pinecone/core-2020-05-10-deduplication huggingface dataset:
Vitamin D receptor distribution in intestines of domesticated sheep Ovis ammon f. aries

The biologically active form of vitamin D, i.e., 1,25-dihydroxycholecalciferol or calcitriol, plays an important role in bone metabolism and calcium homeostasis, which is often disturbed at the onset of lactation in high milk-yielding domestic ruminants. Gene transcription is modulated via vitamin D receptors, but nongenomic effects of vitamin D via membrane receptors have also been described. In the intestines, vitamin D promotes calcium absorption via vitamin D receptors. Vitamin D receptors are of clinical relevance, but have not been systematically assessed within all segments of the intestine in any species. Thus, we present for the first time an immunohistochemical study of the distribution patterns of the vitamin D receptor protein in sheep, which may be the basis for present and future investigations on mineral homeostasis in domestic ruminants. Tissue probes of the intestines were collected from five lambs and five nonlactating and nonpregnant dams, fixed in formalin, embedded in paraffin, and used for the assessment of vitamin D receptor protein. Nuclear vitamin D receptor immunoreaction was scored semiquantitatively and exhibited a segment-specific distribution pattern. Goblet cells always were devoid of any vitamin D receptor immunoreaction. Surface epithelial cells and enterocytes of the crypt openings generally demonstrated only a weak immunoreaction. Basally and/or intermediately located crypt epithelial cells exhibited stronger immunoreactions in duodenum, jejunum, and colon descendens. This basal/intermediate to superficial gradient was most pronounced in the duodenum and less evident in jejunum and colon descendens and not observed in ileum and cecum. There were no age-dependent variations in vitamin D receptor protein expression. Results demonstrate that intestinal vitamin D receptor distribution patterns are segment-specific and strongest immunoreactions correlate with highest intestinal calcium absorptive activities, as reported in literature. Strong expression of vitamin D receptors within the lower half of crypts also suggests a role for calcitriol in epithelial differentiation and cellular homeostasis
Sperm ultrastructure in Bathypolypus bairdii and B. sponsalis (Cephalopoda: Octopoda)

9 páginas, 2 tablas, 6 figurasA morphological comparison of the spermatozoa\ud
of the octopods Bathypolypus bairdii and B. sponsalis\ud
has been carried out by electron microscopy. Although\ud
the mature spermatozoon of B. bairdii is longer and thinner\ud
than that of B. sponsalis, its general ultrastructure\ud
is similar except for some minor differences. Their characteristic\ud
acrosomes, described here for the first time,\ud
consist of a periodically banded cone surrounded by\ud
a double helix whose arrangement has been defined by a\ud
numeric expression. The plasma membrane of sponsalis\ud
that surrounds the acrosome has many projections filled\ud
with abundant granular cytoplasm, which appears as a\ud
star-shaped acrosome in cross-section. The mitochondrial\ud
sheath contains 9–11 mitochondria in bairdii but only 9\ud
in sponsalis. A comparison with other Octopodidae\ud
shows that the nucleus of both species is the largest ever\ud
seen. Our results support the capability of sperm\ud
morphology to discriminate between species and could\ud
even discern at higher taxonomic levelsPeer reviewe
Comparative Skull Osteology of Karsenia koreana (Amphibia, Caudata, Plethodontidae)

The recent discovery of a plethodontid salamander, Karsenia koreana, in Korea challenged our understanding of the biogeographic history of the family Plethodontidae, by far the largest family of salamanders, which otherwise is distributed in the New World with a few European species. Molecular studies suggest that Karsenia forms a clade with Hydromantes (sensu lato), which includes among its species the only other Old World plethodontids. We studied the skull of K. koreana and compared it with that of other plethodontid genera, especially members of the subfamily Plethodontinae, which it resembles most closely in general anatomy. The anatomy of its skull corresponds to the most generalized and apparently ancestral condition for plethodontids. No clearly autapomorphic states were detected, and no synapomorphies can be found that would link it to other genera. The Karsenia skull is cylindrical and well ossified, giving an impression of strength. In contrast, the skull of Hydromantes is highly derived; the skull is flattened and the bones are weakly ossified and articulated. Hydromantes and Karsenia share no unique anatomical features; differences between them are especially evident in the hyobranchial skeleton, which is generalized in Karsenia but highly modified in Hydromantes, which is well known for its highly projectile tongue. Plethodon and Plethodon-like species, including Karsenia and to a lesser degree Ensatina, represent the more generalized and apparently ancestral plethodontid morphology. Specialized morphologies have evolved along only a few morphological axes within the Plethodontidae, resulting in a pattern of rampant homoplasy. Our analysis of the anatomy of the new Asiatic lineage illuminates some potential mechanisms underlying adaptive morphological evolution within the Plethodontidae.The authors thank Jessica Maisano and the members of the DigiMorph CT scan facilities at the University of Texas, Austin, for their help with the scanning and segmentation processes. D. Vieites and R. Bonett collected the Karsenia; Sean Rovito collected the Hydromantes platycephalus that was scanned. They also acknowledge the assistance of M. S. Min and the late S. Y. Yang, and the agencies that provided the necessary collecting permits. James Hanken and an anonymous reviewer contributed numerous comments that greatly improved the manuscriptPeer Reviewe
Sperm ultrastructure of the hydrothermal vent Octopod Vulcanoctopus hydrothermalis

