scholarly journals An Updated Staging System for Cephalochordate Development: One Table Suits Them All

2021 ◽  
Vol 9 ◽  
Author(s):  
João E. Carvalho ◽  
François Lahaye ◽  
Luok Wen Yong ◽  
Jenifer C. Croce ◽  
Hector Escrivá ◽  
...  
Keyword(s):  
Scientific Community ◽  
Growth Curves ◽  
Staging System ◽  
Sister Group ◽  
Developmental Time ◽  
Phylogenetic Position ◽  
The Bahamas ◽  
Different Temperatures ◽  
Genomic Studies ◽  
The 19Th Century

Chordates are divided into three subphyla: Vertebrata, Tunicata, and Cephalochordata. Phylogenetically, the Cephalochordata, more commonly known as lancelets or amphioxus, constitute the sister group of Vertebrata and Tunicata. Lancelets are small, benthic, marine filter feeders, and their roughly three dozen described species are divided into three genera: Branchiostoma, Epigonichthys, and Asymmetron. Due to their phylogenetic position and their stereotypical chordate morphology and genome architecture, lancelets are key models for understanding the evolutionary history of chordates. Lancelets have thus been studied by generations of scientists, with the first descriptions of adult anatomy and developmental morphology dating back to the 19th century. Today, several different lancelet species are used as laboratory models, predominantly for developmental, molecular and genomic studies. Surprisingly, however, a universal staging system and an unambiguous nomenclature for developing lancelets have not yet been adopted by the scientific community. In this work, we characterized the development of the European lancelet (Branchiostoma lanceolatum) using confocal microscopy and compiled a streamlined developmental staging system, from fertilization through larval life, including an unambiguous stage nomenclature. By tracing growth curves of the European lancelet reared at different temperatures, we were able to show that our staging system permitted an easy conversion of any developmental time into a specific stage name. Furthermore, comparisons of embryos and larvae from the European lancelet (B. lanceolatum), the Florida lancelet (Branchiostoma floridae), two Asian lancelets (Branchiostoma belcheri and Branchiostoma japonicum), and the Bahamas lancelet (Asymmetron lucayanum) demonstrated that our staging system could readily be applied to other lancelet species. Although the detailed staging description was carried out on developing B. lanceolatum, the comparisons with other lancelet species thus strongly suggested that both staging and nomenclature are applicable to all extant lancelets. We conclude that this description of embryonic and larval development will be of great use for the scientific community and that it should be adopted as the new standard for defining and naming developing lancelets. More generally, we anticipate that this work will facilitate future studies comparing representatives from different chordate lineages.

scholarly journals An updated staging system for cephalochordate development: one table suits them all

2020 ◽  
Author(s):  
João E. Carvalho ◽  
François Lahaye ◽  
Luok Wen Yong ◽  
Jenifer C. Croce ◽  
Hector Escrivá ◽  
...  
Keyword(s):  
Growth Curves ◽  
Staging System ◽  
Sister Group ◽  
Developmental Time ◽  
Phylogenetic Position ◽  
The Bahamas ◽  
Evolutionary Diversification ◽  
Different Temperatures ◽  
Genomic Studies ◽  
Branchiostoma Lanceolatum

AbstractBackgroundThe chordates are divided into three subphyla: Vertebrata, Tunicata and Cephalochordata. Phylogenetically, the Cephalochordata, more commonly known as lancelets or amphioxus, constitute the sister group of Vertebrata plus Tunicata. Due to their phylogenetic position and their conserved morphology and genome architecture, lancelets are important models for understanding the evolutionary history of chordates. Lancelets are small, marine filter-feeders, and the few dozen species that have so far been described have been grouped into three genera: Branchiostoma, Epigonichthys and Asymmetron. Given their relevance for addressing questions about the evolutionary diversification of chordates, lancelets have been the subjects of study by generations of scientists, with the first descriptions of adult anatomy and developmental morphology dating back to the 19th century. Today, several different lancelet species are used as laboratory models, predominantly for developmental, molecular and genomic studies. It is thus very surprising that there is currently no universal staging system and no unambiguous nomenclature for developing lancelets.ResultsWe illustrated the development of the European amphioxus (Branchiostoma lanceolatum) using confocal microscopy and compiled a streamlined developmental staging system, from fertilization through larval life, with an unambiguous stage nomenclature. By tracing growth curves of the European amphioxus reared at different temperatures, we were able to show that our staging system permits the easy conversion of any developmental time into a defined stage name. Furthermore, comparisons of embryos and larvae from the European amphioxus (B. lanceolatum), the Florida amphioxus (B. floridae), the Chinese amphioxus (B. belcheri), the Japanese amphioxus (B. japonicum) and the Bahamas lancelet (Asymmetron lucayanum) demonstrated that our staging system can readily be applied to other lancelet species.ConclusionsHere, we propose an updated staging and nomenclature system for lancelets. Although the detailed staging description was carried out on developing B. lanceolatum, comparisons with other lancelet species strongly suggest that both staging and nomenclature are applicable to all extant lancelets. We thus believe that this description of embryonic and larval development can be of great use for the scientific community and hope that it will become the new standard for defining and naming developing lancelets.

