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Candida albicans is the single, most frequently isolated human fungal pathogen. As with most fungal pathogens, the factors which contribute to pathogenesis in C. albicans are not known, despite more than a decade of molecular genetic analysis. Candida albicans was thought to be asexual until the discovery of the MTL loci homologous to the mating type (MAT) loci in Saccharomyces cerevisiae led to the demonstration that mating is possible. Using Candida albicans mutants in genes likely to be involved in mating, we analysed the process to determine its similarity to mating in Saccharomyces cerevisiae. We examined disruptions of three of the genes in the MAPK pathway which is involved in filamentous growth in both S. cerevisiae and C. albicans and is known to control pheromone response in the former fungus. Disruptions in HST7 and CPH1 blocked mating in both MTLa and MTL(alpha) strains, whereas disruptions in STE20 had no effect. A disruption in KEX2, a gene involved in processing the S. cerevisiae pheromone Mf(alpha), prevented mating in MTL(alpha) but not MTLa cells, whereas a disruption in HST6, the orthologue of the STE6 gene which encodes an ABC transporter responsible for secretion of the Mfa pheromone, prevented mating in MTLa but not in MTL(alpha) cells. Disruption of two cell wall genes, ALS1 and INT1, had no effect on mating, even though ALS1 was identified by similarity to the S. cerevisiae sexual agglutinin, SAG1. The results reveal that these two diverged yeasts show a surprising similarity in their mating processes.

Fruit set in the muscadine grape (Vitis rotundifolia Michx.) depended on insect cross-pollination, although flowers were well adapted for selfing. Pollinizer cultivars produced about half of their optimal fruit set when selfed, but cross-pollination was needed to reach an optimal fruit set of 33.7%. Eighty-one percent of the overall fruit set in pistillate vines was attributed to insect cross-pollination; wind played only a small role. Diminished fruit set and fewer seeds per berry occurred in cultivars receiving no effective cross-pollination. Components of fruit quality were not profoundly affected by the pollination treatments, although seed set and berry weight in pistillate cultivars was lower in the absence of cross-pollination. Parthenocarpy was rare, except in `Fry Seedless'. Muscadine production throughout the southeastern United States depends on cross-pollination by indigenous insects, particularly bees. To ensure consistently high yields, bees must have safe access to flowers and their nesting sites must be preserved.

Geographic isolation and habitat specialization has aided in the evolution and genetic integrity of the micropterid bass species of North America. Members of the genus Micropterus form a close natural unit with little morphologic and meristic variation. Our goals were to measure the genetic characteristics of and distances between six black bass species by using mitochondrial DNA analysis. Mitochondrial DNA restriction fragment length polymorphisms were examined in Guadalupe bass (M. treculi), largemouth bass (M. salmoides), shoal bass (M. cataractae), smallmouth bass (M. dolomieu), spotted bass (M. punctulatus), and Suwannee bass (M. notius), using 15 restriction endonucleases. The bluegill (Lepomis macrochirus) was used as an outgroup. The phylogeny inferred from Dollo parsimony cladistic analysis concurred with published results from allozyme analyses, yet it was inconsistent with published meristic analyses. Genetic distances between species ranged from 0.0659 to 0.2145, with the largemouth and Suwannee basses showing the greatest divergence from the other black basses. The Guadalupe, smallmouth, and spotted basses were most diverged from the bluegill. The black basses diverged over a broad time frame, with estimated black bass speciation occurring during late Miocene – early Pliocene (3.30–10.73 MYA).

