/*
* -------
* :ATTRIBUTION NOTICE BEGINS
*
* The following JSMsg functions are:
*
* (C) Copyright 2002 - 2004, Creativyst, Inc.
* ALL RIGHTS RESERVED
*
* For more information go to:
* http://www.Creativyst.com/Doc/Std/JSMsg/JSMsg.htm
* or email:
* Support@Creativyst.com
*
* Licensed under the Open Software License version 1.1
*
* END ATTRIBUTION NOTICE:
* -------
*
* The following version token is
* required by aggregators
* -------
* JSMsgVersion:1.0a
* -------
*
* Made by: JSMFeed.pl v1.0e
*/
/* JSCpragma:StartCompress
*/
/* These functions are free software; you can redistribute
* them and/or modify them under the terms of the Open
* Software License (OSL) version 1.1 as published by
* the Open Source Initiative;
*
* This program is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the Open Software License
* version 1.1 for more details.
*
* For the complete details of the Open Software License
* please visit the Open Source Initiative website.
*
*
* These functions are part of a shared convention.
* called JSMsg. Please see the JSMsg document
* for more details.
*
* www.creativyst.com/Doc/Std/JSMsg/JSMsg.htm
*
* -------------------------------------------
* Parts of this code were automatically
* generated and may contain copyrighted
* content from other sources as well.
* Such content may not be used without
* first obtaining explicit permissions
* from their sources.
*
*
*/
function nn_JSMsg() {
this.Title = Array([this.ShortListSize]);
this.Desc = Array([this.ShortListSize]);
this.Author = Array([this.ShortListSize]);
this.Link = Array([this.ShortListSize]);
this.DateN = Array([this.ShortListSize]);
this.MetaKeys = Array([5]);
this.MetaVals = Array([5]);
this.ShortListSize = 10;
this.BeenLoaded = 0;
this.dispNumb;
this.Msg = function(msgPart, msgOffset)
{
document.write( this.Get(msgPart, msgOffset) );
}
this.MsgDay = function(msgPart)
{
document.write( this.GetDay(msgPart) );
}
this.MsgN = function(msgPart, msgNumber)
{
document.write( this.GetN(msgPart, msgNumber) );
}
this.Get = function(msgPart, msgOffset)
{
if(!msgOffset) {
msgOffset = 0;
}
if(!this.BeenLoaded) {
this.BeenLoaded = 1;
dispNumb =
this.getRandInt(this.ShortListSize);
}
return( this.GetN(msgPart, (dispNumb + msgOffset)) );
}
this.GetMsgN = function()
{
return(this.ShortListSize);
}
this.GetDay = function(msgPart)
{
var d = new Date();
var x = d.getDate();
return( this.GetN(msgPart, x) );
}
this.GetN = function(msgPart, msgNumber)
{
return( this.GetNCore(msgPart, msgNumber) );
}
this.GetNCore = function(msgPart, msgNumber)
{
var myTmp;
if(!msgPart) {
msgPart = "Body";
}
if(!msgNumber) {
msgNumber = 0;
}
if(msgNumber >= this.ShortListSize) {
msgNumber = msgNumber % this.ShortListSize;
}
if( this.ok(msgPart,"Type") ) {
return(this.Type[msgNumber]);
}
if( this.ok(msgPart,"Title") ) {
return(this.Title[msgNumber]);
}
if( this.ok(msgPart, "Desc Description Content") ) {
return(this.Desc[msgNumber]);
}
if( this.ok(msgPart,"Body") ) {
return(this.Body[msgNumber]);
}
if( this.ok(msgPart, "Attrib Attribute Source") ) {
return(this.Attrib[msgNumber]);
}
if( this.ok(msgPart, "Author") ) {
if(!this.Author[msgNumber]) {
return(this.Attrib[msgNumber]);
}
return(this.Author[msgNumber]);
}
if( this.ok(msgPart,"DayN Day2N Day") ) {
myTmp = this.DateN[msgNumber];
if(myTmp.length) {
myTmp = myTmp.substr(6,2);
if( this.ok(msgPart,"Day2N") ) {
return(myTmp);
}
if(myTmp.charAt(0) == "0") {
return(myTmp.substr(1,1))
}
return(myTmp);
}
}
if( this.ok(msgPart, "MonthN Month2N") ) {
myTmp = this.DateN[msgNumber];
if(myTmp.length) {
myTmp = myTmp.substr(4,2)
if( this.ok(msgPart,"Month2N") ) {
return(myTmp);
}
if(myTmp.charAt(0) == "0") {
return(myTmp.substr(1,1))
}
return(myTmp);
}
}
if( this.ok(msgPart, "Year2N Year4N YearN Year") ) {
if(this.DateN[msgNumber].length) {
if( this.ok(msgPart,"Year2N") ) {
return(this.DateN[msgNumber].substr(2,2));
}
return(this.DateN[msgNumber].substr(0,4));
}
}
if( this.ok(msgPart,"Time") ) {
myTmp = this.DateN[msgNumber];
return(myTmp.substr(8,6));
}
if( this.ok(msgPart,"Hour2N") ) {
myTmp = this.DateN[msgNumber];
return(myTmp.substr(8,2));
}
if( this.ok(msgPart,"Minute2N") ) {
myTmp = this.DateN[msgNumber];
return(myTmp.substr(10,2));
}
if( this.ok(msgPart,"Link") ) {
return(this.Link[msgNumber]);
}
if( this.ok(msgPart,"LinkTitle") ) {
if(this.MetaMsg(msgPart,"Link") && this.MetaMsg(msgPart,"Title") ) {
if( !this.Link[msgNumber] ) {
return(this.Title[msgNumber]);
}
if( !this.Title[msgNumber] ) {
this.Title[msgNumber] = this.Link[msgNumber];
