Origin Of Vertebrates Research Articles

Pure Spinal Epidural Cavernous Hemangioma: A Rare Cause of Thoracic Myelopathy

Cavernous hemangiomas mostly occur in intracranial structures but they also may occur in the spine very rarely. Even if found, spinal hemangiomas are commonly vertebral origin and solely epidural hemangiomas not originating from the vertebral bone are very rare. Our case is a 65-year-old man presented to us with progressive paraparesis from six months with motor power 3/5 in both lower extremities. The pathology was total epidural spinal hemangioma at D9-10 vertebral level with typical myelopathy like presentation. Bang. J Neurosurgery 2024; 13(2): 149-151

A case report of high cervical spinal infarction after stenting with severe stenosis at the beginning of left vertebral artery.

Spinal cord infarction is an uncommon nervous system disorder. We present a case of high cervical cord infarction caused by stenting of the origin of the left vertebral artery (VA). The incidence of spinal cord infarction is minimal, and it must be distinguished from a number of other disorders. The diagnosis is primarily based on imaging, clinical symptoms, and history. Currently, there is no focused treatment for spinal cord infarction. Thrombolysis, high-dose glucocorticoid shocks, tube dilatation to promote circulation, and nutritional neurotropic medicines given early in the course of the disease can all help to slow the disease's progression. There is no agreement on the etiology, diagnosis, or therapy options for these people. On October 7, 2023, an 81-year-old man was admitted to the hospital primarily for recurrent chest tightness and pain that had persisted for more than 2 years and 1 month. Cerebral angiography upon admission revealed significant blockage of the right VA and stenosis of the left vertebral arterial origin. Six days following admission, a drug-eluting stenting procedure was carried out under local anesthesia to open the left VA origin via the femoral artery. Following the procedure, the patient experienced a progressive loss of muscle strength in all 4 limbs and paraplegia below the cervical 3 spinal cord. One week following the procedure, the patient was released from the hospital. After the procedure, the patient was released 1 week later. After the procedure, the patient's symptoms persisted for a month. High awareness for high cervical cord infarction is required when neck discomfort and limb weakness with progressive progression arises after surgery. Complications of high cervical cord infarction following stenting for stenosis of VA origin are uncommon in clinical settings. Patients' prognoses can be improved by prompt diagnosis and care.

Shared features of blastula and neural crest stem cells evolved at the base of vertebrates.

The neural crest is a vertebrate-specific stem cell population that helped drive the origin and evolution of vertebrates. A distinguishing feature of these cells is their multi-germ layer potential, which has parallels to another stem cell population-pluripotent stem cells of the vertebrate blastula. Here, we investigate the evolutionary origins of neural crest potential by comparing neural crest and pluripotency gene regulatory networks of a jawed vertebrate, Xenopus, and a jawless vertebrate, lamprey. We reveal an ancient evolutionary origin of shared regulatory factors in these gene regulatory networks that dates to the last common ancestor of extant vertebrates. Focusing on the key pluripotency factor pou5, we show that a lamprey pou5 orthologue is expressed in animal pole cells but is absent from neural crest. Both lamprey and Xenopus pou5 promote neural crest formation, suggesting that pou5 activity was lost from the neural crest of jawless vertebrates or acquired along the jawed vertebrate stem. Finally, we provide evidence that pou5 acquired novel, neural crest-enhancing activity after evolving from an ancestral pou3-like clade. This work provides evidence that both the neural crest and blastula pluripotency networks arose at the base of the vertebrates and that this may be linked to functional evolution of pou5.

Evolutionary origin of the chordate nervous system revealed by amphioxus developmental trajectories.

