A SNP/microsatellite genetic linkage map of the Atlantic cod (Gadus morhua)

A first genetic linkage map of the Atlantic cod ( Gadus morhua ) was produced, based on segregation data from 12 full-sib families of Norwegian origin. The map contained 174 single nucleotide polymorphism markers and 33 microsatellites, distributed on 25 linkage groups and had a length of 1225 cM. A significant difference in recombination rates between sexes was found, the average ratio of female:male recombination rates being 1.78 ± 1.62 (SD).     

Retroviral-mediated gene transfer into mammalian cells

Retroviruses may be used as genetic vectors to transfer genes into mammalian cells with high efficiency. We have shown that the N2 vector will transfer a functional bacterial gene for neomycin resistance (NeoR) into more than 80% of mouse spleen foci. A derivative of the N2 vector was constructed to study transfer and expression of the human gene for adenosine deaminase (ADA) in mammalian lymphoid and hematopoietic stem cells. This vector, termed SAX, contains the human ADA cDNA with an SV40 promoter in addition to the NeoR gene. The SAX vector was found to efficiently transfer and express the ADA gene in an ADA-deficient human T-cell line. Gene transfer by SAX using an autologous nonhuman primate bone marrow transplant model resulted in expression of the human ADA gene in peripheral blood cells of treated animals. Human bone marrow treated with SAX produced 1%-2% of colonies in vitro that were expressing the vector genes. Transfer of genes into circulating hematopoietic stem cells of fetal sheep in utero was most efficient; vector gene expression was evident in 20%-40% of hematopoietic colonies. Therefore, retroviral vectors are capable of transferring functional genes into a wide variety of mammalian lymphoid and hematopoietic cells. Such vectors may be useful for clinical trials of gene therapy, that is, the correction of genetic diseases by insertion of a normal gene into a patient's defective cells.     

The rabbit alpha-like globin gene cluster is polymorphic both in the sizes of BamHI fragments and in the numbers of duplicated sets of genes

The alpha-like globin gene cluster in rabbits contains embryonic zeta- globin genes, an adult alpha-globin gene, and theta-globin genes of undetermined function. The basic arrangement of genes, deduced from analysis of cloned DNA fragments, is 5'-zeta 0-zeta 1-alpha 1-theta 1- zeta 2-zeta 3-theta 2-3'. However, the pattern of restriction fragments containing zeta- and theta-globin genes varies among individual rabbits. Analysis of BamHI fragments of genomic DNA from 24 New Zealand white rabbits revealed eight different patterns of fragments containing zeta-globin genes. The large BamHI fragments containing genes zeta 0 and zeta 1 are polymorphic in length, whereas a 1.9-kb fragment containing the zeta 2 gene and the 3.5-kb fragment containing the zeta 3 gene do not vary in size. In contrast to this constancy in the size of the restriction fragments, the copy number of the zeta 2 and zeta 3 genes does vary among different rabbits. No length polymorphism was detected in the BamHI fragments containing the theta-globin genes, but again the copy number varies for restriction fragments containing the theta 2 gene. The alpha 1- and theta 1-globin genes are located in a nonpolymorphic 7.2-kb BamHI fragment. The combined data from hybridization with both zeta and theta probes shows that the BamHI cleavage pattern does not vary within the region 5'-alpha 1-theta 1- zeta 2-zeta 3-theta 2-3', but the pattern genomic blot-hybridization patterns for the progeny of parental rabbits with different zeta-globin gene patterns shows that the polymorphic patterns are inherited in a Mendelian fashion. Two different haplotypes have been mapped based on the genomic blot-hybridization data. The variation in the alpha-like globin gene cluster in the rabbit population results both from differences in the copy number of the duplication block containing the zeta-zeta-theta gene set and from the presence or absence of polymorphic BamHI sites.      

