Read by QxMD icon Read

Journal of Morphology

Yunhan Yang, Yuchao Jing, Jialu Wang, Qian Yang
Tonsils form the topographically first immune barrier of an organism against the invasion of pathogens. We used histology to study the development of tonsils of pigs after birth. At birth, the tonsils consist of diffuse lymphoid tissue without any lymphoid follicle aggregations. At the age of 7 days, lymphoid follicles appeared in the soft palate tonsil. The lymphoid layer of the nasopharyngeal tonsil, soft palate tonsil, and lingual tonsil became thicker, and lymphoid follicles in the lamina propria were clearly visible at the age of 21 days...
June 11, 2018: Journal of Morphology
Guilherme Gainett, Prashant P Sharma, Gonzalo Giribet, Rodrigo H Willemart
The study of sensory structures has the potential to provide insights into the natural history and evolution of animals. The sensory structures of arachnids are usually concentrated on the pedipalps (the tritocerebral appendages) or on the distal podomere (tarsus) of the anterior walking legs, the latter being the case for armored harvestmen (Opiliones, Laniatores). Therefore, modifications of the tarsus could have direct impacts on the sensory equipment of these animals. Using scanning electron microscopy, we investigated the sensory equipment in an extreme case of reduction in tarsal articles in the harvestman Sandokan truncatus (Sandokanidae), which bears a single tarsomere in all legs, and the potential consequences of this reduction...
June 11, 2018: Journal of Morphology
Alexander Tinius, Anthony P Russell, Heather A Jamniczky, Jason S Anderson
Ecological niche partitioning of Anolis lizards of the Greater Antillean islands has been the focus of many comparative studies, and much is known about external morphological convergence that characterizes anole ecomorphs. Their internal anatomy, however, has rarely been explored in an ecomorphological context, and it remains unknown to what degree skeletal morphology tracks the diversity and ecological adaptation of these lizards. Herein, we employ CT scanning techniques to visualise the skeleton of the pelvic girdle in situ, and 3D geometric morphometrics to compare the form of the ilium, ischium, and pubis within and between ecomorphs...
June 11, 2018: Journal of Morphology
Natalia K Taft, Benjamin N Taft, Hailey Henck, Thomas Mehner
Although the ray-finned fishes are named for their bony, segmented lepidotrichia (fin rays), we are only beginning to understand the morphological and functional diversity of this key vertebrate structure. Fin rays support the fin web, and their material properties help define the function of the entire fin. Many earlier studies of fin ray morphology and function have focused on isolated rays, or on rays from only one or two fins. At the same time, relatively little is known about how different preservation techniques affect the material properties of many vertebrate structures, including fin rays...
June 8, 2018: Journal of Morphology
Lorenzo Alibardi
The formation of the regenerating tail blastema of lizards occurs by the multiplication of stem cells but also some dedifferentiation from adult cells may take place after tail loss by autotomy, as it is suggested in the present study. Using 5BrdU-immunocytochemistry and transmission electron microscopy it is shown that part of the damaged tissues undergo progressive cytological de-differentiation (cell reprogramming). This occurs for muscle, fibrocytes, chondrocytes, adipocytes, and cells derived from the spinal cord during the initial 3-8 days post-autotomy of the tail in the wall lizard Podarcis muralis...
June 8, 2018: Journal of Morphology
Günter P Wagner, Oliver W Griffith, Philip J Bergmann, Gaelle Bello-Hellegouarch, Tiana Kohlsdorf, Anjan Bhullar, Cameron D Siler
Evolutionary simplification of autopodial structures is a major theme in studies of body-form evolution. Previous studies on amniotes have supported Morse's law, that is, that the first digit reduced is Digit I, followed by Digit V. Furthermore, the question of reversibility for evolutionary digit loss and its implications for "Dollo's law" remains controversial. Here, we provide an analysis of limb and digit evolution for the skink genus Brachymeles. Employing phylogenetic, morphological, osteological, and myological data, we (a) test the hypothesis that digits have re-evolved, (b) describe patterns of morphological evolution, and (c) investigate whether patterns of digit loss are generalizable across taxa...
