Dietary restriction (DR) extends lifespan in many species which is a well-known phenomenon. Long non-coding RNAs (lncRNAs) play an important role in regulation of cell senescence and important age-related signaling pathways. Here, we profiled the lncRNA and mRNA transcriptome of fruit flies at 7 day and 42 day during DR and fully-fed conditions, respectively. In general, 102 differentially expressed lncRNAs and 1406 differentially expressed coding genes were identified. Most informatively we found a large number of differentially expressed lncRNAs and their targets enriched in GO and KEGG analysis. We discovered some new aging related signaling pathways during DR, such as hippo signaling pathway-fly, phototransduction-fly and protein processing in endoplasmic reticulum etc. Novel lncRNAs XLOC_092363 and XLOC_166557 are found to be located in 10 kb upstream sequences of hairy and ems promoters, respectively. Furthermore, tissue specificity of some novel lncRNAs had been analyzed at 7 day of DR in fly head, gut and fat body. Also the silencing of lncRNA XLOC_076307 resulted in altered expression level of its targets including Gadd45 (involved in FoxO signaling pathway). Together, the results implicated many lncRNAs closely associated with dietary restriction, which could provide a resource for lncRNA in aging and age-related disease field.

Vertebrate β-defensins comprise an important family of antimicrobial peptides that protect organisms from a diverse spectrum of bacteria, viruses, fungi, and protozoan parasites. Previous studies have shown a marked variation in the number of β-defensins among species, but the underlying reason is unclear. To address this question, we performed comprehensive computational searches to study the intact β-defensin genes from 29 vertebrates. Phylogenetic analysis of the β-defensin genes in vertebrates identified frequent changes in the number of β-defensin genes and multiple species-specific gene gains and losses that have been occurring throughout the evolution of vertebrates. The number of intact β-defensin genes varied from 1 in the western clawed frog to 20 in cattle, with numerous expansions and contractions of the gene family throughout vertebrates, especially among tetrapods. The β-defensin gene number in a species is relevant to the ever-changing microbial challenges from the environment that they inhabit. Selection pressure analysis shows there exist three amino acid sites under significant positive selection. Protein structural characteristics analysis suggests that structural diversity determines the diverse functions of β-defensins. Our study provides a new perspective on the relationships among vertebrate β-defensin gene repertoires and different survival circumstances, which helps explain how β-defensins have evolved.

ABSTRACT. Artificial illumination is an important exogenous factor in the control of many physiological and behavioral processes as well as an important environmental factor in the management of laying hens. Melatonin receptors are members of the G protein-coupled receptor family. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. The aim of this study was to examine the effect of monochromatic light on chicken egg reproduction and expression of melatonin receptors in chicken ovarian follicles. A total of 552 19-week-old hens were randomly divided into 4 groups with 138 birds in each group. Each group was randomly divided into 3 replicates with 46 birds in each replicate. Feed and water were provided for ad libitum. Light treatments were: control cool white (400-760 nm), blue (480 nm), green (560 nm), and red (660 nm). The short wavelength (blue light) group produced a greater total number of eggs at 300 days of age than did the long wavelength (red light) group, and the red light group showed higher melatonin receptor type 1A and melatonin receptor 10073 Expression patterns of melatonin receptors in chicken ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 10072-10080 (2015) type 1C mRNA and protein expression. These results suggest that the wavelength of light is closely related to chicken egg number at 300 days of age; there is no effect of monochromatic light on melatonin receptor type 1B.

A deeper understanding of the conserved molecular mechanisms in different taxa have been made possible only because of the evolutionary conservation of crucial signaling pathways. In the present study, we explored the molecular evolutionary pattern of selection signatures in 51 species for 10 genes which are important components of NAD+/Sirtuin pathway and have already been directly linked to lifespan extension in worms and mice. Selection pressure analysis using PAML program revealed that MRPS5 and PPARGC1A were under significant constraints because of their functional significance. FOXO3a also displayed strong purifying selection. All three sirtuins, which were SIRT1, SIRT2 and SIRT6, displayed a great degree of conservation between taxa, which is consistent with the previous report. A significant evolutionary constraint is seen on the anti-oxidant gene, SOD3. As expected, TP53 gene was under significant selection pressure in mammals, owing to its major role in tumor progression. Poly-ADP-ribose polymerase (PARP) genes displayed the most sites under positive selection. Further 3D structural analysis of PARP1 and PARP2 protein revealed that some of these positively selected sites caused a change in the electrostatic potential of the protein structure, which may allow a change in its interaction with other proteins and molecules ultimately leading to difference in the function. Although the functional significance of the positively selected sites could not be established in the variants databases, yet it will be interesting to see if these sites actually affect the function of PARP1 and PARP2.

