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https://www.readbyqxmd.com/read/28683451/sleep-related-electrophysiology-and-behavior-of-tinamous-eudromia-elegans-tinamous-do-not-sleep-like-ostriches
#1
Ryan K Tisdale, Alexei L Vyssotski, John A Lesku, Niels C Rattenborg
The functions of slow wave sleep (SWS) and rapid eye movement (REM) sleep, distinct sleep substates present in both mammals and birds, remain unresolved. One approach to gaining insight into their function is to trace the evolution of these states through examining sleep in as many taxonomic groups as possible. The mammalian and avian clades are each composed of two extant groups, i.e., the monotremes (echidna and platypus) and therian (marsupial and eutherian [or placental]) mammals, and Palaeognaths (cassowaries, emus, kiwi, ostriches, rheas, and tinamous) and Neognaths (all other birds) among birds...
July 7, 2017: Brain, Behavior and Evolution
https://www.readbyqxmd.com/read/28652620/differential-cohesin-loading-marks-paired-and-unpaired-regions-of-platypus-sex-chromosomes-at-prophase-i
#2
Aaron E Casey, Tasman J Daish, Jose Luis Barbero, Frank Grützner
Cohesins are vital for chromosome organisation during meiosis and mitosis. In addition to the important function in sister chromatid cohesion, these complexes play key roles in meiotic recombination, DSB repair, homologous chromosome pairing and segregation. Egg-laying mammals (monotremes) feature an unusually complex sex chromosome system, which raises fundamental questions about organisation and segregation during meiosis. We discovered a dynamic and differential accumulation of cohesins on sex chromosomes during platypus prophase I and specific reorganisation of the sex chromosome complex around a large nucleolar body...
June 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28620997/morphology-and-evolution-of-the-oral-shield-in-marsupial-neonates-including-the-newborn-monito-del-monte-dromiciops-gliroides-marsupialia-microbiotheria-pouch-young
#3
Nanette Y Schneider, Yamila Gurovich
Newborn marsupials can be arranged into three grades of developmental complexity based on their external form, as well as based on their organ systems and their cytology. The dasyurids are considered the least developed marsupials at birth, while didelphids and peramelids are intermediate, and macropods are the most developed. Currently there is still little information on caenolestid and microbiotherid development at birth. Developmental stages can be graded as G1, G2 and G3, with G1 being the least developed at birth, and G3 the most developed...
July 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28608500/morphological-and-molecular-evolution-of-the-ultimobranchial-gland-of-non-mammalian-vertebrates-with-special-reference-to-the-chicken-c-cells
#4
REVIEW
Yoko Kameda
This review summarizes the current understanding of the non-mammalian ultimobranchial gland from morphological and molecular perspectives. Ultimobranchial anlage of all animal species develops from the last pharyngeal pouch. The genes involved in the development of pharyngeal pouches are well conserved across vertebrates. The ultimobranchial anlage of non-mammalian vertebrates and monotremes does not merge with the thyroid, remaining as an independent organ throughout adulthood. Although C cells of all animal species secrete calcitonin, the shape, cellular components and location of the ultimobranchial gland vary from species to species...
June 12, 2017: Developmental Dynamics: An Official Publication of the American Association of Anatomists
https://www.readbyqxmd.com/read/28558801/astroglial-mediated-remodeling-of-the-interhemispheric-midline-during-telencephalic-development-is-exclusive-to-eutherian-mammals
#5
Ilan Gobius, Rodrigo Suárez, Laura Morcom, Annalisa Paolino, Timothy J Edwards, Peter Kozulin, Linda J Richards
The corpus callosum forms the major interhemispheric connection in the human brain and is unique to eutherian (or placental) mammals. The developmental events associated with the evolutionary emergence of this structure, however, remain poorly understood. A key step in callosal formation is the prior remodeling of the interhemispheric fissure by embryonic astroglial cells, which then subsequently act as a permissive substrate for callosal axons, enabling them to cross the interhemispheric midline. However, whether astroglial-mediated interhemispheric remodeling is unique to eutherian mammals, and thus possibly associated with the phylogenetic origin of the corpus callosum, or instead is a general feature of mammalian brain development, is not yet known...