}
myTmp = '\n';
myTmp = myTmp + this.Title[msgNumber] + '\n';
return(myTmp);
}
if( this.MetaMsg(msgPart,"Title") ) {
return(this.Title[msgNumber]);
}
if( this.MetaMsg(msgPart,"Link") ) {
if( this.Link[msgNumber] ) {
myTmp = "\n";
myTmp = myTmp + this.Link[msgNumber] + "\n";
return(myTmp);
}
}
return("");
}
if( this.ok(msgPart,"Cat Category Subject") ) {
return(this.Cat[msgNumber]);
}
if( this.ok(msgPart,"Thumb") ) {
return(this.Thumb[msgNumber]);
}
if( this.ok(msgPart,"Alt") ) {
return(this.Alt[msgNumber]);
}
return("");
}
this.getRandInt = function(RandSz)
{
var t, t2, t3;
t = 0;
while(t < .000001) {
t = Math.random();
t = Math.abs(t);
}
t2 = t * 1000000;
t2 = Math.round(t2);
t3 = t2 % RandSz;
return(t3);
}
this.ok = function(a, b)
{
var t, t2;
if(!this.is(a,b)) {
return(0);
}
return(this.MetaMsg(a));
}
this.is = function(a, b)
{
var t, t2;
t = a + " ";
t2 = b + " ";
t2 = t2.toUpperCase();
t = t.toUpperCase();
if(t2.indexOf(t) == -1) {
return(0);
}
return(1);
}
this.MetaMsg = function(msgCmd)
{
var i,l;
if( this.is(msgCmd, "Title LinkTitle Desc Description Author Link LinkTitle DayN Day2N MonthN Month2N Year2N Year4N YearN Year Time Hour2N Minute2N ") ) {
return(1);
}
else if( this.is(msgCmd, "MetaCount") ) {
return(10);
}
else {
if(this.MetaKeys) {
l = this.MetaKeys.length;
for(i = 0;i < l;i++) {
if(this.MetaKeys[i] == msgCmd) {
return(this.MetaVals[i]);
}
}
}
return(0);
}
}
}
nn = new nn_JSMsg();
/* how slow is the with statement */
with( nn ) {
/* Meta values
*/
MetaKeys[0] = "MetaTitle";
MetaVals[0] = "BioMed Central - Latest Articles";
MetaKeys[1] = "MetaLink";
MetaVals[1] = "http://www.biomedcentral.com/";
MetaKeys[2] = "MetaLinkTitle";
MetaVals[2] = "BioMed Central - Latest Articles";
MetaKeys[3] = "MetaUpdateDate";
MetaVals[3] = "20100729000000";
MetaKeys[4] = "MetaDesc";
MetaVals[4] = "The latest research articles published by BioMed Central";
/* content vaues:
*/
Title[0] = "The impact of single versus mixed schistosome species infections on liver, spleen and bladder morbidity within Malian children pre- and post-praziquantel treatment";
Desc[0] = "Background:\nIn the developing world co-infections and polyparasitism within humans appear to be the rule rather than the exception, be it any combination of inter-specific and/or inter- and intra-Genera mixed infections. Inter-Genera mixed infections might generate synergistic or antagonistic interactions and thereby clinically affect individuals and/or impact parasite epidemiology. Methods: The current study uniquely assesses both Schistosoma mansoni- and Schistosoma haematobium- related morbidity of the liver and the bladder as assessed by ultrasound as well as spleen and liver morbidity through clinical exams. The impact of praziquantel (PZQ) treatment on such potential inter-specific schistosome interactions and resulting morbidity using uniquely detailed longitudinal data (pre- and one year post-PZQ treatment) arising from the National Schistosomiasis Control Program in three areas of Mali: Segou, Koulikoro and Bamako, is also evaluated. At baseline, data were collected from up to 2196 children (aged 7-14 years), 844 of which were infected with S. haematobium only, 124 with S. mansoni only and 477 with both. Follow-up data were collected from up to 1265 children.\nResults:\nResults suggested lower liver morbidity in mixed compared to single S. mansoni infections and higher bladder morbidity in mixed compared to single S. haematobium infections. Single S. haematobium or S. mansoni infections were also associated with liver and spleen morbidity whilst only single S. haematobium infections were associated with bladder morbidity in these children (light S. haematobium infection OR: 4.3, p<0.001 and heavy S. haematobium infection OR: 19, p<0.001). PZQ treatment contributed to the regression of some of the forms of such morbidities. Conclusions: Whilst the precise biological mechanisms for these observations remain to be ascertained, the results illustrate the importance of considering mixed species infections in any analyses of parasite-induced morbidity, including that for the proposed Disability Adjusted Life Years (DALYs) revised estimates of schistosomiasis morbidity.";
Author[0] = "Artemis Koukounari";
Link[0] = "http://www.biomedcentral.com/1471-2334/10/227";
DateN[0] = "20100729000000";
Title[1] = "Nuclear transcription factors in mammalian mitochondria";
