Morphological Evidence Research Articles

Morphological and genetic evidence of hybridisation between Mauremys mutica (Cantor, 1842) and Mauremys leprosa (Schweigger, 1812) in northeast Spain

Abstract Invasive species are one of the leading causes of biodiversity loss. During demographic monitoring of native turtle species in northeast Spain, we captured several alien species of semi-aquatic turtles, including Mauremys mutica. Among them, four individuals of this latter species showed external characteristics that were not fully consistent with the diagnosis of this species. These individuals showed a smaller postocular stripe and 2-3 lateral cervical lines and the typical plastral pattern observed in Mauremys leprosa. The analysis of mitochondrial DNA indicated that the maternal lineage was unequivocally M. mutica (pure or hybrid), but nuclear DNA revealed a heterozygote position at the C-mos gene, matching sequences for this gene in GenBank from both M. leprosa and M. mutica. These results highlight the negative impact of alien turtles, which can genetically contaminate vulnerable native turtle populations.

Morphological and molecular evidence support four new Liberonautes Bott, 1955 (Decapoda, Potamonautidae, Liberonautinae) species of freshwater crabs from Sierra Leone, West Africa

Abstract Four new Liberonautes species of freshwater crabs are described from material collected during an expedition to the rainforests of Sierra Leone, West Africa. Liberonautes kasonko sp. nov., L. njala sp. nov., L. schubarti sp. nov. and L. sugarloaf sp. nov. are recognized based on a combination of morphological characters including the carapace, adult male chelipeds, and first gonopods, and on genetic evidence involving analyses of partial segments of the mitochondrial genes of COI, 16S rRNA and 12S rRNA. Diagnoses, illustrations, and a tree of phylogenetic relationships based on mtDNA sequences, as well as a map showing the distributions of the new species are provided.

Unroughing the cat’s tongue mushrooms: Four new species of Pseudohydnum from Brazil based on morphological and molecular phylogenetic evidence

ABSTRACT Pseudohydnum, commonly known as cat’s tongue mushrooms, is a monophyletic assemblage within Auriculariales, which encompasses species with gelatinous basidiomata, spathulate, flabellate, or shell-shaped pileus, hydnoid hymenophore, globose to ellipsoidal basidiospores, and longitudinally cruciate-septate basidia. According to the available literature, 16 species have been described in Pseudohydnum, mostly represented in temperate-boreal forests of the Northern Hemisphere. However, the limited morphological, molecular, and ecological information, especially from the Southern Hemisphere ecosystems, does not presently allow a reliable assessment of its taxonomic boundaries nor provide a complete picture of the species diversity in the genus. In an ongoing effort to examine specimens collected in dense and mixed ombrophilous forest fragments (Atlantic Rainforest domain) from Southeastern and Southern Brazil, additional taxa assigned to Pseudohydnum were identified. Four new species are recognized based mostly on characters of the pileus surface, stipe, hymenium, and basidiospores. Molecular phylogenetic analyses based on nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode), partial nuc rDNA 28S, and partial RNA polymerase II largest subunit (RPB1) sequences supported the description of these new taxa. Here, we propose Pseudohydnum brasiliense, P. brunneovelutinum, P. cupulisnymphae, and P. viridimontanum as new species. Morphological descriptions, line drawings, habitat photos, and comparisons with closely related taxa are provided. A dichotomous key for identification of currently known Southern Hemisphere Pseudohydnum species is presented.

Molecular and morphological support for transferring the tropical African species of Gnidia to Lasiosiphon (Thymelaeaceae: Thymelaeoideae) and a worldwide synopsis of the species

Lasiosiphon Fresen. (Thymelaeaceae: Thymelaeoideae) is now understood to be a morphologically diverse genus distributed across southern and tropical Africa, Madagascar, and India. It is diagnosed morphologically by ± involucrate, mostly pedunculate heads of pentamerous or tetramerous flowers, with or without petaloid scales, and a bright yellow, orange, or red corolla. The taxonomic history of Lasiosiphon has been marked by several revisions in its circumscription and status, particularly regarding its relationship with Gnidia L. Our phylogenetic analysis of nuclear (ITS) and plastid (matK, rbcL, rps16 and trnL-F) regions of an expanded sampling of the tropical African species of Gnidia provides compelling supporting evidence for existing morphological evidence to include all the tropical African species of Gnidia in Lasiosiphon. We accordingly provide 31 new combinations in Lasiosiphon for species of Gnidia that currently lack combinations in that genus. We also provide a comprehensive nomenclator of all currently recognized Lasiosiphon species at the regional level encompassing their distribution across different geographic regions globally. This will serve as the framework for future taxonomic revisions in the genus.