May 30, 2017: Neural Development
https://www.readbyqxmd.com/read/28531897/magnetic-resonance-imaging-of-the-brain-of-a-monotreme-the-short-beaked-echidna-tachyglossus-aculeatus
#6
Sandilya Cherupalli, Craig D Hardman, Andre Bongers, Ken W S Ashwell
We used magnetic resonance imaging to study the anatomy of cortical regions, nuclear groups, and major tracts in the brain of a monotreme, i.e., the short-beaked echidna (Tachyglossus aculeatus). Our specimens were from a collection held at the Australian Museum in Sydney and had been stored in formaldehyde solution for at least 70 years. Despite this, we were able to detect fine detail in the nuclear divisions of structures as well as in fiber tracts. In particular, we could detect the medial lemniscus as it approached the ventral posterior thalamic nucleus, subdivisions within the ventral posterior thalamic nucleus, lamination and subdivisions within the hippocampal formation, components of the olfactory pathways, and nuclei within the temporal amygdala...
May 23, 2017: Brain, Behavior and Evolution
https://www.readbyqxmd.com/read/28484364/energy-homeostasis-in-monotremes
#7
REVIEW
Stewart C Nicol
In 1803, the French anatomist Étienne Geoffroy Saint-Hilaire decided that the newly described echidna and platypus should be placed in a separate order, the monotremes, intermediate between reptiles and mammals. The first physiological observations showed monotremes had low body temperatures and metabolic rates, and the consensus was that they were at a stage of physiological development intermediate between "higher mammals" and "lower vertebrates." Subsequent studies demonstrated that platypuses and echidnas are capable of close thermoregulation in the cold although less so under hot conditions...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28429755/opossum-apobec1-is-a-dna-mutator-with-retrovirus-and-retroelement-restriction-activity
#8
Terumasa Ikeda, Mayuko Shimoda, Diako Ebrahimi, John L VandeBerg, Reuben S Harris, Atsushi Koito, Kazuhiko Maeda
APOBEC3s (A3s) are single-stranded DNA cytosine deaminases that provide innate immune defences against retroviruses and mobile elements. A3s are specific to eutherian mammals because no direct homologs exist at the syntenic genomic locus in metatherian (marsupial) or prototherian (monotreme) mammals. However, the A3s in these species have the likely evolutionary precursors, the antibody gene deaminase AID and the RNA/DNA editing enzyme APOBEC1 (A1). Here, we used cell culture-based assays to determine whether opossum A1 restricts the infectivity of retroviruses including human immunodeficiency virus type 1 (HIV-1) and the mobility of LTR/non-LTR retrotransposons...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28344905/evolution-of-the-patellar-sesamoid-bone-in-mammals
#9
Mark E Samuels, Sophie Regnault, John R Hutchinson
The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella...
2017: PeerJ
https://www.readbyqxmd.com/read/28326016/early-origin-and-evolution-of-the-angelman-syndrome-ubiquitin-ligase-gene-ube3a
#10
REVIEW
Masaaki Sato
The human Ube3a gene encodes an E3 ubiquitin ligase and exhibits brain-specific genomic imprinting. Genetic abnormalities that affect the maternal copy of this gene cause the neurodevelopmental disorder Angelman syndrome (AS), which is characterized by severe mental retardation, speech impairment, seizure, ataxia and some unique behavioral phenotypes. In this review article, I highlight the evolution of the Ube3a gene and its imprinting to provide evolutionary insights into AS. Recent comparative genomic studies have revealed that Ube3a is most phylogenetically similar to HECTD2 among the human HECT (homologous to the E6AP carboxyl terminus) family of E3 ubiquitin ligases, and its distant evolutionary origin can be traced to common ancestors of fungi and animals...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28132863/immune-endocrine-interactions-in-marsupials-and-monotremes
#11
E Peel, K Belov
Interactions between the immune and endocrine systems are not well studied in marsupials and monotremes. One exception to this is the phenomenon of semelparity, which is well covered in the literature as this is an unusual reproductive strategy amongst mammals and is only observed in some dasyurid and didelphid marsupials. Thymus involution provides a direct link between the endocrine and immune systems and warrants further study in marsupials and monotremes. The thymus is a primary immune tissue which is essential for overall immune function...
