Wnt Pathway Activation Increases Hypoxia Tolerance during Development

Adaptation to hypoxia, defined as a condition of inadequate oxygen supply, has enabled humans to successfully colonize high altitude regions. The mechanisms attempted by organisms to cope with short-term hypoxia include increased ATP production via anaerobic respiration and stabilization of Hypoxia Inducible Factor 1α (HIF-1α). However, less is known about the means through which populations adapt to chronic hypoxia during the process of development within a life time or over generations. Here we show that signaling via the highly conserved Wnt pathway impacts the ability of Drosophila melanogaster to complete its life cycle under hypoxia. We identify this pathway through analyses of genome sequencing and gene expression of a Drosophila melanogaster population adapted over >180 generations to tolerate a concentration of 3.5–4% O₂ in air. We then show that genetic activation of the Wnt canonical pathway leads to increased rates of adult eclosion in low O₂. Our results indicate that a previously unsuspected major developmental pathway, Wnt, plays a significant role in hypoxia tolerance.     

A dried preparation of liposomes containing muramyl tripeptide phosphatidylethanolamine as a potent activator of human blood monocytes to the antitumor state

Summary Studies were performed on the activation of human blood monocytes to the antitumor state by a dried preparation of multilamellar vesicle (MLV) liposomes in which synthetic muramyl tripeptide phosphatidylethanolamine (MTP-PE) was inserted directly into the liposome membrane. Dried liposomes composed of synthetic phospholipids [phosphatidylcholine (PC) and phosphatidylserine (PS) in a molar ratio of 7:3] were prepared by lyophilization. Dried liposome-MTP-PE was found to be superior in several ways to free desmethyl muramyl dipeptide (norMDP) or conventional liposome-MTP-PE, prepared immediately before use. First, dried lipsome-MTP-PE was stable and strongly activated monocytes when stored for over 3 months in a freezer at –°C or even in suspension at 4°C. Second, human monocytes in suspension, as well as in the adherent form, were activated to the tumoricidal state by interaction for at least 4 h with the dried preparation of liposome-MTP-PE. Third, monocytes activated with the dried liposome-MTP-PE or conventionally prepared liposome-MTP-PE maintained their tumoricidal activity for a longer period (4 days) than those activated with free norMDP. These results indicate that the dried preparation of liposome-MTP-PE can be stored for a long time, has a reproducible effect that can be standardized and should be valuable for in situ activation of human monocytes to the tumoricidal state, which is associated with eradication of cancer metastases.     

Mixed company: a framework for understanding the composition and organization of mixed‐species animal groups

Mixed‐species animal groups (MSGs) are widely acknowledged to increase predator avoidance and foraging efficiency, among other benefits, and thereby increase participants' fitness. Diversity in MSG composition ranges from two to 70 species of very similar or completely different phenotypes. Yet consistency in organization is also observable in that one or a few species usually have disproportionate importance for MSG formation and/or maintenance. We propose a two‐dimensional framework for understanding this diversity and consistency, concentrating on the types of interactions possible between two individuals, usually of different species. One axis represents the similarity of benefit types traded between the individuals, while the second axis expresses asymmetry in the relative amount of benefits/costs accrued. Considering benefit types, one extreme represents the case of single‐species groups wherein all individuals obtain the same supplementary, group‐size‐related benefits, and the other extreme comprises associations of very different, but complementary species (e.g. one partner creates access to food while the other provides vigilance). The relevance of social information and the matching of activities (e.g. speed of movement) are highest for relationships on the supplementary side of this axis, but so is competition; relationships between species will occur at points along this gradient where the benefits outweigh the costs. Considering benefit amounts given or received, extreme asymmetry occurs when one species is exclusively a benefit provider and the other a benefit user. Within this parameter space, some MSG systems are constrained to one kind of interaction, such as shoals of fish of similar species or leader–follower interactions in fish and other taxa. Other MSGs, such as terrestrial bird flocks, can simultaneously include a variety of supplementary and complementary interactions. We review the benefits that species obtain across the diversity of MSG types, and argue that the degree and nature of asymmetry between benefit providers and users should be measured and not just assumed. We then discuss evolutionary shifts in MSG types, focusing on drivers towards similarity in group composition, and selection on benefit providers to enhance the benefits they can receive from other species. Finally, we conclude by considering how individual and collective behaviour in MSGs may influence both the structure and processes of communities.     

Physical mapping of an adult plant stripe rust resistance gene from Triticum monococcum

Stripe rust (Puccinia striiformis f. sp. tritici) is one of the major devastating disease which causes large reduction in wheat yield. T. monococcum is an attractive diploid species for gene discovery in wheat with smaller genome size of 5700 Mb compared to 17,300 Mb of bread wheat. An adult plant stripe rust resistance QTL QYrtm.pau-2A was mapped on chromosome 2A flanked by two SSR markers Xwmc170 and Xwmc407. In the present study, two gene based markers Pau_Ta2AL_Gene45 and Pau_Ta2AL_Gene54 developed from 2A specific ESTs were found to map close to QYrtmpau-2A to narrow down the region for candidate gene identification. Utilizing sequence information of these two markers, four BAC clones were identified from the Minimum Tiling Path of 2AL assembly and were sequenced. SSR markers were designed from these BAC sequences and mapped to chromosome 2A. A 50 Mb region of wheat chromomse 2A was identified to harbor stripe rust resistance gene of T. monococcum. Gene based markers identified in the present investigation can be used for marker assisted introgression of QYrtm.pau-2A from T. monococcum to cultivated wheat.     

