The U.S. Culture Collection Network Lays the Foundation for Progress in Preservation of Valuable Microbial Resources.

The U.S. Culture Collection Network was formed in 2012 by a group of culture collection scientists and stakeholders in order to continue the progress established previously through efforts of an ad hoc group. The network is supported by a Research Coordination Network grant from the U.S. National Science Foundation (NSF) and has the goals of promoting interaction among collections, encouraging the adoption of best practices, and protecting endangered or orphaned collections. After prior meetings to discuss best practices, shared data, and synergy with genome programs, the network held a meeting at the U.S. Department of Agriculture (USDA)-Agricultural Research Service (ARS) National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, Colorado in October 2015 specifically to discuss collections that are vulnerable because of changes in funding programs, or are at risk of loss because of retirement or lack of funding. The meeting allowed collection curators who had already backed up their resources at the USDA NCGRP to visit the site, and brought collection owners, managers, and stakeholders together. Eight formal collections have established off-site backups with the USDA-ARS, ensuring that key material will be preserved for future research. All of the collections with backup at the NCGRP are public distributing collections including U.S. NSF-supported genetic stock centers, USDA-ARS collections, and university-supported collections. Facing the retirement of several pioneering researchers, the community discussed the value of preserving personal research collections and agreed that a mechanism to preserve these valuable collections was essential to any future national culture collection system. Additional input from curators of plant and animal collections emphasized that collections of every kind face similar challenges in developing long-range plans for sustainability.

Narrow genetic base shapes population structure and linkage disequilibrium in an industrial oilseed crop, Brassica carinata A. Braun.

Ethiopian mustard (Brassica carinata A. Braun) is an emerging sustainable source of vegetable oil, in particular for the biofuel industry. The present study exploited genome assemblies of the Brassica diploids, Brassica nigra and Brassica oleracea, to discover over 10,000 genome-wide SNPs using genotype by sequencing of 620 B. carinata lines. The analyses revealed a SNP frequency of one every 91.7 kb, a heterozygosity level of 0.30, nucleotide diversity levels of 1.31 × 10-05, and the first five principal components captured only 13% molecular variation, indicating low levels of genetic diversity among the B. carinata collection. Genome bias was observed, with greater SNP density found on the B subgenome. The 620 lines clustered into two distinct sub-populations (SP1 and SP2) with the majority of accessions (88%) clustered in SP1 with those from Ethiopia, the presumed centre of origin. SP2 was distinguished by a collection of breeding lines, implicating targeted selection in creating population structure. Two selective sweep regions on B3 and B8 were detected, which harbour genes involved in fatty acid and aliphatic glucosinolate biosynthesis, respectively. The assessment of genetic diversity, population structure, and LD in the global B. carinata collection provides critical information to assist future crop improvement.

Prostate high-dose-rate brachytherapy as salvage treatment of local failure after previous external or permanent seed irradiation for prostate cancer.

PURPOSE: To report our results in using high-dose-rate (HDR) brachytherapy for salvage of local-only failure, after either external beam radiation or permanent seed implant. METHODS AND MATERIALS: The data from 7 patients treated with salvage HDR brachytherapy at our institution was retrospectively reviewed. Information was gathered from chart review and prostate HDR specific questionnaires completed at followup visits. RESULTS: All 7 patients had local-only failure defined by transrectal biopsy. Median followup is 58 months (range, 27-63), with a 71% disease-free survival rate; median survival has not yet been reached. Two patients died of metastatic disease. There have been no further local failures. There has been no Grade 3 or higher rectal injuries. Five patients (71%) developed symptomatic urethral strictures; two previous seed failures developed incontinence with urethral necrosis, salvaged by placement of artificial sphincter or continent catheter channel. These results compare favorably to reported results with salvage permanent seed brachytherapy, prostatectomy, and cryotherapy. CONCLUSIONS: HDR brachytherapy as salvage of local-only failure after previous radiation has limited data reported to date. The disease control rates and complications of treatment compare very favorably with those reported using other modalities. This approach merits further investigation.

Molecular mapping of QTL alleles of Brassica oleracea affecting days to flowering and photosensitivity in spring Brassica napus.