Variation of the electrophoretic karyotype is common among clinical strains of Candida albicans and chromosome translocation is considered one of the causes of karyotypic variation. Such chromosome translocations may be a mechanism to confer phenotypic diversity on the imperfect fungus C. albicans. A clinical strain, TCH23, from a vaginal candidiasis patient shows distinct carbohydrate assimilation profile, serotype B, no chlamydospore formation and an atypical karyotype (Asakura et al., 1991). To examine the taxonomic relationship among C. albicans, Candida dubliniensis and this strain, we sequenced the internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA. The ITS1 sequence of TCH23 was identical with that of C. albicans but not of C. dubliniensis. Thus, strain TCH23 was classified as a variant of C. albicans with an atypical phenotype. The chromosomal DNAs of this strain were resolved into 13 bands on pulse-field gel electrophoresis (PFGE). Using DNA probes located at or near both ends of each chromosome of C. albicans, we investigated the chromosome organization of this strain. Referring to the SfiI map of C. albicans 1006 (Chu et al., 1993), we found that seven chromosomal DNA bands in strain TCH23 were reciprocal chromosome translocations. One homologue from chromosomes 1, 2 and 6 and both homologues from chromosomes 4 and 7 participated in these events. One translocation product was composed of three SfiI fragments, one each from chromosomes 2, 4 and 7. We deduced the breakpoints of chromosome translocation from the physical map of this strain; between 1J and 1J1, between 2A and 2U, both ends of 4F2, between 6C and 6O and both ends of 7F. Copyright © 2001 John Wiley & Sons, Ltd.

Although the diploid fungus Candida albicans , a human pathogen, has been thought to have no sexual cycle, it normally possesses mating-type–like orthologs ( MTL ) of both of the Saccharomyces cerevisiae mating-type genes ( MAT ) a and α. When strains containing only MTL a or MTL α were constructed by the loss of one homolog of chromosome 5, the site of the MTL loci, MTL a and MTL α strains mated, but like mating types did not. Evidence for mating included formation of stable prototrophs from strains with complementing auxotrophic markers; these contained both MTL alleles and molecular markers from both parents and were tetraploid in DNA content and mononucleate.

Poor patenting performance is often taken as a sign of low inventiveness. This article explores this belief by looking at the case of 19th-century Victoria, where the level of foreign patenting consistently grew at a much faster rate than that of local patenting. By mapping movements in both foreign and Australian revealed technological advantage in Victoria in this period, this article demonstrates that this faster rate of foreign patenting was due not to the technological weaknesses of the Australian colonies, but rather to the nature and timing of their economic development.

This paper uses patent data from Victoria to examine the roles played by skill and experience in Australian invention during the colonial era. In addition to identifying a broadening involvement of Australians in inventive activity in the second half of the nineteenth century, this paper also provides evidence which indicates that technological creativity in Australia in this period did not depend on either the existence of a body of highly skilled workers or major advances in the stock of knowledge of which only they were cognizant. Rather, common sense and the acquisition of basic practical skills appear to have been the only prerequisites for inventiveness. Given the widespread availability of such skills in the colonies, the article concludes that the supply of patentable ideas in nineteenth-century Australia must have been fairly elastic.

In Saccharomyces cerevisiae MATa cells, export of the a-factor mating pheromone is mediated by Ste6p, a member of the ATP-binding cassette (ABC) superfamily of transporters and a close homologue of mammalian multidrug transporter P-glycoproteins (Pgps). We have used functional complementation of a ste6delta mutation to isolate a gene encoding an ABC transporter capable of a-factor export from the pathogenic yeast, Candida albicans. This gene codes for a 1323-amino acid protein with an intramolecular duplicated structure, each repeated half containing six potential hydrophobic transmembrane segments and a hydrophilic domain with consensus sequences for an ATP-binding fold. The predicted protein displays significant sequence similarity to S. cerevisiae Ste6p and mammalian Pgps. The gene has been named HST6, for homologue of STE6. A high degree of structural conservation between the STE6 and the HST6 loci with respect to DNA sequence, physical linkage and transcriptional arrangement indicates that HST6 is the C. albicans orthologue of the S. cerevisiae STE6 gene. We show that the HST6 gene is transcribed in a haploid-specific manner in S. cerevisiae, consistent with the presence in its promoter of a consensus sequence for Mata1p-Matalpha2p binding known to mediate the repression of haploid-specific genes in S. cerevisiae diploid cells. In C. albicans, HST6 is expressed constitutively at high levels in the different cell types analysed (yeast, hyphae, white and opaque), demonstrating that HST6 transcription is not repressed in this diploid yeast, unlike in diploid S. cerevisiae, and suggesting a basic biological function for the Hst6p transporter in C. albicans. The strong similarity between Hst6p and the multidrug transporter Pgps also raises the possibility that Hst6p could be involved in resistance to antifungal drugs in C. albicans.