The common ancestor of all vertebrates had a highly sophisticated nervous system, but questions remain about the evolution of vertebrate neural cell types. The amphioxus, a chordate that diverged before the origin of vertebrates, can inform vertebrate evolution. Here we develop and analyse a single-cell RNA-sequencing dataset from seven amphioxus embryo stages to understand chordate cell type evolution and to study vertebrate neural cell type origins. We identified many new amphioxus cell types, including homologues to the vertebrate hypothalamus and neurohypophysis, rooting the evolutionary origin of these structures. On the basis of ancestor-descendant reconstruction of cell trajectories of the amphioxus and other species, we inferred expression dynamics of transcription factor genes throughout embryogenesis and identified three ancient developmental routes forming chordate neurons. We characterized cell specification at the mechanistic level and generated mutant lines to examine the function of five key transcription factors involved in neural specification. Our results show three developmental origins for the vertebrate nervous system: an anterior FoxQ2-dependent mechanism that is deeply conserved in invertebrates, a less-conserved route leading to more posterior neurons in the vertebrate spinal cord and a mechanism for specifying neuromesoderm progenitors that is restricted to chordates. The evolution of neuromesoderm progenitors may have led to a dramatic shift in posterior neural and mesodermal cell fate decisions and the body elongation process in a stem chordate.

The sensory shark: high-quality morphological, genomic and transcriptomic data for the small-spotted catshark Scyliorhinus canicula reveal the molecular bases of sensory organ evolution in jawed vertebrates.

Cartilaginous fishes (chimaeras and elasmobranchs -sharks, skates and rays) hold a key phylogenetic position to explore the origin and diversifications of jawed vertebrates. Here, we report and integrate reference genomic, transcriptomic and morphological data in the small-spotted catshark Scyliorhinus canicula to shed light on the evolution of sensory organs. We first characterise general aspects of the catshark genome, confirming the high conservation of genome organisation across cartilaginous fishes, and investigate population genomic signatures. Taking advantage of a dense sampling of transcriptomic data, we also identify gene signatures for all major organs, including chondrichthyan specializations, and evaluate expression diversifications between paralogs within major gene families involved in sensory functions. Finally, we combine these data with 3D synchrotron imaging and in situ gene expression analyses to explore chondrichthyan-specific traits and more general evolutionary trends of sensory systems. This approach brings to light, among others, novel markers of the ampullae of Lorenzini electro-sensory cells, a duplication hotspot for crystallin genes conserved in jawed vertebrates, and a new metazoan clade of the Transient-receptor potential (TRP) family. These resources and results, obtained in an experimentally tractable chondrichthyan model, open new avenues to integrate multiomics analyses for the study of elasmobranchs and jawed vertebrates.

Variations in origin level of superior mesenteric artery, inferior mesenteric artery, and coeliac trunk in Indian population.

The abdominal aorta is a continuation of the thoracic aorta and gives off the coeliac trunk, superior mesenteric artery, and inferior mesenteric artery. The focus of our study is to evaluate variations in the origin level in the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and aortic bifurcation in the Indian population and compare with various demographics. The study was retrospective and the local ethics committee approval was taken before starting it. Three hundred patients who were more than 18 years of age and required contrast-enhanced CT studies were included in this. The vertebral origin level of the arteries from the abdominal aorta and aortic bifurcation level was analysed. The most common origin level of the coeliac trunk for both males and females was T12-L1 disc level. The most common origin level of the superior mesenteric artery was L1 upper level. The most common origin level of the inferior mesenteric artery was L3 upper level. The most common level of aortic bifurcation was L4 middle level. There was no statistical difference between the origin of any arteries in males and females in the Indian population. As per our study of the Indian population and the published literature, it is realized that there are significant variations in the origins of the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and abdominal aorta bifurcation in different populations. This study elaborates on potential anatomical variations in the Indian population, particularly the Mumbai city population. Also, our study compares it to different countries' data and their results in variations found in abdominal aorta branches.

Amphioxus (Branchiostoma lanceolatum) in the North Adriatic Sea: ecological observations and spawning behavior.

The European amphioxus (Branchiostoma lanceolatum) is a member of the chordate subphylum Cephalochordata, and, as such, a key model organism for providing insights into the origin and evolution of vertebrates. Despite its significance and global distribution, detailed characterizations of natural populations of cephalochordates are still very limited. This study investigates the abundance, habitat, and spawning behavior of amphioxus in the North Adriatic Sea. Across 32 sampled sites, adult amphioxus were consistently present, reaching densities exceeding 300 individualsm- 2. DNA barcoding confirmed the species as B. lanceolatum, and environmental analyses revealed an amphioxus preference for slightly gravelly sand with low silt content and a correlation between amphioxus density and the presence of specific macroinvertebrate taxa. Remarkably, the amphioxus population was breeding in early spring and possibly late fall, in contrast to the typical late spring/early summer spawning season described for other populations of European amphioxus. Amphioxus adults kept in captivity maintained the spawning seasonality of their place of origin, suggesting the possibility of extending the overall spawning season of European amphioxus in laboratory settings by exploiting populations from diverse geographic origins. This study thus expands our understanding of B. lanceolatum ecology and reproduction in the Mediterranean Sea, emphasizing the role of the North Adriatic Sea as a substantial reservoir.