The herophile species group of Calisto (Lepidoptera : Nymphalidae : Satyrinae), new taxa and historical biogeography

2019 ◽  
Author(s):  
Rayner Núñez ◽  
Alejandro Barro-Cañamero ◽  
Marc C. Minno ◽  
Douglas M. Fernández ◽  
Axel Hausmann
Keyword(s):  
New Species ◽  
New Taxa ◽  
Phylogenetic Trees ◽  
Sister Group ◽  
Species Group ◽  
Phylogenetic Position ◽  
The Bahamas ◽  
Mountain Ranges ◽  
North Eastern ◽  
Eastern Cuba

The genus Calisto is endemic tothe West Indiesand the only representative there of the Satyrinae. Here wereconstruct the evolutionary relationshipsof the herophile group and describe five new species from Cuba: Calisto gundlachi sp. nov., Calisto siguanensis sp. nov., Calisto disjunctus sp. nov., Calisto sharkeyae sp. nov. and Calisto lastrai sp. nov.We employ one mitochondrial and four nuclear markers to assess the phylogenetic position, Maximum Likelihood and Bayesian Inference approaches, of the new taxa. Our phylogenetic trees yielded two strongly supported main clades with four of the new species included within them and C. sharkeyae as sister group to the rest of the major main clade. We conduct time-divergence estimations and ancestral area reconstructions using BEAST and BioGeoBEARS. The group originated 12.15 million years ago during the middle Miocene in north-eastern Cuba, Nipe-Sagua-Baracoa Massif. After 6 million years of in situ evolution most lineages started to colonise other Cuban territories and the Bahamas. This scenario is consistent with key geological events, including the closure of the western Havana–Matanzas channel 8–6 million years ago, the uplift of the Sierra Maestra 6–5 million years ago, and the land connections among Cuban regions during the Miocene–Pleistocene sea level drops. Dispersal and vicariance processes may have occurred, with populations surviving floodings on the major and minor mountain ranges, which remained as ‘islands’. http://zoobank.org/urn:lsid:zoobank.org:act:03690F79-F938-42A0-B234-4A228D5C1913

scholarly journals Potential host ranges of three Asian larval parasitoids of Drosophila suzukii

2021 ◽  
Author(s):  
Kent M. Daane ◽  
Xingeng Wang ◽  
Brian N. Hogg ◽  
Antonio Biondi
Keyword(s):  
Body Size ◽  
Host Species ◽  
Classical Biological Control ◽  
Developmental Time ◽  
The Body ◽  
Phylogenetic Position ◽  
Egg Load ◽  
Drosophila Suzukii ◽  
Larval Parasitoids ◽  
Female Body Size

AbstractAsobara japonica (Hymenoptera: Braconidae), Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) are Asian larval parasitoids of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). This study evaluated these parasitoids’ capacity to attack and develop from 24 non-target drosophilid species. Results showed that all three parasitoids were able to parasitize host larvae of multiple non-target species in artificial diet; A. japonica developed from 19 tested host species, regardless of the phylogenetic position of the host species, L. japonica developed from 11 tested species; and G. brasiliensis developed from only four of the exposed species. Success rate of parasitism (i.e., the probability that an adult wasp successfully emerged from a parasitized host) by the two figitid parasitoids was low in hosts other than the three species in the melanogaster group (D. melanogaster, D. simulans, and D. suzukii). The failure of the figitids to develop in most of the tested host species appears to correspond with more frequent encapsulation of the parasitoids by the hosts. The results indicate that G. brasiliensis is the most host specific to D. suzukii, L. japonica attacks mainly species in the melanogaster group and A. japonica is a generalist, at least physiologically. Overall, the developmental time of the parasitoids increased with the host’s developmental time. The body size of female A. japonica (as a model species) was positively related to host size, and mature egg load of female wasps increased with female body size. We discuss the use of these parasitoids for classical biological control of D. suzukii.