Dietary restriction (DR) is widely regarded as a viable intervention to extend lifespan and healthspan in diverse organisms. The precise molecular regulatory mechanisms are largely unknown. Epigenetic modifications are not stable upon DR and also keep changing with age. Here, we employed whole genome bisulfite sequencing to determine the DNA methylation changes upon DR in adult Drosophila. Our results indicate that although a low level of DNA methylation exists in the adult Drosophila genome, there is no significant difference in DNA methylation levels upon DR when compared to unrestricted flies. This suggests that other epigenetic components such as histone modifications might be altered by DR.

Timeless (Tim) is considered to function as an essential circadian clock gene in Drosophila. Putative homologues of the Drosophila timeless gene have been identified in both mice and humans. While Drosophila contains two paralogs, timeless and timeout, acting in clock/light entrainment and chromosome integrity/photoreception, respectively, mammals contain only one Tim homolog. In this paper, we study the phylogeny of the timeless/timeout family in 48 species [including 1 protozoan (Guillardia theta), 1 nematode (Caenorhabditis elegans), 8 arthropods and 38 chordates], for which whole genome data are available by using MEGA (Molecular Evolutionary Genetics Analysis). Phylogenetic Analysis by Maximum Likelihood (PAML) was used to analyze the selective pressure acting on metazoan timeless/timeout genes. Our phylogeny clearly separates insect timeless and timeout lineages and shows that non-insect animal Tim genes are homologs of insect timeout. In this study, we explored the relatively rapidly evolving timeless lineage that was apparently lost from most deuterostomes, including chordates, and from Caenorhabditis elegans. In contrast, we found that the timeout protein, often confusingly called “timeless” in the vertebrate literature, is present throughout the available animal genomes. Selection results showed that timeout is under weaker negative selection than timeless. Finally, our phylogeny of timeless/timeout showed an evolutionary conservation of the circadian clock gene timeout in Metazoa. This conservation is in line with its multifunctionality, being essential for embryonic development and maintenance of chromosome integrity, among others.

Drosophila formosana (Diptera: Drosophilidae) belongs to the Drosophilidae group of Drosophila. The mitochondrial genome sequence of Drosophila formosana is determined in this study. Mitochondrion of D. formosana is a circular DNA molecule of the 16 100 nucleotide pairs (bp) that contains one encoding region including 37 genes and 1 non-coding A + T-rich region. The similarity and typicality have been showed by the structure and organization analysis. All genes are arranged in the circular DNA molecule. In addition to DN5 that use GTG start codon, all other protein-coding genes (PCGs) start with an ATN start codon. Ten protein-coding genes stop with the termination codon TAN, while other protein-coding genes (PCGs) used incomplete termination codon TA- (cox2, nad5, nad1). The A + T-rich region with a length of 1088 bp is located between rrnS and trnI. The mitochondrial genome of D. formosana has been completely sequenced for the first time in this study.

The evolutionary differences in sensory bristle patterns on the thorax of dipterans are an excellent model for studying the patterns of evolutionary development. We observed that Drosophila melanogaster has two pairs of the large bristles, called macrochaetes, in the dorsocentral (DC) region of the notum, while Musca domestica retains six DC macrochaetes. To explore possible mechanism by which these two dipteran species have different numbers of DC bristles, we compared the corresponding protein sequences, the gene expression levels and the spatial expression patterns of five genes (scute, pnr, ush, hairy, and emc) for bristle development between two species. We also checked the overexpression of scute and emc in transgenic flies. The results demonstrated a strong conservation of five protein sequences between these two species. The mRNA expression of the five genes differed significantly between D. melanogaster and M. domestica. The gene expression patterns exhibited a species‐specific pattern during the larval development stage. It suggests that the function of these genes has been conserved in regulating the development of macrocheates between housefly and fruit fly, whereas the gene expression levels, especially spatial expression patterns lead to species‐specificity in DC bristles.