Introduction. Microtia presents a congenital ear deformity ranging from a minor and barely visible defect to a complete absence of the ear. Currently, there are three options for ear reconstruction: ...autologous costal cartilage, silicon prothesis, and prosthetic ear. Ear reconstruction with autologous costal cartilage is usually performed in two stages. During the first stage, the cartilaginous framework is fabricated and placed under the skin, in the anatomical position of the ear. In the second stage, the elevation of the frame is performed. During these procedures, complications such as vascular compromise of the skin envelope can occur. Cartilage exposure can lead to its resorption and distortion, leading to an unsatisfactory anatomical result, and this should be resolved as soon as possible. Cartilage exposure at the convex part of the frame is especially problematic. The goal of this paper is to show that fascial turnover flap is a safe method to deal with cartilage exposure as a complication. Outlines of cases. We present two patients with anotia and hemifacial microsomia. Both underwent autologous cartilage microtia repair. In both patients, the cartilage exposure at the convex part of the ear was revealed as a complication. Fascial turnover flap has been used to resolve this complication in both patients. Conclusion. Fascial turnover flap is a safe method to deal with cartilage exposure after microtia reconstruction with autologous cartilage.
Chronic hepatitis C (CHC) is a significant cause of liver related morbidity and mortality worldwide. The role of genetics in the host response to hepatitis C virus is not elucidated. Genetic ...variations in
gene are the most common cause of hereditary unconjugated hyperbilirubinemia-Gilbert syndrome. This is the first study investigating the association of
TA repeats promoter genotypes with the degree of liver injury, viremia and biochemical markers in CHC patients with advanced liver injury and late virological relapse.
Genetic testing of
TA repeats promoter genotypes was performed in 42 CHC patients with advanced fibrosis and cirrhosis who achieved sustained virological response and 42 healthy blood donors. CHC patients were evaluated for clinical findings, laboratory tests and imaging.
*28 genotype (7/7 TA repeats) was observed in 23.8% CHC patients and 16.7% healthy controls with no significant difference in genotype frequencies (p=0.49). Pretreatment levels of ferritin and bilirubin were associated with the presence of
genotype, indicating its potential as a predictive marker. However, in our study, there was no correlation of
genotype with the degree of fibrosis or viremia. During antiviral treatment, dose reductions and treatment interruptions, as well as treatment success and occurrence of late virological relapse were not related to the presence of
genotype in CHC patients with severe liver injury.
Frequencies of
genotype are high in both Serbian CHC patients and healthy subjects. The presence of
genotype was not associated with ribavirin-related adverse effects and had no effect on long term outcome in CHC patients.
The modular organization of tetrapod paired limbs and girdles, influenced by the expression of Hox genes is one of the primary driving forces of the evolution of animal locomotion. The increased ...morphological diversification of the paired limbs is correlated with reduced between‐limb covariation, while correlation within the elements is usually higher than between the elements. The tailed amphibians, such as Lissotriton newts, have a biphasic lifestyle with aquatic and terrestrial environments imposing different constraints on limb skeleton. By employing the methods of computerized microtomography and 3D geometric morphometrics, we explored the pattern of morphological variation, disparity, modularity and morphological integration in the proximal parts of the anterior limbs of six species of Eurasian small bodied newts. Although the species significantly differ in limb shape, there is a great overlap in morphology of scapula and humerus, and there are no differences in morphological disparity. For the scapula, the shape differences related to the duration of the aquatic period are in length, depth and curvature. The shape of the humerus is not affected by the length of aquatic period, and shape differences between the species are related to robustness of the body. The length of aquatic period has statistically supported phylogenetic signal. The scapula and humerus are structures of varying modularity. For the humerus, the strongest support on the phylogenetic level was for the capitulum/shaft hypothesis, which can also be interpreted as functional modularity. For the scapula, the greatest support was for the antero‐posterior hypothesis of modularity in case of Lissotriton vulgaris, which can be explained by different functional roles and muscle insertion patterns, while there was no phylogenetic modularity. The modularity patterns seem to correspond with the general tetrapod pattern, with modularity being more pronounced in the distal structure. The future research should include more salamandrid taxa with different habitat preferences and both adult and larval stages, in order to explore how size, phylogeny and ecology affect the morphology and covariation patterns of limbs.
The six studied species of Lissotriton newts significantly differ in limb shape but there is a great overlap in morphology, and there are no differences in morphological disparity. There is a phylogenetic signal in the length of the aquatic period. For the scapula, differences in shape related to duration of the aquatic period are in length, depth and curvature. Scapula is not a modular structure in most cases (except for the antero‐posterior hypothesis in L. vulgaris), while the capitulum/shaft hypothesis is supported for humerus, on the phylogenetic level. The humerus and scapula are not integrated, and the modularity corresponds with the general tetrapod pattern.