Two new taxa of Clematis subsection Pierotianae (Ranunculaceae) in Taiwan

Based on a taxonomic study of Clematis subsect. Pierotianae in Taiwan using morphological evidence, two new taxa are proposed: C. parviloba Gard. ex Champ. subsp. shengzhenii Y.H. Cheng & T.Y.A. Yang and C. pengii Y.H. Cheng & T.Y.A. Yang. Both taxa, endemic to Taiwan, are here described and illustrated and distribution maps of both taxa are presented. Morphological comparisons and a key for identification of the taxa of Clematis subsect. Pierotianae in Taiwan are also given.

Delimitation of Ophioderma teres (Lyman, 1860) and Ophioderma unicolor H.L. Clark, 1940 stat. nov. (Echinodermata: Ophiuroidea), including the description of two new species

Ophioderma teres (Lyman, 1860), an ophiuroid previously believed to have a wide distribution in the eastern Pacific, has been found to have an unclear taxonomic identity. While considered a well-known species, recent studies have revealed that O. teres lacks a holotype and has vague boundaries with its congeners Ophioderma teres unicolor H.L. Clark, 1940 and Ophioderma sodipallaresi Caso, 1986, as well as with two additional new morphotypes detected in Mexico and Nicaragua, causing continuous misidentifications. This study utilized an integrative taxonomy approach based on morphologic, morphometric, and molecular evidence to clarify the taxonomic status of O. teres, O. sodipallaresi, O. teres unicolor, and the two new morphotypes. Data integration led to the following results: 1) the neotype designation and redescription of O. teres; 2) the proposal of O. sodipallaresi as a junior synonym of O. teres; 3) the status change of O. unicolor stat. nov. from subspecies to species, and 4) the description of the morphotypes as the new species Ophioderma aija sp. nov. and Ophioderma bichi sp. nov. An identification key to the eastern Pacific species of Ophioderma was also developed. This work contributes to the knowledge of Ophioderma in the region, increasing the number of described species and providing resources for their accurate identification.

The Cambrian Odaraia alata and the colonization of nektonic suspension-feeding niches by early mandibulates.

The diversity of cephalic morphologies in mandibulates (myriapods and pancrustaceans) was key to their evolutionary success. A group of Cambrian bivalved arthropods called hymenocarines exhibit diagnostic mandibulate traits that illustrate this diversity, but many forms are still poorly known. These include the odaraiids, typified by Odaraia alata from the Burgess Shale (Wuliuan), characterized by its unique tubular carapace and rudder-like tail fan, and one of the largest Cambrian euarthropods at nearly 20 cm in length. Unfortunately, odaraiid cephalic anatomy has been largely unknown, limiting evolutionary scenarios and putting their mandibulate affinities into question. Here, we reinvestigate Odaraia based on new specimens from the Burgess Shale and describe exquisitely preserved mandibles with teeth and adjacent structures: a hypostome, maxillae and potential paragnaths. These structures can be homologized with those of Cambrian fuxianhuiids and extant mandibulates, and suggest that the ancestral mandibulate head could have had a limbless segment but retained its plasticity, allowing for limb re-expression within Pancrustacea. Furthermore, we show the presence of limbs with spinose endites which created a suspension-feeding structure. This discovery provides morphological evidence for suspension feeding among large Cambrian euarthropods and evinces the increasing exploitation of planktonic resources in Cambrian pelagic food webs.

First report of Stagonosporopsis pogostemonis causing root rot on Strawberry in China.