June 8, 2018: Journal of Morphology
Oleksandr Yaryhin, Ingmar Werneburg
The sand lizard, Lacerta agilis, is a classical model species in herpetology. Its adult skull anatomy and its embryonic development are well known. The description of its fully formed primordial skull by Ernst Gaupp, in 1900, was a key publication in vertebrate morphology and influenced many comparative embryologists. Based on recent methodological considerations, we restudied the early cranial development of this species starting as early as the formation of mesenchymal condensations up to the fully formed chondrocranium...
June 8, 2018: Journal of Morphology
Kayla C Hall, Peter J Hundt, John D Swenson, Adam P Summers, Karen D Crow
Batoids are a diverse clade of flat cartilaginous fishes that occur primarily in benthic marine habitats. The skates and rays typically use their flexible pectoral fins for feeding and propulsion via undulatory swimming. However, two groups of rays have adopted a pelagic or bentho-pelagic lifestyle and utilize oscillatory swimming-the Myliobatidae and Gymnuridae. The myliobatids have evolved cephalic lobes, anteriorly extended appendages that are optimized for feeding, while their pectoral fins exhibit several modifications that likely arose in association with functional optimization of pelagic cruising via oscillatory flight...
June 7, 2018: Journal of Morphology
Rolf Elofsson, Ronald H H Kröger
The usual pigmentation pattern in mammalian skin consists of fixed melanocytes in the basal layer of the epidermis, supplying keratinocytes with melanosomes. We observed that the glabrous skin (rhinaria and footpads) of dogs deviates from this pattern. In dogs, melanocytes are found in both the dermis and epidermis. The epidermal melanocytes are situated in the intercellular spaces of the basal and spinous layers. They are characterized by a quantity of cytoplasm containing a centriole, also developing melanosomes, and in some cases annulate lamellae...
June 6, 2018: Journal of Morphology
Madeleine V Ankhelyi, Dylan K Wainwright, George V Lauder
Shark skin is covered with numerous placoid scales or dermal denticles. While previous research has used scanning electron microscopy and histology to demonstrate that denticles vary both around the body of a shark and among species, no previous study has quantified three-dimensional (3D) denticle structure and surface roughness to provide a quantitative analysis of skin surface texture. We quantified differences in denticle shape and size on the skin of three individual smooth dogfish sharks (Mustelus canis) using micro-CT scanning, gel-based surface profilometry, and histology...
May 29, 2018: Journal of Morphology
Jing-Duan Huang, Shin-Yu Lee, Tzu-Yin Chiang, Chung-Cheng Lu, Mong-Fong Lee
The pharaoh cuttlefish, Sepia pharaonis, is an important cephalopod fishery species in southeastern Asia, with understudied reproductive physiology. The present study aimed to investigate the cellular characteristics of epithelial cells found in the nidamental glands (NGs) and accessory NGs (ANGs), as well as the structural connections between these two glands in mature female S. pharaonis. A histological analysis revealed two types of epithelial cells in NGs: Alcian blue-positive, PAS-negative mucosubstance-secreting cells and eosinophilic, PAS-positive granule-secreting cells...
May 6, 2018: Journal of Morphology
George Lawrence Powell, Anthony P Russell, Jennifer Sutey
Postnatal growth patterns within the vertebral column may be informative about body proportions and regionalization. We measured femur length, lengths of all pre-sacral vertebrae, and lengths of intervertebral spaces, from radiographs of a series of 21 Eublepharis macularius, raised under standard conditions and covering most of the ontogenetic body size range. Vertebrae were grouped into cervical, sternal, and dorsal compartments, and lengths of adjacent pairs of vertebrae were summed before analysis. Femur length was included as an index of body size...
May 6, 2018: Journal of Morphology
Sandra Nauwelaerts, Hilary M Clayton
Data describing segmental masses and moments of inertia (MOI) of limb segments are required for inverse dynamic calculations. In horses, these values are usually calculated using regression equations that have been developed from a limited number of horses representing a small number of breeds. The objective of the present study was to evaluate the performance of a scaling method and a pictorial method for estimating of the values of segmental masses, lengths, and MOI in the equine limb segments by comparing their output with the standard technique involving direct measurements...
