae, to accommodate these unique snakehead fishes.

The first records of fossil Corethrellidae (Diptera)

1991 ◽  
Vol 22 (4) ◽  
pp. 457-463 ◽  
Author(s):  
A. Borkent ◽  
R. Szadziewski
Keyword(s):  
New Zealand ◽  
Dominican Republic ◽  
East Germany ◽  
Single Species ◽  
Sister Group ◽  
The Other ◽  
Phylogenetic Position ◽  
Male Adult ◽  
The Family

AbstractThe first fossil Corethrellidae, represented by two male adult Corethrella, are described. One, C. prisca sp. n., is from Saxonian amber collected in East Germany and is of Miocene age (22 Ma). The other, C. nudistyla sp. n., is from Dominican Republic amber and is 15-40 million years old. The family Corethrellidae, because of its phylogenetic position, is presumably of at least Jurassic age. The fossils are typical members of the genus Corethrella and belong to a clade which is the sister group of a single species in New Zealand.

Utility of Secondary Structure in Phylogenetic Reconstructions Using nrDNA ITS Sequences - an Example from Potalieae (Gentianaceae: Asteridae)

2009 ◽  
Vol 34 (2) ◽  
pp. 414-428 ◽  
Author(s):  
Jeanmaire Molina ◽  
Lena Struwe
Keyword(s):  
Secondary Structure ◽  
Bayesian Methods ◽  
Phylogenetic Analyses ◽  
Sister Group ◽  
Structure Alignment ◽  
Nuclear Ribosomal Dna ◽  
Phylogenetic Reconstructions ◽  
The Family ◽  
Medicinal Properties ◽  
Additional Support

The gentians (Gentianaceae, Asteridae) form a morphologically and ecologically diverse group of plants with interesting phytochemical and medicinal properties. The family contains six tribes, but phylogenetic relationships among the three more derived tribes (Gentianeae, Helieae, and Potalieae) are considered ambiguous. In an attempt to resolve alignment ambiguity and provide better scientific support for relationships, the internal transcribed spacer (ITS) of the nuclear ribosomal DNA was aligned for several gentian sequences with reference to the ITS secondary structure proposed for Anvillea radiata (Asteraceae) using Dynalign. We present here the first secondary structure of ITS for Gentianaceae, which may guide alignment of ITS data in other asterids taxa. The study included 42 species, with representatives from tribes Chironieae, Gentianeae, Helieae, and Potalieae, and with the majority of species from Potalieae. Phylogenetic analyses based on secondary structure alignment using parsimony and Bayesian methods provided additional support for Gentianeae plus Helieae as the sister group to Potalieae. Prepusa (Helieae) showed ambivalent associations. Within tribe Potalieae, the subtribes Potaliinae and Lisianthiinae were supported as monophyletic. Bisgoeppertia (Chironieae) was placed unambiguously inside Lisianthius (Potalieae-Lisianthiinae) in all analyses. Neurotheca (Potalieae-Faroinae) was positioned as sister to Lisianthiinae, making subtribe Faroinae paraphyletic.

scholarly journals Genome of Superficieibacter maynardsmithii, a novel, antibiotic susceptible representative of Enterobacteriaceae

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Gherard Batisti Biffignandi ◽  
Marjorie J Gibbon ◽  
Marta Corbella ◽  
Harry A Thorpe ◽  
Cristina Merla ◽  
...  
Keyword(s):  
New Species ◽  
Draft Genome ◽  
Gc Content ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Phylogenomic Analysis ◽  
The Novel ◽  
Antimicrobial Resistance Genes ◽  
The Family ◽  
A New Species

Abstract During a citywide microbiological screening project in Pavia (Italy) a bacterial strain isolated from the surface of an Automated Teller Machine was classified as a Klebsiella sp. by MALDI-TOF spectrometry, and shown to be susceptible to the most antimicrobial classes by phenotypic testing. After Illumina genome sequencing and subsequent assembly, a high-quality draft genome was obtained (size = 5,051,593 bp, N50 = 615,571 bp, largest contig = 1,328,029 bp, N_contig = 17, GC content = 51.58%, coverage = 141.42), absence of antimicrobial resistance genes was confirmed, but the strain resulted to be highly divergent from all Klebsiella, and more related to other Enterobacteriaceae. The higher values of 16S rRNA identity were with members of the genera Citrobacter, Salmonella, and “Superficieibacter.” An ortholog-based phylogenomic analysis indicated a sister group relationship with “Superficieibacter electus,” in a distinct clade from other members of the Enterobacteriaceae family. In order to evaluate whether the novel genome represents a new species of “Superficiebacter,” average nucleotide identity (ANI) and Hadamard analysis were performed on a dataset of 78 Enterobacteriaceae. The novel genome showed an ANI of 87.51% with S. electus, which compared on identity values between other members of the family, clearly indicates that the genome represents a new species within the genus “Superficieibacter.” We propose for the new species the name “Superficieibacter maynardsmithii.”

scholarly journals Ustyurtiidae, a new family of Urodoidea with description of a new genus and two species from Kazakhstan, and discussion on possible affinity of Urodoidea to Schreckensteinioidea (Lepidoptera)

2020 ◽  
Vol 51 (3) ◽  
pp. 444-471 ◽  
Author(s):  
Lauri Kaila ◽  
Kari Nupponen ◽  
Pavel Yu. Gorbunov ◽  
Marko Mutanen ◽  
Maria Heikkilä
Keyword(s):  
Type Species ◽  
New Genus ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Wing Venation ◽  
Morphological Attributes ◽  
New Family ◽  
Group Position ◽  
The Family ◽  
Morphological Differences

Ustyurtiidae Kaila, Heikkilä & Nupponen, a new family of Urodoidea is introduced. The family is based on the genus Ustyurtia Kaila, Heikkilä & Nupponen, gen. n. The genus includes the type species U. zygophyllivora Kaila, Heikkilä & Nupponen, sp. n. and U. charynica Kaila, Heikkilä & Nupponen, sp. n., both from Kazakhstan. These two species, in particular the immature stages, have morphological attributes apomorphic of Urodoidea. The close affinity is also supported by DNA data based on several markers. We consider this new family warranted due to its sister group position to the remaining Urodoidea and a number of significant morphological differences in wing venation, male genitalia and the structure of the cocoon, apomorphic for Ustyurtiidae on the basis of an earlier published phylogeny. All other recognized genera of Urodoidea belong to the family Urodidae. The closest relatives and phylogenetic position of Urodoidea are not firmly established, but Urodoidea and Schreckensteinioidea have morphological similarities which, in the light of genetic analyses appear synapomorphic and possibly uniting these groups, rather than homoplasious as assumed earlier. The affinities of these superfamilies are discussed.

Sign in / Sign up

Export Citation Format

Share Document