vaginosis and Prevotella bivia (Aroutcheva et al, 2001a) Consis

vaginosis and Prevotella bivia (Aroutcheva et al., 2001a). Consistent with this, Lactobacillus strains have been isolated from the human vaginal microbiota for probiotic use against vaginosis-associated pathogens (Reid & Burton, 2002; Reid et al., 2003) on the basis of their ability to produce high levels of hydrogen peroxide (Klebanoff et al., 1991; Hillier et al., 1992, 1993). Moreover, Pridmore et al. (2008) first reported for an

intestinal Lactobacillus that hydrogen peroxide contributes to the killing activity 3-MA manufacturer of L. johnsonii NCC533 against serovar Typhimurium. Consistent with these reports, here, we observed that hydrogen peroxide concentration-dependently kills serovar Typhimurium, G. vaginosis and UPEC strains. Moreover, we report that lactic acid acts synergistically with hydrogen peroxide to kill G. vaginalis, S. typhimurium and UPEC more efficiently. The mechanism underlying the stimulatory effect of lactic acid observed could be related to the observation by Greenacre et al. (2006), who have reported that the lactic acid-induced acid tolerance response causes hydrogen peroxide sensitivity in serovar Typhimurium via the downregulation

of the OxyR regulon. A second mechanism could also be proposed, www.selleckchem.com/products/ldk378.html resulting from the permeabilizing effect of lactic acid on the gram-negative bacterial outer membrane (Alakomi et al., 2000), thus facilitating the passage of molecules across the membrane, and in turn increasing the killing effects of antimicrobial compounds (Niku-Paavola et al., 1999; Alakomi et al., 2000). “
“Candidatus Methylomirabilis oxyfera’; is a polygon-shaped bacterium Methane monooxygenase that was shown to have the unique ability to couple anaerobic methane oxidation to denitrification, through a newly discovered intra-aerobic pathway. Recently, the complete genome of Methylomirabilis oxyfera was assembled into a 2.7-Mb circular single chromosome by metagenomic sequencing. The genome of M. oxyfera

revealed the full potential to perform both methane oxidation and the conversion of nitrite via nitric oxide into oxygen and dinitrogen gas. In this study, we show by immunogold localization that key enzymes from both methane- and nitrite-converting pathways are indeed present in single M. oxyfera cells. Antisera targeting the particulate methane monooxygenase (pMMO) and the cd1 nitrite reductase (NirS) were raised and used for immunogold localization in both single- and double-labelling experiments. Our previous studies have shown that M. oxyfera does not develop pMMO-containing intracytoplasmic membranes as is observed in classical proteobacterial methanotrophs. Our results suggest that in M. oxyfera, the pMMO and NirS enzymes localized to the cytoplasmic membrane and periplasm, respectively. Further, double-labelling showed co-occurrence of pMMO and NirS in single M. oxyfera cells.

Our study could not address this issue as the study population wa

Our study could not address this issue as the study population was too small and there was a large range of viral loads among patients with viruses harbouring the L90M mutation. Another concern is the significance of the L90M mutation in choosing a therapeutic regimen in naïve patients. A recent study showed that a single transmitted DRM is not an indicator for transmission of a more extensive resistance profile [25], but further investigations evaluating the efficacy of various regiments in treating L90M-harbouring patients are needed. In conclusion, Omipalisib mw this study provides data on transmitted viruses harbouring DRMs in Tel Aviv, Israel.

All patients with transmitted DRMs were from the MSM ERC. In contrast to the findings of other studies from industrialized countries, there was a high rate of PI-associated DRMs. Clustering was shown to possibly facilitate the spread of viruses harbouring these mutations. Questions regarding viral fitness and therapeutic strategy remain open and call for a larger prospective

investigation of this unique patient group. O.P. is a fellow of the Edmond J. Safra Bioinformatics program at Tel Aviv University and of the Converging Technologies scholarship program. T.P. is supported by grants from the Israel Science Foundation (878/09) and the National Evolutionary Synthesis Center (NESCent; NSF #EF-0905606). We thank Esther Eshkol for editorial assistance. “
“The aim of the study was to assess whether a simple, Selleck Ibrutinib routinely available measure of antiretroviral therapy (ART) adherence predicts viral rebound at the next HIV viral load (VL) measurement in virally suppressed patients. The analysis was performed on the Royal Free HIV Cohort, London, UK. Each ‘drug coverage–viral load episode’ (DCVL episode) Etoposide cost was defined as a 6-month period immediately prior to a VL ≤50 HIV-1 RNA copies/mL (time-zero), during which the patient had been continuously on HAART, with all measured VLs ≤50 copies/mL. The next VL after time-zero was used to assess whether VL rebound (defined as >200 copies/mL) had occurred.