Assignment of orthologous relationships among mammalian alpha-globin genes by examining flanking regions reveals a rapid rate of evolution

In order to study the relationships among mammalian alpha-globin genes, we have determined the sequence of the 3' flanking region of the human alpha 1 globin gene and have made pairwise comparisons between sequenced alpha-globin genes. The flanking regions were examined in detail because sequence matches in these regions could be interpreted with the least complication from the gene duplications and conversions that have occurred frequently in mammalian alpha-like globin gene clusters. We found good matches between the flanking regions of human alpha 1 and rabbit alpha 1, human psi alpha 1 and goat I alpha, human alpha 2 and goat II alpha, and horse alpha 1 and goat II alpha. These matches were used to align the alpha-globin genes in gene clusters from different mammals. This alignment shows that genes at equivalent positions in the gene clusters of different mammals can be functional or nonfunctional, depending on whether they corrected against a functional alpha-globin gene in recent evolutionary history. The number of alpha-globin genes (including pseudogenes) appears to differ among species, although highly divergent pseudogenes may not have been detected in all species examined. Although matching sequences could be found in interspecies comparisons of the flanking regions of alpha- globin genes, these matches are not as extensive as those found in the flanking regions of mammalian beta-like globin genes. This observation suggests that the noncoding sequences in the mammalian alpha-globin gene clusters are evolving at a faster rate than those in the beta-like globin gene clusters. The proposed faster rate of evolution fits with the poor conservation of the genetic linkage map around alpha-globin gene clusters when compared to that of the beta-like globin gene clusters. Analysis of the 3' flanking regions of alpha-globin genes has revealed a conserved sequence approximately 100-150 bp 3' to the polyadenylation site; this sequence may be involved in the expression or regulation of alpha-globin genes.      

Lipid Peroxidation by the Manganese Peroxidase of Phanerochaete chrysosporium Is the Basis for Phenanthrene Oxidation by the Intact Fungus

The manganese peroxidase (MnP) of Phanerochaete chrysosporium supported Mn(II)-dependent, H₂O₂-independent lipid peroxidation, as shown by two findings: linolenic acid was peroxidized to give products that reacted with thiobarbituric acid, and linoleic acid was peroxidized to give hexanal. MnP also supported the slow oxidation of phenanthrene to 2,2′-diphenic acid in a reaction that required Mn(II), oxygen, and unsaturated lipids. Phenanthrene oxidation to diphenic acid by intact cultures of P. chrysosporium occurred to the same extent that oxidation in vitro did and was stimulated by Mn. These results support a role for MnP-mediated lipid peroxidation in phenanthrene oxidation by P. chrysosporium.     

Prey selection in coastal Eurasian otters Lutra Iutra

Prey preferences and dietary differences between sex and age categories of Eurasian otters were studied in coastal Norwegian habitats Relative to their trapping frequency potential prey species with hard, spiny exoskeletons (crabs and sea urchins) or otherwise tough, spiny integuments (Labridae) were much less frequently found in spraints than fish species with soft integuments Spines did not protect fish with otherwise soft integuments from otter predation The number of non-fish taxa per otter stomach did not vary significantly between otter age categories despite presumed differences in hunting abilities (small cubs large cubs and subadults, adults) Relative frequency of occurrence of crabs and sea urchins was < 5% in the stomachs in each of these otter categories Anadromous, katadromous and freshwater fish species were infrequently eaten The coastal otter population during the study period probably had access to an adequate, and preferred, supply of marine fish prey
At the otter population level no prey size selection was conclusively demonstrated within the range of fish sizes sampled However, fish sizes eaten differed significantly between otter sex and age categories The fish sizes per stomach were on average larger in males than in females, regardless of age Adult males tended to eat the largest fishes Among the self provisioning age categories (subadult and adult otters) fish lengths differed significantly between otter males and females, but not between the otter age categories, and did not covary significantly with otter body length Fish eaten by females with old placental scars (potential mothers of fisheating cubs) were significantly smaller than those eaten by small cubs, provisioned by their mothers     

Quantitative analysis of growth and volatile fatty acid production by the anaerobic ruminal bacterium Megasphaera elsdenii T81