2 figuras, 1 tablaSperm ultrastructure of the deep-sea\ud
hydrothermal vent octopod Vulcanoctopus hydrothermalis has been carried out by transmission electron microscopy.\ud
Spermatozoa of this species have the shortest head observed so far in octopodids. The acrosome possesses a helix with six gyres. The rod-shaped nucleus is short\ud
and wide in relation with other octopodids. Noteworthy features along the nucleus are the regularly disposed dense bands of cytoplasm, which have not been observed before in octopodids. The nuclear fossa is very short and wavy. Mitochondrial sheath has 10 elongated mitochondria running parallel to the axoneme-coarse fibers complex. Sperm morphology of V. hydrothermalis resembles that of Enteroctopus dofleini, suggesting a\ud
close phylogenetic relationship.Peer reviewe
Comparative gastrointestinal morphology of three small mammalian insectivores : Acomys spinosissimus (Rodentia), Crocidura cyanea (Eulipotyphla), and Amblysomus hottentotus (Afrosoricida)

The gastrointestinal morphology was investigated in three mammalian insectivorous species, namely Acomys spinosissimus, Crocidura cyanea, and Amblysomus hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species and to explore whether anatomical gastrointestinal adaptations are associated with the insectivorous diet of these species. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three insectivores. Hematoxylin and Eosin (H&E) and Alcian Blue/Periodic Acid Schiff (AB/PAS) were used for morphological assessment. In all three species, the stomach was simple and uncompartmentalized. The internal aspect of the stomach in A. spinosissimus was hemi-glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. Paneth cells were not observed in the intestinal tracts of C. cyanea and A. hottentotus. Acomys spinosissimus was the only species studied that had a cecum. The proximal colonic region of A. spinosissimus had V-shaped mucosal folds. Histologically, C. cyanea had villi throughout the entire gastrointestinal tract (GIT), whereas for A. hottentotus villi were not present in the most distal gastrointestinal regions. In both C. cyanea and A. hottentotus, longitudinal mucosal folds were present in the distal part of the colon. The GITs of C. cyanea and A. hottentotus showed little morphological differentiation namely, a simple, glandular stomach and the lack of a cecum.http://www.interscience.wiley.com/journal/35280/homehb201
Elongated hindguts in desert-living dung beetles (Scarabaeidae : Scarabaeinae) feeding on dry dung pellets or plant litter

Most adult dung beetles (Scarabaeidae: Scarabaeinae) feed on fresh, wet dung of larger herbivorous or omnivorous mammals. As refractory plant fragments are selected out before ingestion, the food is presumed easily digestible. However, members of the desert-living scarabaeine genus Pachysoma (probably evolved from an ancestor closely related to the wet-dung feeding genus Scarabaeus) select dry dung pellets and/or plant litter. Thus, they ingest a much higher proportion of structural plant material, which nevertheless appears to be digested rather efficiently. This study investigates morphological modifications of the gut for this digestion in adults of eight Pachysoma species, both pellet and litter feeders. To ascertain hypothesized ancestral conditions, four fresh-dung feeding Scarabaeus species were also examined. The latter have the usual dung beetle gut consisting of a long, simple midgut, followed by an equally simple, much shorter hindgut of the same width. Lengths of midguts (M) and hindguts (H) divided by body length (B) for comparison between species of different size are: 4.9–6.3 (M/B) and 0.7–0.8 (H/B), which is normal for dung feeders. In Pachysoma, lengths are 6.3–6.5 (M/B) and 1.0–1.4 (H/B) in pellet feeders, and 4.4–5.0 (M/B) and 2.0–2.5 (H/B) for litter feeders. Hindguts are still morphologically undifferentiated and of midgut width, but clearly longer, particularly in litter feeders. Presumably, plant fragments in the food are digested, at least partly, in the hindgut. If so, the morphological adaptation is unusual: simple elongation rather than the expansion of part of the hindgut, as found in several other plant- or detritus-feeding scarabaeids.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-4687hb2013ab201
Skeletal indicators of ecological specialization in pika (Mammalia, Ochotonidae)

