scholarly journals Evidence from the resurrected family Polyrhabdinidae Kamm, 1922 (Apicomplexa: Gregarinomorpha) supports the epimerite, an attachment organelle, as a major eugregarine innovation

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11912
Author(s):  
Gita G. Paskerova ◽  
Tatiana S. Miroliubova ◽  
Andrea Valigurová ◽  
Jan Janouškovec ◽  
Magdaléna Kováčiková ◽  
...  

Background Gregarines are a major group of apicomplexan parasites of invertebrates. The gregarine classification is largely incomplete because it relies primarily on light microscopy, while electron microscopy and molecular data in the group are fragmentary and often do not overlap. A key characteristic in gregarine taxonomy is the structure and function of their attachment organelles (AOs). AOs have been commonly classified as “mucrons” or “epimerites” based on their association with other cellular traits such as septation. An alternative proposal focused on the AOs structure, functional role, and developmental fate has recently restricted the terms “mucron” to archigregarines and “epimerite” to eugregarines. Methods Light microscopy and scanning and transmission electron microscopy, molecular phylogenetic analyses of ribosomal RNA genes. Results We obtained the first data on fine morphology of aseptate eugregarines Polyrhabdina pygospionis and Polyrhabdina cf. spionis, the type species. We demonstrate that their AOs differ from the mucron in archigregarines and represent an epimerite structurally resembling that in other eugregarines examined using electron microscopy. We then used the concatenated ribosomal operon DNA sequences (SSU, 5.8S, and LSU rDNA) of P. pygospionis to explore the phylogeny of eugregarines with a resolution superior to SSU rDNA alone. The obtained phylogenies show that the Polyrhabdina clade represents an independent, deep-branching family in the Ancoroidea clade within eugregarines. Combined, these results lend strong support to the hypothesis that the epimerite is a synapomorphic innovation of eugregarines. Based on these findings, we resurrect the family Polyrhabdinidae Kamm, 1922 and erect and diagnose the family Trollidiidae fam. n. within the superfamily Ancoroidea Simdyanov et al., 2017. Additionally, we re-describe the characteristics of P. pygospionis, emend the diagnoses of the genus Polyrhabdina, the family Polyrhabdinidae, and the superfamily Ancoroidea.

Phytotaxa ◽  
2017 ◽  
Vol 297 (2) ◽  
pp. 139 ◽  
Author(s):  
Charlotte Sletten Bjorå ◽  
MARTE ELDEN ◽  
INGER NORDAL ◽  
ANNE K. BRYSTING ◽  
TESFAYE AWAS ◽  
...  

Sister group relations of Ethiopian species of Anthericum and Chlorophytum and variation patterns in the C. gallabatense and C. comosum complexes were studied using molecular phylogenetic analyses, morphometrics, and scanning electron microscopy of seed surfaces. Results indicate that molecular data largely support previous morphological conclusions, and that speciation has occurred in Ethiopia at least three times in Anthericum and repeatedly within different subclades of Chlorophytum. Areas particularly rich in endemic species are the lowland area around Bale Mountains in SE Ethiopia and in the Beninshangul Gumuz regional state in W Ethiopia near the border to Sudan. A new species, Chlorophytum mamillatum Elden & Nordal, is described, and the names C. tordense and C. tetraphyllum are re-instated.


2016 ◽  
Vol 4 (1) ◽  
pp. 35 ◽  
Author(s):  
Topik Hidayat ◽  
Adi Pancoro

<p>Early information<br />resulted from molecular phylogenetic studies of many important<br />ornamental crops is often less attention to many<br />growers and farmers. Phylogenetics is one of the most preferable<br />method in systematics to reconstruct evolutionary<br />relationships of groups of biological organisms in order to<br />understand their biodiversities. This has been revolutionized<br />by DNA sequences data. In this method, a group of organisms<br />that shares many identical characteristics are considered<br />to be closely related; deriving from a common<br />ancestor and is assumed to have similar genetic patterns<br />and biochemical properties. By these basic principles,<br />molecular phylogenetics plays important roles in revealing a<br />basic knowledge on pattern of relationships to which<br />genetic resources can be improved. Over the past decade,<br />botanists have done several thousand phylogenetic analyses<br />based on molecular data of economically and horticulturally<br />important crops. Orchids are the best example for this.<br />There is no doubt that most orchid plants had played roles in<br />horticulture and hybridization. At present, many infrageneric<br />and intergeneric hybrids are available commercially. Successful<br />hybridization can be achieved if two or more individual<br />plants understudy are closely related in respect to their<br />genetics and evolution.</p>