In the literature on British economic decline entrepreneurship is typically assessed by its outcome. By contrast, this paper argues that the soundness of entrepreneurship is best tested by viewing it ex ante. In other words, it is the process, and not the product, of entrepreneurship that is important in determining its quality. When this is accepted, competence, rather than infallibility, becomes the criterion by which entrepreneurship is best judged. In the latter half of the article, this approach is applied to the British paper industry's search for a new source of cellulose in the second half of the nineteenth century.

For most of the nineteenth century Britain held an undisputed lead in the field of paper-machine technology. By the 1890s this lead had been lost to America. This article argues that Britain's loss...

The effects of four mulching systems (pine bark, black woven fabric, black plastic, white-over-black plastic) on plant growth yield and fruit quality of five southern highbush blueberry clones were studied. Plant growth and fruit yields of plants grown on pine bark or white-over-black plastic were not different and were significantly higher than growth and yield of plants grown on the black mulches. The mulching systems did not significantly affect berry weight, soluble solids, titratable acidity, soluble solids/acid ratio, an-thocyanins, skin firmness or subjective quality after three weeks of refrigerated storage. There were significant effects of clone on each of these parameters.

This paper examines the introduction of piecework, a key aspect of the Soviet workplace, in occupied East Germany. As elsewhere, its implementation encountered persistent hostility from the workforce. What made this episode different, though, was that this process occurred within a context of acute economic and political uncertainty. As this paper demonstrates, the party’s various efforts to control the workplace laid the foundations for the Sovietisation of East Germany. This paper utilises a wide range of primary sources to recount this story. It focuses its attention not just on worker resistance, but also on the interactions between party and worker, between different organisations operating within the occupation zone, between the Soviet military and German communists, and within the party itself. It argues that the introduction of piecework was part of a dual process whereby the party acquired control of the economy and then learnt how to direct it. To achieve the latter, it first needed to learn how to control and direct itself. This paper also illustrates the importance of signalling mechanisms in a planned economy.

Tifblue rabbiteye blueberries {Vacciniwn ashei, Reade) were harvested twice daily (09:00, 14:30) and held under one of two conditions (cooled room, outside in shade) for six holding times (0, 1.5, 3, 6, 12, 24 hours after harvest) before refrigeration. Blueberries rejected when sorted were affected by harvest time (more rejected from 14:30 harvest), holding condition (more rejected from shade treatments) and holding time (more rejected as holding time increased). Storage defects after 21 days at 4.4°C (40°F) were affected by holding time (% defects increased with holding time). Treatments were intended to simulate the conditions of a small grower with limited facilities.

The DNA sequence of a Candida albicans genomic fragment known to complement the arginine mutation designated arg57 in strain 1006 contains an ORF of 1404 nucleotides (nt) predicting a protein of 468 amino acids (aa). Database searches indicated that the deduced protein shares 75% identity and 85% similarity with the ARG4 protein of Saccharomyces cerevisiae. Analysis of the percent aa identity between C. albicans and S. cerevisiae sequences included in available databases suggested these values are within the range expected for biosynthetic enzymes from the two organisms which share similar function. Experiments to isolate C. albicans ARG4 by complementation in an arg4 strain of S. cerevisiae yielded a plasmid (pARG4-1) with a restriction map identical to that of the sequenced clone. From these data, we conclude that the gene previously designated ARG57 is in fact ARG4 encoding the enzyme argininosuccinate lyase (ASL). These results were unexpected, since ARG57 had been localized to chromosome 7, while a mutation causing an ASL deficiency had been linked to ade1, which is on chromosome R. Transformation of C. albicans strains with pARG4-1 indicated it complemented the arginine auxotrophy in strains TMSU221 and 1435, a derivative of 1006. Examination of commonly utilized C. albicans arginine auxotrophs by spheroplast fusion analysis indicated these strains comprise two complementation groups: one consisting of 1006 and TMSU221, which are arg4, and the other of A642, hOG318, hOG357, FC18-6 and WC-5-4, which possess an undefined defect in the arginine biosynthetic pathway which we designate arg100.

