Selective Pressures to Maintain Attachment Site Specificity of Integrative and Conjugative Elements

Integrative and conjugative elements (ICEs) are widespread mobile genetic elements that are usually found integrated in bacterial chromosomes. They are important agents of evolution and contribute to the acquisition of new traits, including antibiotic resistances. ICEs can excise from the chromosome and transfer to recipients by conjugation. Many ICEs are site-specific in that they integrate preferentially into a primary attachment site in the bacterial genome. Site-specific ICEs can also integrate into secondary locations, particularly if the primary site is absent. However, little is known about the consequences of integration of ICEs into alternative attachment sites or what drives the apparent maintenance and prevalence of the many ICEs that use a single attachment site. Using ICEBs1, a site-specific ICE from Bacillus subtilis that integrates into a tRNA gene, we found that integration into secondary sites was detrimental to both ICEBs1 and the host cell. Excision of ICEBs1 from secondary sites was impaired either partially or completely, limiting the spread of ICEBs1. Furthermore, induction of ICEBs1 gene expression caused a substantial drop in proliferation and cell viability within three hours. This drop was dependent on rolling circle replication of ICEBs1 that was unable to excise from the chromosome. Together, these detrimental effects provide selective pressure against the survival and dissemination of ICEs that have integrated into alternative sites and may explain the maintenance of site-specific integration for many ICEs.United States. Public Health Service (Grant GM050895

Physicochemical characteristics and fatty acid composition of the meat from korean native black pig with different slaughter weight

The Korean native black pig (KNP) have several desirable meat qualities, which are highly demanded by Koreans in spite of its slow growth rate, low feed efficiency, and small litter size. The aim of this study was to evaluate meat quality and fatty acid composition of KNP at different slaughter weight in order to provide information to industry. Ninety female KNP of the same age (220 days) were divided into three groups by live body weights (30 pigs per each group); live weight of 50~59 kg (T1), 60~69 kg (T2) and 70~80 kg (T3), respectively. After slaughtering the longissimus dorsi muscle (LD) and backfat from each group were obtained after 24 hr chilling. Crude protein content and shear force of LD from T3 was higher than that from T1 and pH of LD was significantly lower in that from T1 than from T2 and T3. Color measurement indicated that LD of T2 group had a higher L*-value and lower a*-value than those of T1 and T3. Slaughter weight of KNP generally did not affect the fatty acid composition of LD and backfat but the content of oleic acid (C18:1) of T2 in LD was significantly higher than those of T1 and T3. The results may provide basic information to industry to promote the production and processing of KNP, and assist in meeting the Korean consumer's demand.N

Effect of Dietary Kocetin™ on Meat Quality of Hanwoo Loin

This study was performed to determine the effects of dietary Kocetin^(TM) on meat quality of Hanwoo(Korean native cattle) beef. Samples were divided into 3 groups; dietary supplementation of Kocetin^(TM)(KC) at 21 and 42 ppm(n=4), and non-supplemented control(n=3) for 75 days. The KC composed of 10% of quercetin which was a bioactive compound. After slaughtering the Hanwoo, each loin from 10 Hanwoos were obtained and analyzed. Dietary supplementation of KC did not affect the final pH, water holding capacity, drip loss, cooking loss, surface color, total phenolics content, radical scavenging activity, and sensory scores. Dietary quercetin also showed no difference in both TBARS and VBN values. Textural profile analysis results also showed no difference, except for adhesiveness and springness. Springness was significantly higher in loin from Hanwoo treated by dietary KC at 42 ppm when compared to control. Results revealed that the loin from Hanwoo fed dietary KC up to 42 ppm (approximately 4.2 ppm of quercetin) was not sufficient to have clear positive effects on meat quality of loin.N

Continuity of Care in Children’s Mental Health: Development of a Measure

A new measure, Continuity of Care in Children’s Mental Health (C3MH), is presented. The study involved item generation, pre-testing, pilot testing, and validation. The C3MH was administered to 364 parents recruited from 13 children’s mental health agencies in Ontario, Canada. The measure includes five scales supported by confirmatory factor analysis. Scale validity was supported through analyses of relationships with established measures of satisfaction, problem severity, and therapeutic alliance, as well as through known-group differences. The results of a pilot youth-report version (N = 57) are presented. The C3MH will be a useful tool for assessing improvements in system integration