In Henan, strawberry cultivation occurs on approximately 10,000 hectares, with annual production approaching 230,000 tons. In April 2022, a root rot disease with a 10% incidence rate was observed on the strawberry cultivars 'Ningyu' and 'Sweet Charlie' grown in plastic greenhouses (0.7 ha) located in Xingyang (113.39°E, 34.79°N), Henan, China. Disease symptoms included yellowing of the outer mature leaves, stunted growth, and subsequent wilting of the entire plant. The roots developed dark brown spots, which gradually turned necrotic (Figures 1a, 1b). To determine the causal agent, four symptomatic plants (two plants per cultivar) were collected. Twelve symptomatic root tissues (three root tissue samples per plant) were surface sterilized with 75% ethanol and 0.1% mercuric chloride, washed thrice in sterile water, air dried, and then placed on PDA at 25°C for 3 days. Eight pure isolates were obtained by hyphal-tip isolation (Fang 2007). Each colony had a dark olivaceous green to brown, cottony appearance with a round margin, and the reverse side was grey-black near the center (Figure 1c). Conidia were ellipsoidal, aseptate, with rounded ends, and 3.1 to 4.8 μm × 1.0 to 2.5 μm in size (Figure 1d). Chlamydospores were ellipsoidal, pale brown, and 7.9 to 11.9 μm × 7.6 to 10.7 μm in size (Figure 1e). A representative fungus isolate, designated as Z5, was selected for further molecular identification. Genomic DNA was extracted from the mycelia of isolate Z5, and four gene partial regions (ITS, TUB2, RPB2, and LSU) were amplified using the primer pairs ITS1/ITS4, Bt-2a/Bt-2b, RPB2-5F/RPB2-7CR and LROR/LR5, respectively (White et al.1990, O'Donnell et al.1997, Reeb et al. 2004, Rehner and Samuels 1994). PCR products were sequenced and submitted to GenBank with the following accession numbers OQ130480 (ITS), OQ190093 (TUB2), OQ190092 (RPB2), and OQ255570 (LSU). BLASTn search revealed that the ITS, TUB2, RPB2, and LSU gene sequences of isolate Z5 showed 99.42% (513/516 bp), 99.69% (320/321 bp), 100% (1071/1071 bp), and 100% (857/857 bp) identity with those of ex-type S. pogostemonis stain ZHKUCC 21-0001 (Dong et al. 2021), respectively. A phylogenetic tree was constructed showing that Z5 clustered with S. pogostemonis (Figure 2). The isolates in this study were identified as S. pogostemonis based on morphological and molecular evidence. To confirm pathogenicity, five one-month-old 'Ningyu' cultivar strawberry seedlings were planted in sterilized nursery soil mixed with wheat grains (0.5% w/w) coated with Z5 mycelia (Fang 2007). An equal number of strawberry seedlings were placed in pots filled with non-infected potting mix to serve as controls. The seedlings were kept in a greenhouse under a 12 h light/dark photoperiod at 25°C. After two weeks, the inoculated seedlings displayed symptoms such as leaf wilting and root necrosis, similar to those observed in the greenhouses, while the control seedlings showed no symptoms (Figures 1f, 1g). The experiment was performed thrice. The identical fungus was re-isolated from the symptomatic roots and identified as S. pogostemonis based on morphological characteristics and molecular analysis, thus fulfilling Koch's postulates. This is the first report of S. pogostemonis causing root rot on strawberries worldwide. Our findings will contribute to a more comprehensive study on investigating and managing this disease.

Taxonomic revision of Marasmius Fr. and Marasmiaceae Roze ex Kühner based on multigene phylogenetics and morphological evidence

Taxonomic revision of Marasmius Fr. and Marasmiaceae Roze ex Kühner based on multigene phylogenetics and morphological evidence

Inflammation, Oxidative Stress, and Endothelial Dysfunction in the Pathogenesis of Vascular Damage: Unraveling Novel Cardiovascular Risk Factors in Fabry Disease.