The evolution of larvae in temnospondyls and the stepwise origin of amphibian metamorphosis.

The question of what the ancient life cycle of tetrapods was like forms a key component in understanding the origin of land vertebrates. The existence of distinct larval forms, as exemplified by many lissamphibians, and their transformation into adults is an important aspect in this field. The temnospondyls, the largest clade of Palaeozoic-Mesozoic non-amniote tetrapods, covered a wide ecomorphological range from fully aquatic to terrestrial taxa. In various species, rich ontogenetic data have accumulated over the past 130 years, permitting the study of early phases of temnospondyl development. In temnospondyls, eight ontogenetic phases have been identified in which the skeleton formed. In branchiosaurids and the eryopiform Sclerocephalus, large parts of the ossification sequence are now known. Most taxa in which small specimens are preserved had aquatic larvae with external gills that superficially resemble larval salamanders. In the edopoids, dvinosaurs, and eryopiforms, the larvae developed slowly, with incompletely ossified axial and appendicular skeletons, but possessed a fast-developing dermal skull with strong teeth. Irrespective of adult terrestriality or a fully aquatic life, there was no drastic transformation during later ontogeny, but a slow and steady acquisition of adult features. In dissorophoids, the limbs developed at a much faster pace, whereas skull formation was slowed down, especially in the amphibamiforms, and culminating in the neotenic Branchiosauridae. In the zatracheid Acanthostomatops, slow but profound transformation led to a fully terrestrial adult. The basal dissorophoid Stegops retained rapid development of dermal skull bones and established a fully dentigerous, strongly ossified palate early. In Micromelerpeton, formation of the last skull bones was slightly delayed and metamorphosis remained a long and steady phase of morphological transformations. In amphibamiforms, metamorphosis became more drastic, with an increasing number of events packed into a short phase of ontogeny. This is exemplified by Apateon, Platyrhinops, and Amphibamus in which this condensation was maximised. We distinguish three different types of metamorphosis (morphological, ecological and drastic) that evolved cumulatively in early tetrapods and within temnospondyls.

The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes.

Attempts to explain the origin and diversification of vertebrates have commonly invoked the evolution of feeding ecology, contrasting the passive suspension feeding of invertebrate chordates and larval lampreys with active predation in living jawed vertebrates. Of the extinct jawless vertebrates that phylogenetically intercalate these living groups, the feeding apparatus is well-preserved only in the early diverging stem-gnathostome heterostracans. However, its anatomy remains poorly understood. Here, we use X-ray microtomography to characterize the feeding apparatus of the pteraspid heterostracan Rhinopteraspis dunensis (Roemer, 1855). The apparatus is composed of 13 plates arranged approximately bilaterally, most of which articulate from the postoral plate. Our reconstruction shows that the oral plates were capable of rotating around the transverse axis, but likely with limited movement. It also suggests the nasohypophyseal organs opened internally, into the pharynx. The functional morphology of the apparatus in Rhinopteraspis precludes all proposed interpretations of feeding except for suspension/deposit feeding and we interpret the apparatus as having served primarily to moderate the oral gape. This is consistent with evidence that at least some early jawless gnathostomes were suspension feeders and runs contrary to macroecological scenarios that envisage early vertebrate evolution as characterized by a directional trend towards increasingly active food acquisition.

The origins of gas exchange and ion regulation in fish gills: evidence from structure and function.