Zootaxa ◽  
2019 ◽  
Vol 4551 (5) ◽  
pp. 556 ◽  
Author(s):  
TATIANA KORSHUNOVA ◽  
RAHUL MEHROTRA ◽  
SPENCER ARNOLD ◽  
KENNET LUNDIN ◽  
BERNARD PICTON ◽  
...  

An integrative molecular and morphological study is presented for the family Unidentiidae. Molecular phylogenetic analyses were conducted with the inclusion of all previous and newly obtained molecular data for the family Unidentiidae Millen & Hermosillo 2012. A new species of the genus Unidentia Millen & Hermosillo 2012, U. aliciae sp. nov., is described from Thailand as part of an inventory of sea slugs at Koh Tao. All up-to-date available morphological data for the species of the genus Unidentia is for the first time summarized. Morphological differences among the different species of Unidentia are clarified showing that every species has its own distinguishable morphological traits. According to the new molecular and morphological data, the family Unidentiidae is re-confirmed as a well-supported taxon of the aeolidacean nudibranchs. The taxonomy and phylogeny of the Aeolidacea in the light of the family Unidentiidae is briefly discussed and necessity of a fine-scale and narrowly-defined taxa approach instead of a ‘‘superlumping’’ one is highlighted. 


Phytotaxa ◽  
2019 ◽  
Vol 424 (4) ◽  
pp. 253-261 ◽  
Author(s):  
TAI-MIN XU ◽  
YU-HUI CHEN ◽  
CHANG-LIN ZHAO

A new wood-inhabiting fungal species, Trechispora yunnanensis sp. nov., is proposed based on morphological characteristics and molecular phylogenetic analyses. The species is characterized by resupinate basidiomata, rigid and fragile up on drying, cream to pale greyish hymenial surface; a monomitic hyphal system with generative hyphae bearing clamp connections, IKI-, CB-; ellipsoid, hyaline, thick-walled, ornamented, IKI-, CB- basidiospores measuring as 7–8.5 × 5–5.5 µm. The internal transcribed spacer (ITS) and the large subunit (LSU) regions of nuclear ribosomal RNA gene sequences of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood (ML), maximum parsimony (MP) and bayesian inference methods (BPP). The phylogenetic analyses based on molecular data of ITS+nLSU sequences showed that T. yunnanensis formed a monophyletic lineage with a strong support (100% ML, 100% MP, 1.00 BPP) and was closely related to T. byssinella and T. laevis. Both morphological characteristics and results of molecular phylogenetic analyses confirmed the placement of the new species in Trechispora.


2021 ◽  
Vol 12 ◽  
Author(s):  
Boo Seong Jeon ◽  
Myung Gil Park

The phylum Perkinsozoa is known as an exclusively parasitic group within alveolates and is widely distributed in various aquatic environments from marine to freshwater environments. Nonetheless, their morphology, life cycle, the identity of the host, and physiological characteristics remain still poorly understood. During intensive sampling along the west coast of Korea in October and November 2017, a new parasitoid, which shares several characteristics with the extant families Perkinsidae and Parviluciferaceae, was discovered and three strains of the new parasitoid were successfully established in cultures. Cross-infection experiments showed that among the examined planktonic groups, only dinoflagellates were susceptible to the new parasitoid, with infections observed in species belonging to eight genera. Even though the new parasitoid shared many morphological and developmental characteristics with other Perkinsozoan parasites, it differed from them by its densely packed trophocyte structure without a large vacuole or hyaline material during the growth stage. These characteristics are common among Parviluciferaceae members. Furthermore, through palintomic extracellular sporogenesis, it produced characteristic interconnected sporocytes resembling a string of beads. Phylogenetic analyses based on the small subunit and large subunit ribosomal DNA sequences revealed that the new parasitoid was distantly related to the family Parviluciferaceae and was more closely related to the families Perkinsidae and Xcellidae. Morphological, ultrastructural, and molecular data on the new parasitoid raised the need to erect a new family, i.e., Pararosariidae, within the phylum Perkinsozoa with Pararosarium dinoexitiosum gen. et sp. nov. as the type species. The isolation and establishment in culture of the new parasitoid outside the family Parviluciferaceae in the present study would contribute to the better understanding of the diversity of Perkinsozoan parasites and provide useful material for comparisons to other parasite species in the further study.