Perhaps the most unexpected of Frederick Taylor‟s legacies is the alleged influence his ideas had in the Soviet world. This paper explores this contention by examining the introduction of differential piece rates and „scientific‟ norms—both key aspects of the Taylorist and Soviet systems—in East Germany between 1945 and 1951. As elsewhere, these measures faced stiff opposition. What made this experience different was that their introduction took place in the context of extreme economic and political uncertainty. As this paper outlines, the party‟s various attempts to impose workplace control laid the foundations for the Sovietisation of East Germany. This paper uses a variety of primary sources to tell this story. It concentrates its attention not just on worker resistance to change, but also on how the interactions between party and worker, between different organisations within the occupation zone, between the Soviets and German communists, and within the party itself came together to see piecework entrenched within the East German workplace. While Taylor‟s ideas influenced the party in this process, they did so only after they had been fed through the prisms of Leninism, Stalinism and Soviet experience. East Germany‟s communists were Tayloristic, not Taylorist.

Freeze-dried fruits of two strawberry cultivars, Sweet Charlie and Carlsbad, and two blueberry cultivars, Tifblue and Premier were sequentially extracted with hexane, 50% hexane/ethyl acetate, ethyl acetate, ethanol, and 70% acetone/water at ambient temperature. Each extract was tested separately for in vitro anticancer activity on cervical and breast cancer cell lines. Ethanol extracts from all four fruits strongly inhibited CaSki and SiHa cervical cancer cell lines and MCF-7 and T47-D breast cancer cell lines. An unfractionated aqueous extract of raspberry and the ethanol extract of Premier blueberry significantly inhibited mutagenesis by both direct-acting and metabolically activated carcinogens.

Introduction So far we have examined the overseas movement of British people and British goods. This chapter concerns itself with Britain's other great export of the pre-First World War period: its capital. We seek to uncover the key relationships and mechanisms that made possible a massive and rapid movement of money across borders. For many scholars, it is this ‘runaway quality of global finance’ that lay at the very heart of the forces integrating the world economy in the nineteenth and twentieth centuries. Certainly, it had a profound and lasting effect, in its wake opening up new regions of the world, delivering efficiency gains from improved transport and communication, and widening the scope of the multi-lateral payments system. Britain's imperial and financial pre-eminence are, moreover, traditionally understood to have been two sides of the same coin. Yet appearances can be deceptive. While the empire was at times prized by British investors, these same investors also freely sank even larger sums of money outside it. ‘Imperial piety’ or ‘British traditions’, of themselves, could not and did not replace the profit motive. Rather, it was the attractions of the rapidly expanding temperate regions of recent settlement – political stability, economic security and protection within the law – that mattered. These attractions were not confined to the British World, even if they manifested themselves most strongly there.

Introduction The idea that social connections matter, and can be thought of in networked terms, should startle few scholars. Dubbed a ‘metaphor for our times’, networks are currently given a prominent role in historical and contemporary social analysis, as well as in debates about globalisation. Yet the term ‘network’ tends to be employed rather casually. The technological and social aspects of networks are not always sufficiently differentiated, while networks seemingly encompass an ever-wider range of human activities and forms of interaction. At worst, the network concept serves as little more than a shorthand for human behaviour deemed too collective to be determined by pure individual choice, yet too diffuse and personal to be taken up by formal state or market institutions. There is clearly a danger here. If networks can be taken to mean almost any kind of informal set of interpersonal connections, the term is likely to be too imprecise to have much purchase. As one commentator warns, ‘if everything is a network then nothing is’. Hence great care is required in assessing the importance of networks as agents of historical change. In the following chapters we explore how a variety of social networks created links between individuals and groups, and how these links in turn facilitated the movement of commodities, money, information and people across national or, more accurately, colonial borders. That said, it must be emphasised at the outset that causative relationships between two phenomena cannot be inferred from spatial and temporal co-existence alone.