Earliness of flowering and maturity are important traits in spring Brassica napus canola-whether grown under long- or short-day condition. By use of a spring B. napus mapping population carrying the genome content of B. oleracea and testing this population under 10 to 18 h photoperiod and 18 to 20 0C (day) temperature conditions, we identified a major QTL on the chromosome C1 affecting flowering time without being influenced by photoperiod and temperature, and a major QTL on C9 affecting flowering time under a short photoperiod (10 h); in both cases, the QTL alleles reducing the number of days to flowering in B. napus were introgressed from the late flowering species B. oleracea. Additive effect of the C1 QTL allele at 14 to18 h photoperiod was 1.1 to 2.9 days; however, the same QTL allele exerted an additive effect of 6.2 days at 10 h photoperiod. Additive effect of the C9 QTL at 10 h photoperiod was 2.8 days. These two QTL also showed significant interaction in the control of flowering only under a short-day (10 h photoperiod) condition with an effect of 2.3 days. A few additional QTL were also detected on the chromosomes C2 and C8; however, none of these QTL could be detected under all photoperiod and temperature conditions. BLASTn search identified several putative flowering time genes on the chromosomes C1 and C9 and located the physical position of the QTL markers in the Brassica genome; however, only a few of these genes were found within the QTL region. Thus, the molecular markers and the genomic regions identified in this research could potentially be used in breeding for the development of early flowering photoinsensitive B. napus canola cultivars, as well as for identification of candidate genes involved in flowering time variation and photosensitivity.

Microarray analysis of bast fibre producing tissues of Cannabis sativa identifies transcripts associated with conserved and specialised processes of secondary wall development.

The mechanisms underlying bast fibre differentiation in hemp (Cannabis sativa L.) are largely unknown. We hybridised a cDNA microarray with RNA from fibre enriched tissues extracted at three different positions along the stem axis. Accordingly, we identified transcripts that were enriched in tissues in which phloem fibres were elongating or undergoing secondary wall thickening. These results were consistent with a dynamic pattern of cell wall deposition involving tissue specific expression of a large set of distinct glycosyltransferases and glycosylhydrolases apparently acting on polymers containing galactans, mannans, xylans, and glucans, as well as raffinose-series disaccharides. Putative arabinogalactan proteins and lipid transfer proteins were among the most highly enriched transcripts in various stem segments, with different complements of each expressed at each stage of development. We also detected stage-specific expression of brassinosteroid-related transcripts, various transporters, polyamine and phenylpropanoid related genes, and seven putative transcription factors. Finally, we observed enrichment of many transcripts with unknown biochemical function, some of which had been previously implicated in fibre development in poplar or cotton. Together these data complement and extend existing biochemical models of bast fibre development and secondary wall deposition and highlight uncharacterised, but conserved, components of these processes.

An approach to predict risks to wildlife populations from mercury and other stressors.

Ecological risk assessments for mercury (Hg) require measured and modeled information on exposure and effects. While most of this special issue focuses on the former, i.e., distribution and fate of Hg within aquatic food webs, this paper describes an approach to predict the effects of dietary methylmercury (CH3Hg) on populations of piscivorous birds. To demonstrate this approach, the U.S. Environmental Protection Agency's National Health and Environmental Effects Research Laboratory (U.S. EPA NHEERL) is working cooperatively with environmental and conservation organizations to develop models to predict CH3Hg effects on populations of the common loon, Gavia immer. Specifically, a biologically-based toxicokinetic model is being used to extrapolate CH3Hg effects on the reproduction of a tested bird species, the American kestrel (Falco sparverius), to the loon. Population models are being used to incorporate stressor effects on survival and reproduction into projections of loon population effects. Finally, habitat and spatially-explicit population models are being used to project results spatially, assess the relative importance of CH3Hg and non-chemical stressors, and produce testable predictions of the effects of biologically-available Hg on loon populations. This stepwise process provides an integrated approach to estimate the impact on wildlife populations of regulations that limit atmospherically-distributed Hg, and to develop risk-based population-level regulatory criteria.