Desc[1] = "Nuclear transcription factors have been detected in mammalian mitochondria and may directly regulate mitochondrial gene expression. Emerging genomics techniques may overcome outstanding challenges in this field.";
Author[1] = "";
Link[1] = "http://genomebiology.com/2010/11/7/215";
DateN[1] = "20100729000000";
Title[2] = "Neuronal transcription factor Brn-3a(l) is over expressed in high-grade ovarian carcinomas and tumor cells from ascites of patients with advanced-stage ovarian cancer\n\n";
Desc[2] = "Objectives: In view of the recent association of Brn-3 transcription factors with neuroblastomas, cervical, breast, and prostate cancers we examined the expression of Brn-3a(l) in normal ovaries and in different histological grades of ovarian tumors. The expression of Brn-3a(l) was also evaluated in normal ovarian and cancer cell lines and tumor cells isolated from the ascites of advanced-stage ovarian cancer patients.\nMethods:\nNormal ovaries, benign, borderline, grades 1, 2 and 3 ovarian tumors were analyzed by immunohistochemistry for Brn-3a(l) expression. A total of 46 ovarian specimens were included in the study. Immunofluorescence was used to investigate the expression of Brn-3a in normal ovarian and cancer cell lines. Brn-3a(l) expression was also evaluated by Western blot in tumor cells isolated from ascites of advanced-stage ovarian cancer patients and also in ovarian cancer cell lines.\nResults:\nNearly 12% of normal and benign ovarian tissues and 57% of borderline ovarian tumors were positive for epithelial Brn-3a(l) expression. Stromal staining was higher and it constituted 40% of normal non-cancerous ovaries compared to 50 and 86% in benign and borderline tumors. On the other hand, 85-100% of grades 1, 2 & 3 ovarian tumors demonstrated nuclear and cytoplasmic Brn-3a(l) staining in the epithelium. Stromal staining in grades1, 2 and 3 tumors constituted 71-88% of total staining. Overall, immunoreactive Brn-3a was present in all grades of ovarian tumors. The extent of epithelial and stromal Brn-3a staining was significantly different between the normal and histological grades of tumors (epithelial-chi square=41.01, df=20, P=0.004, stromal-chi square=24.66. df=15, P=0.05). The extent of epithelial staining was significantly higher in grades 1 and 2 ovarian tumors compared to normal ovaries and benign ovarian tumors (p<0.05). In parallel, stromal staining was significantly higher in grade 3 tumors compared to normal ovaries (p<0.05). In addition, cytoplasmic and nuclear Brn-3a expression was evident in ovarian cancer cell lines while no such expression was observed in SV40 antigen immortalized normal ovarian cell lines.\nConclusion:\nThese data suggest that like other cancers, Brn-3a(l) expression is enhanced in ovarian tumors and its expression is consistent with its known role in inhibiting apoptosis and enhancing tumorigenesis. Specific targeting of Brn-3a may provide a useful strategy for regulating multiple tumor related genes involved with ovarian carcinomas.";
Author[2] = "Nuzhat Ahmed";
Link[2] = "http://www.ovarianresearch.com/content/3/1/17";
DateN[2] = "20100729000000";
Title[3] = "Overexpression of hTERT increases stem-like properties and decreases spontaneous differentiation in human mesenchymal stem cell lines";
Desc[3] = "To overcome loss of stem-like properties and spontaneous differentiation those hinder the expansion and application of human mesenchymal stem cells (hMSCs), we have clonally isolated permanent and stable human MSC lines by ectopic overexpression of primary cell cultures of hMSCs with HPV 16 E6E7 and human telomerase reverse transcriptase (hTERT) genes. These cells were found to have a differentiation potential far beyond the ordinary hMSCs. They expressed trophoectoderm and germline specific markers upon differentiation with BMP4 and retinoic acid, respectively. Furthermore, they displayed higher osteogenic and neural differentiation efficiency than primary hMSCs or hMSCs expressed HPV16 E6E7 alone with a decrease in methylation level as proven by a global CpG island methylation profile analysis. Notably, the demethylated CpG islands were highly associated with development and differentiation associated genes. Principal component analysis further pointed out the expression profile of the cells converged toward embryonic stem cells. These data demonstrate these cells not only are a useful tool for the studies of cell differentiation both for the mesenchymal and neurogenic lineages, but also provide a valuable source of cells for cell therapy studies in animal models of skeletal and neurological disorders.";