Nematology ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1131-1140
Author(s):  
Jianfeng Gu ◽  
Munawar Maria ◽  
Yiwu Fang ◽  
Majid Pedram

Summary During quarantine inspections, a new species of Hoplotylus was detected from the rhizosphere of the Japanese maple, Acer palmatum, imported into China from Japan. Hoplotylus japonicus n. sp. is characterised by a stout 431-602 μm long body, well-developed 20.0-24.5 μm long stylet with tulip-shaped knobs having rounded sides in lateral view and a rounded anterior margin, excretory pore located slightly posterior to the hemizonid, usually empty, spermatheca, conical tail with a spike-like projection, which is distally smooth on the dorsal side, and males not found. It was morphologically compared with four currently known species of the genus, viz., H. femina, H. montanus, H. silvaticus, and H. sjacobi. In molecular phylogenetic analyses using 18S, 28S and internal transcribed spacer (ITS) ribosomal DNA sequences, the new species formed a clade with the only currently sequenced species of the genus, H. femina, in all phylogenies. This is the second species of the genus characterised by molecular data and the second species recovered from Japan.


Phytotaxa ◽  
2019 ◽  
Vol 391 (5) ◽  
pp. 277 ◽  
Author(s):  
SALILAPORN NUANKAEW ◽  
SATINEE SUETRONG ◽  
TUKSADON WUTIKHUN ◽  
UMPAWA PINRUAN

A new species of a hyphomycetous fungus, Hermatomyces trangensis, was collected during an investigation of the diversity of palm fungi in Na Yong district, Trang province, Southern Thailand, and is introduced in this paper based on morphological and molecular evidence. The fungus is characterized by the production of only one type of conidia, globose or subglobose in front view, broadly ellipsoidal or oblong in lateral view, with dark brown to black central cells and subhyaline to pale brown peripheral cells and sporulation in culture. Phylogenetic analyses of combined SSU rDNA, LSU rDNA, ITS rDNA, TEF1 and RPB2 sequence data using maximum parsimony, maximum likelihood and Bayesian inference approaches placed the fungus within a strongly supported clade with other Hermatomyces species within the family Hermatomycetaceae (Pleosporales, Dothideomycetes). Morphologically, it is similar to other taxa with only one type of conidia such as H. sphaericus, H. sphaericoides and H. verrucosus but molecular data clearly support H. trangensis as distinct from those species.


2019 ◽  
Vol 94 ◽  
Author(s):  
S.V. Shchenkov ◽  
S.A. Denisova ◽  
G.A. Kremnev ◽  
A.A. Dobrovolskij

Abstract The phylogenetic position of most xiphidiocercariae from subgroups Cercariae virgulae and Cercariae microcotylae remains unknown or unclear, even at the family level. In this paper, we studied the morphology and molecular phylogeny of 15 microcotylous and virgulate cercariae (11 new and four previously described ones). Based on morphological and molecular data, we suggested five distinct morphological types of xiphidiocercariae, which are a practical alternative to Cercariae virgulae and Cercariae microcotylae subgroups. Four of these types correspond to actual digenean taxa (Microphallidae, Lecithodendriidae, Pleurogenidae and Prosthogonimidae), while the fifth is represented by Cercaria nigrospora Wergun, 1957, which we classified on the basis of molecular data for the first time. We reassessed the relative importance of morphological characters used for the classification of virgulate and microcotylous cercariae, and discussed the main evolutionary trends within xiphidiocercariae. Now stylet cercariae can be reliably placed into several sub-taxa of Microphalloidea on the basis of their morphological features.