Drug coverage, our measure of adherence, was calculated as the proportion of days in the 6-month period covered by a valid prescription for at least three antiretroviral drugs. A total of 376 (2.4%) VL rebounds occurred in 15 660 DCVL episodes among 1632 patients. Drug coverage was 100% for 32% of episodes, 95–99% for 16% of episodes and ≤60% for 10% of episodes. The risk ratio of rebound associated with a 10% increase in drug coverage, adjusted for potential confounding variables, was 0.93 (95% confidence interval 0.88–0.98). Antiretroviral drug coverage assessed at the time of VL measurement in patients with undetectable VL is potentially clinically useful for predicting VL rebound at the next VL measurement.

Maraviroc and raltegravir were not included in this study as FDA

Maraviroc and raltegravir were not included in this study as FDA approval for these agents occurred near the end of our evaluation period. For persons starting more than one of the target medications over the study period, the first VHA out-patient prescription

for each target medication was counted. To reduce the number of prescriptions for patients whose care was transferred to the VHA and who were already on a medication of interest, only veterans with out-patient prescription records for at least 1 quarter (90 days) prior to their first prescription for a target medication were included. For each quarter post-approval, we measured the uptake of each medication, defined as the number of new patients with prescriptions for the medication. The start dates for the first quarter for each agent were: atazanavir, Akt inhibitor June 2003; darunavir, June 2006; tipranavir, June 2005; and lopinavir/ritonavir, September 2000. For each quarter, we determined the number of providers who first wrote a new prescription for one of the four medications and the Vincristine mw number of providers who prescribed any antiretroviral. Based on provider type, providers were categorized as physician, physician trainee (student/resident/fellow) or physician extender (nurse/physician assistant/clinical pharmacist).

Clinics where prescriptions were initiated were categorized as infectious disease (ID), primary care or other. fantofarone For each quarter we determined

the cumulative number of facilities that had prescribed each of the target medications. Based on the facility location of the qualifying new out-patient prescription, the prescription was assigned to a Centers for Disease Control and Prevention (CDC) geographical region: Northcentral, Northeast, South or West. To provide a benchmark for the regional uptake of new antiretrovirals, we determined the total number of antiretroviral prescription fills during the period from March 2003 (3 months prior to the earliest approval date for a target medication) to December 2007. For comparison, if the uptake of a new medication matched the prescribing of other antiretrovirals, the percentage of the new prescriptions occurring in a specific region should match the percentage of all antiretroviral fills for that region. For example, if 20% of all antiretroviral fills occurred in the West then one would expect the West to account for 20% of the new prescriptions for a target medication; if the West accounted for >20% of the new prescriptions for a medication, that would indicate that the West had greater uptake of the medication than expected. Medication uptake by region was determined for three time periods: quarters 1 and 2 post FDA approval (period 1), quarters 3–6 post-approval (period 2), and quarters 7+ post-approval until 31 December 2007 (period 3).

1a) Transcription initiation at the melR promoter is dependent o

1a). Transcription initiation at the melR promoter is dependent on activation PD0325901 in vitro by CRP and is repressed by MelR binding to a single target site (denoted R) overlapping the melR transcript start. Wade et al. (2000) reported that efficient MelR-dependent repression of the melR promoter requires upstream sequences

that covered the melAB promoter and that the most important element in repression is MelR binding at target site 2. Further detailed analysis by Samarasinghe et al. (2008) showed that MelR bound at sites 1 and 1′ plays a role in repression, and images from atomic force microscopy suggested that repression is due to a nucleoprotein complex consisting of four MelR subunits and ~170 base pairs of DNA between MelR-binding

target site 2 and target site R. Most members of the AraC family of transcription regulators function as homodimers of two subunits with the N-terminal domain of each subunit involved in ligand binding and dimerization, and the C-terminal domain responsible for DNA binding (Gallegos et al., 1997). C-terminal domains of AraC family members are highly conserved, this website carry two helix-turn-helix motifs and bind to asymmetric ~18 base pair target operator sequences. As it is well established that effective transcriptional repression can result from the two subunits of a single AraC dimer binding to two separated target sites (Schleif, 2010), and as MelR has been shown to dimerise (Bourgerie et al., 1997; Kahramanoglou et al., 2006), we revisited the E. coli Non-specific serine/threonine protein kinase melibiose operon regulatory region