The postcranial skeleton, phylogenetic position, and probable lifestyle of the Early Triassic reptile Procolophon trigoniceps

2003 ◽  
Vol 40 (4) ◽  
pp. 527-556 ◽  
Author(s):  
Michael deBraga
Keyword(s):  
South Africa ◽  
Morphological Study ◽  
Lower Triassic ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Early Triassic ◽  
Postcranial Skeleton ◽  
Sister Clade ◽  
Key Innovations

A morphological study of the postcranial skeleton of Procolophon trigoniceps from the Lower Triassic of South Africa and Antarctica is undertaken. Procolophon shares a sister-group relationship with the procolophonid Tichvinskia from the Lower Triassic of Russia and is a basal member of Procolophonidae. This clade also includes the enigmatic taxon Sclerosaurus, believed most recently to be a pareiasaur relative. Owenettids form a separate lineage from Procolophonidae and are predominantly restricted to the Permian of both South Africa and Madagascar. A phylogenetically based assessment is considered, in which specialized modern taxa (sand lizards) are compared to their nonfossorial sister clade, allowing for "key innovations" to be identified. A similar comparison between owenettids and procolophonids reveals a number of apparent "key innovations" within procolophonids that are suggestive of a burrowing lifestyle for Procolophon.

Improved resolution of recalcitrant nodes in the animal phylogeny through the analysis of genome gene content and morphology

2021 ◽  
Author(s):  
Ksenia Juravel ◽  
Luis Porras ◽  
Sebastian Hoehna ◽  
Davide Pisani ◽  
Gert Wörheide
Keyword(s):  
Common Ancestor ◽  
Sister Group ◽  
The Other ◽  
Gene Content ◽  
Statistical Hypothesis ◽  
Phylogenetic Position ◽  
Last Common Ancestor ◽  
Statistical Hypothesis Testing ◽  
Animal Phylogeny ◽  
Phylogenetic Hypotheses

An accurate phylogeny of animals is needed to clarify their evolution, ecology, and impact on shaping the biosphere. Although multi-gene alignments of up to several hundred thousand amino acids are nowadays routinely used to test hypotheses of animal relationships, some nodes towards the root of the animal phylogeny are proving hard to resolve. While the relationships of the non-bilaterian lineages, primarily sponges (Porifera) and comb jellies (Ctenophora), have received much attention since more than a decade, controversies about the phylogenetic position of the worm-like bilaterian lineage Xenacoelomorpha and the monophyly of the "Superphylum" Deuterostomia have more recently emerged. Here we independently analyse novel genome gene content and morphological datasets to assess patterns of phylogenetic congruence with previous amino-acid derived phylogenetic hypotheses. Using statistical hypothesis testing, we show that both our datasets very strongly support sponges as the sister group of all the other animals, Xenoacoelomorpha as the sister group of the other Bilateria, and largely support monophyletic Deuterostomia. Based on these results, we conclude that the last common animal ancestor may have been a simple, filter-feeding organism without a nervous system and muscles, while the last common ancestor of Bilateria might have been a small, acoelomate-like worm without a through gut.

No longer endemic to Africa: Kribiodosis Kieffer, 1921 (Diptera, Chironomidae) new to Oriental China with a phylogeny and expanded adult generic diagnoses

Zootaxa ◽  
2021 ◽  
Vol 5072 (6) ◽  
pp. 560-574
Author(s):  
WU HAN ◽  
JIE LIU ◽  
YIFAN LUO ◽  
HONGQU TANG
Keyword(s):  
New Species ◽  
Mixed Model ◽  
Dna Barcode ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Generic Diagnosis ◽  
Likelihood Methods ◽  
Core Member ◽  
Maximum Likelihood Methods ◽  
African Genus

Kribiodosis Kieffer, 1921, an African genus of Chironomini (Diptera: Chironomidae), is newly recorded from the Oriental region through a new species K. cantonensis sp. n. Detailed descriptions of the male, female and a DNA barcode are provided. With the inclusion of the new species bearing scutal tubercle and fused tibial comb, the generic diagnosis needs revision and expansion. The phylogenetic position of Kribiodosis within the tribe Chironomini is explored based on five concatenated genetic makers (18S, 28S, CAD1, CAD4 and COI-3P) using both mixed-model Bayesian inference and maximum likelihood methods. Kribiodosis is placed as a core member of the Microtendipes group but its precise sister group remains unclear. Inclusion of the analysis of Nilodosis Kieffer, another Chironomini genus with an African-Oriental distribution, reveals an unexpected robust position as sister to a large and diverse inclusive group of many Chironomini.  