Megasphaera elsdenii T81 grew on either dl-lactate or d-glucose at similar rates (0.85 h^?1) but displayed major differences in the fermentation of these substrates. Lactate was fermented at up to 210-mM concentration to yield acetic, propionic, butyric, and valeric acids. The bacterium was able to grow at much higher concentrations of d-glucose (500 mM), but never removed more than 80 mM of glucose from the medium, and nearly 60 % the glucose removed was sequestered as intracellular glycogen, with low yields of even-carbon acids (acetate, butyrate, caproate). In the presence of both substrates, glucose was not used until lactate was nearly exhausted, even by cells pregrown on glucose. Glucose-grown cultures maintained only low extracellular concentrations of acetate, and addition of exogenous acetate increased yields of butyrate, but not caproate. By contrast, exogenous acetate had little effect on lactate fermentation. At pH 6.6, growth rate was halved by exogenous addition of 60 mM propionate, 69 mM butyrate, 44 mM valerate, or 33 mM caproate; at pH 5.9, these values were reduced to 49, 49, 18, and 22 mM, respectively. The results are consistent with this species’ role as an effective ruminal lactate consumer and suggest that this organism may be useful for industrial production of volatile fatty acids from lactate if product tolerance could be improved. The poor fermentation of glucose and sensitivity to caproate suggests that this strain is not practical for industrial caproate production.     

Insomnia,Excessive Sleepiness,Excessive Fatigue,Anxiety, Depression and Shift Work Disorder in Nurses Having Less than 11 Hours in-Between Shifts

Study objective

To assess if less than 11 hours off work between work shifts (quick returns) was related to insomnia, sleepiness, fatigue, anxiety, depression and shift work disorder among nurses.

Methods

A questionnaire including established instruments measuring insomnia (Bergen Insomnia Scale), sleepiness (Epworth Sleepiness Scale), fatigue (Fatigue Questionnaire), anxiety/depression (Hospital Anxiety and Depression Scale) and shift work disorder was administered. Among the 1990 Norwegian nurses who participated in the study; 264 nurses had no quick returns, 724 had 1–30 quick returns and 892 had more than 30 quick returns during the past year. 110 nurses did not report the number of quick returns during the past year. The prevalence of insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder was calculated within the three groups of nurses. Crude and adjusted logistic regression analyses were performed to assess the relation between quick returns and such complaints.

Results

We found a significant positive association between quick returns and insomnia, excessive sleepiness, excessive fatigue and shift work disorder. Anxiety and depression were not related to working quick returns.

Conclusions

There is a health hazard associated with quick returns. Further research should aim to investigate if workplace strategies aimed at reducing the number of quick returns may reduce complaints among workers.     

Methicillin-Resistant Staphylococcus aureus (MRSA) Is Increasing in Norway: A Time Series Analysis of Reported MRSA and Methicillin-Sensitive S. aureus Cases, 1997–2010

Background

Accurate estimates of the incidence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections are needed to inform public health policies. In Norway, where both MRSA infection and carriage are notifiable conditions, the reported incidence of MRSA is slowly increasing. However, the proportion of MRSA in relation to all S. aureus isolates is unknown, making it difficult to determine if the rising incidence is real or an artifact of an increasing number of tests performed.

Aim

To characterize recent trends in MRSA infections and obtain a more complete understanding of the MRSA level in Norway.

Methods

All reported cases of MRSA and methicillin-sensitive S. aureus (MSSA) from Oslo County (1997–2010) and Health Region East (2008–2008), representing approximately 11% and 36% of the Norwegian population, respectively, were analyzed using a stochastic time series analysis to characterize trends.

Results

In Oslo County, the proportion of methicillin-resistant cases increased from 0.73% to 3.78% during the study period and was well modeled by an exponential growth with a doubling constant of 5.7 years (95% CI 4.5–7.4 years). In Health Region East, the proportion of MRSA cases increased from 0.4% to 2.1% from 2002 to 2008, with a best-fitting linear increase of 0.26% (95% CI 0.21–0.30%) per year. In both cases, the choice of a linear or exponential model for the time trend produced only marginally different model fits. We found no significant changes due to revised national MRSA guidelines published in June 2009. Significant variations in the increasing time trend were observed in the five hospitals within the region. The yearly reported incidence of MSSA was relatively stable in both study areas although we found seasonal patterns with peaks in August.

Conclusion

The level of MRSA is increasing in Norway, and the proportion of methicillin resistance in all S. aureus isolates are higher than the reported proportion of MRSA in invasive infections.