Genetic diversity assessment and genome-wide association study reveal candidate genes associated with component traits in sweet potato (Ipomoea batatas (L.) Lam).

The Korean sweet potatoes were bred by various cultivars introduced from Japanese, American, Porto Rico, China, and Burundi. This issue enriched their genetic diversity but also resulted in a mixture of cultivars. For genotyping, we collected and sequenced 66 sweet potato germplasms from different localities around Korea, including 36 modern cultivars, 5 local cultivars, and 25 foreign cultivars. This identified 447.6 million trimmed reads and 324.8 million mapping reads and provided 39,424 single nucleotide polymorphisms (SNPs) markers. Phylogenetic clustering and population structure analysis distinctly classified these germplasms into 5 genetic groups, group 1, group 2, group 3, group 4, and group 5, containing 20, 15, 10, 7, and 14 accessions, respectively. Sixty-three significant SNPs were selected by genome-wide association for sugar composition-related traits (fructose, glucose, and total sugars), total starch, amylose content, and total carotenoid of the storage root. A total of 37 candidate genes encompassing these significant SNPs were identified, among which, 7 genes were annotated to involve in sugar and starch metabolism, including galactose metabolism (itf04g30630), starch and sucrose metabolism (itf03g13270, itf15g09320), carbohydrate metabolism (itf14g10250), carbohydrate and amino acid metabolism (itf12g19270), and amino sugar and nucleotide sugar metabolism (itf03g21950, itf15g04880). This results indicated that sugar and starch are important characteristics to determine the genetic diversity of sweet potatoes. These findings not only illustrate the importance of component traits to genotyping sweet potatoes but also explain an important reason resulting in genetic diversity of sweet potato.

Longitudinal and prospective assessment of prenatal maternal sleep quality and associations with newborn hippocampal and amygdala volume.

BACKGROUND: The rapid maturation of the fetal brain renders the fetus susceptible to prenatal environmental signals. Prenatal maternal sleep quality is known to have important health implications for newborns including risk for preterm birth, however, the effect on the fetal brain is poorly understood. METHOD: Participants included 94 pregnant participants and their newborns (53% female). Pregnant participants (Mage = 30; SDage= 5.29) reported on sleep quality three times throughout pregnancy. Newborn hippocampal and amygdala volumes were assessed using structural magnetic resonance imaging. Multilevel modeling was used to test the associations between trajectories of prenatal maternal sleep quality and newborn hippocampal and amygdala volume. RESULTS: The overall trajectory of prenatal maternal sleep quality was associated with hippocampal volume (left: b = 0.00003, p = 0.013; right: b = 0.00003, p = .008). Follow up analyses assessing timing of exposure indicate that poor sleep quality early in pregnancy was associated with larger hippocampal volume bilaterally (e.g., late gestation left: b = 0.002, p = 0.24; right: b = 0.004, p = .11). Prenatal sleep quality was not associated with amygdala volume. CONCLUSION: These findings highlight the implications of poor prenatal maternal sleep quality and its role in contributing to newborn hippocampal development.

Factors associated with bronchiectasis in Korea: a national database study.

BACKGROUND: Many important clinical features of bronchiectasis have been reported. However, the factors were evaluated using a specific disease cohort. Thus, clinical factors associated with bronchiectasis have not been well assessed in comparison to the general population. The aim of this study was to evaluate the factors associated with bronchiectasis using a national representative database. METHODS: We conducted a cross-sectional study using data from the Korean National Health and Nutrition Examination Survey 2007-2009. To evaluate factors associated with bronchiectasis, a multivariable logistic analysis was used with adjustment for demographic and socioeconomic factors. RESULTS: In the present study, the prevalence of bronchiectasis was 0.4%. Compared with subjects without bronchiectasis, subjects with bronchiectasis were older (55.1 vs. 44.4 years, P<0.001) and had lower body mass index (BMI) (23.2 vs. 24.2 kg/m2, P<0.001). The proportions of low family income (70.5% vs. 40.2%, P<0.001) and low educational level (less than high school) (85.3% vs. 70.6%, P=0.041) were higher in subjects with bronchiectasis than in subjects without bronchiectasis. Regarding comorbidities, subjects with bronchiectasis were more likely to have asthma (17.8% vs. 2.9%, P<0.001), previous history of pulmonary tuberculosis (TB) (43.5% vs. 5.0%, P<0.001), osteoporosis (19.1% vs. 7.8%, P=0.002), and depression (9.3% vs. 3.0%, P=0.015) compared with subjects without bronchiectasis. In addition, subjects with bronchiectasis had more respiratory symptoms and poorer quality of life measured using the EuroQoL five dimensions questionnaire (EQ-5D) index (0.87 vs. 0.93, P<0.001) than subjects without bronchiectasis. In multivariable logistic regression analysis, low family income (adjusted odds ratio, OR =3.83, 95% confidence interval, CI: 1.46-10.03), asthma (adjusted OR =3.73, 95% CI: 1.29-10.79), pulmonary TB (adjusted OR =7.88, 95% CI: 2.65-23.39), and the presence of airflow limitation (adjusted OR =2.98, 95% CI: 1.01-8.98) were independently associated with bronchiectasis. CONCLUSIONS: Subjects with bronchiectasis suffered from more respiratory symptoms with limited physical activity and poorer quality of life than the general population. Factors independently associated with bronchiectasis were lower family income and comorbid pulmonary conditions, such as previous pulmonary TB, asthma, and airflow limitation.