Multilevel assessment of the Lacertid lizard cranial modularity Urošević, Aleksandar; Ljubisavljević, Katarina; Ivanović, Ana
Journal of zoological systematics and evolutionary research,
February 2019, 2019-02-00, 20190201, Letnik:
57, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Different factors and processes that produce phenotypic variation at the individual, population, or interspecific level can influence or alter the covariance structure among morphological traits. ...Therefore, studies of the patterns of integration and modularity at multiple levels—static, ontogenetic, and evolutionary, can provide invaluable data on underlying factors and processes that structured morphological variation, directed, or constrained evolutionary changes. Our dataset, consisting of cranium shape data for 14 lizard species from the family Lacertidae, with substantial samples of hatchlings and adults along with their inferred evolutionary relationships, enabled us to assess modularity and morphological integration at all three levels. Five, not mutually exclusive modularity hypotheses of lizard cranium, were tested, and the effects of allometry on intensity and the pattern of integration and modularity were estimated. We used geometric morphometrics to extract symmetric and asymmetric, as well as allometric and nonallometric, components of shape variation. At the static level, firm confirmation of cranial modularity was found for hypotheses which separate anterior and posterior functional compartments of the skull. At the ontogenetic level, two alternative hypotheses (the “anteroposterior” and “neurodermatocranial” hypotheses) of ventral cranial modularity were confirmed. At the evolutionary level, the “neurodermatocranial” hypothesis was confirmed for the ventral cranium, which is in accordance with the pattern observed at the ontogenetic level. The observed pattern of static modularity could be driven by functional demands and can be regarded as adaptive. Ontogenetic modularity and evolutionary modularity show the same developmental origin, indicating conservatism of modularity patterns driven by developmental constraints.
We used cranium shape data of 14 lacertid lizard speciesto test patterns of modularity using five alternative hypotheses at three levels – static, ontogenetic, and evolutionary. We found somewhat different pattern of covariation at the static compared to the ontogenetic and evolutionary levels. Our results indicate that in lacertid lizards, developmental integration is evolutionarily conservative and ontogenetically constrained. Functional covariation patterns observed at the static but not at the evolutionary level could have been adaptive and arisen through selection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Serially homologous structures may have complex patterns of regionalization and morphological integration, influenced by developmental Hox gene expression and functional constraints. The vertebral ...column, consisting of a number of repeated, developmentally constrained, and highly integrated units—vertebrae—is such a complex serially homologous structure. Functional diversification increases regionalization and modularity of the vertebral column, particularly in mammals. For salamanders, three concepts of regionalization of the vertebral column have been proposed, recognizing one, two, or three presacral regions. Using three‐dimensional geometric morphometrics on vertebra models acquired with microcomputerized tomography scanning, we explored the covariation of vertebrae in four closely related taxa of small‐bodied newts in the genus Lissotriton. The data were analyzed by segmented linear regression to explore patterns of vertebral regionalization and by a two‐block partial least squares method to test for morphological integration. All taxa show a morphological shift posterior to the fifth trunk vertebra, which corresponds to the two‐region concept. However, morphological integration is found to be strongest in the mid‐trunk. Taken jointly, these results indicate a highly integrated presacral vertebral column with a subtle two‐region differentiation. The results are discussed in relation to specific functional requirements, developmental and phylogenetic constraints, and specific requirements posed by a biphasic life cycle and different locomotor modes (swimming vs. walking). Further research should be conducted on different ontogenetic stages and closely related but ecologically differentiated species.
A summary of the regionalization in the trunk region of the vertebral column of Eurasian small‐bodied newts.
Research Highlights
•
The studied taxa of Lissotriton newts show a common pattern of regionalization, with a morphological transition after the fifth trunk vertebra.
•
The vertebral column is morphologically integrated, most strongly in the center of the trunk region.
•
Taken jointly, these results indicate a highly integrated presacral vertebral column with a subtle two‐region differentiation.
We conducted a study of intraspecific differentiation and sexual dimorphism in skulls of giant deer found in Serbia by employing methods of geometric morphometrics. The sample consisted of nine males ...(seven belonging to Megaloceros giganteus cf. ruffii and two belonging to subspecies M. giganteus cf. giganteus) and two females (both classified as M. giganteus cf. ruffii), photographed in ventral and lateral views. The statistical analyses did find significant shape differences between possible subspecies and sexes for the lateral cranium view but not for the ventral. Possible subspecies differed in the overall skull robustness. Sexual shape dimorphism consisted of transition from higher and elongated skulls in females, to more robust and dorsoventrally flattened skulls in males. The allometry was not proven to be statistically significant, but the shape changes related to size variation could be visually described. Some of the shape differences related to sexual dimorphism can be interpreted as an adaptation for bearing large antlers in males. Even with small sample size, we got statistically supported differences between possible subspecies and sexual shape dimorphism in the lateral view of the giant deer skull. In analyses that showed no statistical support, methods of geometric morphometrics still provided good visualization of shape variation.