Author[3] = "Chih-Chien Tsai";
Link[3] = "http://www.jbiomedsci.com/content/17/1/64";
DateN[3] = "20100729000000";
Title[4] = "Piecing together the problems in diagnosing low-level chromosomal mosaicism";
Desc[4] = "Low-level somatic chromosomal mosaicism, which usually arises from post-zygotic errors, is a known cause of several well defined genetic syndromes and has been implicated in various multifactorial diseases. It is, however, not easy to diagnose, as various physical and technical factors complicate its identification.";
Author[4] = "Caroline Robberecht";
Link[4] = "http://genomemedicine.com/content/2/7/47";
DateN[4] = "20100729000000";
Title[5] = "MacroH2A subtypes contribute antagonistically to the transcriptional regulation of the ribosomal cistron during seasonal acclimatization of the carp fish";
Desc[5] = "Background:\nThe incorporation of histone variants into chromatin is one of the epigenetic mechanisms used for regulation of gene expression. MacroH2A (mH2A) is a histone variant which displays two different subtypes in vertebrates: mH2A1 and mH2A2. Although, mH2A has been associated with gene silencing, recent studies indicate that mH2A subtypes could contribute more widely to transcriptional regulation. We have previously demonstrated that gene-reprogramming response mediates the carp fish adaptation to the environment. Within this context, we have described that ribosomal DNA (rDNA) transcription is seasonally regulated in carp. However, little evidence has been reported onto how epigenetic mechanisms contribute to environmental adaptation and, in particular, on ribosomal cistron regulation.\nResults:\nIn this study, we demonstrate the occurrence of differential chromatin incorporation of mH2A subtypes through carp seasonal adaptation and that this event concurs with opposite transcriptional states. Moreover, we observed that carp ribosomal cistron is enriched in mH2A1 during winter, and conversely, in mH2A2 during summer. Consistently, mH2A1 co-localizes with a heterochromatin marker (H3K27me2) and mH2A2 with an euchromatin marker (H3K4me3). These results were consistent with enrichment of the mH2A subtypes in the L41 promoter gene.\nConclusions:\nWe have characterized both mH2A subtypes from carp fish, and evaluated their participation in the regulation of the ribosomal cistron. Our findings revealed that the differential incorporation of mH2A subtypes could regulate gene expression during the acclimatization process of carp. In this context, we report new evidence that reveal a differential chromatin incorporation of mH2A subtypes through the environmental adaptation process, which concurs with antagonist transcriptional states in the carp ribosomal cistron.";
Author[5] = "Ingrid Araya";
Link[5] = "http://www.epigeneticsandchromatin.com/content/3/1/14";
DateN[5] = "20100729000000";
Title[6] = "Seasonal influences on sleep and executive function in the migratory White-crowned Sparrow\n\n(Zonotrichia leucophrys gambelii)\n\n";
Desc[6] = "Background:\nWe have previously shown that the White-crowned Sparrow (WCS) decreases sleep by 60% during a period of migratory restlessness relative to a non-migratory period when housed in a 12h light: 12h dark cycle. Despite this sleep reduction, accuracy of operant performance was not impaired, and in fact rates of responding were elevated during the migratory period, effects opposite to those routinely observed following enforced sleep deprivation. To determine whether the previously observed increases in operant responding were due to improved performance or to the effects of migration on activity level, here we assessed operant performance using a task in which optimal performance depends on the bird's ability to withhold a response for a fixed interval of time (differential-reinforcement-of-low-rate-behavior, or DRL); elevated response rates ultimately impair performance by decreasing access to food reward. To determine the influence of seasonal changes in day length on sleep and behavioral patterns, we recorded sleep and assessed operant performance across 4 distinct seasons (winter, spring, summer and fall) under a changing photoperiod.