May 1, 2018: Journal of Morphology
Brett R Aiello, Adam R Hardy, Chery Cherian, Aaron M Olsen, Courtney P Orsbon, Melina E Hale, Mark W Westneat
The organization of tissues in appendages often affects their mechanical properties and function. In the fish family Labridae, swimming behavior is associated with pectoral fin flexural stiffness and morphology, where fins range on a continuum from stiff to relatively flexible fins. Across this diversity, pectoral fin flexural stiffness decreases exponentially along the length of any given fin ray, and ray stiffness decreases along the chord of the fin from the leading to trailing edge. In this study, we examine the morphological properties of fin rays, including the effective modulus in bending (E), second moment of area (I), segmentation, and branching patterns, and their impact on fin ray stiffness...
April 25, 2018: Journal of Morphology
Alois Lametschwandtner, Bernd Minnich
To demonstrate the 3D microvascular anatomy of the brain of the model organism Xenopus laevis Daudin scanning electron microscopy of vascular corrosion casts was correlated with light microscopy of stained 7 µm thick serial tissues sections. Results showed that supplying arteries descended from the leptomeningeal surface without remarkable branchings straight to the subventricular zone where they branched and capillarized. Capillaries showed few H- and/or Y-shaped anastomoses during their centrifugal course toward the leptomeningeal surface where they drained into cerebral venules and veins...
April 25, 2018: Journal of Morphology
Lauren Sumner-Rooney, Julia D Sigwart
Molluscs demonstrate astonishing morphological diversity, and the relationships among clades have been debated for more than a century. Molluscan nervous systems range from simple 'ladder-like' cords to the complex brains of cephalopods. Chitons (Polyplacophora) are assumed to retain many molluscan plesiomorphies, lacking neural condensation and ganglionic structure, and therefore a brain. We reconstructed three-dimensional anatomical models of the nervous system in eight species of chitons in an attempt to clarify chiton neuroarchitecture and its variability...
April 23, 2018: Journal of Morphology
Jimena García-Rodríguez, Cheryl Lewis Ames, José Eduardo A R Marian, Antonio Carlos Marques
Cubozoans (box jellyfish) are gonochoristic cnidarians with distinct reproductive strategies. This comparative histological study examines the gonad organization of Alatina alata and Copula sivickisi, two box jellyfish species that exhibit different modes of internal fertilization. A. alata reproduces via spermcasting aggregations while C. sivickisi reproduces via copulation; in both cases, internal fertilization occurs in the gastrovascular cavity. Herein, we provide the first histological description of subgastric sacs-structures unique to C...
June 2018: Journal of Morphology
Taro Nojiri, Ingmar Werneburg, Nguyen Truong Son, Vuong Tan Tu, Takenori Sasaki, Yu Maekawa, Daisuke Koyabu
Cochlear morphology has been regarded as one of the key traits to understand the origin and evolution of echolocation in bats, given its functionality and performance for receiving echolocation sonar. While numerous researchers have compared adult-stage morphology, few have studied the prenatal development of the cochlea. Here, we provide the first detailed three-dimensional description of the prenatal cranial development in bats, using Rhinolophus thomasi as a model, with particular interest to the petrosal which houses the cochlea...
June 2018: Journal of Morphology
Dylan K Wainwright, Sam Ingersoll, George V Lauder
Tunas of the genus Thunnus possess many morphological and physiological adaptations for their high-performance epipelagic ecology. Although Thunnus anatomy has been studied, there are no quantitative studies on the structure of their scales. We investigated the scales of bigeye tuna (Thunnus obesus) from ten regions of the body using micro computed tomography (µCT)-scanning and histology to quantitatively and qualitatively compare regional scale morphology. We found a diversity of scale sizes and shapes across the body of bigeye tuna and discriminant function analysis on variables derived from µCT-data showed that scales across the body differ quantitatively in shape and size...
June 2018: Journal of Morphology
Alberto A Castro, Theodore Garland
We have used selective breeding with house mice to study coadaptation of morphology and physiology with the evolution of high daily levels of voluntary exercise. Here, we compared hindlimb bones and muscle masses from the 11th generation of four replicate High Runner (HR) lines of house mice bred for high levels of voluntary wheel running with four non-selected control (C) lines. Mass, length, diameter, and depth of the femur, tibia-fibula, and metatarsal bones, as well as masses of gastrocnemius and quadriceps muscles, were compared by analysis of covariance with body mass or body length as the covariate...
June 2018: Journal of Morphology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"