16,231 research outputs found

    The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales).

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    Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species), and 13 smaller genera (< 10 species each). In this paper, phylogenetic relationships of the tribe Polysiphonieae are analysed, with particular emphasis on the genera Carradoriella, Fernandosiphonia, Melanothamnus, Neosiphonia, Polysiphonia sensu stricto, Streblocladia and Vertebrata. We evaluated the consistency of 14 selected morphological characters in the identified clades. Based on molecular phylogenetic (rbcL and 18S genes) and morphological evidence, two speciose genera are recognized: Vertebrata (including the type species of the genera Ctenosiphonia, Enelittosiphonia, Boergeseniella and Brongniartella) and Melanothamnus (including the type species of the genera Fernandosiphonia and Neosiphonia). Both genera are distinguished from other members of the Polysiphonieae by synapomorphic characters, the emergence of which could have provided evolutionarily selective advantages for these two lineages. In Vertebrata trichoblast cells are multinucleate, possibly associated with the development of extraordinarily long, photoprotective, trichoblasts. Melanothamnus has 3-celled carpogonial branches and plastids lying exclusively on radial walls of the pericentral cells, which similarly may improve resistance to damage caused by excessive light. Other relevant characters that are constant in each genus are also shared with other clades. The evolutionary origin of the genera Melanothamnus and Vertebrata is estimated as 75.7-95.78 and 90.7-138.66 Ma, respectively. Despite arising in the Cretaceous, before the closure of the Tethys Seaway, Melanothamnus is a predominantly Indo-Pacific genus and its near-absence from the northeastern Atlantic is enigmatic. The nomenclatural implications of this work are that 46 species are here transferred to Melanothamnus, six species are transferred to Vertebrata and 13 names are resurrected for Vertebrata

    Sequence alignment, mutual information, and dissimilarity measures for constructing phylogenies

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    Existing sequence alignment algorithms use heuristic scoring schemes which cannot be used as objective distance metrics. Therefore one relies on measures like the p- or log-det distances, or makes explicit, and often simplistic, assumptions about sequence evolution. Information theory provides an alternative, in the form of mutual information (MI) which is, in principle, an objective and model independent similarity measure. MI can be estimated by concatenating and zipping sequences, yielding thereby the "normalized compression distance". So far this has produced promising results, but with uncontrolled errors. We describe a simple approach to get robust estimates of MI from global pairwise alignments. Using standard alignment algorithms, this gives for animal mitochondrial DNA estimates that are strikingly close to estimates obtained from the alignment free methods mentioned above. Our main result uses algorithmic (Kolmogorov) information theory, but we show that similar results can also be obtained from Shannon theory. Due to the fact that it is not additive, normalized compression distance is not an optimal metric for phylogenetics, but we propose a simple modification that overcomes the issue of additivity. We test several versions of our MI based distance measures on a large number of randomly chosen quartets and demonstrate that they all perform better than traditional measures like the Kimura or log-det (resp. paralinear) distances. Even a simplified version based on single letter Shannon entropies, which can be easily incorporated in existing software packages, gave superior results throughout the entire animal kingdom. But we see the main virtue of our approach in a more general way. For example, it can also help to judge the relative merits of different alignment algorithms, by estimating the significance of specific alignments.Comment: 19 pages + 16 pages of supplementary materia

    NG peptides: A novel family of neurophysin-associated neuropeptides

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    NOTICE: this is the author’s version of a work that was accepted for publication in GENE. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in GENE, [VOL 458, ISSUE 1-2, (2010)] DOI: 10.1016/j.gene.2010.03.00