to investigate whether two DNA sites for MelR could be manipulated to produce efficient MelR-dependent repression of the melR promoter. In this work, we exploited the low-copy-number lac expression vector plasmid, pRW50, encoding resistance to tetracycline (Lodge et al., 1992). The starting points of the work were pRW50 derivatives carrying the TB22 and TB23 EcoRI-HindIII fragments (Fig. 1b) containing the E. coli melR promoter, as described by Samarasinghe et al. (2008). These recombinant pRW50 derivatives each carry a melR promoter::lacZ fusion, and they were propagated in the WAM1321 E. coli K-12 Δlac Δmel strain to measure melR promoter activity. Cells were grown in minimal medium with fructose, as a carbon source, and 35 μg mL−1 tetracycline, as in the study by Samarasinghe et al. (2008), and the Miller (1972) method was used to quantify β-galactosidase expression. For the different melR promoter fusions studied here in our conditions in the absence of MelR, β-galactosidase activity levels range from 360 to 400 standard Miller units. To quantify repression by MelR, cells also carried pJW15, encoding melR or empty vector, pJW15ΔmelR, and 80 μg mL−1 ampicillin was included in the media, as described by Kahramanoglou et al. (2006). In experiments to measure effects due to MalI, cells also carried pACYC–malI, encoding malI or empty vector, pACYC-ΔHN (Lloyd et al.

This study shows the ability of ventral mesencephalic

tis

This study shows the ability of ventral mesencephalic

tissue to ameliorate some of the lesion-induced deficits, PARP inhibitor trial and the power of operant testing in detecting small but significant improvements. The behavioural tests presented are useful drug-free approaches for evaluating cell-based therapies. “
“Repeated administration of psychostimulant drugs or stress can elicit a sensitized response to the stimulating and reinforcing properties of the drug. Here we explore the mechanisms in the nucleus accumbens (NAc) whereby an acute restraint stress augments the acute locomotor response to cocaine. This was accomplished by a combination of behavioral pharmacology, microdialysis measures of extracellular dopamine and glutamate, and Western blotting for GluR1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor (AMPAR). A single exposure to restraint stress 3 weeks before testing revealed that enduring locomotor sensitization to cocaine was paralleled by an increase in extracellular dopamine in the core, but not the shell subcompartment, of the NAc. Wistar rats pre-exposed to Enzalutamide acute stress showed increased basal levels of glutamate

in the core, but the increase in glutamate by acute cocaine was blunted. The alterations in extracellular glutamate seem to be relevant, as blocking AMPAR by 6-cyano-7-nitroquinoxaline-2,3-dione microinjection into the core prevented both the behavioral cross-sensitization and the augmented increase in cocaine-induced extracellular dopamine. Further implicating glutamate, the locomotor response to AMPAR stimulation in the core was potentiated, but not in the shell of pre-stressed animals, and this was accompanied by an increase in NAc GluR1 surface expression. This study provides evidence that the long-term expression of restraint stress-induced behavioral cross-sensitization to cocaine recapitulates some mechanisms

thought to underpin the sensitization induced by daily cocaine administration, and shows that long-term neurobiological changes induced click here in the NAc by acute stress are consequential in the expression of cross-sensitization to cocaine. “
“The visual field is retinotopically represented in early visual areas. It has been suggested that when adult primary visual cortex (V1) is deprived of normal retinal input it is capable of large-scale reorganisation, with neurons inside the lesion projection zone (LPZ) being visually driven by inputs from intact retinal regions. Early functional magnetic resonance imaging (fMRI) studies in humans with macular degeneration (MD) report > 1 cm spread of activity inside the LPZ border, whereas recent results report no shift of the LPZ border. Here, we used fMRI population receptive field measurements to study, for the first time, the visual cortex organisation of one macaque monkey with MD and to compare it with normal controls.