Presenting a blend of economics and law, this book provides unique insights as well as practical guidance for negotiators considering major issues on the agendas of bilateral and regional preferential trading agreements (PTAs).

International audience

International audience

Analysis of the karyotypes of multiple Candida albicans isolates by pulsed-field electrophoresis confirms the observation by Lasker et al. of eight chromosomes. The genes previously assigned to chromosome 1 in fact fall into two groups, one (including ADE1, SOR9, and CDC10) is linked to the ribosomal DNA genes on a chromosome called R, whereas the others are found on chromosome 1. Chromosome R varies in electrophoretic mobility among strains, usually running equal to or faster than chromosome 1 but in rare cases running slower than chromosome 1. In strain 1012A, the decreased mobility of one homolog is associated with the very large majority of the rDNA genes being on that homolog; the second homolog, with only a few copies, migrates with chromosome 2. Linkage analysis by using spheroplast fusion confirms the gene assignments made by hybridization to blots of the electrophoretic karyotype. A newly cloned gene, LYS2, hybridizes to chromosome 1.

Candida dubliniensis and Candida albicans, the most common human fungal pathogen, have most of the same genes and high sequence similarity, but C. dubliniensis is less virulent. C. albicans causes both mucosal and hematogenously disseminated disease, C. dubliniensis mostly mucosal infections. Pulse-field electrophoresis, genomic restriction enzyme digests, Southern blotting, and the emerging sequence from the Wellcome Trust Sanger Institute were used to determine the karyotype of C. dubliniensis type strain CD36. Three chromosomes have two intact homologues. A translocation in the rDNA repeat on chromosome R exchanges telomere-proximal regions of R and chromosome 5. Translocations involving the remaining chromosomes occur at the Major Repeat Sequence. CD36 lacks an MRS on chromosome R but has one on 3. Of six other C. dubliniensis strains, no two had the same electrophoretic karyotype. Despite extensive chromosome rearrangements, karyotypic differences between C. dubliniensis and C. albicans are unlikely to affect gene expression. Karyotypic instability may account for the diminished pathogenicity of C. dubliniensis.

Background: The 10.9× genomic sequence of Candida albicans, the most important human fungal pathogen, was published in 2004. Assembly 19 consisted of 412 supercontigs, of which 266 were a haploid set, since this fungus is diploid and contains an extensive degree of heterozygosity but lacks a complete sexual cycle. However, sequences of specific chromosomes were not determined. Results: Supercontigs from Assembly 19 (183, representing 98.4% of the sequence) were assigned to individual chromosomes purified by pulse-field gel electrophoresis and hybridized to DNA microarrays. Nine Assembly 19 supercontigs were found to contain markers from two different chromosomes. Assembly 21 contains the sequence of each of the eight chromosomes and was determined using a synteny analysis with preliminary versions of the Candida dubliniensis genome assembly, bioinformatics, a sequence tagged site (STS) map of overlapping fosmid clones, and an optical map. The orientation and order of the contigs on each chromosome, repeat regions too large to be covered by a sequence run, such as the ribosomal DNA cluster and the major repeat sequence, and telomere placement were determined using the STS map. Sequence gaps were closed by PCR and sequencing of the products. The overall assembly was compared to an optical map; this identified some misassembled contigs and gave a size estimate for each chromosome. Conclusion: Assembly 21 reveals an ancient chromosome fusion, a number of small internal duplications followed by inversions, and a subtelomeric arrangement, including a new gene family, the TLO genes. Correlations of position with relatedness of gene families imply a novel method of dispersion. The sequence of the individual chromosomes of C. albicans raises interesting biological questions about gene family creation and dispersion, subtelomere organization, and chromosome evolution., National Institute of Allergy and Infectious Diseases (U.S.) (contract N01 AI05406), National Institute of Allergy and Infectious Diseases (U.S.) (grant R01 AI 16567), National Research Council (U.S.). Genome Health Initiative, Canadian Institutes for Health Research (grant HOP 67260), Canadian Institutes for Health Research (grant MOP 42516), Ministry of Education, Culture, Sports, Science and Technology of Japan (Grant-in-Aid for Scientific Research)