scholarly journals “Candidatus Bacilloplasma,” a Novel Lineage of Mollicutes Associated with the Hindgut Wall of the Terrestrial Isopod Porcellio scaber (Crustacea: Isopoda)

2007 ◽  
Vol 73 (17) ◽  
pp. 5566-5573 ◽  
Author(s):  
Rok Kostanjšek ◽  
Jasna Štrus ◽  
Gorazd Avguštin
Keyword(s):  
Electron Microscopy ◽  
Sequence Similarity ◽  
Mycoplasma Hominis ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Porcellio Scaber ◽  
Terrestrial Isopod ◽  
Transmission Electron ◽  
A Cell

ABSTRACT Pointed, rod-shaped bacteria colonizing the cuticular surface of the hindgut of the terrestrial isopod crustacean Porcellio scaber (Crustacea: Isopoda) were investigated by comparative 16S rRNA gene sequence analysis and electron microscopy. The results of phylogenetic analysis, and the absence of a cell wall, affiliated these bacteria with the class Mollicutes, within which they represent a novel and deeply branched lineage, sharing less than 82.6% sequence similarity to known Mollicutes. The lineage has been positioned as a sister group to the clade comprising the Spiroplasma group, the Mycoplasma pneumoniae group, and the Mycoplasma hominis group. The specific signature sequence was identified and used as a probe in in situ hybridization, which confirmed that the retrieved sequences originate from the attached rod-shaped bacteria from the hindgut of P. scaber and made it possible to detect these bacteria in their natural environment. Scanning and transmission electron microscopy revealed a spherically shaped structure at the tapered end of the rod-shaped bacteria, enabling their specific and exclusive attachment to the tip of the cuticular spines on the inner surface of the gut. Specific adaptation to the gut environment, as well as phylogenetic positioning, indicate the long-term association and probable coevolution of the bacteria and the host. Taking into account their pointed, rod-shaped morphology and their phylogenetic position, the name “Candidatus Bacilloplasma” has been proposed for this new lineage of bacteria specifically associated with the gut surface of P. scaber.

Corrigendum to: Cladistic analysis and revision of Piestus Gravenhorst with remarks on related genera (Coleoptera : Staphylinidae : Piestinae)

2013 ◽  
Vol 27 (1) ◽  
pp. 129
Author(s):  
Edilson Caron ◽  
Cibele S. Ribeiro-Costa ◽  
Alfred F. Newton
Keyword(s):  
Cladistic Analysis ◽  
Taxonomic Revision ◽  
Sister Group ◽  
Morphological Characters ◽  
Valid Species ◽  
Phylogenetic Position ◽  
Neotropical Forests ◽  
Rove Beetles ◽  
New Synonyms ◽  
Branch Support