Development of a PCR-RFLP assay for the identification of Lactococcus lactis ssp. lactis and cremoris

The development of new starter culture of Lactococcus lactis for the manufacture of fermented dairy products with unique characteristics usually requires the isolation and identification of L. lactis up to subspecies level. Therefore, a rapid and specific PCR-RFLP assay has been developed. Forward and reverse primer sets were designed targeting the conserved house keeping gene htrA and yueF encoding a trypsin-like serine protease and a non-proteolytic protein from peptidase family M16, respectively, of L. lactis. Amplicons of 265 bp and 447 bp of htrA and yueF, respectively, were subjected to restriction fragment length polymorphism analysis. Restriction of the 265 bp amplicons with TaqI produced DNA bands of 90 bp and 175 bp with ssp. lactis, and 66 bp and 199 bp with ssp. cremoris. Similarly, restriction of PCR product of 447 bp size with AluI produced digested fragments of 125 bp and 322 bp with ssp. lactis, and 71 bp and 376 bp with ssp. cremoris. The designed primer sets were observed to be specific to L. lactis because other bacteria could not be amplified. The ssp. lactis and cremoris of L. lactis could be identified by restriction of PCR products of htrA and yueF with TaqI and AluI, respectively.     

Diversity analysis of dairy and non-dairy strains of Lactococcus lactis ssp. lactis by multilocus sequence analysis (MLSA)

The genetic diversity of 31 identified strains of Lactococcus lactis ssp. lactis isolated from different dairy and non-dairy sources were investigated at gene level using multilocus sequence analysis (MLSA) and PCR-RFLP based on the differences in four selected partial protein coding gene sequences: araT, encoding aromatic amino acid-specific aminotransferase; dtpT, encoding di/tri peptide transporter; yueF, encoding non-proteolytic protein, peptidase, M16 family; and pdhA, encoding pyruvate dehydrogenase E1 component α-subunit. A set of seven test strains from different isolation sources and one reference strain, L. lactis ssp. lactis NCDC 094, were analyzed by MLSA. The strains showed distinct diversity among themselves and exhibited a greater percent similarity with reference strains L. lactis ssp. lactis CV56 (CP002365.1), IL1403 (AE005176.1), and KF147 (CP001834.1) in comparison with L. lactis ssp. cremoris NZ9000 (CP002094.1), MG1363 (AM406671.1), and SK11 (CP00425.1). The MLSA revealed one distinct genomic lineage within strains exclusively of L. lactis ssp. lactis. This analysis also revealed no source-wise genetic relationship in the test strains analyzed. Further, PCR-RFLP of araT, dtpT, yueF and pdhA also characterized the single genomic lineage exclusively of L. lactis ssp. lactis within a total of 24 test strains.     

Comparative analysis of chromosome 2A molecular organization in diploid and hexaploid wheat

Molecular Biology Reports - Diploid A genome wheat species harbor immense genetic variability which has been targeted and proven useful in wheat improvement. Development and deployment of...     

Alkaloid production in Vernonia cinerea: Callus, cell suspension and root cultures

Fast-growing callus, cell suspension and root cultures of Vernonia cinerea, a medicinal plant, were analyzed for the presence of alkaloids. Callus and root cultures were established from young leaf explants in Murashige and Skoog (MS) basal media supplemented with combinations of auxins and cytokinins, whereas cell suspension cultures were established from callus cultures. Maximum biomass of callus, cell suspension and root cultures were obtained in the medium supplemented with 1 mg/L alpha-naphthaleneacetic acid (NAA) and 5 mg/L benzylaminopurine (BA), 1.0 mg/L NAA and 0.1 mg/L BA and 1.5 mg/L NAA, respectively. The 5-week-old callus cultures resulted in maximum biomass and alkaloid contents (750 microg/g). Cell suspension growth and alkaloid contents were maximal in 20-day-old cultures and alkaloid contents were 1.15 mg/g. A 0.2-g sample of root tissue regenerated in semi-solid medium upon transfer to liquid MS medium containing 1.5 mg/L NAA regenerated a maximum increase in biomass of 6.3-fold over a period of 5 weeks. The highest root growth and alkaloid contents of 2 mg/g dry weight were obtained in 5-week-old cultures. Maximum alkaloid contents were obtained in root cultures in vitro compared to all others including the alkaloid content of in vivo obtained with aerial parts and roots (800 microg/g and 1.2 mg/g dry weight, respectively) of V. cinerea.     

Data mining of transcriptional biomarkers at different cotton fiber developmental stages

Functional & Integrative Genomics - Advancement of the gene expression study provides comprehensive information on pivotal genes at different cotton fiber development stages. For the betterment...     

Modeling breast cancer in vivo and ex vivo reveals an essential role of Pin1 in tumorigenesis

Phosphorylation on certain Ser/Thr-Pro motifs is a major oncogenic mechanism. The conformation and function of phosphorylated Ser/Thr-Pro motifs are further regulated by the prolyl isomerase Pin1. Pin1 is prevalently overexpressed in human cancers and implicated in oncogenesis. However, the role of Pin1 in oncogenesis in vivo is not known. We have shown that Pin1 ablation is highly effective in preventing oncogenic Neu or Ras from inducing cyclin D1 and breast cancer in mice, although it neither affects transgene expression nor mammary gland development. Moreover, we have developed an ex vivo assay to uncover that a significant fraction of primary mammary epithelial cells from Neu or Ras mice display various malignant properties long before they develop tumors in vivo. Importantly, these early transformed properties are effectively suppressed by Pin1 deletion, which can be fully rescued by overexpression of cyclin D1. Thus, Pin1 is essential for tumorigenesis and is an attractive anticancer target. Our ex vivo assay can be used to study early events of breast cancer development in genetically predisposed mice.