January 27, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28007525/the-mammalian-cretaceous-cochlear-revolution
#12
REVIEW
Geoffrey A Manley
The hearing organs of amniote vertebrates show large differences in their size and structure between the species' groups. In spite of this, their performance in terms of hearing sensitivity and the frequency selectivity of auditory-nerve units shows unexpectedly small differences. The only substantial difference is that therian, defined as live-bearing, mammalian groups are able to hear ultrasonic frequencies (above 15-20 kHz), whereas in contrast monotreme (egg laying) mammals and all non-mammalian amniotes cannot...
December 19, 2016: Hearing Research
https://www.readbyqxmd.com/read/27898108/monotreme-glucagon-like-peptide-1-in-venom-and-gut-one-gene-two-very-different-functions
#13
Enkhjargal Tsend-Ayush, Chuan He, Mark A Myers, Sof Andrikopoulos, Nicole Wong, Patrick M Sexton, Denise Wootten, Briony E Forbes, Frank Grutzner
The importance of Glucagon like peptide 1 (GLP-1) for metabolic control and insulin release sparked the evolution of genes mimicking GLP-1 action in venomous species (e.g. Exendin-4 in Heloderma suspectum (gila monster)). We discovered that platypus and echidna express a single GLP-1 peptide in both intestine and venom. Specific changes in GLP-1 of monotreme mammals result in resistance to DPP-4 cleavage which is also observed in the GLP-1 like Exendin-4 expressed in Heloderma venom. Remarkably we discovered that monotremes evolved an alternative mechanism to degrade GLP-1...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27889918/inner-ear-labyrinth-anatomy-of-monotremes-and-implications-for-mammalian-inner-ear-evolution
#14
Julia A Schultz, Ulrich Zeller, Zhe-Xi Luo
The monophyletic clade Monotremata branches early from the rest of the mammalian crown group in the Jurassic and members of this clade retain many ancestral mammalian traits. Thus, accurate and detailed anatomical descriptions of this group can offer unique insight into the early evolutionary history of Mammalia. In this study, we examine the inner ear anatomy of two extant monotremes, Ornithorhynchus anatinus and Tachyglossus aculeatus, with the primary goals of elucidating the ancestral mammalian ear morphology and resolving inconsistencies found within previous descriptive literature...
November 27, 2016: Journal of Morphology
https://www.readbyqxmd.com/read/27825298/the-ut-family-of-mhc-class-i-loci-unique-to-non-eutherian-mammals-has-limited-polymorphism-and-tissue-specific-patterns-of-expression-in-the-opossum
#15
Katina V Krasnec, Anthony T Papenfuss, Robert D Miller
BACKGROUND: The Major Histocompatibility Complex (MHC) class I family of genes encode for molecules that have well-conserved structures, but have evolved to perform diverse functions. The availability of the gray, short-tailed opossum, Monodelphis domestica whole genome sequence has allowed for analysis of MHC class I gene content in this marsupial. Utilization of a novel method to search for MHC related domain structures revealed a previously unknown family of MHC class I-related genes...