Gill function in gas exchange and ion regulation has played key roles in the evolution of fishes. In this review, we summarize data from the fields of palaeontology, developmental biology and comparative physiology for when and how the gills first acquired these functions. Data from across disciplines strongly supports a stem vertebrate origin for gas exchange structures and function at the gills with the emergence of larger, more active fishes. However, the recent discovery of putative ionocytes in extant cephalochordates and hemichordates suggests that ion regulation at gills might have originated much earlier than gas exchange, perhaps in the ciliated pharyngeal arches in the last common ancestor of deuterostomes. We hypothesize that the ancestral form of ion regulation served a filter-feeding function in the ciliated pharyngeal arches, and was later coopted in vertebrates to regulate extracellular ion and acid-base balance. We propose that future research should explore ionocyte homology and function across extant deuterostomes to test this hypothesis and others in order to determine the ancestral origins of ion regulation in fish gills.

Anciently duplicated genes continuously recruited to heart expression in vertebrate evolution are associated with heart chamber increase.

Although gene/genome duplications in the early stage of vertebrates have been thought to provide major resources of raw genetic materials for evolutionary innovations, it is unclear whether they continuously contribute to the evolution of morphological complexity during the course of vertebrate evolution, such as the evolution from two heart chambers (fishes) to four heart chambers (mammals and birds). We addressed this issue by our heart RNA-Seq experiments combined with published data, using 13 vertebrates and one invertebrate (sea squirt, as an outgroup). Our evolutionary transcriptome analysis showed that number of ancient paralogous genes expressed in heart tends to increase with the increase of heart chamber number along the vertebrate phylogeny, in spite that most of them were duplicated at the time near to the origin of vertebrates or even more ancient. Moreover, those paralogs expressed in heart exert considerably different functions from heart-expressed singletons: the former are functionally enriched in cardiac muscle and muscle contraction-related categories, whereas the latter play more basic functions of energy generation like aerobic respiration. These findings together support the notion that recruiting anciently paralogous genes that are expressed in heart is associated with the increase of chamber number in vertebrate evolution.

Exciting Fossil Discoveries Shed Light on the Origin and Evolution of Fishes and Reptiles

Over the last decade, numerous important vertebrate fossils have been discovered by scientists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences (CAS), which have significantly enriched understanding about the origin and early evolution of fish, amphibians, and reptiles. Particularly, researches about the origin of jawed vertebrates and origin of birds have systematically revised previous thoughts. These studies also demonstrate the globally leading role played by IVPP research teams in this field.

ХРОНИЧЕСКИЕ БОЛИ В ГРУДНОЙ КЛЕТКЕ В ПОВСЕДНЕВНОЙ РАБОТЕ ВРАЧА ОБЩЕЙ ПРАКТИКИ

Chronic pain remains one of the topical problems of modern medicine. The most common causes of chronic chest pain in patients over 60 years of age are diseases of the cardiovascular and respiratory system, connective tissue diseases, oncologic diseases, secondary dorsalgias. At a young age, such pain is associated with maladaptive motor stereotype of work, concomitant psychological problems, the presence of musculoskeletal pain. Differential diagnosis is made between diseases of vertebral and non-vertebral origin, costochondral, costosternal pain syndromes, pain associated with the joints of the shoulder girdle. Chest pain is an interdisciplinary medical problem, but, nevertheless, the primary appeal of these patients is to therapists and general practitioners. Patients with chest pain need a multidisciplinary approach to diagnosis and selection of individual therapy.

Evolutionary mechanisms and practical significance of reproductive success and clonal diversity in unisexual vertebrate polyploids.

Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary "dead end" due to the accumulation of deleterious mutations and absence of genetic diversity. However, some unisexual polyploids have developed strategies to avoid genomic decay, and thus provide ideal models to unveil unexplored evolutionary mechanisms, from the reproductive success to clonal diversity creation. This article reviews the evolutionary mechanisms for overcoming meiotic barrier and generating genetic diversity in unisexual vertebrates, and summarizes recent research advancements in the polyploid Carassius complex. Gynogenetic gibel carp (Carassius gibelio) is a unique amphitriploid that has undergone a recurrent autotriploidy and has overcome the bottleneck of triploid sterility via gynogenesis. Recently, an efficient strategy in which ploidy changes, including from amphitriploid to amphitetraploid, then from amphitetraploid to novel amphitriploid, drive unisexual-sexual-unisexual reproduction transition and clonal diversity has been revealed. Based on this new discovery, multigenomic reconstruction biotechnology has been used to breed a novel strain with superior growth and stronger disease resistance. Moreover, a unique reproduction mode that combines both abilities of ameiotic oogenesis and sperm-egg fusion, termed as ameio-fusiongensis, has been discovered, and it provides an efficient approach to synthesize sterile allopolyploids. In order to avoid ecological risks upon escape and protect the sustainable property rights of the aquaculture seed industry, a controllable fertility biotechnology approach for precise breeding is being developed by integrating sterile allopolyploid synthesis and gene-editing techniques. This review provides novel insights into the origin and evolution of unisexual vertebrates and into the attempts being made to exploit new breeding biotechnologies in aquaculture.

Henri de Lacaze-Duthiers and the ascidian hypothesis.

In 1830, Cuvier and Geoffroy Saint-Hilaire confronted each other in a famous debate on the unity of the animal kingdom, which permeated the zoology of the 19th century. From that time, a growing number of naturalists attempted to understand the large-scale relationships among animals. And among all the questions, that of the origin of vertebrates was one of the most controversial. Analytical methods based on comparative anatomy, embryology and paleontology were developed to identify convincing homologies that would reveal a logical sequence of events for the evolution of an invertebrate into the first vertebrate. Within this context, several theories have clashed on the question of the identity of the ancestor of vertebrates. Among the proposals, a group of rather discrete organisms, the ascidians, played a central role. Because he had discovered an ascidian with a particularly atypical larval development, the Molgula, Henri de Lacaze-Duthiers, a rigorous and meticulous naturalist, became involved in the ascidian hypothesis. While the visionary mind of Lacaze-Duthiers led him to establish a particularly innovative methodology and the first marine biology station in Europe, at Roscoff, the tailless tadpole of the Molgula prevented him from recognizing the ancestor of vertebrates. This old 19th century story echoes the ever-present questions driving the field of Eco-Evo-Devo.

Parallel evolution of picobirnaviruses from distinct ancestral origins.

Picobirnaviruses (PBVs) are small, bi-segmented, double-stranded RNA viruses frequently associated with gastrointestinal and recently linked to respiratory infections. Detected in hosts from distant biological kingdoms, debate swirls as to their age and origins and whether they are prokaryotic or eukaryotic viruses. Our evolutionary analysis revealed a contemporaneous emergence for PBV, as PBV-R1&3 species arose ~350 years ago with both segments, whereas the more ancient species, PBV-R2, initially lacked capsid. Integrated phylogenetic reconstruction defined two origins for PBV, determining PBV-R1&3 species descended from Reovirus and PBV-R2 branched with Partitivirus ancestors. These results, coupled with the heterogeneity of Shine-Dalgarno motifs, argue against a prokaryotic origin. Epistatic interactions identified in the RdRp of PBV-R1&3 evidenced the constraints imposed by vertebrate host immunity, whereas its absence in PBV-R2 concurs with its fungal origin. After acquisition of capsid, PBV-R2 increased its adaptive and functional divergences in RdRp domains and the compactness of its RNA structure to enable encapsidation. While their pathogenicity remains an open question, picobirnaviruses likely originated from both fungal and avian hosts: parallel evolution mechanisms have driven the genetic similarities shared among present-day PBV species.IMPORTANCEPicobirnaviruses (PBVs) are highly heterogeneous viruses encoding a capsid and RdRp. Detected in a wide variety of animals with and without disease, their association with gastrointestinal and respiratory infections, and consequently their public health importance, has rightly been questioned. Determining the "true" host of Picobirnavirus lies at the center of this debate, as evidence exists for them having both vertebrate and prokaryotic origins. Using integrated and time-stamped phylogenetic approaches, we show they are contemporaneous viruses descending from two different ancestors: avian Reovirus and fungal Partitivirus. The fungal PBV-R2 species emerged with a single segment (RdRp) until it acquired a capsid from vertebrate PBV-R1 and PBV-R3 species. Protein and RNA folding analyses revealed how the former came to resemble the latter over time. Thus, parallel evolution from disparate hosts has driven the adaptation and genetic diversification of the Picobirnaviridae family.