This article uses money order data to examine the determinants of British migrant remittances prior to 1914. Using panel data and cointegration analysis, it provides evidence of four distinct types of remittance behavior, lending support to Lucas and Stark's theory that remittances are driven by an implicit contract between remitter and remittee. The relative strengths of these different forms of remittance varied across the English-speaking world, with the largest differences occurring between migrants residing in America and those in the self-governing dominions. The explanation for these differences is seen to lie in the distinctive nature of British emigration to America.

The release of the diploid genomic sequence of Candida albicans and its recent community-based annotation have permitted a number of studies which have significantly advanced our understanding of the biology of this important human pathogen. These advances range from analysis of genomic changes to differential gene expression under a variety of conditions. A few general conclusions can be drawn from the data presently in hand; one can expect more and more new insights as the number and kind of experiments grows.

Plants are proven sources of useful anti-tumor and chemopreventative compounds. Hence, identification of phytochemicals useful in dietary prevention and intervention of cancer is of paramount importance. The initial step in the formation of cancer is damage to the genome of a somatic cell producing a mutation in an oncogene or a tumor-suppressor gene. Fresh juices and organic solvent extracts from the fruits of strawberry, blueberry, and raspberry were evaluated for their ability to inhibit the production of mutations by the direct-acting mutagen methyl methanesulfonate and the metabolically activated carcinogen benzo[a]pyrene. Juice from strawberry, blueberry, and raspberry fruit significantly inhibited mutagenesis caused by both carcinogens. Ethanol extracts from freeze-dried fruits of strawberry cultivars (Sweet Charlie and Carlsbad) and blueberry cultivars (Tifblue and Premier) were also tested. Of these, the hydrolyzable tannin-containing fraction from Sweet Charlie strawberries was most effective at inhibiting mutations.

Trastuzumab is an effective treatment for patients with metastatic breast cancer (MBC) that overexpresses HER-2. A high incidence of brain metastases (BM) has been noted in patients receiving trastuzumab. A retrospective chart review was conducted of 100 patients commencing trastuzumab for metastatic breast cancer from July 1999 to December 2002, at the Christie Hospital. Seven patients were excluded; five patients developed central nervous system metastases prior to starting trastuzumab, and inadequate data were available for two. Out of the remaining 93 patients, 23 (25%) have developed BM to date. In all, 46 patients have died, and of these 18 (39%) have been diagnosed with BM prior to death. Of the 23 patients developing BM, 18 (78%) were hormone receptor negative and 18 (78%) had visceral disease. Univariate analysis showed a significant association between the development of cerebral disease and both hormone receptor status and the presence of visceral disease. In conclusion, a high proportion of patients with MBC treated with trastuzumab develop symptomatic cerebral metastases. HER-2-positive breast cancer may have a predilection for the brain, or trastuzumab therapy may change the disease pattern by prolonging survival. New strategies to address this problem require investigation in this group of patients.