November 8, 2016: BMC Immunology
https://www.readbyqxmd.com/read/27802151/the-private-life-of-echidnas-using-accelerometry-and-gps-to-examine-field-biomechanics-and-assess-the-ecological-impact-of-a-widespread-semi-fossorial-monotreme
#16
Christofer J Clemente, Christine E Cooper, Philip C Withers, Craig Freakley, Surya Singh, Philip Terrill
The short-beaked echidna (Tachyglossus aculeatus) is a monotreme and therefore provides a unique combination of phylogenetic history, morphological differentiation and ecological specialisation for a mammal. The echidna has a unique appendicular skeleton, a highly specialised myrmecophagous lifestyle and a mode of locomotion that is neither typically mammalian nor reptilian, but has aspects of both lineages. We therefore were interested in the interactions of locomotor biomechanics, ecology and movements for wild, free-living short-beaked echidnas...
October 15, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27757425/comparative-cranial-morphology-in-living-and-extinct-platypuses-feeding-behavior-electroreception-and-loss-of-teeth
#17
Masakazu Asahara, Masahiro Koizumi, Thomas E Macrini, Suzanne J Hand, Michael Archer
The modern platypus, Ornithorhynchus anatinus, has an eye structure similar to aquatic mammals; however, platypuses also have a "sixth sense" associated with the bill electro- and mechanoreception that they use without opening their eyes underwater. We hypothesize that Ornithorhynchus and the Miocene taxon Obdurodon have different sensory capacities, which may have resulted from differences in foraging behavior. To estimate differences in foraging, sensory systems, and anatomical divergence between these monotremes, we compared their skull morphologies...
October 2016: Science Advances
https://www.readbyqxmd.com/read/27713568/characterisation-of-the-immune-compounds-in-koala-milk-using-a-combined-transcriptomic-and-proteomic-approach
#18
Katrina M Morris, Denis O'Meally, Thiri Zaw, Xiaomin Song, Amber Gillett, Mark P Molloy, Adam Polkinghorne, Katherine Belov
Production of milk is a key characteristic of mammals, but the features of lactation vary greatly between monotreme, marsupial and eutherian mammals. Marsupials have a short gestation followed by a long lactation period, and milk constituents vary greatly across lactation. Marsupials are born immunologically naïve and rely on their mother's milk for immunological protection. Koalas (Phascolarctos cinereus) are an iconic Australian species that are increasingly threatened by disease. Here we use a mammary transcriptome, two milk proteomes and the koala genome to comprehensively characterise the protein components of koala milk across lactation, with a focus on immune constituents...
October 7, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27563341/resolving-the-evolution-of-the-mammalian-middle-ear-using-bayesian-inference
#19
Héctor E Ramírez-Chaves, Vera Weisbecker, Stephen Wroe, Matthew J Phillips
BACKGROUND: The minute, finely-tuned ear ossicles of mammals arose through a spectacular evolutionary transformation from their origins as a load-bearing jaw joint. This involved detachment from the postdentary trough of the mandible, and final separation from the dentary through resorption of Meckel's cartilage. Recent parsimony analyses of modern and fossil mammals imply up to seven independent postdentary trough losses or even reversals, which is unexpected given the complexity of these transformations...
2016: Frontiers in Zoology
https://www.readbyqxmd.com/read/27557648/formation-and-dissociation-of-sperm-bundles-in-monotremes
#20
Brett Nixon, Heath Ecroyd, Jean-Louis Dacheux, Francoise Dacheux, Valerie Labas, Steve D Johnston, Russell C Jones
As monotremes are the earliest offshoot of the mammalian lineage, the platypus and short-beaked echidna were studied as model animals to assess the origin and biological significance of adaptations considered unique to therian mammals: epididymal maturation and subsequent capacitation. We show that spermatozoa from both species assemble into bundles of approximately 100 cells during passage through the epididymis and that an epididymal protein, secreted protein, acidic, cysteine-rich (osteonectin) (SPARC), is involved in bundle formation...
August 24, 2016: Biology of Reproduction
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