Gene coexpression networks reveal molecular interactions underlying cichlid jaw modularity

Background The oral and pharyngeal jaw of cichlid fishes are a classic example of evolutionary modularity as their functional decoupling boosted trophic diversification and contributed to the success of cichlid adaptive radiations. Most studies until now have focused on the functional, morphological, or genetic aspects of cichlid jaw modularity. Here we extend this concept to include transcriptional modularity by sequencing whole transcriptomes of the two jaws and comparing their gene coexpression networks. Results We show that transcriptional decoupling of gene expression underlies the functional decoupling of cichlid oral and pharyngeal jaw apparatus and the two units are evolving independently in recently diverged cichlid species from Lake Tanganyika. Oral and pharyngeal jaw coexpression networks reflect the common origin of the jaw regulatory program as there is high preservation of gene coexpression modules between the two sets of jaws. However, there is substantial rewiring of genetic architecture within those modules. We define a global jaw coexpression network and highlight jaw-specific and species-specific modules within it. Furthermore, we annotate a comprehensive in silico gene regulatory network linking the Wnt and AHR signalling pathways to jaw morphogenesis and response to environmental cues, respectively. Components of these pathways are significantly differentially expressed between the oral and pharyngeal jaw apparatus. Conclusion This study describes the concerted expression of many genes in cichlid oral and pharyngeal jaw apparatus at the onset of the independent life of cichlid fishes. Our findings suggest that – on the basis of an ancestral gill arch network—transcriptional rewiring may have driven the modular evolution of the oral and pharyngeal jaws, highlighting the evolutionary significance of gene network reuse. The gene coexpression and in silico regulatory networks presented here are intended as resource for future studies on the genetics of vertebrate jaw morphogenesis and trophic adaptation.

Assessment of the dental status of drug-addicted patients with parafunction of the dental-jaw apparatus

The number of drug addicts in the world is growing every year. The aim of the study was to assess the dental status of drug-addicted patients with parafunction of the dental-jaw apparatus. We used clinical, analytical, functional and histological research methods. 119 drug-addicted and 110 non-drug-dependent patients aged 18 to 54 were examined. In order to confirm the presence of parafunctions of the dental-jaw apparatus in patients, we conducted an occludogram study, as well as an assessment of the index of parafunctions of the masticatory muscles and the degree of their severity. The structure of tooth tissues was examined by histological method. Examination of drug-addicted patients revealed the presence of numerous carious cavities, secondary adentia, enamel erosion, pathological abrasion, signs of gingivitis and periodontitis, tooth chipping. The prevalence of parafunction of the dental-jaw apparatus, in particular bruxism, in drug-addicted patients is 1.56 times higher than this figure among non-drug addicts. The results of the occludogram and the index of parafunctions of the masticatory muscles differ significantly between the study groups. The mean value of the masticatory muscle parafunction index among drug-addicted patients is 2.06 times significantly higher than the value among non-drug-addicted men and 2.03 times higher among women. Histological examination of the tooth tissues of drug-addicted patients indicates a disorder of the mineralization of both enamel and dentin. Thinning of the peripheral zone of the pulp, which is normally represented by a layer of odontoblasts, which provide regeneration and nutrition of dentin, is more common in persons under 25 years of age. Drug use adversely affects the dental status of patients and the condition of the hard tissues of the tooth.

New insights into the morphology and evolution of the ventral pharynx and jaws in Histriobdellidae (Eunicida, Annelida)

The jaw apparatus in several annelid families represents a powerful tool for systematic approaches and evolutionary investigations. Nevertheless, for several taxa, this character complex has scarcely been investigated, and complete comparative analyses of all annelid jaws are lacking. In our comprehensive study, we described the fine structure of the jaw apparatus and the ventral pharyngeal organ (VPO) in Histriobdella homari – a minute ectocommensal of lobsters putatively belonging to the Eunicida – using different comparative morphological approaches, including SEM, TEM, CLSM and subsequent 3D reconstruction. The H. homari jaw apparatus is composed of ventral paired mandibles and dorsal symmetrical maxillae consisting of numerous dental plates, ventral carriers and an unpaired dorsal rod, and the general assemblage and arrangement of the different parts are highly comparable to those of other eunicid families. The jaw ultrastructure of histriobdellids resembles that of the families Dorvilleidae and (juvenile) Onuphidae. Furthermore, our data reveal that in the process of development of the jaw apparatus, the mandibles, maxillae II and unpaired dorsal rod are formed first, and the remaining maxillae and ventral carriers appear later. Notably, the muscular apparatus differs from that in Dorvilleidae and Onuphidae in terms of the number and arrangement of muscle fibers encompassing the jaws – not only because of the very small size of Histriobdella but also because histriobdellid maxillary protraction occurs due to straightening of the dorsal rod and thus requires a different muscular scaffold. Based on our investigations, the arrangement of the muscular apparatus of the jaws, the presence of paired ventral carriers and the dorsal rod, and the morphology of the ventral pharyngeal organ represent a histriobdellid autapomorphy. Our datasets form a basis for further comparative analyses to elucidate the evolution of Eunicida and jaw-bearing Annelida.

