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We report a new visualization tool for analysis of whole-genome assembly-assembly alignments, the Comparative Genome Viewer (CGV) ( https://ncbi.nlm.nih.gov/genome/cgv/ ). CGV visualizes pairwise same-species and cross-species alignments provided by National Center for Biotechnology Information (NCBI) using assembly alignment algorithms developed by us and others. Researchers can examine large structural differences spanning chromosomes, such as inversions or translocations. Users can also navigate to regions of interest, where they can detect and analyze smaller-scale deletions and rearrangements within specific chromosome or gene regions. RefSeq or user-provided gene annotation is displayed where available. CGV currently provides approximately 800 alignments from over 350 animal, plant, and fungal species. CGV and related NCBI viewers are undergoing active development to further meet needs of the research community in comparative genome visualization.

TERMINAL FLOWER1 (TFL1)-like genes are highly conserved in plants and are thought to function in the maintenance of meristem indeterminacy. Recently, we described six maize (Zea mays) TFL1-related genes, named ZEA CENTRORADIALIS1 (ZCN1) to ZCN6. To gain insight into their functions, we generated transgenic maize plants overexpressing their respective cDNAs driven by a constitutive promoter. Overall, ectopic expression of the maize TFL1-like genes produced similar phenotypes, including delayed flowering and altered inflorescence architecture. We observed an apparent relationship between the magnitude of the transgenic phenotypes and the degree of homology between the ZCN proteins. ZCN2, -4, and -5 form a monophylogenetic clade, and their overexpression produced the strongest phenotypes. Along with very late flowering, these transgenic plants produced a \"bushy\" tassel with increased lateral branching and spikelet density compared with nontransgenic siblings. On the other hand, ZCN1, -3, and -6 produced milder effects. Among them, ZCN1 showed moderate effects on flowering time and tassel morphology, whereas ZCN3 and ZCN6 did not change flowering time but still showed effects on tassel morphology. In situ hybridizations of tissue from nontransgenic plants revealed that the expression of all ZCN genes was associated with vascular bundles, but each gene had a specific spatial and temporal pattern. Expression of four ZCN genes localized to the protoxylem, whereas ZCN5 was expressed in the protophloem. Collectively, our findings suggest that ectopic expression of the TFL1-like genes in maize modifies flowering time and inflorescence architecture through maintenance of the indeterminacy of the vegetative and inflorescence meristems.

Flowering time is a fundamental trait of maize adaptation to different agricultural environments. Although a large body of information is available on the map position of quantitative trait loci for flowering time, little is known about the molecular basis of quantitative trait loci. Through positional cloning and association mapping, we resolved the major flowering-time quantitative trait locus, Vegetative to generative transition 1 (Vgt1), to an [almost equal to]2-kb noncoding region positioned 70 kb upstream of an Ap2-like transcription factor that we have shown to be involved in flowering-time control. Vgt1 functions as a cis-acting regulatory element as indicated by the correlation of the Vgt1 alleles with the transcript expression levels of the downstream gene. Additionally, within Vgt1, we identified evolutionarily conserved noncoding sequences across the maize-sorghum-rice lineages. Our results support the notion that changes in distant cis-acting regulatory regions are a key component of plant genetic adaptation throughout breeding and evolution.

The design and construction of buildings and engineering structures on permafrost soils under climate change conditions require the development of technical solutions to improve the reliability of the functioning of engineering structure foundations. To ensure an all-season freezing of base soils and maintain design temperatures without interseasonal pauses, a three-circuit system for the year-round thermal stabilization of base soils is proposed, and its effectiveness is evaluated based on the test results at a testing field.

Two maize genes with predicted translational similarity to the Arabidopsis FIE (Fertilization-Independent Endosperm) protein, a repressor of endosperm development in the absence of fertilization, were cloned and analyzed. Genomic sequences of fie1 and fie2 show significant homology within coding regions but none within introns or 5′ upstream. The fie1 gene is expressed exclusively in the endosperm of developing kernels starting at ∼6 days after pollination. fie1 is an imprinted gene showing no detectable expression of the paternally derived fie1 allele during kernel development. Conversely, fie2 is expressed in the embryo sac before pollination. After pollination, its expression persists, predominantly in the embryo and at lower levels in the endosperm. The paternal fie2 allele is not expressed early in kernel development, but its transcription is activated at 5 days after pollination. fie2 is likely to be a functional ortholog of the Arabidopsis FIE gene, whereas fie1 has evolved a distinct function. The maize FIE2 and sorghum FIE proteins form a monophyletic group, sharing a closer relationship to each other than to the FIE1 protein, suggesting that maize fie genes originated from two different ancestral genomes.

A set of oat-maize chromosome addition lines with individual maize (Zea mays L.) chromosomes present in plants with a complete oat (Avena sativa L.) chromosome complement provides a unique opportunity to analyze the organization of centromeric regions of each maize chromosome. A DNA sequence, MCS1a, described previously as a maize centromere-associated sequence, was used as a probe to isolate cosmid clones from a genomic library made of DNA purified from a maize chromosome 9 addition line. Analysis of six cosmid clones containing centromeric DNA segments revealed a complex organization. The MCS1a sequence was found to comprise a portion of the long terminal repeats of a retrotransposon-like repeated element, termed CentA. Two of the six cosmid clones contained regions composed of a newly identified family of tandem repeats, termed CentC. Copies of CentA and tandem arrays of CentC are interspersed with other repetitive elements, including the previously identified maize retroelements Huck and Prem2. Fluorescence in situ hybridization revealed that CentC and CentA elements are limited to the centromeric region of each maize chromosome. The retroelements Huck and Prem2 are dispersed along all maize chromosomes, although Huck elements are present in an increased concentration around centromeric regions. Significant variation in the size of the blocks of CentC and in the copy number of CentA elements, as well as restriction fragment length variations were detected within the centromeric region of each maize chromosome studied. The different proportions and arrangements of these elements and likely others provide each centromeric region with a unique overall structure.