A study was conducted to determine the presence of resveratrol, pterostilbene, and piceatannol in Vaccinium berries. Samples representing selections and cultivars of 10 species from Mississippi, North Carolina, Oregon, and Canada were analyzed by gas chromatography/mass spectrometry. Resveratrol was found in Vaccinium angustifolium (lowbush blueberry), Vaccinium arboretum (sparkleberry), Vaccinium ashei (rabbiteye blueberry), Vaccinium corymbosum (highbush blueberry), Vaccinium elliottii (Elliott's blueberry), Vaccinium macrocarpon (cranberry), Vaccinium myrtillus (bilberry), Vaccinium stamineum (deerberry), Vaccinium vitis-ideae var. vitis-ideae (lingonberry), and Vaccinium vitis-ideae var. minor (partridgeberry) at levels between 7 and 5884 ng/g dry sample. Lingonberry was found to have the highest content, 5884 ng/g dry sample, comparable to that found in grapes, 6471 ng/g dry sample. Pterostilbene was found in two cultivars of V. ashei and in V. stamineum at levels of 99-520 ng/g dry sample. Piceatannol was found in V. corymbosum and V. stamineum at levels of 138-422 ng/g dry sample. These naturally occurring stilbenes, known to be strong antioxidants and to have cancer chemopreventive activities, will add to the purported health benefits derived from the consumption of these small fruits.

Single-nucleotide polymorphisms (SNPs) are essential tools for studying a variety of organismal properties and processes, such as recombination, chromosomal dynamics, and genome rearrangement. This paper describes the development of a genome-wide SNP map for Candida albicans to study mitotic recombination and chromosome loss. C. albicans is a diploid yeast which propagates primarily by clonal mitotic division. It is the leading fungal pathogen that causes infections in humans, ranging from mild superficial lesions in healthy individuals to severe, life-threatening diseases in patients with suppressed immune systems. The SNP map contains 150 marker sequences comprising 561 SNPs and 9 insertions-deletions. Of the 561 SNPs, 437 were transition events while 126 were transversion events, yielding a transition-to-transversion ratio of 3:1, as expected for a neutral accumulation of mutations. The average SNP frequency for our data set was 1 SNP per 83 bp. The map has one marker placed every 111 kb, on average, across the 16-Mb genome. For marker sequences located partially or completely within coding regions, most contained one or more nonsynonymous substitutions. Using the SNP markers, we identified a loss of heterozygosity over large chromosomal fragments in strains of C. albicans that are frequently used for gene manipulation experiments. The SNP map will be useful for understanding the role of heterozygosity and genome rearrangement in the response of C. albicans to host environments.

One hundred and twenty Candida albicans clinical isolates from the late 1980s and early 1990s were examined for homozygosity at the MTL locus. Of these, 108 were heterozygous (MTLa/MTLalpha), whereas seven were MTLa and five were MTLalpha. Five of the homozygous isolates were able to switch to the opaque cell morphology, while opaque cells were not detectable among the remaining seven. Nevertheless, all but one of the isolates homozygous at the MTL locus were shown to mate and to yield cells containing markers from both parents; the non-mater was found to have a frameshift in the MTLalpha1 gene. In contrast to Saccharomyces cerevisiae, C. albicans homozygotes with no active MTL allele failed to mate rather than mating as a cells. There was no correlation between homozygosity and fluconazole resistance, mating and fluconazole resistance or switching and fluconazole resistance, in part because most of the strains were isolated before the widespread use of this antifungal agent, and only three were in fact drug resistant. Ten of the 12 homozygotes had rearranged karyotypes involving one or more homologue of chromosomes 4, 5, 6 and 7. We suggest that karyotypic rearrangement, drug resistance and homozygosity come about as the result of induction of hyper-recombination during the infection process; hence, they tend to occur together, but each is the independent result of the same event. Furthermore, as clinical strains can mate and form tetraploids, mating and marker exchange are likely to be a significant part of the life cycle of C. albicans in vivo.

We present the diploid genome sequence of the fungal pathogen Candida albicans . Because C. albicans has no known haploid or homozygous form, sequencing was performed as a whole-genome shotgun of the heterozygous diploid genome in strain SC5314, a clinical isolate that is the parent of strains widely used for molecular analysis. We developed computational methods to assemble a diploid genome sequence in good agreement with available physical mapping data. We provide a whole-genome description of heterozygosity in the organism. Comparative genomic analyses provide important clues about the evolution of the species and its mechanisms of pathogenesis.