Pika species generally fall into two ecotypes, meadow‐dwelling (burrowing) or talus‐dwelling, a classification that distinguishes a suite of different ecological, behavioral, and life history traits. Despite these differences, little morphological variation has previously been documented to distinguish among ecotypes. The aim of this study was to test whether postcranial features related to burrowing are present in meadow‐dwelling species and whether talus‐dwelling species exhibit postcranial modifications related to frequent leaping between rocks. To test this, the scapula, humerus, ulna, radius, innominate, femur, tibia, and calcaneus of 15 species were studied and measured. Twenty‐three measurements were taken on 199 skeletons, and 19 indices were constructed from these measurements. Indices were compared between the two ecotypes using Student's  t ‐test. Comparisons among ecotypes, species, and subgenera were made using one‐way ANOVA with the Tukey honest significant difference post hoc test. Multivariate results were generated using principal components analyses. Thirteen forelimb and hind limb indices proved significant in distinguishing the meadow‐dwelling, talus‐dwelling, and intermediate forms. A number of these indices are associated with burrowing or leaping in other mammals, providing some support for the hypothesis that postcranial modifications in pika are related to locomotor differences. This evidence of morphological responses to ecological specialization will be useful for reconstructing the paleobiology of extinct taxa, assessing the behavioral variability of extant species, and improving our understanding of the evolutionary history of pikas. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc
Cartilage, bone and intermandibular connective tissue in the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)

The connective tissue that links the bones of the mandible in the Australian lungfish, Neoceratodus forsteri, has been described as an intermandibular cartilage, and as such has been considered important for phylogenetic analyses among lower vertebrates. However, light and electron microscopy of developing lungfish jaws demonstrates that the intermandibular tissue, like the connective tissue that links the bones of the upper jaw, contains fibroblasts and numerous bundles of collagen fibrils, extending from the trabeculae of the bones supporting the tooth plates. It differs significantly in structure and in staining reactions from the cartilage and the bone found in this species. In common with the cladistian Polypterus and with actinopterygians and some amphibians, lungfish have no intermandibular cartilage. The connective tissue linking the mandibular bones has no phylogenetic significance for systematic grouping of lungfish, as it is present in a range of different groups among lower vertebrates.Griffith Sciences, Griffith School of EnvironmentFull Tex
Kupffer cell structure in the juvenile Nile crocodile, Crocodylus niloticus

The morphology of Kupffer cells was
examined in the liver of the juvenile Nile crocodile
using light microscopy and transmission electron
microscopy. Pleomorphic Kupffer cells were located in
the sinusoids, in the space of Disse, in the hepatic
parenchyma and often connected adjacent sinusoids.
The cell surfaces were irregular due to the presence of
filopodia and lamelliapodia with phagocytosis of white
blood cells, red blood cells and thrombocytes being evident.
The cells were in close contact with endothelial
cells and pit cells in the sinusoidal lumen and with
stellate cells in the space of Disse. The cytoplasm contained
large phagosomes comprising a combination of
ceroid pigment, melanosomes and siderosomes. The
nuclei were often indented and eccentrically placed due
to the presence of the phagosomes. Conspicuous clusters
of membrane-bound tubular organelles with a filamentous
or crystalline interior were observed in the
cytoplasm. The clusters were sometimes separated into
smaller groups around phagosomes. A clear zone
existed between the limiting membrane and the interior
of these tubular organelles with the electron-dense
interior profiles being, respectively, circular, angular or
divided. The tubular organelles have not previously
been described in Kupffer cells and possibly represent
lysosomes with specialized functions. Mitochondria,
microtubules, Golgi profiles, granular and smooth endoplasmic
reticulum, and a few cytoplasmic lipid droplets
were also present. The presence of the tubular organelles
and the occurrence of the Kupffer cells in different
locations in the liver of the juvenile Nile crocodile are
indicative of particularly active and mobile cells.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-4687hb201
Timing of cranial suture closure in placental mammals: Phylogenetic patterns, intraspecific variation, and comparison with marsupials

Used as markers of postnatal growth closure sequences of 22 ectocranial sutures and synchondroses were recorded in a sample of 1161 skulls belonging to 38 species from all major placental clades: Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires (Boreoeutheria). The maximum closure level, which is not significantly correlated to body mass, is higher in Afrotheria and Xenarthra than in Boreoeutheria. Only the basioccipito-basisphenoid and the basioccipito-exoccipital synchondroses close in all species sampled, the supraoccipito-exoccipital and the inter-parietal sutures do in most species. Parsimov retrieved more heterochronic shifts for Afrotheria and Xenarthra than for Boreoeutheria. The amount of intraspecific variation differs among the species sampled being high among xenarthran species and low among afrotherians. Specimens (162) representing 12 marsupial genera were also analysed. Placentals exhibit a larger number of suture closures than marsupials and in both groups the sutures at the base of the skull are the first to fuse starting with the basioccipito-exoccipital
The comparative gastrointestinal morphology of five species of muroid rodents found in Saudi Arabia