Rove beetles of the genus Piestus Gravenhorst, 1806 are commonly captured under the bark of or inside decaying logs from Neotropical forests. Piestus belongs to the subfamily Piestinae, historically an ill-defined dumping-ground for Staphylinidae defined by plesiomorphic characters, but which has gradually been restricted in concept and currently includes only six additional extant genera worldwide. Piestinae in this restricted sense has been considered a probably monophyletic subfamily, but its status and phylogenetic position, as a possible sister-group of Osoriinae within the recently proposed Oxyteline group of staphylinid subfamilies, are uncertain and need confirmation. The main aim of the present study was to provide a morphological cladistic analysis and complete taxonomic revision of Piestus, which, as the type and most speciose genus of Piestinae, is critical for future phylogenetic studies involving the subfamily. In our study, the monophyly of Piestus is established and phylogenetic relationships among its species are proposed based on 70 adult morphological characters. Piestus is supported by 11 synapomorphies and high branch support. All species of Piestus are revised and the genus is redefined. The genus contains 43 species, including 13 species described here for the first time. The previously proposed subgenera Antropiestus Bernhauer, 1917, Eccoptopiestus Scheerpeltz, 1952, Elytropiestus Scheerpeltz, 1952, Lissopiestus Scheerpeltz, 1952, Piestus s. str., Trachypiestus Scheerpeltz, 1952 and Zirophorus Dalman, 1821 have not been confirmed, as they were found to be poly- or paraphyletic, or are here removed from Piestus, and therefore subgenera are not used. The main taxonomic changes are as follows. Lissopiestus, syn. nov. is proposed as new synonym of Eleusis Laporte, 1835 and its species, E. interrupta (Erichson, 1840), comb. rest., is transferred again to that genus. Antropiestus, syn. nov. and Eccoptopiestus, syn. nov. are proposed as new synonyms of Hypotelus Erichson, 1839 and their species, H. laevis (Solsky, 1872), comb. nov. and H. andinus (Bernhauer, 1917), comb. nov., are transferred to Hypotelus. Fourteen new synonymies are proposed (valid species listed first): P. lacordairei Laporte, 1835 = Z. furcatus Sharp, 1887, syn. nov.; P. capricornis Laporte, 1835 = P. frontalis Sharp, 1876, syn. nov.; P. pennicornis Fauvel, 1864 = P. plagiatus Fauvel, 1864, syn. nov.; P. rectus Sharp, 1876, syn. nov.; P. pygialis Fauvel, 1902, syn. nov.; P. surinamensis Bernhauer, 1928, syn. nov.; P. minutus Erichson, 1840 = P. nigrator Fauvel, 1902, syn. nov.; P. sulcatus Gravenhorst, 1806 = P. sanctaecatharinae Bernhauer, 1906, syn. nov.; P. condei Wendeler, 1955, syn. nov.; P. gounellei Fauvel, 1902 = P. wasmanni Fauvel, 1902, syn. nov.; P. mexicanus Laporte, 1835 = P. alternans Sharp, 1887, syn. nov.; P. aper Sharp, 1876 = P. schadei Scheerpeltz, 1952, syn. nov.; P. angularis Fauvel, 1864 = P. crassicornis Sharp, 1887, syn. nov.; H. andinus (Bernhauer, 1917) = P. strigipennis Bernhauer, 1921, syn. nov. One species is revalidated: P. fronticornis (Dalman, 1821), stat. rev., and one synonym is restored: P. penicillatus (Dalman, 1821) = P. erythropus Erichson, 1840, syn. rest. Neotypes are designated for P. lacordairei Laporte, 1835 and Oxytelus bicornis Olivier, 1811, and lectotypes are designated for P. puncticollis Fauvel, 1902, P. capricornis variety muticus Fauvel, 1902, P. zischkai Scheerpeltz, 1951, P. pennicornis Fauvel, 1864, P. plagiatus Fauvel, 1864, P. pygmaeus Laporte, 1835, P. niger Fauvel 1864, P. minutus Erichson, 1840, P. nigratror Fauvel, 1902, P. sulcatus Gravenhorst, 1806, P. sanctaecatharinae Bernhauer, 1906, P. sulcipennis Scheerpeltz, 1952, P. aper Sharp, 1876, P. schadei Scheerpeltz, 1952 and P. andinus Bernhauer, 1917.

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.

scholarly journals More than 1000 ultraconserved elements provide evidence that turtles are the sister group of archosaurs

2012 ◽  
Vol 8 (5) ◽  
pp. 783-786 ◽  
Author(s):  
Nicholas G. Crawford ◽  
Brant C. Faircloth ◽  
John E. McCormack ◽  
Robb T. Brumfield ◽  
Kevin Winker ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Common Ancestor ◽  
Sister Group ◽  
Single Copy ◽  
Recent Analysis ◽  
Phylogenetic Position ◽  
Ultraconserved Elements ◽  
Sequence Capture ◽  
Genomic Scale ◽  
Nuclear Loci

We present the first genomic-scale analysis addressing the phylogenetic position of turtles, using over 1000 loci from representatives of all major reptile lineages including tuatara. Previously, studies of morphological traits positioned turtles either at the base of the reptile tree or with lizards, snakes and tuatara (lepidosaurs), whereas molecular analyses typically allied turtles with crocodiles and birds (archosaurs). A recent analysis of shared microRNA families found that turtles are more closely related to lepidosaurs. To test this hypothesis with data from many single-copy nuclear loci dispersed throughout the genome, we used sequence capture, high-throughput sequencing and published genomes to obtain sequences from 1145 ultraconserved elements (UCEs) and their variable flanking DNA. The resulting phylogeny provides overwhelming support for the hypothesis that turtles evolved from a common ancestor of birds and crocodilians, rejecting the hypothesized relationship between turtles and lepidosaurs.

Sign in / Sign up

Export Citation Format

Share Document