A G Ponniah, Director, Central Institute of Brackishwater Aquac

A. G. Ponniah, Director, Central Institute of Brackishwater Aquaculture for his critical comments on this work. “
“Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000) was the first pathogen to be demonstrated to infect Arabidopsis and to cause

disease symptoms in the laboratory setting. However, the defense response to Pst DC3000 was unclear in tobacco. In this report, the expression profiles of twelve defense response–related genes were analyzed after treatment with salicylic acid (SA), jasmonic acid (JA), and pathogen Pst DC3000 by qRT-PCR. According to our results, it could be presented that the genes primarily induced by SA were also induced to higher levels after Pst DC3000 infection. SA accumulation could be induced to a higher level than that of JA after Pst DC3000 infection. In addition, buy GDC-0199 SA could result in hypersensitive

response (HR), which did not completely depend on accumulation of reactive oxygen species. These results Selleck PFT�� indicated that tobacco mainly depended on SA signaling pathway rather than on JA signaling pathway in response to Pst DC3000. Further study demonstrated that JA could significantly inhibit the accumulation of SA and the generation of the HR induced by Pst DC3000. “
“Characteristic feature of the most of Selenomonas ruminantium cryptic plasmids is the presence of short, conserved sequences encompassing the gene for replication protein creating a potential rep gene cassette. PCR-based experiment was designed to analyse the genetic organization of putative plasmid rep modules and to assess

S. ruminantium plasmid Non-specific serine/threonine protein kinase biodiversity. Analysed PCR amplicons contained single open reading frames encoding for putative replication proteins. While most of the derived protein sequences were often found to be conserved among putative plasmid molecules, at noncoding regions, genetic variability was observed to various extents. Complete nucleotide sequence of a plasmid was determined that contained probably a new rep gene only distantly related to known selenomonas Rep proteins but at noncoding regions shared high homology with already known plasmids. Our results document considerable structural instability and sequence variability of analysed rep gene cassettes and suggest a modular structure of S. ruminantium plasmids potentially accessible for rep gene module exchanges. Selenomonas ruminantium is a gram-negative, obligate anaerobic bacterium isolated from the rumen of herbivores (Lessel and Breed, 1954). Significant metabolic role of Selenomonas strains in rumen is given by their capability to convert succinate to propionate, effectively utilize lactate and many amino acids (Ricke et al., 1996) and make a considerable contribution of vitamin B12 to the rumen environment (Dryden et al., 1962). Highly dense rumen microbial environment represents an ideal place and makes good preconditions for gene transfer mediated by mobile gene elements, such as plasmids, phages or transposons.


“Hippocampal plasticity (eg neurogenesis) likely plays a


“Hippocampal plasticity (e.g. neurogenesis) likely plays an important role in maintaining addictive behavior and/or relapse. This study assessed whether rats with differential propensity to drug-seeking behavior, bred Low-Responders

(bLR) and bred High-Responders (bHR) to novelty, show differential neurogenesis regulation after cocaine exposure. Using specific immunological markers, we labeled distinct populations of adult stem cells in the dentate gyrus at different time-points of the cocaine sensitization process; Ki-67 for newly born cells, NeuroD for cells this website born partway, and 5-bromo-2′-deoxyuridine for older cells born prior to sensitization. Results show that: (i) bHRs exhibited greater psychomotor response to cocaine than bLRs; (ii) acute cocaine did not www.selleckchem.com/products/Dasatinib.html alter cell proliferation in bLR/bHR rats; (iii) chronic cocaine decreased cell proliferation in bLRs only, which became amplified through the course of abstinence; (iv) neither chronic cocaine nor cocaine abstinence affected the survival of immature neurons in

either phenotype; (v) cocaine abstinence decreased survival of mature neurons in bHRs only, an effect that paralleled the greater psychomotor response to cocaine; and (vi) cocaine treatment did not affect the ratio of neurons to glia in bLR/bHR rats as most cells differentiated into neurons in both lines. Thus, cocaine exerts distinct check details effects on neurogenesis in bLR vs. bHR rats, with a decrease in the birth of new progenitor cells in bLRs and a suppression of the survival of new neurons in bHRs, which likely leads to an earlier decrease in formation of new connections. This latter effect in bHRs could contribute to their enhanced degree of cocaine-induced psychomotor

