Evolution of genetic networks for human creativity

The genetic basis for the emergence of creativity in modern humans remains a mystery despite sequencing the genomes of chimpanzees and Neanderthals, our closest hominid relatives. Data-driven methods allowed us to uncover networks of genes distinguishing the three major systems of modern human personality and adaptability: emotional reactivity, self-control, and self-awareness. Now we have identified which of these genes are present in chimpanzees and Neanderthals. We replicated our findings in separate analyses of three high-coverage genomes of Neanderthals. We found that Neanderthals had nearly the same genes for emotional reactivity as chimpanzees, and they were intermediate between modern humans and chimpanzees in their numbers of genes for both self-control and self-awareness. 95% of the 267 genes we found only in modern humans were not protein-coding, including many long-non-coding RNAs in the self-awareness network. These genes may have arisen by positive selection for the characteristics of human well-being and behavioral modernity, including creativity, prosocial behavior, and healthy longevity. The genes that cluster in association with those found only in modern humans are over-expressed in brain regions involved in human self-awareness and creativity, including late-myelinating and phylogenetically recent regions of neocortex for autobiographical memory in frontal, parietal, and temporal regions, as well as related components of cortico-thalamo-ponto-cerebellar-cortical and cortico-striato-cortical loops. We conclude that modern humans have more than 200 unique non-protein-coding genes regulating co-expression of many more protein-coding genes in coordinated networks that underlie their capacities for self-awareness, creativity, prosocial behavior, and healthy longevity, which are not found in chimpanzees or Neanderthals

Quaternionic Root Systems and Subgroups of the Aut(F4)Aut(F_{4})

Cayley-Dickson doubling procedure is used to construct the root systems of some celebrated Lie algebras in terms of the integer elements of the division algebras of real numbers, complex numbers, quaternions and octonions. Starting with the roots and weights of SU(2) expressed as the real numbers one can construct the root systems of the Lie algebras of SO(4),SP(2)= SO(5),SO(8),SO(9),F_{4} and E_{8} in terms of the discrete elements of the division algebras. The roots themselves display the group structures besides the octonionic roots of E_{8} which form a closed octonion algebra. The automorphism group Aut(F_{4}) of the Dynkin diagram of F_{4} of order 2304, the largest crystallographic group in 4-dimensional Euclidean space, is realized as the direct product of two binary octahedral group of quaternions preserving the quaternionic root system of F_{4}.The Weyl groups of many Lie algebras, such as, G_{2},SO(7),SO(8),SO(9),SU(3)XSU(3) and SP(3)X SU(2) have been constructed as the subgroups of Aut(F_{4}). We have also classified the other non-parabolic subgroups of Aut(F_{4}) which are not Weyl groups. Two subgroups of orders192 with different conjugacy classes occur as maximal subgroups in the finite subgroups of the Lie group $G_{2}$ of orders 12096 and 1344 and proves to be useful in their constructions. The triality of SO(8) manifesting itself as the cyclic symmetry of the quaternionic imaginary units e_{1},e_{2},e_{3} is used to show that SO(7) and SO(9) can be embedded triply symmetric way in SO(8) and F_{4} respectively

Quaterionic Construction of the W(F_4) Polytopes with Their Dual Polytopes and Branching under the Subgroups B(B_4) and W(B_3)*W(A_1)

4-dimensional $F_{4}$ polytopes and their dual polytopes have been constructed as the orbits of the Coxeter-Weyl group $W(F_{4})$ where the group elements and the vertices of the polytopes are represented by quaternions. Branchings of an arbitrary \textbf{$W(F_{4})$} orbit under the Coxeter groups $W(B_{4}$ and $W(B_{3}) \times W(A_{1})$ have been presented. The role of group theoretical technique and the use of quaternions have been emphasizedComment: 26 pages, 10 figure

Anoxia- and hypoxia-induced expression of LDH-A* in the Amazon Oscar, Astronotus crassipinis

Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant. Exposure of juveniles to acute hypoxia and anoxia resulted in increased LDH-A gene expression in skeletal and cardiac muscles. When exposed to graded hypoxia juveniles show decreased LDH-A expression. In adults, the levels of LDH-A mRNA did not increase in hypoxic or anoxic conditions. Our results demonstrate that, when given time for acclimation, fish at different life-stages are able to respond differently to survive hypoxic episodes

Bone Regeneration Using Periodontal Ligament Cells Seeded on Silk Scaffold

Objectives: Bone replacement is one of the critical steps for management of oral bone defects. Many methods have been used to restore such defect. However, biocompatibility and increasing donor site morbidity are still among the main challenges. The current study aims to investigate the potential of using human periodontal ligament cells (hPDLCs) for bone formation, with Bombyx mori fibroin (BMF) silk as a scaffold material. Methods: Human periodontal ligament cells were isolated from human extracted molar teeth that were granted from Leeds Dental School tissue bank. Foam scaffolds were fabricated from BMF in cylindrical shapes. Sterilised scaffolds were subjected to surface modification with 20% Fetal bovine serum (FBS). Calcein fluorescence staining was used to label the cells before being seeded dynamically (4x103 cell/mm3) on BMF scaffolds. For in-vitro experiments, all samples were incubated in osteogenic medium for 21 days. Another group of seeded scaffolds were placed in diffusion chambers and implanted in peritoneal space of CD1 nude mice to evaluate the growth in-vivo. To study the cellular ingrowth, extracellular matrix formation and mineral deposition, all samples were prepared and stained for histological examination. Furthermore, the expression of osteogenic proteins e.g. collagen type I, osteopontin and osteocalcin was detected with immunohistochemical (IHC) stains. Results: After 24 hrs of in-vitro seeding, hPDLCs begin to spread over the scaffold surface as shown by fluorescence microscope images. Cell density increased over a period of 14 days. Histological examination demonstrated that both in-vitro and in-vivo samples showed ingrowth of cells and formation of abundant amounts of extracellular matrix and collagen bundles. Moreover, the presence of black-stained extracellular deposits was detected after staining with Von Kossa stain. Also, osteogenic proteins were detected in both groups. Conclusions: Human periodontal ligament cells that isolated from extracted teeth can proliferate and differentiate into osteoblast-like cells when grown in particular culturing conditions, also, they enhance bone-like tissue formation, both in-vitro and in-vivo