Anderson-Fabry disease (AFD), a genetic disorder caused by mutations in the α-galactosidase-A (GLA) gene, disrupts lysosomal function, leading to vascular complications. The accumulation of globotriaosylceramide (Gb3) in arterial walls triggers upregulation of adhesion molecules, decreases endothelial nitric oxide synthesis, and induces reactive oxygen species production. This cascade results in fibrotic thickening, endothelial dysfunction, hypercontractility, vasospasm, and a pro-thrombotic phenotype. AFD patients display increased intima-media thickness (IMT) and reduced flow-mediated dilation (FMD), indicating heightened cardiovascular risk. Nailfold capillaroscopy (NFC) shows promise in diagnosing and monitoring microcirculatory disorders in AFD, though it remains underexplored. Morphological evidence of AFD as a storage disorder can be demonstrated through electron microscopy and immunodetection of Gb3. Secondary pathophysiological disturbances at cellular, tissue, and organ levels contribute to the clinical manifestations, with prominent lysosomal inclusions observed in vascular, cardiac, renal, and neuronal cells. Chronic accumulation of Gb3 represents a state of ongoing toxicity, leading to increased cell turnover, particularly in vascular endothelial cells. AFD-related vascular pathology includes increased renin-angiotensin system activation, endothelial dysfunction, and smooth muscle cell proliferation, resulting in IMT increase. Furthermore, microvascular alterations, such as atypical capillaries observed through NFC, suggest early microvascular involvement. This review aims to unravel the complex interplay between inflammation, oxidative stress, and endothelial dysfunction in AFD, highlighting the potential connections between metabolic disturbances, oxidative stress, inflammation, and fibrosis in vascular and cardiac complications. By exploring novel cardiovascular risk factors and potential diagnostic tools, we can advance our understanding of these mechanisms, which extend beyond sphingolipid accumulation to include other significant contributors to disease pathogenesis. This comprehensive approach can pave the way for innovative therapeutic strategies and improved patient outcomes.

Historical and morphological evidence for a remnant population of Lake Erie cisco Coregonus artedi (albus) in Crystal Lake, Pennsylvania

The cisco (Coregonus artedi) population in Crystal Lake, Pennsylvania, is of great scientific interest as it either originated from Lake Erie or Lake Ontario. Cisco in Lake Erie once supported the largest freshwater fishery in the world, but populations were extirpated by 1960. We conducted a morphological analysis of Crystal Lake cisco to determine whether it was consistent with a distinctive Lake Erie form (albus), which was also historically documented, albeit rarely, in western Lake Ontario. Using principal component analysis, we compared eight morphometric ratios and one meristic from our Crystal Lake cisco collection with historical and contemporary collections of cisco from Lakes Erie and Ontario. Maximum likelihood ellipse overlaps between Crystal Lake cisco and presumed albus (the dominant Lake Erie form prior to extirpation) collections averaged 54%. For all groups, the greatest morphological overlap (73.9%) occurred between Crystal Lake and 1957 Lake Erie cisco, which only differed from Crystal Lake cisco in dorsal fin length. Alternatively, overlap between Crystal Lake cisco and all other Lake Ontario collections averaged 3.2%. Our results demonstrate that Crystal Lake cisco are likely an albus form; furthermore, historical documentation and our morphological results suggest a Lake Erie origin. Substantial overlap between Crystal Lake cisco and Lake Ontario albus collected in 1917 is likely explained by continuous entrainment of Lake Erie larvae into Lake Ontario. We suspect this created an albus metapopulation spanning Lakes Erie and Ontario, yet albus are no longer observed in either lake today.

Taxonomy of the genus Ctenomys (Rodentia: Ctenomyidae) in central Argentina: Redefining the limits of Ctenomys bergi Thomas, 1902

Ctenomys Blainville, 1826 (known as tuco-tucos) is considered one of the most diverse genus within mammals; however, its taxonomy is far from resolved. In recent years, new species have been described, and many other forms have been synonymized, while other lineages remain as candidate species. In this work, based on molecular and morphological evidence, we proposed that C. “rosendopascuali”, a taxon considered as a nomen nudum, is in fact a synonym of C. bergi Thomas, 1902. The molecular phylogeny based on the mitochondrial cytochrome b gene showed that individuals from populations a priori assigned to C. bergi and C. “rosendopascuali” were not reciprocally monophyletic. Additionally, geometric morphometric analyses based on cranial morphology showed significant overlap in the morphospace of these two taxa. Our results also show a high genetic similarity among C. bergi, C. “yolandae”, and C. bonettoi Contreras and Berry, 1982, questioning the taxonomic status of the latter two taxa and highlighting the need for exhaustive comparison with C. bergi. We also identified a second locality for a highly divergent lineage within the Mendocinus group (Quijadas lineage). Our study confirms the divergence of this lineage and highlights the need to further taxonomic studies in order to evaluate whether it represents a possible undescribed Ctenomys species.