The fungal pathogen Candida albicans switches from a yeast-like to a filamentous mode of growth in response to a variety of environmental conditions. We examined the morphogenetic behavior of C. albicans yeast cells lacking the BCY1 gene, which encodes the regulatory subunit of protein kinase A. We cloned the BCY1 gene and generated a bcy1 tpk2 double mutant strain because a homozygous bcy1 mutant in a wild-type genetic background could not be obtained. In the bcy1 tpk2 mutant, protein kinase A activity (due to the presence of the TPK1 gene) was cyclic AMP independent, indicating that the cells harbored an unregulated phosphotransferase activity. This mutant has constitutive protein kinase A activity and displayed a defective germinative phenotype in N -acetylglucosamine and in serum-containing medium. The subcellular localization of a Tpk1-green fluorescent protein (GFP) fusion protein was examined in wild-type, tpk2 null, and bcy1 tpk2 double mutant strains. The fusion protein was observed to be predominantly nuclear in wild-type and tpk2 strains. This was not the case in the bcy1 tpk2 double mutant, where it appeared dispersed throughout the cell. Coimmunoprecipitation of Bcy1p with the Tpk1-GFP fusion protein demonstrated the interaction of these proteins inside the cell. These results suggest that one of the roles of Bcy1p is to tether the protein kinase A catalytic subunit to the nucleus.

We have cloned the Candida albicans TPK2 gene encoding a cAMP-dependent protein kinase (PKA) catalytic subunit and generated a tpk2 homozygous null mutant to assess its ability to germinate in liquid media. N-acetylglucosamine (GlcNAc)-induced germ-tube formation was attenuated in the tpk2 strain and enhanced by compounds that are known to increase the PKA activity in situ. Germination was completely blocked in the presence of the myristoylated derivative of the heat-stable PKA inhibitor (MyrPKI). These results indicate that TPK1 acts positively in regulating the morphogenetic transition in C. albicans in the absence of the TPK2 gene. We were able to identify an mRNA from this second form of PKA in both wild-type and tpk2 null mutant cells. We found that PKA activity measured in the mutant lacking the TPK2 gene was about 10% of that displayed by the wild-type. The finding that the germinative response of tpk2 null mutant to serum was severely diminished at low serum concentrations indicates that the level of PKA is an important determinant of filamentous growth at low serum concentrations. The extent of germination attained at higher serum concentrations (5%) was similar in the wild-type and in the tpk2 null mutant strains suggesting that under these conditions germination was triggered through a PKA-independent pathway. Fil: Cloutier, Monikca. GREB Laval University; Canadá Fil: Castilla Lozano, Maria del Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Invetigaciones Bioquímicas y Fisiologicas; Argentina Fil: Bolduc, Nathalie. GREB Laval University; Canadá Fil: Zelada, Alicia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Invetigaciones Bioquímicas y Fisiologicas; Argentina Fil: Martineau, Philippe. GREB Laval University; Canadá Fil: Bouillon, Marlène. GREB Laval University; Canadá Fil: Magee, Beatrice B.. University of Minnesota; Estados Unidos Fil: Di Bernardo, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Invetigaciones Bioquímicas y Fisiologicas; Argentina Fil: Giasson, Luc. GREB Laval University; Canadá Fil: Cantore, Maria Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Invetigaciones Bioquímicas y Fisiologicas; Argentina

The belief that Britain’s empire markets were soft is well entrenched in the literature. It is, however, a belief that has been largely untested. Indeed, the literature does not even offer an explicit definition of softness. This paper attempts to fill this gap by discussing the meaning of the term and, then, posing the question whether between 1870 and 1914 Britain’s fastest growing markets – Australasia and Canada – can in fact be reasonably labelled soft, as has often been assumed. The paper concludes that the demand for British imports in these markets were driven more by income and price considerations than by colonial sentiment or preference.