\nResults:\nSleep amount changed in response to photoperiod in winter and summer, with longest sleep duration in the winter. Sleep duration in the spring and fall migratory periods were similar to what we previously reported, and were comparable to sleep duration observed in summer. The most striking difference in sleep during the migratory periods compared to non-migratory periods was the change from discrete day-night temporal organization to an almost complete temporal fragmentation of sleep. The birds' ability to perform on the DRL task was significantly impaired during both migratory periods, but optimal performance was sustained during the two non-migratory periods.\nConclusions:\nBirds showed dramatic changes in sleep duration across seasons, related to day length and migratory status. Migration was associated with changes in sleep amount and diurnal distribution pattern, whereas duration of sleep in the non-migratory periods was largely influenced by the light-dark cycle. Elevated response rates on the DRL task were observed during migration but not during the short sleep duration of summer, suggesting that the migratory periods may be associated with decreased inhibition/increased impulsivity. Although their daily sleep amounts and patterns may vary by season, birds are susceptible to sleep loss throughout the year, as evidenced by decreased responding rates following enforced sleep deprivation.";
Author[6] = "Stephanie Jones";
Link[6] = "http://www.biomedcentral.com/1471-2202/11/87";
DateN[6] = "20100729000000";
Title[7] = "Association of bovine leptin polymorphisms with energy output and energy storage traits in progeny tested Holstein-Friesian dairy cattle sires";
Desc[7] = "Background:\nLeptin modulates appetite, energy expenditure and the reproductive axis by signalling via its receptor the status of body energy stores to the brain. The present study aimed to quantify the associations between 10 novel and known single nucleotide polymorphisms in genes coding for leptin and leptin receptor with performance traits in 848 Holstein-Friesian sires, estimated from performance of up to 43,117 daughter-parity records per sire.\nResults:\nAll single nucleotide polymorphisms were segregating in this sample population and none deviated (P>0.05) from Hardy-Weinberg equilibrium. Complete linkage disequilibrium existed between the novel polymorphism LEP-1609, and the previously identified polymorphisms LEP-1457 and LEP-580. LEP-2470 associated (P<0.05) with milk protein concentration and calf perinatal mortality. It had a tendency to associate with milk yield (P<0.1). The G allele of LEP-1238 was associated (P<0.05) with reduced milk fat concentration, reduced milk protein concentration, longer gestation length and tended to associate (P<0.1) with an increase in calving difficulty, calf perinatal mortality and somatic cells in the milk. LEP-963 exhibited an association (P<0.05) with milk fat concentration, milk protein concentration, calving difficulty and gestation length. It also tended to associate with milk yield (P<0.1). The R25C SNP associated (P<0.05) with milk fat concentration, milk protein concentration, calving difficulty and length of gestation. The T allele of the Y7F SNP significantly associated with reduced angularity (P<0.01) and reduced milk protein yield (P<0.05). There was also a tendency (P<0.1) for Y7F to associate with increased body condition score, reduced milk yield and shorter gestation (P<0.1). A80V associated with reduced survival in the herd (P<0.05).\nConclusions:\nSeveral leptin polymorphisms (LEP-2470, LEP-1238, LEP-963, Y7F and R25C) associated with the energetically expensive process of lactogenesis. Only SNP Y7F associated with energy storage. Associations were also observed between leptin polymorphisms and calving difficulty, gestation length and calf perinatal mortality. The lack of an association between the leptin variants investigated with calving interval in this large data set would question the potential importance of these leptin variants, or indeed leptin, in selection for improved fertility in the Holstein-Friesian dairy cow.";
Author[7] = "Linda Giblin";
Link[7] = "http://www.biomedcentral.com/1471-2156/11/73";
DateN[7] = "20100729000000";
Title[8] = "Increasing delivery of an outdoor journey intervention to people with stroke: A feasibility study involving five community rehabilitation teams";
