Age, experience, social goals, and engagement with research scientists may promote innovation in ecological restoration

Innovation in ecological restoration is necessary to achieve the ambitious targets established in United Nations conventions and other global restoration initiatives. Innovation is also crucial for navigating uncertainties in repairing and restoring ecosystems, and thus practitioners often develop innovations at project design and implementation stages. However, innovation in ecological restoration can be hindered by many factors (e.g., time and budget constraints, and project complexity). Theory and research on innovation has been formally applied in many fields, yet explicit study of innovation in ecological restoration remains nascent. To assess the use of innovation in restoration projects, including its drivers and inhibitors, we conducted a social survey of restoration practitioners in the United States. Specifically, we assessed relationships between project-based innovation and traits of the individual practitioner (including, for example, age, gender, experience); company (including, for example, company size and company's inclusion of social goals); project (including, for example, complexity and uncertainty); and project outcomes (such as completing the project on time/on budget and personal satisfaction with the work). We found positive relationships between project-based innovation and practitioner traits (age, gender, experience, engagement with research scientists), one company trait (company's inclusion of social goals in their portfolio), and project traits (project complexity and length). In contrast, two practitioner traits, risk aversion and the use of industry-specific information, were negatively related to project-based innovation. Satisfaction with project outcomes was positively correlated with project-based innovation. Collectively, the results provide insights into the drivers and inhibitors of innovation in restoration and suggest opportunities for research and application.

Scientific foundations for an ecosystem goal, milestones and indicators for the post-2020 global biodiversity framework

Despite substantial conservation efforts, the loss of ecosystems continues globally, along with related declines in species and nature's contributions to people. An effective ecosystem goal, supported by clear milestones, targets and indicators, is urgently needed for the post-2020 global biodiversity framework and beyond to support biodiversity conservation, the UN Sustainable Development Goals and efforts to abate climate change. Here, we describe the scientific foundations for an ecosystem goal and milestones, founded on a theory of change, and review available indicators to measure progress. An ecosystem goal should include three core components: area, integrity and risk of collapse. Targets-the actions that are necessary for the goals to be met-should address the pathways to ecosystem loss and recovery, including safeguarding remnants of threatened ecosystems, restoring their area and integrity to reduce risk of collapse and retaining intact areas. Multiple indicators are needed to capture the different dimensions of ecosystem area, integrity and risk of collapse across all ecosystem types, and should be selected for their fitness for purpose and relevance to goal components. Science-based goals, supported by well-formulated action targets and fit-for-purpose indicators, will provide the best foundation for reversing biodiversity loss and sustaining human well-being.

Alpine treeline ecotones are potential refugia for a montane pine species threatened by bark beetle outbreaks

Warming-induced mountain pine beetle (Dendroctonus ponderosae; MPB) outbreaks have caused extensive mortality of whitebark pine (Pinus albicaulis; WBP) throughout the species' range. In the highest mountains where WBP occur, they cross alpine treeline ecotones (ATEs) where growth forms transition from trees to shrub-like krummholz, some of which survived recent MPB outbreaks. This observation motivated the hypothesis that ATEs are refugia for WBP because krummholz growth forms escape MPB attack and have the potential to produce viable seed. To test this hypothesis, we surveyed WBP mortality along transects from the ATE edge (locally highest krummholz WBP) downslope into the forest and, to distinguish if survival mechanisms are unique to ATEs, across other forest ecotones (OFEs) from the edge of WBP occurrence into the forest. We replicated this design at 10 randomly selected sites in the U.S. Northern Rocky Mountains. We also surveyed reproduction in a subset of ATE sites. Mortality was nearly absent in upper ATEs (mean ± SE percent dead across all sites of 0.03% ± 0.03% 0-100 m from the edge and 14.1% ± 1.7% 100-500 m from the edge) but was above 20% along OFEs (21.4 ± 5.2% 0-100 m and 32.4 ± 2.7% 100-500 m from the edge). We observed lower reproduction in upper ATEs (16 ± 9.9 cones/ha and 12.9 ± 5.3 viable seeds/cone 0-100 m from the edge) compared to forests below (317.1 ± 64.4 cones/ha and 32.5 ± 2.5 viable seeds/cone 100-500 m from the edge). Uniquely high WBP survival supports the hypothesis that ATEs serve as refugia because krummholz growth forms escape MPB attack. However, low reproduction suggests ATE refugia function over longer time periods. Beyond our WBP system, we propose that plant populations in marginal environments are candidate refugia if distinct phenotypes result in reduced disturbance impacts.