behavioral sensitization. “
“The genes in the imprinted cluster on human chromosome 15q11–q13 are known to contribute to psychiatric conditions such as schizophrenia and autism. Major disruptions of this interval leading to a lack of paternal allele expression give rise to Prader–Willi syndrome (PWS), a neurodevelopmental disorder with core symptoms of a failure to thrive in infancy and, on emergence from infancy, learning disabilities and over-eating. Individuals with PWS also display a number of behavioural problems and an increased incidence of neuropsychiatric abnormalities, which recent work indicates involve aspects of frontal dysfunction. To begin to examine the contribution of genes in this interval to relevant psychological and behavioural phenotypes, we exploited the imprinting centre (IC) deletion mouse model for PWS (PWS-IC+/−) and the five-choice serial reaction time task (5-CSRTT), which is primarily an assay of visuospatial attention and response control that is highly sensitive to frontal manipulations. Locomotor activity, open-field behaviour and sensorimotor gating were also assessed.

The microcin undergoes post-translational modification with a tri

The microcin undergoes post-translational modification with a trimer of N-(2,3-dihydroxybenzoyl) linked to the C-terminal serine residue by a β-d-glucose. This modification which has been shown to bind iron mimics a catechol-type siderophore and significantly increases the toxicity of the peptide (Thomas et al., 2004; Destoumieux-Garzón et al., 2006). A number of bacterial pathogens with specific mammalian hosts possess systems for

directly obtaining iron from host proteins such as transferrin and lactoferrin, which sequester free iron in the body’s extracellular fluids. The most thoroughly characterized of these systems is the transferrin transport system of Neisseria gonorrhoeae and Neisseria meningitidis (Noinaj et al., 2012). Transferrin-binding protein A (TbpA),

a 100 kDa integral outer membrane protein and transferrin-binding protein Galunisertib supplier B (TbpB) an 80 kDa membrane anchored coreceptor form the basis of this system. TbpA, a TonB-dependent receptor strongly binds transferrin and acts as the conduit for transport of the liberated ferric iron across the outer membrane; however, it lacks the ability to distinguish between the apo and holo forms of the protein (Moraes et al., 2009). The coreceptor TbpB has a strong affinity for the iron loaded transferrin Nivolumab order only and acts synergistically with TbpA, considerably increasing the efficiency of iron import (Anderson et al., 1994). Following binding and extraction of iron, apo-transferrin is released from the complex (Lee & Schryvers, 1988). The importance of

this system for fitness is demonstrated by the fact that its inactivation renders N. gonorrhoeae avirulent (Cornelissen et al., 1998). The majority of iron in a mammalian host is stored intracellularly as haemoglobin (Rohde et al., 2002). As such, haemoglobin Bcl-w and the haem it contains represent an important iron source for invading pathogens (Wandersman & Stojiljkovic, 2000). As a result, pathogenic bacteria commonly secrete haemolysins and cytolysins that lyse host cells and release haemoglobin and other haemoproteins (Krewulak & Vogel, 2008). Uptake of the liberated haem is then achieved by a number of specialized systems, which in Gram-negative bacteria generally consist of a TonB-dependent outer membrane receptor, a periplasmic-binding protein and an ABC transporter (Tong & Guo, 2009). An example of a system, where a cell surface receptor directly acquires free or protein-bound haem, is the two-component HpuA/B system of N. meningitidis, which is evolutionarily and mechanistically related to the transferrin-binding system discussed earlier (Rohde et al., 2002). A second system indentified in a number of Gram-negative bacteria and characterized in the opportunistic pathogens P.

That is, parafoveal and peri-foveal regions would probably be ove

That is, parafoveal and peri-foveal regions would probably be over-represented as these regions of the retina would be more often trained on the intended environmental object of interest and, in turn, the representation of the fovea should be partially reduced. We have derived a simple ‘Altered Cortical Magnification Model’, using the observed values from the work of Adams and Horton to illustrate the potential impact of such remapping on the cortical representations for inputs at various eccentricities

(see Fig. 1). This simple model makes some clear predictions. Spatial representation around the fovea would be expected to lead to only marginal changes in the absolute extent of cortex responding to central stimulation (given the truly enormous tract of V1 dedicated to the central region) whereas the NU7441 in vivo relative changes in representation outside of the parafoveal

region would be expected to substantially Cobimetinib ic50 increase the extent of cortex responding to presentations at this eccentricity (given the initially very sparse representations at such eccentricities). Very few studies have examined how altered eye movements and resultant fixation patterns might influence cortical processing of visual information in ASD (Dalton et al., 2005). Given the close link between eye movements and visual cortical representations, as well as the observed deficits in oculomotor control in autism, we hypothesized that individuals with autism would exhibit alterations in the early PTK6 cortical representations of peripheral visual space. To test this, VEPs as well as visually evoked spread spectrum response potentials (VESPA)

