Quadruplexes of human telomere DNA analogs designed to contain G:A:G:A,G:G:A:A,and A:A:A:A tetrads

Replacement of two to four guanines by adenines in the human telomere DNA repeat dG₃(TTAG₃)₃ did not hinder the formation of quadruplexes if the substitutions took place in the terminal tetrad bridged by the diagonal loop of the intramolecular antiparallel three‐tetrad scaffold, as proved by CD and PAGE in both Na⁺ and K⁺ solutions. Thermodynamic data showed that, in Na⁺ solution, the dG₃(TTAG₃)₃ quadruplex was destabilized, the least by the two G:A:G:A tetrads, the most by the G:G:A:A tetrad in which the adenosines replaced syn‐guanosines. In physiological K⁺ solution, the highest destabilization was caused by the 4A tetrad. In K⁺, only the unmodified dG₃(TTAG₃)₃ quadruplex rearranged into a K⁺‐dependent quadruplex form, none of the multiple adenine‐modified structures did so. This may imply biological consequences for nonrepaired A‐for‐G mutations. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 880–886, 2010.     

Coenzyme A: back in action

Coenzyme A (CoA) is a ubiquitous essential cofactor that plays a central role in the metabolism of carboxylic acids, including short- and long-chain fatty acids. In the last few years, all of the genes encoding the CoA biosynthetic enzymes have been identified and the structures of several proteins in the pathway have been determined. CoA is assembled in five steps from pantothenic acid and pathway intermediates are common to both prokaryotes and eukaryotes. In spite of the identical biochemistry, remarkable sequence differences among some of the prokaryotic and eukaryotic enzymes have been revealed by comparative genomics. Renewed interest in CoA has arisen from the realization that the biosynthetic pathway is a target for antibacterial drug discovery and from the unexpected association of a human neurodegenerative disorder with mutations in pantothenate kinase. The purpose of this review is to integrate previous knowledge with the most recent findings in the genetics, enzymology and regulation of CoA biosynthesis in bacteria, plants and mammals.     

Magic: A Problem in Semantics

Anthropologists, from Tylor to the present, have so defined magic that, although it might shade into or overlap with religion, it is a separate phenomenon distinct from religion. Theorists have made different features the chief means of differentiation, but no matter how defined the distinction cannot be easily or consistently maintained. This paper suggests that the concept of magic as a distinct entity is the factitious result of ethnocentric classification, and that magic should be included within religion as one type of the practices of which religious ritual is composed.     

Sex in Space: A Synthesis

The five papers in this Special Section illustrate that pollination processes are often disrupted by changing plant distributions. They further demonstrate that plant pollination and seed production outcomes are highly complex due to multidimensional spatial effects and numerous interactive biological responses of both plants and pollinators at individual and population scales. Nevertheless, these studies also lend support to some emerging generalities that (through modeling) begin to provide a coherent framework by which further research, and ultimately management planning, could proceed.     

Flexibility in manufacturing: A survey

This article is an attempt to survey the vast literature on flexibility in manufacturing that has accumulated over the last 10 to 20 years. The survey begins with a brief review of the classical literature on flexibility in economics and organization theory, which provides a background for manufacturing flexibility. Several kinds of flexibilities in manufacturing are then defined carefully along with their purposes, the means to obtain them, and some suggested measurements and valuations. Then we examine the interrelationships among the several flexibilities. Various empirical studies and analytical/optimization models dealing with these flexibilities are reported and discussed. The article concludes with suggestions for some possible future research directions.     

Otomycosis in Iran: A Review

Fungal infection of the external auditory canal (otitis externa and otomycosis) is a chronic, acute, or subacute superficial mycotic infection that rarely involves middle ear. Otomycosis (swimmer’s ear) is usually unilateral infection and affects more females than males. The infection is usually symptomatic and main symptoms are pruritus, otalgia, aural fullness, hearing impairment, otorrhea, and tinnitus. Fungal species such as yeasts, molds, dermatophytes, and Malassezia species are agents for otitis externa. Among molds, Aspergillus niger was described as the most common agent in the literature. Candida albicans was more prevalent than other yeast species. Otomycosis has a worldwide distribution, but the prevalence of infection is related to the geographical location, areas with tropical and subtropical climate showing higher prevalence rates. Otomycosis is a secondary infection and is more prevalent among swimmers. As a result, a higher incidence is reported in summer season, when more people interested in swimming. Incidence of otomycosis in our review ranged from 5.7 to 81 %, with a mean value of 51.3 %. Our results showed that 78.59 % of otomycosis agents were Aspergillus, 16.76 % were Candida species, and the rest (4.65 %) were other saprophytic fungi. Among Iranian patients, incidence of infection was highest in summer, followed by autumn, winter, and spring. In Iran, otomycosis was most prevalent at the age of 20–40 years and the lowest prevalence was associated with being <10 years old. The sex ratio of otomycosis in our study was (M/F) 1:1.53.     

Testosterone in biosociology: A memoir

A contribution to a special issue on Hormones and Human Competition.The author looks back at his four decades of research on testosterone in the context of biosociology – its accomplishments, pitfalls, outstanding questions, and future directions.     

Semaphorin 3A: A new player in bone remodeling

Semaphorin 3A (Sema3A) is a protein identified originally as a diffusible axonal chemorepellent. Sema3A has multifunctional roles in embryonic development, immune regulation, vascularization, and oncogenesis. Bone remodeling consists of two phases: the removal of mineralized bone by osteoclasts and the formation of new bone by osteoblasts, and plays an essential role in skeletal diseases such as osteoporosis. Recent studies have shown that Sema3A is implicated in the regulation of osteoblastgenesis and osteoclastgenesis. Moreover, low bone mass in mice with specific knockout of Sema3A in the neurons indicates that Sema3A regulates bone remodeling indirectly. This review highlights recent advances on our understanding of the role of sema3A as a new player in the regulation of bone remodeling and proposes the potential of sema3A in the diagnosis and therapy of bone diseases.     

Somatic Mosaicism in Hemophilia A: A Fairly Common Event

Mutations in the large gene of clotting factor VIII (FVIII) are the most common events leading to severe human bleeding disorder. The high proportion of de novo mutations observed in this gene raises the possibility that a significant proportion of such mutations does not derive from a single germ cell but instead should be attributed to a germline or somatic mosaic originating from a mutation during early embryogenesis. The present study explores this hypothesis by using allele-specific PCR to analyze 61 families that included members who had sporadic severe hemophilia A and known FVIII gene defects. The presence of somatic mosaicisms of varying degrees (0.2%-25%) could be shown in 8 (13%) of the 61 families and has been confirmed by a mutation-enrichment procedure. All mosaics were found in families with point mutations (8 [25%] of 32 families). In the subgroup of 8 families with CpG transitions, the percentage with mosaicism increased to 50% (4 of 8 families). In contrast, no mosaics were observed in 13 families with small deletions/insertions or in 16 families with intron 22 inversions. Our data suggest that mosaicism may represent a fairly common event in hemophilia A. As a consequence, risk assessment in genetic counseling should include consideration of the possibility of somatic mosaicism in families with apparently de novo mutations, especially families with the subtype of point mutations.