Meriones rex (King jird), Meriones libycus
(Libyan jird), Acomys dimidiatus (Eastern spiny
mouse), Acomys cahirinus (Egyptian spiny mouse), and
Dipodillus dasyurus (Wagner’s dipodil) are five species
of small rodents of the superfamily Muroidea with distributions
in Eastern Africa, Egypt, and the desert
regions of the Arabian Peninsula. Water is scarce in
these regions and may result in relatively lowdigestible
food. The aim of the present study is to
describe and compare the gastrointestinal tract morphology
and morphometry of these five species in order
to elucidate whether morphology is influenced by phylogeny
or dietary preference. Each segment of the gastrointestinal
tract of each species was macroscopically
examined and the length and basal surface area of
each segment was measured. Standard histologic procedures
were performed to determine a surface enlargement
factor to determine the mucosal luminal surface
area. A unilocular-hemiglandular stomach was
observed in all the species examined. The caeca of all
the species were long and arranged into a loose spiral
toward the caecal tip with the ileocaecal and caeco-colic
openings positioned close together. Two rows of oblique
folds could be observed in the proximal colon of all species
except in D. dasyurus which had longitudinal
folds. Morphometric analysis showed the largest stomach
in A. cahirinus and the largest caecum and colon
in M. libycus. All the species can be grouped in the
family Muridae in two subfamilies and similarities
were observed including the hemiglandular stomach
and relatively large caecum. It could be concluded that
phylogeny plays an important role in determining gastrointestinal
morphology while diet plays a subordinate
role in the desert rodents in the present study.Harry Crossley Foundation and Deanship of Scientific Research at the King Saud University (research group project No.RGP_VPP_020).http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-4687hb201
Morphological properties of the last primaries, the tail feathers, and the alulae of Accipiter nisus, Columba livia, Falco peregrinus, and Falco tinnunculus

We investigated the mechanical properties (Young's modulus, bending stiffness, barb separation forces) of the tenth primary of the wings, of the alulae and of the middle tail feathers of Falco peregrinus. For comparison, we also investigated the corresponding feathers in pigeons (Columba livia), kestrels (Falco tinnunculus), and sparrowhawks (Accipiter nisus). In all four species, the Young's moduli of the feathers ranged from 5.9 to 8.4 GPa. The feather shafts of F. peregrinus had the largest cross-sections and the highest specific bending stiffness. When normalized with respect to body mass, the specific bending stiffness of primary number 10 was highest in F. tinnunculus, while that of the alula was highest in A. nisus. In comparison, the specific bending stiffness, measured at the base of the tail feathers and in dorso-ventral bending direction, was much higher in F. peregrinus than in the other three species. This seems to correlate with the flight styles of the birds: F. tinnunculus hovers and its primaries might therefore withstand large mechanical forces. A. nisus has often to change its flight directions during hunting and perhaps needs its alulae for this maneuvers, and in F. peregrinus, the base of the tail feathers might need a high stiffness during breaking after diving
Scaling of the appendicular skeleton of the giraffe (Giraffa camelopardalis)

Giraffes have remarkably long and slender limb bones, but it is unknown how they
grow with regard to body mass, sex and neck length. In this study we measured the
length, medio-lateral diameter (ML), cranio-caudal diameter (CC) and circumference of
the humerus, radius, metacarpus, femur, tibia and metatarsus in 10 fetuses, 21
females and 23 males of known body masses. Allometric exponents were determined
and compared. We found the average bone length increased from 340±50mm at birth
to 700±120mm at maturity, while average diameters increased from 30±3mm to
70±11mm. Fetal bones increased with positive allometry in length (relative to body
mass) and in diameter (relative to body mass and length). In postnatal giraffes bone
lengths and diameters increased iso- or negatively allometric relative to increases in
body mass, except for the humerus CC diameter which increased with positive
allometry. Humerus circumference also increased with positive allometry, that of the
radius and tibia isometrically and the femur and metapodials with negative allometry.Relative to increases in bone length, both the humerus and femur widened with
positive allometry. In the distal limb bones ML diameters increased isometrically
(radius, metacarpus) or positively allometric (tibia, metatarsus) while the
corresponding CC widths increased with negative allometry and isometrically
respectively. Except for the humerus and femur, exponents were not significantly
different between corresponding front and hind limb segments.
We concluded that the patterns of bone growth in males and females are identical. In
fetuses the growth of the appendicular skeleton is faster than it is after birth which is a
pattern opposite to that reported for the neck. Allometric exponents seemed
unremarkable compared to the few species described previously, and pointed to the
importance of neck elongation rather than leg elongation during evolution.
Nevertheless, the front limb bones and especially the humerus may show adaptation
to behaviors such as drinking posture.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-46872016-05-31hb201