Nematology ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Daniel Leduc ◽  
Frederic Sinniger

Because of their relatively simple body plan, the number of morphological characters used to differentiate between closely related nematode genera is often limited. In addition, boundaries among genera sometimes become blurred due to the appearance of new trait combinations as more new species are described. Molecular phylogenetic analyses can address the shortcomings of morphological taxonomy by clarifying relationships among closely related species and genera and can help identify which morphological characters are taxonomically informative. Here, we describeLaxus sakihariiaesp. n. from shallow subtidal sands on Sesoko Island in the Okinawa prefecture, investigate phylogenetic relationships with other stilbonematine species and genera based on SSU rDNA sequences, and provide the first LSU rDNA sequence for the subfamily. The new species can be easily distinguished from all other species of the genus by the presence in the male of subventral and ventral rows of stout and spine-like setae in the pre- and postcloacal regions. This feature suggests affinities with the closely related genusLeptonemella, although the SSU consensus tree clearly shows that the new species forms a monophyletic clade together with the otherLaxusspecies for which sequences are available. The structure of the cephalic capsule inL. sakihariiaesp. n., which consists of a block layer between the median and basal zones of the cephalic cuticle, is consistent with the placement of this species. This trait is not currently used as a diagnostic feature, but our finding suggests that the structure of the cephalic capsule may be taxonomically useful for differentiating between some stilbonematine genera.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3354 ◽  
Author(s):  
Timur G. Simdyanov ◽  
Laure Guillou ◽  
Andrei Y. Diakin ◽  
Kirill V. Mikhailov ◽  
Joseph Schrével ◽  
...  

Background Gregarines are a group of early branching Apicomplexa parasitizing invertebrate animals. Despite their wide distribution and relevance to the understanding the phylogenesis of apicomplexans, gregarines remain understudied: light microscopy data are insufficient for classification, and electron microscopy and molecular data are fragmentary and overlap only partially. Methods Scanning and transmission electron microscopy, PCR, DNA cloning and sequencing (Sanger and NGS), molecular phylogenetic analyses using ribosomal RNA genes (18S (SSU), 5.8S, and 28S (LSU) ribosomal DNAs (rDNAs)). Results and Discussion We present the results of an ultrastructural and molecular phylogenetic study on the marine gregarine Ancora sagittata from the polychaete Capitella capitata followed by evolutionary and taxonomic synthesis of the morphological and molecular phylogenetic evidence on eugregarines. The ultrastructure of Ancora sagittata generally corresponds to that of other eugregarines, but reveals some differences in epicytic folds (crests) and attachment apparatus to gregarines in the family Lecudinidae, where Ancora sagittata has been classified. Molecular phylogenetic trees based on SSU (18S) rDNA reveal several robust clades (superfamilies) of eugregarines, including Ancoroidea superfam. nov., which comprises two families (Ancoridae fam. nov. and Polyplicariidae) and branches separately from the Lecudinidae; thus, all representatives of Ancoroidea are here officially removed from the Lecudinidae. Analysis of sequence data also points to possible cryptic species within Ancora sagittata and the inclusion of numerous environmental sequences from anoxic habitats within the Ancoroidea. LSU (28S) rDNA phylogenies, unlike the analysis of SSU rDNA alone, recover a well-supported monophyly of the gregarines involved (eugregarines), although this conclusion is currently limited by sparse taxon sampling and the presence of fast-evolving sequences in some species. Comparative morphological analyses of gregarine teguments and attachment organelles lead us to revise their terminology. The terms “longitudinal folds” and “mucron” are restricted to archigregarines, whereas the terms “epicystic crests” and “epimerite” are proposed to describe the candidate synapomorphies of eugregarines, which, consequently, are considered as a monophyletic group. Abolishing the suborders Aseptata and Septata, incorporating neogregarines into the Eugregarinida, and treating the major molecular phylogenetic lineages of eugregarines as superfamilies appear as the best way of reconciling recent morphological and molecular evidence. Accordingly, the diagnosis of the order Eugregarinida Léger, 1900 is updated.


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