    RANCANG BANGUN GAME EDUKASI PENGENALAN TAKSONOMI HEWAN MAMALIA VERTEBRATA MENGGUNAKAN UNITY 3D

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    Dalam pelajaran Biologi diperlukan kemampuan untuk menghafal, terutama pada sub pokok bahasan klasifikasi makhluk hidup mengenai taksonomi hewan mamalia vertebrata. Proses pembelajaran yang secara teori menyebabkan siswa mengalami kesulitan dalam memahami pelajaran tersebut. Oleh karena itu, diperlukan sebuah aplikasi yang dapat membantu siswa untuk belajar biologi terutama tentang taksonomi hewan mamalia vertebrata menjadi lebih mudah. Saepti Ferarum adalah aplikasi permainan edukasi tentang pengenalan taksonomi hewan mamalia vertebrata dengan tampilan permainan 3D di personal computer. Game ini di bangun dan di rancang menggunakan Unity 3D dan menggunakan metodologi RAD (Rapid Application Development). Dimana tahapan yang dimiliki dalam metodolodi RAD (Rapid Application Development) yaitu : pemodelan bisnis, pemodelan data, pemodelan proses, pembuatan aplikasi, pengujian dan pergantian. Pengujian pada permainan ini dilakukan dengan menggunakan metode blackbox dan kuesioner. Melalui kuesioner ini, didapatkan kesimpulan bahwa sebanyak 90,67% responden menyatakan game Saepti Ferarum ini dapat dijadikan sebagai media alternatif pembelajaran pengenalan taksonomi hewan mamalia vertebrata khusunya bagi siswa menengah pertam

    Mapping the Space of Genomic Signatures

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    We propose a computational method to measure and visualize interrelationships among any number of DNA sequences allowing, for example, the examination of hundreds or thousands of complete mitochondrial genomes. An "image distance" is computed for each pair of graphical representations of DNA sequences, and the distances are visualized as a Molecular Distance Map: Each point on the map represents a DNA sequence, and the spatial proximity between any two points reflects the degree of structural similarity between the corresponding sequences. The graphical representation of DNA sequences utilized, Chaos Game Representation (CGR), is genome- and species-specific and can thus act as a genomic signature. Consequently, Molecular Distance Maps could inform species identification, taxonomic classifications and, to a certain extent, evolutionary history. The image distance employed, Structural Dissimilarity Index (DSSIM), implicitly compares the occurrences of oligomers of length up to kk (herein k=9k=9) in DNA sequences. We computed DSSIM distances for more than 5 million pairs of complete mitochondrial genomes, and used Multi-Dimensional Scaling (MDS) to obtain Molecular Distance Maps that visually display the sequence relatedness in various subsets, at different taxonomic levels. This general-purpose method does not require DNA sequence homology and can thus be used to compare similar or vastly different DNA sequences, genomic or computer-generated, of the same or different lengths. We illustrate potential uses of this approach by applying it to several taxonomic subsets: phylum Vertebrata, (super)kingdom Protista, classes Amphibia-Insecta-Mammalia, class Amphibia, and order Primates. This analysis of an extensive dataset confirms that the oligomer composition of full mtDNA sequences can be a source of taxonomic information.Comment: 14 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1307.375

    Kemampuan Mahasiswa Pendidikan Biologi Dalam Praktikum Sistematika Vertebrata Tahun Akademik 2016/2017

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    Vertebrata systematics is a compulsory subject for students Faculty of Biology Education University of Muhammadiyah Surakarta, with the number of SKS is 1 and 100 minutes fora one-time meeting. The purpose of this study is to determine the ability of students in practicum Vertebrata Systematics in Biology Education Studies Program of FKIP University of Muhammadiyah Surakarta academic year 2016/2017. This research is expost facto research using data of practicum value and student questionnaire result. The results showed that the final value of the practice is in the category of very good with an average of 80,86 and the questionnaire of student’s ability for internal factors are in good category with an average of 62.77 and external factors are in good category with average 76.80. Based on these results, it can be concluded that student’s ability in practicum Vertebrata Systematics in Biology Education Studies Program of FKIP University of Muhammadiyah Surakarta academic year 2016/2017 is in good category