The paper presents new age and petrological–geochemical data on the rocks of the Valovayam River area (Kamchatka Isthmus) and some areas of the Sredinny Range of Kamchatka (Orlov Volcano, Polovinnaya, Stolbovaya, and Matera mountains). Analysis of the obtained data shows that the spatial and temporal association of the intraplate and island-arc volcanism in the Valovayam River area is not accidental, but resulted from melting of a common source related to the mantle diapir. Additional data on the composition of the mantle xenoliths and the traces of their melting in the form of residual glasses make it possible to relate the formation of different rock series into a single process. A two-stage petrogenetic model is proposed: (1) formation of “black pyroxenites” as a result of melting of mantle lherzolites and (2) formation of the whole rock assemblage through melting of the same lherzolites and newly formed pyroxenites. The concurrent study of the rocks of similar age from the Valovayam River area and the Sredinny Range allows us to distinguish two types of adakites: high-Si adakites (HSA) in the former area and low-Si adakites (LSA) in the latter. The formation of the first type is related to the fractionation, melting, and breakdown of amphibole, while the formation of the second type was controlled by the fractionation and melting of pyroxene.

The paper focuses on a collection of photographs recently (2016) donated to the Museum of Byzantine Culture of Thessaloniki, Greece, by Georges Kiourtzian, a Byzantine scholar associated with the College de France in Paris. The 17 mounted silver-prints date from the October Revolution of 1917 and portray the destruction by bombardments of churches and other monuments in the Kremlin, Moscow. Once part of the archive of Thomas Whittemore, the American Byzantine scholar, the photographs were discarded by the Byzantine Library in Paris, only to be collected by Georges Kiourtzian and then to find their way to the collection of the Museum of Byzantine Culture. This paper sheds light on the complicated itinerary of those photographs: from their production as documentation, to their use as propaganda material, to the Byzantine Library and their eventual discarding, and finally to their new life as museum artefacts in the Museum of Byzantine Culture. The disputed narrative of the photographs are revealed, along with challenges and potentials that reorganization and integration in this recent museum presents for unravelling contested dynamics of the collection.

We report on the construction of maize minichromosomes using shuttle vectors harboring native centromeric segments, origins of replication, selectable marker genes, and telomeric repeats. These vectors were introduced into scutellar cells of maize immature embryos by microprojectile bombardment. Several independent transformation events were identified containing minichromosomes in addition to the normal diploid complement of 20 maize chromosomes. Immunostaining indicated that the minichromosomes recruited centromeric protein C, which is a specific component of the centromere/kinetochore complex. Minichromosomes were estimated to be 15-30 Mb in size based on cytological measurements. Fluorescent in situ hybridization (FISH) showed that minichromosomes contain the centromeric, telomeric, and exogenous unique marker sequences interspersed with maize retrotransposons. Minichromosomes were detected for at least a year in actively dividing callus cultures, providing evidence for their stability through numerous cell cycles. Plants were regenerated and minichromosomes were detected in root tips, providing confirmation of their normal replication and transmission during mitosis and through organogenesis. Assembly of maize artificial chromosomes may provide a tool to study centromere function and a foundation for developing new high capacity vectors for plant functional genomics and breeding.

The phosphatidylethanolamine-binding proteins (PEBPs) represent an ancient protein family found across the biosphere. In animals they are known to act as kinase and serine protease inhibitors controlling cell growth and differentiation. In plants the most extensively studied PEBP genes, the Arabidopsis (Arabidopsis thaliana) FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) genes, function, respectively, as a promoter and a repressor of the floral transition. Twenty-five maize (Zea mays) genes that encode PEBP-like proteins, likely the entire gene family, were identified and named Zea mays CENTRORADIALIS (ZCN), after the first described plant PEBP gene from ANTIRRHINUM: The maize family is expanded relative to eudicots (typically six to eight genes) and rice (Oryza sativa; 19 genes). Genomic structures, map locations, and syntenous relationships with rice were determined for 24 of the maize ZCN genes. Phylogenetic analysis assigned the maize ZCN proteins to three major subfamilies: TFL1-like (six members), MOTHER OF FT AND TFL1-like (three), and FT-like (15). Expression analysis demonstrated transcription for at least 21 ZCN genes, many with developmentally specific patterns and some having alternatively spliced transcripts. Expression patterns and protein structural analysis identified maize candidates likely having conserved gene function of TFL1. Expression patterns and interaction of the ZCN8 protein with the floral activator DLF1 in the yeast (Saccharomyces cerevisiae) two-hybrid assay strongly supports that ZCN8 plays an orthologous FT function in maize. The expression of other ZCN genes in roots, kernels, and flowers implies their involvement in diverse developmental processes.