Integrating Subjective and Objective Dimensions of Resilience in Fire-Prone Landscapes

Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives and definitions of resilience is a complex and often unrecognized challenge to applying resilience concepts to social-ecological systems (SESs) management. Using wildfire as an example, we develop a framework to expose and separate two important dimensions of resilience: the inherent properties that maintain structure, function, or states of an SES and the human perceptions of desirable or valued components of an SES. In doing so, the framework distinguishes between value-free and human-derived, value-explicit dimensions of resilience. Four archetypal scenarios highlight that ecological resilience and human values do not always align and that recognizing and anticipating potential misalignment is critical for developing effective management goals. Our framework clarifies existing resilience theory, connects literature across disciplines, and facilitates use of the resilience concept in research and land-management applications.

Importance of considering soils in seed transfer zone development: evidence from a study of the native Bromus marginatus

Seed transfer zones, which define the geographical relationship between adaptive traits and environmental factors, are increasingly used to determine the source populations that can be combined in restoration and revegetation. Climatic variables have been the most commonly used environmental data in transfer zone development, even though soils are also a primary selective force on plants. We assessed the importance of including soils in seed transfer zones using Bromus marginatus, a native grass used for restoration and revegetation in the western United States, as an example. Seeds were collected from 64 populations across Montana and Idaho and grown in a common garden for two years. We assessed among-population variation based on 11 traits related to germination rate, plant size, vigor, inflorescence number, survival, and carbon isotope discrimination (∆¹³ ), and used this variation to develop seed transfer zone maps using two approaches: (1) a conventional approach, using only climatic variables (climate only) and (2) an expanded approach that included soils and climatic variables (soils + climate). The most influential drivers of trait variation were factors related to soil water availability: soil order, available water content (AWC), and organic carbon levels. Populations from areas with andic soils, which have high soil AWC and soil organic carbon, had low germination, limited first-year survival, low ∆¹³ , and small seeds. Growing season length and winter temperatures were also predictive of trait variation. In comparison to climate-only models, soils + climate models explained 11% more variance (120% relative increase) for ∆¹³ and an average of 4.5% more (27% relative increase) for growth traits and survival. The transfer zone map developed using soils + climate differed from the climate-only map in both spatial pattern of ecotypic variation and number of transfer zones; the soils + climate map had more zones and a higher proportion of small (<4 km² ) transfer zone patches, while the climate-only map had more large patches >37 km² . Including soils in transfer zone development may identify adaptive trait variation that is obscured by large-scale differences in climate and could improve plant materials used for ecosystem management.

Visions of Restoration in Fire-Adapted Forest Landscapes: Lessons from the Collaborative Forest Landscape Restoration Program

Collaborative approaches to natural resource management are becoming increasingly common on public lands. Negotiating a shared vision for desired conditions is a fundamental task of collaboration and serves as a foundation for developing management objectives and monitoring strategies. We explore the complex socio-ecological processes involved in developing a shared vision for collaborative restoration of fire-adapted forest landscapes. To understand participant perspectives and experiences, we analyzed interviews with 86 respondents from six collaboratives in the western U.S., part of the Collaborative Forest Landscape Restoration Program established to encourage collaborative, science-based restoration on U.S. Forest Service lands. Although forest landscapes and group characteristics vary considerably, collaboratives faced common challenges to developing a shared vision for desired conditions. Three broad categories of challenges emerged: meeting multiple objectives, collaborative capacity and trust, and integrating ecological science and social values in decision-making. Collaborative groups also used common strategies to address these challenges, including some that addressed multiple challenges. These included use of issue-based recommendations, field visits, and landscape-level analysis; obtaining support from local agency leadership, engaging facilitators, and working in smaller groups (sub-groups); and science engagement. Increased understanding of the challenges to, and strategies for, developing a shared vision of desired conditions is critical if other collaboratives are to learn from these efforts.

Can local adaptation research in plants inform selection of native plant materials? An analysis of experimental methodologies

Local adaptation is used as a criterion to select plant materials that will display high fitness in new environments. A large body of research has explored local adaptation in plants, however, to what extent findings can inform management decisions has not been formally evaluated. We assessed local adaptation literature for six key experimental methodologies that have the greatest effect on the application of research to selecting plant materials for natural resource management: experimental environment, response variables, maternal effects, intraspecific variation, selective agents, and spatial and temporal variability. We found that less than half of experiments used reciprocal transplants or natural field conditions, which are both informative for revegetation and restoration. Population growth rate was rarely (5%) assessed, and most studies measured only single generations (96%) and ran for less than a year. Emergence and establishment are limiting factors in successful revegetation and restoration, but the majority of studies measured later life‐history stages (66%). Additionally, most studies included limited replication at the population and habitat levels and tested response to single abiotic selective factors (66%). Local adaptation research should be cautiously applied to management; future research could use alternative methodologies to allow managers to directly apply findings.

Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes

Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.

Wildland fire as a self-regulating mechanism: the role of previous burns and weather in limiting fire progression

Theory suggests that natural fire regimes can result in landscapes that are both self-regulating and resilient to fire. For example, because fires consume fuel, they may create barriers to the spread of future fires, thereby regulating fire size. Top-down controls such as weather, however, can weaken this effect. While empirical examples demonstrating this pattern-process feedback between vegetation and fire exist, they have been geographically limited or did not consider the influence of time between fires and weather. The availability of remotely sensed data identifying fire activity over the last four decades provides an opportunity to explicitly quantify-the ability of wildland fire to limit the progression of subsequent fire. Furthermore, advances in fire progression mapping now allow an evaluation of how daily weather as a top-down control modifies this effect. In this study, we evaluated the ability of wildland fire to create barriers that limit the spread of subsequent fire along a gradient representing time between fires in four large study areas in the western United States. Using fire progression maps in conjunction with weather station data, we also evaluated the influence of daily weather. Results indicate that wildland fire does limit subsequent fire spread in all four study areas, but this effect decays over time; wildland fire no longer limits subsequent fire spread 6-18 years after fire, depending on the study area. We also found that the ability of fire to regulate, subsequent fire progression was substantially reduced under extreme conditions compared to moderate weather conditions in all four study areas. This study increases understanding of the spatial feedbacks that can lead to self-regulating landscapes as well as the effects of top-down controls, such as weather, on these feedbacks. Our results will be useful to managers who seek to restore natural fire regimes or to exploit recent burns when managing fire.

Assessing the performance of sampling designs for measuring the abundance of understory plants

Accurate estimation of responses of understory plants to disturbance is essential for understanding the efficacy of management activities. However, the ability to assess changes in the abundance of plants may be hampered by inappropriate sampling methodologies. Conventional methods for sampling understory plants may be precise for common species but may fail to adequately characterize abundance of less common species. We tested conventional (modified Whittaker plots and Daubenmire and point-line intercept transects) and novel (strip adaptive cluster sampling [SACS]) approaches to sampling understory plants to determine their efficacy for quantifying abundance on control and thinned-and-burned treatment units in Pinus ponderosa forests in western Montana, USA. For species grouped by growth-form and for common species, all three conventional designs were capable of estimating cover with a 50% relative margin of error with reasonable sample sizes (3-36 replicates for growth-form groups; 8-14 replicates for common species); however, increasing precision to 25% relative margin of error required sample sizes that may be infeasible (11-143 replicates for growth-form groups; 28-54 replicates for common species). All three conventional designs required enormous sample sizes to estimate cover of nonnative species as a group (29-60 replicates) and of individual less common species (62-118 replicates), even with a 50% relative margin of error. SACS was the only design that efficiently sampled less common species, requiring only 6-11% as many replicates relative to conventional designs. Conventional designs may not be effective for estimating abundance of the majority of forest understory plants, which are typically patchily distributed with low abundance, or of newly establishing nonnative plants. Novel methods such as SACS should be considered in investigations when cover of these species is of concern.

Leadership: a new frontier in conservation science

Leadership is a critical tool for expanding the influence of conservation science, but recent advances in leadership concepts and practice remain underutilized by conservation scientists. Furthermore, an explicit conceptual foundation and definition of leadership in conservation science are not available in the literature. Here we drew on our diverse leadership experiences, our reading of leadership literature, and discussions with selected conservation science leaders to define conservation-science leadership, summarize an exploratory set of leadership principles that are applicable to conservation science, and recommend actions to expand leadership capacity among conservation scientists and practitioners. We define 2 types of conservation-science leadership: shaping conservation science through path-breaking research, and advancing the integration of conservation science into policy, management, and society at large. We focused on the second, integrative type of leadership because we believe it presents the greatest opportunity for improving conservation effectiveness. We identified 8 leadership principles derived mainly from the "adaptive leadership" literature: recognize the social dimension of the problem; cycle frequently through action and reflection; get and maintain attention; combine strengths of multiple leaders; extend your reach through networks of relationships; strategically time your effort; nurture productive conflict; and cultivate diversity. Conservation scientists and practitioners should strive to develop themselves as leaders, and the Society for Conservation Biology, conservation organizations, and academia should support this effort through professional development, mentoring, teaching, and research.

