Results 131 to 140 of about 1,321 (169)
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Genome Duplication in Early Vertebrates: Insights from Agnathan Cytogenetics
Cytogenetic and Genome Research, 2013Agnathans represent a remnant of a primitive offshoot of the vertebrates, and the long evolutionary separation between their 2 living groups, namely hagfishes and lampreys, could explain profound biological differences, also in karyotypes and genome sizes.
Caputo +7 more
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The Agnathan Ark: The Origin of Craniate Brains
Brain, Behavior and Evolution, 1996An outgroup analysis of head organization of tunicates, lancelets and craniates indicates that the origin of craniates involved the development of a new muscular pharyngeal pump, which was a key innovation underlying the evolution of a more metabolically active group of chordates.
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Review of the unique and dominant lectin pathway of complement activation in agnathans
Developmental & Comparative Immunology, 2023As the most primitive vertebrates, lampreys are significant in understanding the early origin and evolution of the vertebrate innate and adaptive immune systems. The complement system is a biological response system with complex and precise regulatory mechanisms and plays an important role in innate and adaptive immunity.
Jiali Lu +3 more
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Agnathan muscle pyruvate kinases : properties and evolutionary affinities
2021This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
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First Report of a Mitochondrial Pseudogene in Agnathan Vertebrates (Cyclostomata: Petromyzontidae)
Journal of Molecular Evolution, 2018We report herein the characterization of a nuclear paralog of a fragment of the mitochondrial genome (a numt) in two closely related species of lampreys (Ichthyomyzon spp.). Although numts have been characterized in several vertebrate taxa, numts have yet to be reported for fishes in general.
Rex Meade Strange, Kimberly J. Delaney
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Yet more reflections on agnathan-gnathostome relationships
Journal of Vertebrate Paleontology, 1984ABSTRACT Evidence for two competing theories of relationships between Recent agnathans (hagfishes and lampreys) and gnathostomes is reviewed. The hypothesis that lampreys and gnathostomes are sister-groups is favored. The more obvious structures (fins, gill chambers, skeleton) seen in fossil agnathans are discussed and conclusions about their ...
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Squamation of the thelodont agnathanPhlebolepis
Journal of Vertebrate Paleontology, 1986ABSTRACT The study of more than 250 articulated specimens of the thelodont Phlebolepis elegans (Upper Silurian, Estonia) has shown how the morphology and sculpture pattern of scales depend upon their position on the body. Five morphological scale varieties are distinguished for several Silurian thelodonts. Phlebolepis ornata n.sp.
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CO2 transport in agnathan blood: evidence of erythrocyte Cl−/HCO3− exchange limitations
Respiration Physiology, 1990CO2 transport properties of blood were examined in the lamprey Petromyzon marinus and the hagfish Myxine glutinosa. In order to evaluate possible chloride/bicarbonate exchange limitations, experiments were conducted under control conditions and in the presence of an ionophore to permit equilibrium distribution of chloride, bicarbonate, and protons ...
B L, Tufts, R G, Boutilier
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Sequencing of amphioxus PSMB5 / 8 gene and phylogenetic position of agnathan sequences
Gene, 2002Reanalyses of vertebrate PSMB5 and PSMB8 genes were conducted with a newly obtained amphioxus sequence. The phylogenetic analysis indicated that the amphioxus sequence is an outgroup of both vertebrate PSMB5 and PSMB8 genes. The agnathan sequences were previously thought to be closer to PSMB5 than PSMB8 sequences.
Naoko, Takezaki +2 more
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The First Vertebrates, Jawless Fishes, the Agnathans
2014Vertebrates arose over 500 million years ago (MYA) but traces of their appearance only occur during the Ordovician period about 460 MYA. These primeval, small fish-like vertebrates are popularly known as the ostracoderms and during the 100 million years of their existence they were comprised of about 600 species.
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