Diagnostics and correction of dental pathology in rodents and lagomorphs

The article presents the different types of abnormal bite found in rodents and lagomorphs. Methods of diagnosis, treatment and prognosis are considered. Some malocclusions are curable, while others can only be controlled in the course of life through regular examination by a veterinary doctor and periodic correction. The need to conduct a complete examination of the oral cavity and find the cause of the disease is emphasized, since this will seriously affect the prognosis. When establishing a diagnosis, it is necessary to obtain information about the animal from the owner and conduct a thorough clinical examination of all patients, and, if necessary, using a radiology examination. Animals suffering from systemic diseases require special attention, and in severe conditions, life-threatening should urgently respond to treatment. Therapeutic measures for this pathology provide for dental correction, including the elimination of problems associated with excessive tooth growth, consists in filing the hooks and revising the commissure. Sometimes teeth affected by caries must be removed. All procedures are performed strictly under general anesthesia. The main reason for the occurrence of such diseases is the inheritance of an incorrect configuration of the bones of the skull and teeth (a genetic defect in the jaw apparatus). In recent years, as a result of the low level of breeding work, the number of such animals has increased in several cases. However, there are a number of other reasons: improper feeding (an excess of succulent feed in the diet and a lack of coarse ones), a lack of ascorbic acid and an excess of selenium; other metabolic disorders; violations of the density of dental tissues due to errors in feeding (violation of the exchange of calcium, phosphorus and vitamin D); trauma in the head area; diseases of the temporomandibular joint; tumors; refusal to eat in the presence of other diseases accompanied by pain and discomfort for the animal.

Complete mitochondrial genome of Iniistius trivittatus and unique variation in two observed inserts between rRNA and tRNA genes in wrasses

Background The family Labridae made up of 519 species in the world. The functional evolution of the feeding-related jaws leaded to differentiation of species, and the pharyngeal jaw apparatus evolved independently, but evolutionary mechanism still remain unaddressed in wrasses. Mitogenomes data can be used to infer genetic diversification and investigate evolutionary history of wrasses, whereas only eight complete mitogenomes in this family have been sequenced to date. Here, we sequenced the complete mitogenomes of Iniistius trivittatus to investigate genetic differentiation among wrasse species. Results We sequenced the complete mitogenomes of I. trivittatus using a novel PCR strategy. The I. trivittatus mitogenomes is 16,820 bp in length and includes 13 protein -coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region. Compared to eight known mitochondrial genome, 2 additional noncoding regions (lengths of 121 and 107 bp), or so-called inserts, are found in the intergenic regions 12S rRNA - tRNAVal - 16S rRNA. The presumed origin of the two rare inserts is from tRNA- related retrotransposons. Compared with cytochrome b gene, the two insert sequences are highly conserved at the intraspecies level, but they showed significant variation and low similarity (< 70%) at the interspecies level. The insert events were only observed in I. trivittatus by checking the phylogenetic trees based on the complete mitogenomes of Labrida species. This finding provides evidence that in the mitogenomes, retrotransposon inserts result in intraspecific homoplasmy and interspecific heteroplasmy by natural selection and adaptation to various environments. Conclusions This study found additional mitogenome inserts limited in wrasse species. The rRNA genes with inserts might have experienced a selective pressure for adaptation to feeding modes. Such knowledge can enable a better understanding of molecular mechanism underlying morphological evolution in wrasses.

DETERMINATION OF THE STRUCTURE OF ACUTE INJURY OF TEMPORARY AND PERMANENT FRONTAL TEETH IN CHILDREN, ANALYSIS OF DIAGNOSTIC AND TREATMENT MEASURES AND THEIR EFFECTS

The aim: To determine the structure of acute injuries of temporary and permanent frontal teeth in children, to analyze the applied diagnostic and treatment measures for acute tooth trauma and to investigate their effectiveness. Materials and methods: The subject of the study were 31 children aged 2-12 years with acute temporary and permanent tooth trauma. Methods: clinical (radiological, thermodiagnosis), medical and statistical. Results: The number of injured permanent teeth was greater than the number of injured temporary teeth. The pattern of temporary and permanent tooth injuries differed, so in temporary teeth dislocations were observed, and in permanent teeth fractures prevailed over dislocations. In our opinion, this is due to the peculiarities of the anatomy of the temporary teeth. Usually, the therapeutic tactics of acute temporary teeth injuries is to remove them, despite their important role in the growth and development of jaws, physiological formation and eruption of permanent teeth. The therapeutic tactics of dynamic observation in the case of intrusive dislocation of the temporary tooth were selected in the clinic of the Department of Pediatric Dentistry. In some cases, with a slight change in the position of the temporary tooth, self-regulation of its position was observed, in other cases the tooth remained dystopic, but its viability remained in 50% of cases. Therapeutic tactics of acute injuries of permanent teeth were selected according to the type of trauma. In the case of permanent tooth dislocation, with a slight change in its position, tooth immobilization was carried out by splinting with fiberglass tape and photopolymer composite material. Conclusions: Our observations have shown that the complex of modern specialized medical care for the affected children with acute traumatic injuries of the teeth should be guided by their preservation, which ensures the subsequent normal formation of the dental-jaw apparatus. To ensure these conditions, a long, reliable immobilization of the damaged tooth is required as soon as possible after injury.