Abnahme und Ablieferung von DV-Anlagen

Im Anschluss an den Beitrag über die Abnahme technischer Anlagen in CR 1991, 1-6 soll eine Auswahl der Rechtsprechung zur Abnahme und Ablieferung von DV-Anlagen untersucht werden. Dabei wird die Tendenz erkennbar, den Zeitpunkt der Abnehme gem. § 640 BGB als Auslöser der Zahlungspflicht und Verjährungsbeginn der Gewährleistungsrechte möglichst weit hinauszuschieben. Bedenklich erscheint diese Ausdehnung des Schutzes dort, wo die für die werkvertragliche Abnahme entwickelten Kriterien auf die kaufrechtliche Ablieferung übertragen werden, auf die sie wegen der andersartigen Ausgestaltung des Kaufvertrages jedoch nicht passen. Auch bei der vertraglichen Ausgestaltung des Abnahmeverfahrens ist auf §§ 10 Nr. 1 und 5 AGBG und die hierzu von der Rechtsprechung entwickelten Grundsätze Rücksicht zu nehmen, wie anhand einer Auswahl von Vertragsmustern gezeigt werden soll

Grey wolf genomic history reveals a dual ancestry of dogs

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canisfamiliaris) lived(1-8). Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT8840,000-30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.Peer reviewe

The history of Coast Salish “woolly dogs” revealed by ancient genomics and Indigenous Knowledge

Ancestral Coast Salish societies in the Pacific Northwest kept long-haired “woolly dogs” that were bred and cared for over millennia. However, the dog wool–weaving tradition declined during the 19th century, and the population was lost. In this study, we analyzed genomic and isotopic data from a preserved woolly dog pelt from “Mutton,” collected in 1859. Mutton is the only known example of an Indigenous North American dog with dominant precolonial ancestry postdating the onset of settler colonialism. We identified candidate genetic variants potentially linked with their distinct woolly phenotype. We integrated these data with interviews from Coast Salish Elders, Knowledge Keepers, and weavers about shared traditional knowledge and memories surrounding woolly dogs, their importance within Coast Salish societies, and how colonial policies led directly to their disappearance

The effect of structural variation on crossover positioning in Arabiopsis thaliana

One of the advantages of sexual reproduction is the possibility of forming new combinations of alleles through crossovers (COs) that swap portions of the maternal and paternal homologous chromosomes during meiosis, making new trait combinations available for natural selection. The rate of CO formation and the locations of CO events can therefore affect the co-inheritance of traits. Although several factors that influence CO rates and distributions have been identified, detailed knowledge of how the CO landscape is established remains superficial. This is largely because characterizing the CO landscape has traditionally been laborious and imprecise. In this study, we engineered cost-effective methods for performing high-throughput sequencing on large populations of recombinant individuals to generate precise CO maps. Using this approach, we examined the influence of large- and small-scale genomic structural variations on CO frequency and positioning by generating a CO map from over 2000 individuals of an F2 population derived from two Arabidopsis thaliana accessions with high-quality reference genomes: Col and Ler. With these data, we were able to characterize a landscape of over 15,000 CO events within a single F2 cross, representing the densest CO map available for a higher eukaryote. We examined the frequency of COs within and around inversions, insertions, deletions, translocations, and tandem copy number variations. COs occurred rarely within these structural variants, but CO rates were often slightly elevated in the flanking regions. Other hypervariable regions of the genome, such as disease resistance gene clusters, exhibited both high and low CO rates. COs were strongly associated with regions of open chromatin. We conclude that COs are generally suppressed within regions containing structural variation, but that this effect does not depend on the size of the variant region and is only marginally affected by the variant type

An Ultra High-Density Arabidopsis thaliana Crossover Map That Refines the Influences of Structural Variation and Epigenetic Features

Many environmental, genetic, and epigenetic factors are known to affect the frequency and positioning of meiotic crossovers (COs). Suppression of COs by large, cytologically visible inversions and translocations has long been recognized, but relatively little is known about how smaller structural variants (SVs) affect COs. To examine fine-scale determinants of the CO landscape, including SVs, we used a rapid, cost-effective method for high-throughput sequencing to generate a precise map of >17,000 COs between the Col-0 and Ler-0 accessions of Arabidopsis thaliana COs were generally suppressed in regions with SVs, but this effect did not depend on the size of the variant region, and was only marginally affected by the variant type. CO suppression did not extend far beyond the SV borders and CO rates were slightly elevated in the flanking regions. Disease resistance gene clusters, which often exist as SVs, exhibited high CO rates at some loci, but there was a tendency toward depressed CO rates at loci where large structural differences exist between the two parents. Our high-density map also revealed in fine detail how CO positioning relates to genetic (DNA motifs) and epigenetic (chromatin structure) features of the genome. We conclude that suppression of COs occurs over a narrow region spanning large- and small-scale SVs, representing an influence on the CO landscape in addition to sequence and epigenetic variation along chromosomes