Snub 24-Cell Derived from the Coxeter-Weyl Group W(D4)

Snub 24-cell is the unique uniform chiral polytope in four dimensions consisting of 24 icosahedral and 120 tetrahedral cells. The vertices of the 4-dimensional semi-regular polytope snub 24-cell and its symmetry group {(W(D_{4})\mathord{/{\vphantom {(W(D_{4}) C_{2}}}. \kern-\nulldelimiterspace} C_{2}}):S_{3} of order 576 are obtained from the quaternionic representation of the Coxeter-Weyl group \textbf{$W(D_{4}).$}The symmetry group is an extension of the proper subgroup of the Coxeter-Weyl group \textbf{$W(D_{4})$}by the permutation symmetry of the Coxeter-Dynkin diagram \textbf{$D_{4} .$} The 96 vertices of the snub 24-cell are obtained as the orbit of the group when it acts on the vector \textbf{$\Lambda =(\tau, 1, \tau, \tau)$}or\textbf{}on the vector\textbf{$\Lambda =(\sigma, 1, \sigma, \sigma)$}in the Dynkin basis with\textbf{$\tau =\frac{1+\sqrt{5}}{2} {\rm and}\sigma =\frac{1-\sqrt{5}}{2} {\rm .}$} The two different sets represent the mirror images of the snub 24-cell. When two mirror images are combined it leads to a quasi regular 4D polytope invariant under the Coxeter-Weyl group \textbf{$W(F_{4}).$}Each vertex of the new polytope is shared by one cube and three truncated octahedra. Dual of the snub 24 cell is also constructed. Relevance of these structures to the Coxeter groups \textbf{$W(H_{4}){\rm and}W(E_{8})$}has been pointed out.Comment: 15 pages, 8 figure

Periodontal regeneration capacity of human periodontal ligament-derived stromal cells

Restoring periodontal defect is still one of the clinical challenges; this is due to the complex structure and diversity of cell types in this joint. The advancement in tissue engineering and cell therapy, make it possible to recruit these approaches to overcome this challenge. This study aims to investigate the capacity of HPDLSCs to differentiation into the main periodontal cell types and enhance the regeneration process. The isolated HPDLSCs were cultured to be characterised for the presence progenitor cell using colony forming unit method. Flow cytometry was used to measure the expression of mesenchymal and hematopoietic cell markers. Furthermore, multilineage cells differentiation was induced. Cells then were seeded on silk scaffold and incubated both in vitro and in vivo in nude mice to examine cellular growth and differentiation. The isolated cells expressed a higher level of MSCs markers in comparison to Hematopoietic markers. Also, these cells showed the ability to proliferate and differentiate into osteogenic, fibrogenic, chondrogenic and adipogenic cues. In Vitro and In Vivo experiments demonstrated the ability of those cells to attach and spread on silk scaffold; In addition to the cellular activities that became evident through the formation of collagen fibres along with the deposition of extracellular minerals. In conclusion, HPDLSCs possess the essential progenitor cells that could differentiate into the primary periodontal cells; Thus, enhancing the periodontal regeneration process

Human periodontal ligament stromal cells: the isolation and characterisation

Restoring periodontal defect is still one of the most challenging clinical needs; this is due to the complex structure and diversity of cell types in this joint. The advancement in tissue engineering and cell therapy made it possible to utilise these approaches to overcome such a challenge. This study aimed to investigate the characteristics of isolated human periodontal ligament cells (HPDLCs), and the multi-linage differentiation capacity of these cells to enhance the regeneration process. Human periodontal ligament cells were isolated from healthy extracted third molar teeth. Colony forming unit-fibroblasts (CFU-f) was used to determine the presence of progenitor cells within the isolated cell population. Further characterisation was conducted by examining the expression levels of mesenchymal stem cells markers (CD29, CD73, STRO-1) as well as the levels of hematopoietic markers (CD34 and CD45), using flow cytometry. Multilineage cells differentiation was induced using adipogenic, chondrogenic, osteogenic and fibrogenic media. Then, the HPDLCs were seeded on 3D Bombyx mori silk fibroin scaffolds in vitro for five weeks and analysed using histology, immunohistochemistry and biochemical assays to confirm proliferation and differentiation processes. Afterwards, the samples were implanted into the peritoneal space of nude mice using diffusion chambers for further seven weeks. All samples were then retrieved from animal models and processed for histology. The data of CFU-f assay demonstrated attachment and proliferation of cultured cells subpopulation onto the vessel’s surface indicating the presence of progenitor stromal cells. Also, HPDLCs expressed higher levels of MSCs markers in comparison to the lower levels of hematopoietic markers. These cells showed the ability to proliferate and differentiate into adipogenic, chondrogenic, osteogenic and fibrogenic cues. Both, in vitro and in vivo experiments demonstrated the ability of those cells to attach and spread on silk scaffolds; as well as performing other cellular activities like formation of collagen fibres, along with the deposition of extracellular minerals. In conclusion, this study showed that HPDLCs contain the essential progenitor stromal cells, which have the capacity to differentiate into the main periodontal cells; this could indicate the role of these cells in enhancing the periodontal regeneration process