18 research outputs found

    B-Chromosome Ribosomal DNA Is Functional in the Grasshopper Eyprepocnemis plorans

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    B-chromosomes are frequently argued to be genetically inert elements, but activity for some particular genes has been reported, especially for ribosomal RNA (rRNA) genes whose expression can easily be detected at the cytological level by the visualization of their phenotypic expression, i.e., the nucleolus. The B24 chromosome in the grasshopper Eyprepocnemis plorans frequently shows a nucleolus attached to it during meiotic prophase I. Here we show the presence of rRNA transcripts that unequivocally came from the B24 chromosome. To detect these transcripts, we designed primers specifically anchoring at the ITS-2 region, so that the reverse primer was complementary to the B chromosome DNA sequence including a differential adenine insertion being absent in the ITS2 of A chromosomes. PCR analysis carried out on genomic DNA showed amplification in B-carrying males but not in B-lacking ones. PCR analyses performed on complementary DNA showed amplification in about half of B-carrying males. Joint cytological and molecular analysis performed on 34 B-carrying males showed a close correspondence between the presence of B-specific transcripts and of nucleoli attached to the B chromosome. In addition, the molecular analysis revealed activity of the B chromosome rDNA in 10 out of the 13 B-carrying females analysed. Our results suggest that the nucleoli attached to B chromosomes are actively formed by expression of the rDNA carried by them, and not by recruitment of nucleolar materials formed in A chromosome nucleolar organizing regions. Therefore, B-chromosome rDNA in E. plorans is functional since it is actively transcribed to form the nucleolus attached to the B chromosome. This demonstrates that some heterochromatic B chromosomes can harbour functional genes.This study was supported by a grant from the Spanish Ministerio de Ciencia e Innovación (CGL2009-11917), and was partially performed by FEDER funds. M. Ruiz-Estévez was supported by a fellowship (FPU) from the Spanish Ministerio de Ciencia e Innovación

    Perinatal asphyxia: current status and approaches towards neuroprotective strategies, with focus on sentinel proteins

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    Delivery is a stressful and risky event menacing the newborn. The mother-dependent respiration has to be replaced by autonomous pulmonary breathing immediately after delivery. If delayed, it may lead to deficient oxygen supply compromising survival and development of the central nervous system. Lack of oxygen availability gives rise to depletion of NAD+ tissue stores, decrease of ATP formation, weakening of the electron transport pump and anaerobic metabolism and acidosis, leading necessarily to death if oxygenation is not promptly re-established. Re-oxygenation triggers a cascade of compensatory biochemical events to restore function, which may be accompanied by improper homeostasis and oxidative stress. Consequences may be incomplete recovery, or excess reactions that worsen the biological outcome by disturbed metabolism and/or imbalance produced by over-expression of alternative metabolic pathways. Perinatal asphyxia has been associated with severe neurological and psychiatric sequelae with delayed clinical onset. No specific treatments have yet been established. In the clinical setting, after resuscitation of an infant with birth asphyxia, the emphasis is on supportive therapy. Several interventions have been proposed to attenuate secondary neuronal injuries elicited by asphyxia, including hypothermia. Although promising, the clinical efficacy of hypothermia has not been fully demonstrated. It is evident that new approaches are warranted. The purpose of this review is to discuss the concept of sentinel proteins as targets for neuroprotection. Several sentinel proteins have been described to protect the integrity of the genome (e.g. PARP-1; XRCC1; DNA ligase IIIα; DNA polymerase β, ERCC2, DNA-dependent protein kinases). They act by eliciting metabolic cascades leading to (i) activation of cell survival and neurotrophic pathways; (ii) early and delayed programmed cell death, and (iii) promotion of cell proliferation, differentiation, neuritogenesis and synaptogenesis. It is proposed that sentinel proteins can be used as markers for characterising long-term effects of perinatal asphyxia, and as targets for novel therapeutic development and innovative strategies for neonatal care

    Scientific Reports / Facial Aesthetics in Young Adults after Cleft Lip and Palate Treatment over Five Decades

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    Cleft Lip and Palate (CLP) - a common facial malformation in newborns is typically corrected by surgical intervention to allow for normal speech development, psychosocial adjustment, and facial attractiveness. The long term treatment outcome can be evaluated after a number of years, possibly in adulthood. We investigated the aesthetics of the nasolabial region by subjective ratings. To compare various surgical approaches we recruited 12 raters to evaluate 429 patients. Expert and lay raters judged photographs from patients, who have completed treatment with one of three different surgical strategies performed in our institution over 50 years. Facial photographs were cropped, presented to the raters in a randomized sequence, and judged by the raters on a 5 point Likert scale. The subjective ratings between the raters revealed a fair to substantial inter-rater reliability. The average ratings of the surgical outcome improved continuously over the investigated 5 decades. Despite possible differences between raters and rater groups this overall result was consistently seen in the gender groups (male/female), or expertise related groups (expert/lay). Our analysis revealed that patients with bilateral CLP scored worse than patients with unilateral CLP when treated in the fifties; more recently treated patients of both groups scored similarly.(VLID)463726
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