A miniaturized nigrostriatal-like circuit regulating locomotor performance in a protochordate

To gain insight into the evolution of motor control systems at the origin of vertebrates, we have investigated higher-order motor circuitry in the protochordate Oikopleura dioica. We have identified a highly miniaturized circuit in Oikopleura with a projection from a single pair of dopaminergic neurons to a small set of synaptically coupled GABAergic neurons, which in turn exert a disinhibitory descending projection onto the locomotor central pattern generator. The circuit is reminiscent of the nigrostriatopallidal system in the vertebrate basal ganglia, in which disinhibitory circuits release specific movements under the modulatory control of dopamine. We demonstrate further that dopamine is required to optimize locomotor performance in Oikopleura, mirroring its role in vertebrates. A dopamine-regulated disinhibitory locomotor control circuit reminiscent of the vertebrate nigrostriatopallidal system was thus already present at the origin of ancestral chordates and has been maintained in the face of extreme nervous system miniaturization in the urochordate lineage.

Dimeric G-quadruplex motifs-induced NFRs determine strong replication origins in vertebrates

Replication of vertebrate genomes is tightly regulated to ensure accurate duplication, but our understanding of the interplay between genetic and epigenetic factors in this regulation remains incomplete. Here, we investigated the involvement of three elements enriched at gene promoters and replication origins: guanine-rich motifs potentially forming G-quadruplexes (pG4s), nucleosome-free regions (NFRs), and the histone variant H2A.Z, in the firing of origins of replication in vertebrates. We show that two pG4s on the same DNA strand (dimeric pG4s) are sufficient to induce the assembly of an efficient minimal replication origin without inducing transcription in avian DT40 cells. Dimeric pG4s in replication origins are associated with formation of an NFR next to precisely-positioned nucleosomes enriched in H2A.Z on this minimal origin and genome-wide. Thus, our data suggest that dimeric pG4s are important for the organization and duplication of vertebrate genomes. It supports the hypothesis that a nucleosome close to an NFR is a shared signal for the formation of replication origins in eukaryotes.

Editorial: Tribute to Tiiu Märss and Philippe Janvier (16th International Symposium on Early and Lower Vertebrates)

The International Symposium on Early and Lower Vertebrates (ISELV) aims to promote thestudy of the origin and early evolution of our own evolutionary lineage. This volume serves as an example ofthe most recent symposium held in Valencia, Spain, in June 2022. Since its inception in 1967, the ISELV hasbeen organized 15 times prior to the latest conference in Valencia, which marked the 16th edition and the firsttime it was held in Spain in over 50 years. This symposium stands out as the sole recurring international meetingexclusively dedicated to the Palaeozoic vertebrate research community, putting special emphasis on topicsconcerning the origin, diversity, and early evolution of vertebrates (including the first tetrapods). The compilationpresented in this volume represents the culmination of these conferences and serves as our tribute totwo distinguished researchers in the field of Early Vertebrates: Dr. Philippe Janvier from the Muséum Nationald’Histoire Naturelle in Paris and Dr. Tiiu Märss from Tallinn University of Technology in Estonia.

Three amphioxus reference genomes reveal gene and chromosome evolution of chordates

The slow-evolving invertebrate amphioxus has an irreplaceable role in advancing our understanding of the vertebrate origin and innovations. Here we resolve the nearly complete chromosomal genomes of three amphioxus species, one of which best recapitulates the 17 chordate ancestor linkage groups. We reconstruct the fusions, retention, or rearrangements between descendants of whole-genome duplications, which gave rise to the extant microchromosomes likely existed in the vertebrate ancestor. Similar to vertebrates, the amphioxus genome gradually establishes its three-dimensional chromatin architecture at the onset of zygotic activation and forms two topologically associated domains at the Hox gene cluster. We find that all three amphioxus species have ZW sex chromosomes with little sequence differentiation, and their putative sex-determining regions are nonhomologous to each other. Our results illuminate the unappreciated interspecific diversity and developmental dynamics of amphioxus genomes and provide high-quality references for understanding the mechanisms of chordate functional genome evolution.