Desc[8] = "Background:\nContrary to recommendations in a national clinical guideline, baseline audits from five community-based stroke rehabilitation teams demonstrated an evidence-practice gap; only 17% of eligible people with stroke were receiving targeted rehabilitation to increase outdoor journeys, by occupational therapists and physiotherapists. The primary aim of this feasibility study was to design, test and evaluate the impact of an implementation program, intended to change the behaviour of community rehabilitation teams. A secondary aim was to measure the impact of this change on client outcomes.\nMethods:\nA before-and-after study design was used. The primary data collection method was a medical record audit. Five community rehabilitation teams and a total of 12 professionals were recruited, including occupational therapists, physiotherapists and a therapy assistant. A medical record audit was conducted twice over 12 months (total of 77 records pre-intervention, 53 records post-intervention), against a guideline recommendation about delivering outdoor journey sessions to people with stroke. A behavioural intervention (the Out-and-About implementation program) was used to help change team practice; active components of the intervention feedback about the audit, barrier identification and tailored education to target known barriers. The primary outcome measure was the proportion of medical records containing evidence of multiple outdoor journey sessions. Other outcomes of interest included the proportion of medical records that contained evidence of screening for outdoor journeys and driving by team members, and changes in patient outcomes. A small sample of community-dwelling people with stroke (n=23) provided pre-post outcome data over three months. Data were analysed using descriptive statistics and t-tests.\nResults:\nMedical record audits found that teams were delivering six or more outdoor journeys to 17% of people with stroke pre-intervention, rising to 32% 12 months post intervention. This change represents a modest change in practice behaviour (15%) across teams. More people with stroke (57%) reported getting out of the house as often as they wanted after receiving the outdoor journey intervention compared to 35% one year earlier; other quality of life outcomes also improved.\nConclusions:\nThe Out-and-About implementation program helped rehabilitation teams to change their practice, implement evidence and improve client outcomes. This behavioural intervention requires more rigorous evaluation using a cluster randomised trial design.";
Author[8] = "Annie McCluskey";
Link[8] = "http://www.implementationscience.com/content/5/1/59";
DateN[8] = "20100729000000";
Title[9] = "Single-stranded heteroduplex intermediates in lambda Red homologous recombination";
Desc[9] = "Background:\nThe Red proteins of lambda phage mediate probably the simplest and most efficient homologous recombination reactions yet described. However the mechanism of dsDNA recombination remains undefined.\nResults:\nHere we show that the Red proteins can act via full length single stranded intermediates to establish single stranded heteroduplexes at the replication fork. We created asymmetrically digestible dsDNA substrates by exploiting the fact that Red alpha exonuclease activity requires a 5' phosphorylated end, or is blocked by phosphothioates. Using these substrates, we found that the most efficient configuration for dsDNA recombination occurred when the strand that can prime Okazaki-like synthesis contained both homology regions on the same ssDNA molecule. Furthermore, we show that Red recombination requires replication of the target molecule.\nConclusions:\nHence we propose a new model for dsDNA recombination, termed 'beta' recombination, based on the formation of ssDNA heteroduplexes at the replication fork. Implications of the model were tested using (i) an in situ assay for recombination, which showed that recombination generated mixed wild type and recombinant colonies; and (ii) the predicted asymmetries of the homology arms, which showed that recombination is more sensitive to non-homologies attached to 5' than 3' ends. Whereas beta recombination can generate deletions in target BACs of at least 50 kb at about the same efficiency as small deletions, the converse event of insertion is very sensitive to increasing size. Insertions up to 3 kb are most efficiently achieved using beta recombination, however at greater sizes, an alternative Red-mediated mechanism(s) appears to be equally efficient. These findings define a new intermediate in homologous recombination, which also has practical implications for recombineering with the Red proteins.";
Author[9] = "Marcello Maresca";
Link[9] = "http://www.biomedcentral.com/1471-2199/11/54";
DateN[9] = "20100729000000";
} // end with block