Twenty-three morphometric characteristics of spiny-cheek crayfish Faxonus limosus from Danube, Serbia, were analyzed to describe the general body shape. Forty-eight specimens were caught in May 2022 ...and January 2023 and measured for morphometric variation. Also, the values of two crayfish condition indices, Fulton?s condition factor (FCF) and crayfish constant (CC), were determined. Most of the analyzed characteristics were moderately variable (CV 10-30%). Principal component analysis (PCA) was applied to the morphological measurements. All the variables make similar contributions to the variance of the first principal component. The highest contributions are from variables CEF and ARL. ARW, CPH, ABH, CPW, and ROW significantly contributed to the second principal component variance. The population of spiny-cheek crayfish at the investigated site has a relatively stable age structure.
Afghanistan is a herpetologically understudied country with few published papers since the end of “Afghanistan’s Golden Age” from the 1930s to the 1970s. Although a detailed checklist of the ...herpetofauna of the country, based on exploration of herpetodiversity using biodiversity archives, has been published recently, there still exist additional historical data that have not been considered. This is the case for a so far unknown collection of lizards from Afghanistan deposited in the herpetological collection of the Institute for Biological Research “Siniša Stanković at the University of Belgrade, Belgrade, Serbia. The material comes from field research conducted in 1972 and contains 27 specimens in seven lizard genera representing four families (Agamidae, Gekkonidae, Lacertidae, Scincidae). This historical collection was examined and basic morphometric data, field data, and photographs are provided, comparing the distributional data with published datasets. Updated species distribution maps reveal new locality or province records and an important range extension for
Eurylepis taeniolata
Blyth, 1854 which represents the northernmost record for this species in Afghanistan. In addition, one further distribution record for the
Bufotes viridis
(Laurenti, 1768) complex from the same research trip is noted.
Serial homology or the repetition of equivalent developmental units and their derivatives is a phenomenon encountered in a variety of organisms, with the vertebrate axial skeleton as one of the most ...notable examples. Serially homologous structures can be viewed as an appropriate model system for studying morphological integration and modularity, due to the strong impact of development on their covariation. Here, we explored the pattern of morphological integration of the cranium and the first three serially homologous structures (atlas, first, and second trunk vertebrae) in salamandrid salamanders, using micro‐CT scanning and three‐dimensional geometric morphometrics. We explored the integration between structures at static and evolutionary levels. Effects of allometry on patterns of modularity were also taken into account. At the static level (within species), we analyzed inter‐individual variation in shape to detect functional modules and intra‐individual variation to detect developmental modules. Significant integration (based on inter‐individual variation) among all structures was detected and allometry is shown to be an important integrating factor. The pattern of intra‐individual, asymmetric variation indicates statistically significant developmental integration between the cranium and the atlas and between the first two trunk vertebrae. At the evolutionary level (among species), the cranium, atlas, and trunk vertebrae separate as different modules. Our results show that morphological integration at the evolutionary level coincides with morphological and functional differentiation of the axial skeleton, allowing the more or less independent evolutionary changes of the cranial skeleton and the vertebral column, regardless of the relatively strong integration at the static level. The observed patterns of morphological integration differ across levels, indicating different impacts of developmental and phylogenetic constraints and functional demands.
This study explored how development, function, and evolution affect the patterns of morphological integration of serially homologous structures. The strength of morphological integration between cranium, atlas, first and second trunk vertebrae in salamandrids was quantified at multiple levels. Patterns of integration between adjacent and non‐adjacent elements and their strength differed at the static (on symmetric and asymmetric component of shape variation) and evolutionary levels. Our results indicate different impacts of functional demands and developmental and phylogenetic constraints on morphological integration.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Alpine habitats are exposed to increasing anthropogenic pressure and climate change. The negative impacts can lead to chronic stress that can affect the survival and reproductive success of ...individuals and even lead to population extinction. In this study, we analyse different morphological and ecological traits and indices of abiotic and biotic stressors (such as head size and shape, fluctuating asymmetry, body condition index, tail autotomy, and population abundance) in alpine and subalpine populations of two lacertid species (Zootoca vivipara and Lacerta agilis) from Serbia and North Macedonia. These lizards live under different conditions: allotopy/syntopy, different anthropogenic pressure, and different levels of habitat protection. We found differences between syntopic and allotopic populations in pileus size, body condition index (in both species), pileus shape, fluctuating asymmetry (in L. agilis), and abundance (in Z. vivipara). Differences between populations under anthropogenic pressure and populations without it were observed in pileus shape, body condition index (in both species), pileus size, fluctuating asymmetry, tail autotomy and abundance (in L. agilis). On the basis of our results, it is necessary to include other stress indicators in addition to fluctuating asymmetry to quickly observe and quantify the negative effects of threat factors and apply protective measures.
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