A new species of Impatiens (Balsaminaceae) from Southern Xizang, China with supplementary knowledge on I. leptocarpa Hook. f.

A new species, Impatiens lhunzeensis (Balsaminaceae), and a new record of I. leptocarpa from southern Xizang, China are reported and described in this study. Based on morphological and phylogenetic evidence, both I. lhunzeensis and I. leptocarpa are assigned to I. sect. Racemosae. The new species forms a clade with I. drepanophora, I. eubotrya and I. principis, while I. leptocarpa is phylogenetically close to I. radiata and I. harae. The new species has a sympatric distribution with and is morphologically similar to both I. radiata and I. harae, but differs by the hairy stem, the densely hairy leaf blade, the raceme inflorescence, the reniform dorsal petals, the navicular lower sepal, the broadly ovate to sub-orbicular upper petals and the triangular oblong lower petals.

Morphological and ecological evidence for the recognition of Anacolia baueri (Bartramiaceae) as distinct from A. menziesii

Morphological and ecological evidence for the recognition of Anacolia baueri (Bartramiaceae) as distinct from A. menziesii

Isolated, neglected, and likely threatened: a new species of Magoniella (Polygonaceae) from the seasonally dry tropical forests of Northern Colombia and Venezuela revealed from nuclear, plastid, and morphological data.

Seasonally tropical dry forests (SDTFs) in the American tropics are a highly diverse yet poorly understood and endangered ecosystem scattered from Northern Mexico to Southern Argentina. One floristic element of the STDFs is the genus Magoniella (Polygonaceae), which includes two liana species, M. laurifolia and M. obidensis, which have winged fruits and are distributed from Costa Rica to Southern Brazil. In a field expedition to the SDTFs of the Colombian Caribbean in 2015, morphologically distinctive individuals of Magoniella were found. In this study, we investigated the species boundaries within Magoniella and determined the phylogenetic position of these morphologically distinctive individuals in the tribe Triplaridae. We compiled morphological trait data across 19 specimens of both species and produced newly sequenced nuclear-plastid DNA data for M. obidensis. Morphometric analyses revealed significant differences in fruit length and perianth size among individuals from the Colombian Caribbean compared to M. obidensis and bract length when compared to M. laurifolia. Maximum likelihood analysis of non-conflicting nuclear and plastid datasets placed the Colombian Caribbean individuals as sister to M. obidensis with maximum statistical support. Additionally, pairwise sequence comparisons of the nuclear ribosomal ITS and the lfy2i loci consistently showed 15-point mutations (10 transitions, five transversions) and six 2 bp-long substitutions that differ between M. obidensis and the Colombian Caribbean individuals. Our morphological and molecular evidence thus suggests that the Colombian Caribbean individuals of Magoniella represent a divergent population from M. laurifolia and M. obidensis, which we describe and illustrate as a new species, M. chersina. Additionally, we provide nomenclatural updates for M. laurifolia and M. obidensis. This study highlights the power of combining morphological and molecular evidence in documenting and naming plant diversity.

MC4R Localizes at Excitatory Postsynaptic and Peri-Postsynaptic Sites of Hypothalamic Neurons in Primary Culture.

The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor (GPCR) that is expressed in several brain locations encompassing the hypothalamus and the brainstem, where the receptor controls several body functions, including metabolism. In a well-defined pathway to decrease appetite, hypothalamic proopiomelanocortin (POMC) neurons localized in the arcuate nucleus (Arc) project to MC4R neurons in the paraventricular nuclei (PVN) to release the natural MC4R agonist α-melanocyte-stimulating hormone (α-MSH). Arc neurons also project excitatory glutamatergic fibers to the MC4R neurons in the PVN for a fast synaptic transmission to regulate a satiety pathway potentiated by α-MSH. By using super-resolution microscopy, we found that in hypothalamic neurons in a primary culture, postsynaptic density protein 95 (PSD95) colocalizes with GluN1, a subunit of the ionotropic N-methyl-D-aspartate receptor (NMDAR). Thus, hypothalamic neurons form excitatory postsynaptic specializations. To study the MC4R distribution at these sites, tagged HA-MC4R under the synapsin promoter was expressed in neurons by adeno-associated virus (AAV) gene transduction. HA-MC4R immunofluorescence peaked at the center and in proximity to the PSD95- and NMDAR-expressing sites. These data provide morphological evidence that MC4R localizes together with glutamate receptors at postsynaptic and peri-postsynaptic sites.