    A new genus and species of sabretooth, Oriensmilus liupanensis (Barbourofelinae, Nimravidae, Carnivora), from the middle Miocene of China suggests barbourofelines are nimravids, not felids

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    Since the early 2000s, a revival of a felid relationship for barbourofeline sabretooths has become popular due to recent discoveries of fragmentary fossils from Africa. According to this view, barbourofelines trace their common ancestor with felids through shared similarities in dental morphology going back to the early Miocene of Africa and Europe. However, whether or not such an idea is represented in the basicranial morphology, a conservative area of high importance in family-level relationships, is yet to be tested. A nearly complete skull of Oriensmilus liupanensis gen. and sp. nov. from the middle Miocene Tongxin Basin of northern China represents the most primitive known barbourofeline with an intact basicranial region, affording an opportunity to re-examine the relationship of felids and nimravines. We also present an update on East Asian records of barbourofelines. The new skull of Oriensmilus possesses a suite of characters shared with nimravines, such as the lack of an ossified (entotympanic) bullar floor, absence of an intrabullar septum, lack of a ventral promontorial process of the petrosal, presence of a small rostral entotympanic on the dorsal side of the caudal entotympanic, and a distinct caudal entry of the internal carotid artery and nerve that pierces the caudal entotympanic at the junction of the ossified and unossified caudal entotympanics. The absence of an ossified bullar floor in O. liupanensis and its presence in those from the middle Miocene of Sansan, France thus help to bracket the transition of this character, which must have happened in the early part of the middle Miocene. Spatial relationships between bullar construction and the middle ear configuration of the carotid artery in Oriensmilus strongly resemble those in nimravines but are distinctly different from felids and other basal feliforms. Despite the attractive notion that early barbourofelines arose from a Miocene ancestor that also gave rise to felids, the basicranial evidence argues against this view. http://zoobank.org/urn:http://lsid:zoobank.org:pub:2DE98DBC-4D02-4E18-9788-0B0D8587E73F

    Going nuclear: gene family evolution and vertebrate phylogeny reconciled

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    Gene duplications have been common throughout vertebrate evolution, introducing paralogy and so complicating phylogenctic inference from nuclear genes. Reconciled trees are one method capable of dealing with paralogy, using the relationship between a gene phylogeny and the phylogeny of the organisms containing those genes to identify gene duplication events. This allows us to infer phylogenies from gene families containing both orthologous and paralogous copies. Vertebrate phylogeny is well understood from morphological and palaeontological data, but studies using mitochondrial sequence data have failed to reproduce this classical view. Reconciled tree analysis of a database of 118 vertebrate gene families supports a largely classical vertebrate phylogeny

    The marine macroalgae of Cabo Verde archipelago : an updated checklist

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    An updated list of the names of the marine macroalgae of Cabo Verde, an archipelago of ten volcanic islands in the central Atlantic Ocean, is presented based on existing reports, and includes the addition of 36 species. The checklist comprises a total of 372 species names, of which 68 are brown algae (Ochrophyta), 238 are red algae (Rhodophyta) and 66 green algae (Chlorophyta). New distribution records reveal the existence of 10 putative endemic species for Cabo Verde islands, nine species that are geographically restricted to the Macaronesia, five species that are restricted to Cabo Verde islands and the nearby Tropical Western African coast, and five species known to occur only in the Maraconesian Islands and Tropical West Africa. Two species, previously considered invalid names, are here validly published as Colaconema naumannii comb. nov. and Sebdenia canariensis sp. nov.The present work was generated in the context of the Project PADDLE - Planning in the liquid world with tropical stakes, funded by the European Union’s Horizon 2020 Research and Innovation Programme under Grant 734271. DG was supported with the FCT postdoctoral grant SFRH/BPD/64963/2009. CIBIO-Açores is maintained with Portuguese (UID/BIA/50027/2013) and Azorean (POCI-01-0145-FEDER-006821) funding.info:eu-repo/semantics/publishedVersio
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