Implementation of National Fire Plan treatments near the wildland-urban interface in the western United States

Because of increasing concern about the effects of catastrophic wildland fires throughout the western United States, federal land managers have been engaged in efforts to restore historical fire behavior and mitigate wildfire risk. During the last 5 years (2004-2008), 44,000 fuels treatments were implemented across the western United States under the National Fire Plan (NFP). We assessed the extent to which these treatments were conducted in and near the wildland-urban interface (WUI), where they would have the greatest potential to reduce fire risk in neighboring homes and communities. Although federal policies stipulate that significant resources should be invested in the WUI, we found that only 3% of the area treated was within the WUI, and another 8% was in an additional 2.5-km buffer around the WUI, totaling 11%. Only 17% of this buffered WUI is under federal ownership, which significantly limits the ability of federal agencies to implement fire-risk reduction treatments near communities. Although treatments far from the WUI may have some fire mitigation benefits, our findings suggest that greater priority must be given to locating treatments in and near the WUI, rather than in more remote settings, to satisfy NFP goals of reducing fire risk to communities. However, this may require shifting management and policy emphasis from public to private lands.

Thinning and burning result in low-level invasion by nonnative plants but neutral effects on natives

Many historically fire-adapted forests are now highly susceptible to damage from insects, pathogens, and stand-replacing fires. As a result, managers are employing treatments to reduce fuel loadings and to restore the structure, species, and processes that characterized these forests prior to widespread fire suppression, logging, and grazing. However, the consequences of these activities for understory plant communities are not well understood. We examined the effects of thinning and prescribed fire on plant composition and diversity in Pinus ponderosa forests of eastern Washington (USA). Data on abundance and richness of native and nonnative plants were collected in 70 stands in the Colville, Okanogan, and Wenatchee National Forests. Stands represented one of four treatments: thinning, burning, thinning followed by burning, or control; treatments had been conducted 3-19 years before sampling. Multi-response permutation procedures revealed no significant effect of thinning or burning on understory plant composition. Similarly, there were no significant differences among treatments in cover or richness of native plants. In contrast, nonnative plants showed small, but highly significant, increases in cover and richness in response to both thinning and burning. In the combined treatment, cover of nonnative plants averaged 2% (5% of total plant cover) but did not exceed 7% (16% of total cover) at any site. Cover and richness of nonnative herbs showed small increases with intensity of disturbance and time since treatment. Nonnative plants were significantly less abundant in treated stands than on adjacent roadsides or skid trails, and cover within these potential source areas explained little of the variation in abundance within treated stands. Although thinning and burning may promote invasion of nonnative plants in these forests, our data suggest that their abundance is limited and relatively stable on most sites.

Short-term effects of timber harvest and forest edges on ground-layer mosses and liverworts

Limited information exists on the effects of forest management practices on bryophytes, despite their importance to forest ecosystems. We examined short-term responses of ground-layer bryophytes to logging disturbance and creation of edges in mature Pseudotsuga forests of western Washington (USA). The abundance and richness of species were measured in four 1-ha forest aggregates (patches of intact forest) and in surrounding logged areas before and after structural retention harvests. One year after treatment, species richness, total cover, and frequency of most moss and liverwort taxa declined within harvest areas. Within forest aggregates, mosses did not show significant edge effects; however, richness and abundance of liverworts declined with proximity to the aggregate edge. Our results suggest that, over short time frames, 1-ha-sized aggregates are sufficient to maintain most common mosses through structural retention harvests but are not large enough to prevent declines or losses of liverworts. Thus, current standards for structural retention, which allow for aggregates as small as 0.2 ha, may be inadequate to retain the diversity and abundance of species found in mature, undisturbed forests.Key words: bryophyte, edge effects, forest borders, forest management, logging effects, structural retention harvest.