Didymocarpuspingyuanensis (Gesneriaceae), a new species endemic to Danxia landscape from Guangdong Province, China, and two new combinations in Didymocarpus.

Didymocarpuspingyuanensis, endemic to the Danxia landscape in Pingyuan County, Guangdong, China, is described and illustrated here. This species can be distinguished from other members of Didymocarpussect.Heteroboea by its calyx deeply 5-lobed to about three quarters of its length. The phylogenetic position of the new species within Didymocarpus was examined using nuclear ribosomal internal transcribed spacer (ITS) sequences. Based on phylogenetics analysis and morphological evidence, we propose two new combinations, elevating the two varieties to species level, namely D.yinzhengii and D.gamosepalus.

Taxonomic studies of Cycas debaoensis (Cycadaceae) from China

Traditionally, species delimitation based on morphological and distributional evidence often leads to over- or underestimation of species diversity. The primary distribution area of Cycas debaoensis includes two habitats, which were initially published as two separate species, i.e., C. debaoensis in the karst habitat, and C. panshuiensis, which was originally published as Cycas gracilis Y.Y. Huang, Y.C. Zhong et Z.F. Lu, in the sand habitat. However, field investigations and population sampling in these two habitats revealed a certain degree of morphological transition and variation among the populations. Subsequent population genetic analysis showed minimal genetic differentiation among the populations in the two habitats, suggesting that they should be merged as a single species. Additionally, the typification of the name C. debaoensis is also discussed.

Four New Species of Jelly Fungi from Northeastern China.

Four new species of jelly fungi were described from northeastern China based on morphological and molecular evidence. These new species were classified into the four genera Sirobasidium (Sirobasidium jilinense), Calocera (Calocera velutina), Dacrymyces (Dacrymyces jauensis), and Dacryopinax (Dacryopinax manghanensis). Maximum likelihood and Bayesian analyses were performed using a combined nuc rDNA internal transcribed spacer region (ITS) and nuc 28S rDNA (nrLSU) dataset for the construction of phylogenetic trees. Morphological descriptions, line illustrations, and the ecological habits of these new species are provided.

Evidence of mitochondria origin of SARS-CoV-2 double-membrane vesicles: a review.

Coronavirus Disease-19 (COVID-19) pandemic is caused by SARS-CoV-2 that has infected more than 600 million people and killed more than 6 million people worldwide. This infection affects mainly certain groups of people that have high susceptibility to present severe COVID-19 due to comorbidities. Moreover, the long-COVID-19 comprises a series of symptoms that may remain in some patients for months after infection that further compromises their health. Thus, since this pandemic is profoundly affecting health, economy, and social life of societies, a deeper understanding of viral replication cycle could help to envisage novel therapeutic alternatives that limit or stop COVID-19. Several findings have unexpectedly discovered that mitochondria play a critical role in SARS-CoV-2 cell infection. Indeed, it has been suggested that this organelle could be the origin of its replication niches, the double membrane vesicles (DMV). In this regard, mitochondria derived vesicles (MDV), involved in mitochondria quality control, discovered almost 15 years ago, comprise a subpopulation characterized by a double membrane. MDV shedding is induced by mitochondrial stress, and it has a fast assembly dynamic, reason that perhaps has precluded their identification in electron microscopy or tomography studies. These and other features of MDV together with recent SARS-CoV-2 protein interactome and other findings link SARS-CoV-2 to mitochondria and support that these vesicles are the precursors of SARS-CoV-2 induced DMV. In this work, the morphological, biochemical, molecular, and cellular evidence that supports this hypothesis is reviewed and integrated into the current model of SARS-CoV-2 cell infection. In this scheme, some relevant questions are raised as pending topics for research that would help in the near future to test this hypothesis. The intention of this work is to provide a novel framework that could open new possibilities to tackle SARS-CoV-2 pandemic through mitochondria and DMV targeted therapies.