Nature and nurture. Genetic and environmental factors on the relationship between back pain and sleep quality.

BACKGROUND: Chronic low back pain (LBP), neck pain (NP), and sleep quality (SQ) are genetically influenced. All three conditions frequently co-occur and shared genetic aetiology on a pairwise base has been reported. However, to our knowledge, no study has yet investigated if these three conditions are influenced by the same genetic and environmental factors and the extent and pattern of genetic overlap between them, hence the current research. METHODS: The sample included 2134 participants. Lifetime prevalence of NP and LBP were assessed through a dichotomous self-reported question derived from the Spanish National Health Survey. SQ was measured using the Pittsburgh Sleep Quality Index Questionnaire. A common pathway model with sleep quality and back pain as latent factors was fitted. RESULTS: Our results highlight that a latent back pain factor, including both NP and LBP, is explained by both genetic (41%) and environmental (59%) factors. There are also significant unique environmental factors for NP (33%) and LBP (37%) respectively. Yet, specific genetic factors were scant (9%) for NP and negligible for LBP (0%). Genetic and environmental factors affecting SQ only contribute with 3% and 5% of the variance, respectively, to the common latent back pain variable. CONCLUSIONS: NP and LBP share most of their genetic variance, while environmental effects show greater specificity for each of the back pain locations. Associations with SQ were of a limited magnitude. SIGNIFICANCE: Our results confirm a significant association between both chronic NP and LBP and sleep quality. Such relationship comprises both genetic and environmental factors, with a greater relative weight of the latter. A large part of the individual variance for chronic LBP and chronic NP can be accounted for by a latent common factor of 'back pain'. Genetic influences for LBP and NP were mainly shared. However, environmental influences were common for both problems and specific for each of them in similar magnitudes

Regulation of vertebrate myotome development by the p38 MAP kinase-MEF2 signaling pathway.

Biochemical and cell culture studies have characterized the myocyte enhancer factor 2 (MEF2) transcriptional regulatory proteins as obligatory partners for the myogenic regulatory factors (MRFs) in the differentiation of myogenic cells in culture. However, the role of MEF2 activation in somitic myogenesis has not been fully characterized. Here, we report a critical interaction between the p38 mitogen-activated protein kinase (p38 MAPK) and MEF2 in the developing somite myotome. We document expression of MEF2A and p38 MAPK proteins in the somite of 9.5 dpc mouse embryos concurrent with Myf 5 protein expression. We also observed that abrogation of p38 MAPK signaling blocks MEF2 activation using a MEF2 transgenic 'sensor' mouse. Inhibition of p38 MAPK signaling concurrently inhibited myogenic differentiation in somite cultures and in embryos in vivo using transplacental injection of a p38 inhibitor (SB203580). Finally, we document that commitment to the myogenic lineage is not appreciably affected by p38 MAPK inhibition since the activation of an early marker of myogenic commitment (Myf 5) occurs normally when p38 MAPK signaling is inhibited. Thus, we present novel evidence indicating a crucial role for p38 MAPK signaling to the MEF2 transcriptional regulators during early mammalian somite development and myotome formation

Phylogenetic relationships of Italian Bellevalia

The seven Bellevalia species and subspecies known from Italy, representing about 10% of the genus and three out of six sections, were studied. An integrated morphological, karyological and molecular approach was used to infer phylogenetic and systematic relationships among them. B. romana (the generitype) is the most distinctive species on karyotype asymmetry grounds. B. boissieri and B.dubia, usually considered as subspecies of one species (the latter endemic to Sicily), deserve specific status based on biparental nrDNA markers (internal transcribed spacer, ITS), since they do not form a single clade. The allotetraploid endemic B. pelagica, morphologically similar to B. romana, is sister to the latter under parsimony, both in morphological and ITS trees; it is also related with B. dubia, based on karyotype asymmetry and a uniparental cpDNA marker (trnL(UAA)-trnF(GAA) IGS (intergenic spacer)). A second allotetraploid endemic, B. webbiana, is closely related, on morphological, karyological and molecular grounds, with B. boissieri and B. ciliata, and also with B. trifoliata, three species that might all involved in its origin. B. sect. Conicae Feinbr. and sect. Nutantes Feinbr. are here typified, the former (type: B. ciliata) is most likely a synonym of the latter (type: B. trifoliata). © 2013 Società Botanica Italiana