Trends in antihypertensive drug therapy of ambulatory patients by US office-based physicians

This study assessed trends from 1980 to 1995 in ambulatory patients' antihypertensive drug therapy by US office-based physicians for visits in which hypertension was the principal diagnosis and compared these trends with the respective guidelines given in 5 Joint National Committee (JNC) Reports on Detection, Evaluation, and Treatment of High Blood Pressure published around the same time period. Data from the National Center for Health Statistics' National Ambulatory Medical Care Surveys for 1980, 1985, 1990, and 1995 were used. From 1980 to 1995, there was no significant trend in the percentage of hypertension visits that did not mention any antihypertensive drug (20% to 27%). Further analyses focused on those hypertension visits in which at least 1 antihypertensive drug was used. Across the years, antihypertensive drug visits mentioning calcium channel blockers or ACE inhibitors significantly increased; those noting diuretics significantly decreased. However, in 1995, antihypertensive drug visits that included a diuretic and/or a beta-adrenergic blocker equalled 53%; these are the antihypertensive drug classes preferred by the JNC V. Physician antihypertensive drug prescribing was generally consistent with the basic antihypertensive drug guidelines of the JNC reports.

State-space modeling of the relationship between air quality and mortality

A portion of a population is assumed to be at risk, with the mortality hazard varying with atmospheric conditions including total suspended particulates (TSP). This at-risk population is not observed and the hazard function is unknown; we wish to estimate these from mortality count and atmospheric variables. Consideration of population dynamics leads to a state-space representation, allowing the Kalman Filter (KF) to be used for estimation. A harvesting effect is thus implied; high mortality is followed by lower mortality until the population is replenished by new arrivals. The model is applied to daily data for Philadelphia, PA, 1973-1990. The estimated hazard function rises with the level of TSP and at extremes of temperature and also reflects a positive interaction between TSP and temperature. The estimated at-risk population averages about 480 and varies seasonally. We find that lags of TSP are statistically significant, but the presence of negative coefficients suggests their role may be partially statistical rather than biological. In the population dynamics framework, the natural metric for health damage from air pollution is its impact on life expectancy. The range of hazard rates over the sample period is 0.07 to 0.085, corresponding to life expectancies of 14.3 and 11.8 days, respectively.

The genome sequence of Drosophila melanogaster

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

A BAC-based physical map of the major autosomes of Drosophila melanogaster

We constructed a bacterial artificial chromosome (BAC)-based physical map of chromosomes 2 and 3 of Drosophila melanogaster, which constitute 81% of the genome. Sequence tagged site (STS) content, restriction fingerprinting, and polytene chromosome in situ hybridization approaches were integrated to produce a map spanning the euchromatin. Three of five remaining gaps are in repeat-rich regions near the centromeres. A tiling path of clones spanning this map and STS maps of chromosomes X and 4 was sequenced to low coverage; the maps and tiling path sequence were used to support and verify the whole-genome sequence assembly, and tiling path BACs were used as templates in sequence finishing.

Comparative genomics of the eukaryotes

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

Medication therapy in ambulatory medical care. National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, 1992

OBJECTIVES

This report describes medications provided or prescribed during ambulatory medical care visits in 1992. Total ambulatory care medication therapy combines data from office-based physicians, hospital outpatient departments (OPD's), and hospital emergency departments (ED's). Drug therapy is described along three dimensions: number of drugs provided or prescribed (drug mention), whether a visit had any drugs mentioned (drug visit), and average number of drugs mentioned per 100 visits (drug mention rate). Utilization in ambulatory care settings is compared in terms of patient, drug, provider, and visit characteristics.

METHODS

Annual use of medication therapy was determined using data collected in the 1992 National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS). NAMCS includes office visits to nonfederal physicians principally engaged in office practice. The target universe of NHAMCS includes visits to ED's and OPD's of non-Federal, short-stay, or general hospitals. Sample data were weighted to produce annual estimates. Drug mentions are defined as the number of drugs mentioned on the patient record from.

RESULTS

An estimated 1.1 billion medications were provided or prescribed at ambulatory care visits in 1992. The setting with the greatest percent of visits with medication therapy was the ED; OPD's had the lowest percent with medications. Patients at the ED were provided more pain relief type drugs. The rate of drug mentions and percent of visits with medications were significantly higher in OPD clinics of general medicine and pediatrics compared with other types of OPD clinics. In office-based settings, physicians specializing in cardiovascular diseases were most likely to prescribe medications. Also, cardiovascular-renal type drugs accounted for the largest percent of office-based drug mentions. Visits with illness diagnoses are most likely to receive medication therapy. Trend data comparing 1980 to 1992 office-based mentions showed significant changes on several characteristics: single-ingredient drug status, physician specialty, and patient age.

CONCLUSIONS

The profile of patients using office- and hospital-based ambulatory care settings are quite different as is the case-mix of conditions. These differences play an important role in medications utilized. The aging of the U.S. population from 1980 to 1992 appeared to have significant effects on several drug mention characteristics.