(Lalor et al., 2006, 2009; Frey et al., 2010) were obtained for stimuli presented either at the center of gaze or at a parafoveal location. Because there is an ongoing debate on whether impaired magnocellular processing contributes to visual processing differences in ASD (Spencer et al., 2000; Milne et al., 2002; Robertson et al., 2012) and the proportion of magnocellular cells increases with increasing retinal eccentricity (Connolly & Van Essen, 1984) we also employed stimuli specifically biased towards activation of magnocellular neurons (Butler et al., 2007; Foxe et al., 2008; Lalor & Foxe, 2009). In visual cortex, magnocellular neurons feed predominantly into the dorsal stream, known as the ‘where’ pathway for its role in movement processing and object localization (Mishkin & Ungerleider, 1982). The combination of stimuli biased towards different visual pathways and different stimulus eccentricities was expected to yield a sensitive measure of visual cortical representation in ASD. Twenty-two children with a diagnosis of ASD (one female) between 7 and 17 years of age (mean = 11.3; SD = 2.7) and 31 typically developing (TD) children (11 female) between 6 and 18 years of age (mean = 12.3; SD = 3.0) participated in this study.

Curiously, the stop codons of the convergently oriented ORFs Smlt

Curiously, the stop codons of the convergently oriented ORFs Smlt0783–Smlt0784 and Smlt4197–Smlt4198, are contributed by interleaved

SMAG dimers. The same holds for ORFs Smlt1380–Smlt1381 and Smlt0188–Smlt0189, the stop codons of each being contributed by interleaved selleck inhibitor SMAG trimers. Some SMAGs located between convergently oriented ORFs are at a close distance from the stop codons of both. Accordingly, the number of the ORFs immediately flanked by SMAGs is higher than the number of repeats (501 vs. 406). By contrast, we found only 81 SMAGs located 1–50 bp from ORF stop codons, and 16 that overlap ORF start codons and encode 4–29 aminoacids. About 1/3 of the ORFs flanked 5′ by SMAGs (26/97) carries SMAG sequences also at the 3′ end. K279a ORFs at a close distance from SMAGs are listed in Table S2. Thirty SMAGs are entirely located within ORFs. These repeats can be sorted

into two main groups. Sixteen out of 30 lie within ORFs encoding small hypothetical proteins that do not exhibit significant homology to ORFs encoded by either the S. maltophilia R551-3 or other prokaryotic genomes, and thus plausibly do not correspond to authentic gene products. Similar conclusions were reached for short ORFs interrupted by REPs in Pseudomonas syringae (Tobes & Pareja, 2005). The remaining 14 repeats are found at the same relative genome coordinates in the R551-3 DNA. However, only six interrupted ORFs are conserved in the two strains. SMAGs within ORFs are listed in Table S3. On the whole, intergenic SMAGs are SRT1720 found at 747 loci. Of these, 370 separate unidirectionally transcribed ORFs, 343 convergently transcribed ORFs and only 34 divergently transcribed ORFs. The size of repeated DNA families may vary among isolates. To gain a rough estimate of the size of SMAG families scattered in the other two sequenced S. maltophilia genomes, repeats perfectly matching the 40 SMAG sequence variants found in K279a DNA enough were searched in R551-3 and SKA14 DNAs. The relative abundance of the five SMAG subfamilies is comparable

in the three genomes. However, their sizes varied, SMAG-2 elements being more abundant in R551-3 and SKA14 and SMAG-3 being predominant in K279a DNA (Fig. 4). The degree of conservation of SMAG sequences was checked by direct sequence comparisons. Thirty-two regions of the K279a chromosome containing SMAG-3 dimers were analyzed in R551-3. Dimers were conserved in 10 regions, missing in nine and replaced in 13 by SMAG-1 or SMAG-2 sequences (monomers or dimers). Fifty K279a intergenic regions containing SMAG-1 HH dimers were also checked in R551-3 DNA. Most (91%) of the K279a SMAG-1 fit the consensus WGCCGGCCgctGGCCGCCW, and have been called α units, and only 4% fit the consensus CGCCGGGCcatGCCCGGCG, and have been called β units (lowercase letters denote loop sequences).