Jamie Sherman

Vernalization, the requirement of a long exposure to low temperatures to induce flowering, is an essential adaptation of plants to cold winters. We have shown recently that the vernalization gene VRN-1 from diploid wheat Triticum monococcum is the meristem identity gene APETALA1, and that deletions in its promoter were associated with spring growth habit. In this study, we characterized the allelic variation at the VRN-1 promoter region in polyploid wheat. The Vrn-A1a allele has a duplication including the promoter region. Each copy has similar foldback elements inserted at the same location and is flanked by identical host direct duplications. This allele was found in more than half of the hexaploid varieties but not among the tetraploid lines analyzed here. The Vrn-A1b allele has two mutations in the HDD region and a 20-bp deletion in the 5′ UTR compared with the winter allele. The Vrn-A1b allele was found in both tetraploid and hexaploid accessions but at a relatively low frequency. Among the tetraploid wheat accessions, we found two additional alleles with 32 bp and 54 bp deletions that included the HDD region. We found no size polymorphisms in the promoter region among the winter wheat varieties. The dominant Vrn-A1 allele from two spring varieties from Afghanistan and Egypt and all the dominant Vrn-B1 and Vrn-D1 alleles included in this study showed no differences from their respective recessive alleles in promoter sequences. Based on these results, we concluded that the VRN-1 genes should have additional regulatory sites outside the promoter region studied here. © Springer-Verlag 2004.

Growth habit varies among accessions of hexaploid wheat. The winter habit genotype requires a cold treatment to induce flowering and is generally planted in the fall. Spring habit genotypes flower in the absence of a vernalization treatment. Spring habit is conferred by a dominant allele at any of the three VRN-1 loci, but varieties carrying the VRN-A1 locus are the most frequent and usually flower earlier. To facilitate selection in populations segregating at the VRN-A1 locus and to assist in genotyping wheat accessions of unknown VRN-1 composition, a PCR-based marker for growth habit would be useful. The VRN-A1 gene was recently cloned allowing for the development of markers for growth habit. In this report, we designed primer sets specific for the VRN-A1 locus, and used them to amplify an 810-bp segment of the VRN-A1 gene between intron 4 and exon 8 from 40 spring wheat lines and 37 winter wheat lines. Three diagnostic nucleotide changes were identified that differentiated the dominant Vrn-A1 and recessive vrn-A1 alleles in 75 out of the 77 genotypes analyzed in this study. One of these differences resulted in the presence of an additional AciI restriction site in the allele for spring growth habit. This difference was exploited to develop a cleavage amplification polymorphic sequence that can be used to determine the allelic state at VRN-A1 in germplasm collections, and as a marker in backcross breeding projects. An additional pair of dominant markers was developed from a different polymorphism.

Algorithms are powerful because we invest in them the power to do things. With such promise, they can transform the ordinary, say snapshots along a robotic vacuum cleaner’s route, into something much more, such as a clean home. Echoing David Graeber’s revision of fetishism, we argue that this easy slip from technical capabilities to broader claims betrays not the “magic” of algorithms but rather the dynamics of their exchange. Fetishes are not indicators of false thinking, but social contracts in material form. They mediate emerging distributions of power often too nascent, too slippery or too disconcerting to directly acknowledge. Drawing primarily on 2016 ethnographic research with computer vision professionals, we show how faith in what algorithms can do shapes the social encounters and exchanges of their production. By analyzing algorithms through the lens of fetishism, we can see the social and economic investment in some people’s labor over others. We also see everyday opportunities for social creativity and change. We conclude that what is problematic about algorithms is not their fetishization but instead their stabilization into full-fledged gods and demons – the more deserving objects of critique.