Cytogenetic analysis of chromosome region 89A of Drosophila melanogaster: isolation of deficiencies and mapping of Po, Aldox-1 and transposon insertions

We have initiated a cytogenetic analysis of chromosome region 89A of Drosophila melanogaster by isolating a set of radiation-induced mutations causing loss of function of P[(w)B]1-1, a transposon bearing the white locus inserted in 89A. Complementation tests and cytological examination of these chromosomes identified four new deficiencies (Df(3R)Po2, Df(3R)Po3, Df(3R)Po4 and Df(3R)c(3)G2). The new deficiencies and three previously identified deficiencies (Df(3R)sbd26, Df(3R)sbd45 and Df(3R)sbd105) were tested for the ability to complement mutations in the enzyme loci Po and Aldox-1, the indirect flight muscle genes Tm2 and act88F, the morphological mutations jvl, sbd2 and Sb, the vital loci srp, pnr and mor, and a newly described vital locus l(3)89Aa. We also used linkage analysis to determine the order and relative positions of P[(w)B]1-1 and an independent transposon insertion, P[w+]21, with respect to cv-c, Po, Aldox-1 and sbd2. Cytological examination of the deficiencies and analysis of the transformed lines by in situ hybridization permits the correlation of genetically defined regions with specific polytene chromosome bands. A revised cytogenetic map of the 88F-89B region is presented.

Timing of mitotic chromosome loss caused by the ncd mutation of Drosophila melanogaster

We studied the timing of mitotic loss of maternally and paternally derived chromosomes among the progeny of Drosophila melanogaster females homozygous for an amorphic mutation in ncd, a gene encoding a kinesin-like protein. In order to determine the division at which chromosome loss occurs, we estimated the fraction of XO nuclei resulting from X chromosome loss by scoring the phenotype of 47 adult cuticular landmarks in 160 XX-XO mosaics (gynandromorphs) derived from maternal X chromosome loss, and 33 gynandromorphs derived from paternal X chromosome loss. The results show that while most of the mitotic loss of maternally derived chromosomes occurs at the first cleavage division, the mitotic loss of paternally derived chromosomes occurs only at the second and later divisions. This means that paternally derived chromosomes are immune from the effects of ncd prior to karyogamy, which occurs after the first cleavage division. We discuss the implications of these results for the function of the ncd gene product and for other kinesin-like proteins in Drosophila.

Genetic analysis of the claret locus of Drosophila melanogaster

The claret (ca) locus of Drosophila melanogaster comprises two separately mutable domains, one responsible for eye color and one responsible for proper disjunction of chromosomes in meiosis and early cleavage divisions. Previously isolated alleles are of three types: (1) alleles of the claret (ca) type that affect eye color only, (2) alleles of the claret-nondisjunctional (cand) type that affect eye color and chromosome behavior, and (3) a meiotic mutation, non-claret disjunctional (ncd), that affects chromosome behavior only. In order to investigate the genetic structure of the claret locus, we have isolated 19 radiation-induced alleles of claret on the basis of the eye color phenotype. Two of these 19 new alleles are of the cand type, while 17 are of the ca type, demonstrating that the two domains do not often act as a single target for mutagenesis. This suggests that the two separately mutable functions are likely to be encoded by separate or overlapping genes rather than by a single gene. One of the new alleles of the cand type is a chromosome rearrangement with a breakpoint at the position of the claret locus. If this breakpoint is the cause of the mutant phenotype and there are no other mutations associated with the rearrangement, the two functions must be encoded by overlapping genes.

Assimilation of cholesterol by Lactobacillus acidophilus

Considerable variation was found among strains of Lactobacillus acidophilus isolated from the fecal flora of pigs with regard to the ability to grow well in the presence of bile and to assimilate cholesterol from a laboratory growth medium. The uptake of cholesterol occurred only when the culture(s) was growing in the presence of bile under anaerobic conditions. Consumption of L. acidophilus RP32, which was selected for its ability to grow well in the presence of bile and to assimilate cholesterol from the laboratory medium, significantly inhibited increases in serum cholesterol levels of pigs (P less than 0.05) fed a high-cholesterol diet. Consumption of L. acidophilus P47, which was selected for its ability to grow in the presence of bile and lack of ability to remove cholesterol from the growth medium, failed to have a similar effect. This indicates that certain strains of L. acidophilus act directly on cholesterol in the gastrointestinal tract, and thus may be beneficial in reducing serum cholesterol levels.