The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains.
The migratory response of Echinostoma caproni to host feeding was examined in female ICR mice. Thirty-six mice were each infected with 20 metacercariae of E. caproni . Twenty-eight days post-infection, food, but not water, was withheld for 24 hr. Mice were haphazardly divided into 4 groups of 9, and each group received one of the following treatments: (1) 0.25 g glucose, (2) access to standard lab chow, (3) 0.5 ml saline, and (4) continued fasting. Three mice from each treatment group were killed 1, 2, and 4 hr post-treatment. The intestine of each mouse was removed, flash-frozen, and stored in a conventional freezer for later examination. Intestines were partially thawed, measured, and opened longitudinally, and the position of each worm, or worm cluster was measured. The intestine was divided into equal 5% segments based on the initial measurement and locations of worms, and worm clusters were recorded from the appropriate section of the intestine for analysis. There was no significant effect of treatment in the position of worms at 1 hr. There was a posterior shift in worm position in all treatment groups at 2 hr, except in the saline-treated mice; however, only worms in the glucose-fed mice were significantly posterior to the unfed controls. From 2 to 4 hr, there was a significant anterior movement of worms in both the glucose and chow-fed mice. The data strongly suggest that E. caproni responds to the initiation of gastric activity of the host by migrating anteriorly in the ileum. The specific stimulus for this migration is unknown.
Background. Maternal obesity and physical inactivity have been identified as correlates of overweight and obesity and physical inactivity in older preadolescents; however, no study has explored this relationship in Hispanic preadolescents. Furthermore, the relation between maternal physical activity (PA) and blood pressure (BP) in Hispanic preadolescents has not been examined. Purpose. This study aimed to assess the associations between Hispanic mothers' PA and body mass index (BMI) and their preadolescents' PA, screen time, BP, and BMI. Methods. Data of 118 mother-child (aged 2 to 10 years) dyads enrolled in a cross-sectional study of metabolic syndrome in Hispanic preadolescents at a community health center in Johnson City, TN were used. Parent and child questionnaires were used to ascertain mothers' BMI and PA and preadolescents' PA and screen time. Preadolescents' height, weight, and BP were measured. Multiple logistic regression was used to examine the association between child and maternal variables, adjusting for mother's education and the child's sex and age. Results. Pradolescents of obese mothers were more likely than preadolescents of mothers with normal weight to engage in less than three days of at least 60 minutes of vigorous PA per week (OR: 6.47: 95% CI: 1.61-26.0). Preadolescents whose mothers did not engage in moderate PA were more likely to engage in less than three days of at least 60 minutes of vigorous PA per week (OR: 2.92, CI: 1.18-7.24); and have elevated BP (OR: 2.50, 95% CI: 1.02-4.53) than preadolescents whose mothers engaged in moderate PA. Discussion. Our results show a negative relationship between maternal obesity and preadolescent PA, and a positive relationship between lower maternal PA and elevated BP and lower PA in Hispanic
It is recommended that prenatal care include nutrition counseling; however, <70% of women report receipt of nutrition counseling during pregnancy. In this study, we aimed to characterize prenatal nutrition counseling (PNC) among large-for-gestational age deliveries at a low-income and minority-serving hospital by performing a retrospective chart review of infants with a birth weight > 4000 g. Of the 2380 deliveries, 165 met the inclusion criteria. Demographics, PNC receipt, and pregnancy outcomes were compared among normal-weight (NW; BMI: 18.5–24.9 kg/m2, 19%, n = 31), overweight (OW; BMI: 25–29.9 kg/m2, 29%, n = 48), and obese (OB; BMI > 30 kg/m2, 52%, n = 86) women. The majority (78%, n = 129) of women were Hispanic White with a mean age of 30.4 ± 5.7 yrs and gestational weight gain of 12.1 ± 5.8 kgs. A total of 62% (n = 103) of women received PNC. A total of 57% gained above the Institute of Medicine (IOM) recommendations (n = 94). OB women were 2.6 and 2.1 times more likely to receive PNC than OW (95% CI: 1.1–2.0) and NW (95% CI: 0.9–1.9) women, respectively. Women who gained within the IOM recommendations for their pre-pregnancy body mass index (BMI) were 50% less likely to receive PNC than women who gained above the IOM recommendations for their pre-pregnancy weight (χ = 4.45, p = 0.035; OR = 0.48, CI: 0.24 to 0.95). Infant birthweight was significantly higher among women who received PNC (4314 ± 285 vs. 4197 ± 175 g, p = 0.004). These data suggest that PNC was directed toward women who enter pregnancy in the obese weight category and/or gain excessively across gestation. Future studies should provide PNC to all women to evaluate whether it reduces the risk of delivering large-for-gestational age deliveries across all maternal weight categories. Additionally, more work is needed to identify the types of PNC that are most effective for this high-risk population.
Background. Maternal obesity and physical inactivity have been identified as correlates of overweight and obesity and physical inactivity in older preadolescents; however, no study has explored this relationship in Hispanic preadolescents. Furthermore, the relation between maternal physical activity (PA) and blood pressure (BP) in Hispanic preadolescents has not been examined. Purpose. This study aimed to assess the associations between Hispanic mothers' PA and body mass index (BMI) and their preadolescents' PA, screen time, BP, and BMI. Methods. Data of 118 mother-child (aged 2 to 10 years) dyads enrolled in a cross-sectional study of metabolic syndrome in Hispanic preadolescents at a community health center in Johnson City, TN were used. Parent and child questionnaires were used to ascertain mothers' BMI and PA and preadolescents' PA and screen time. Preadolescents' height, weight, and BP were measured. Multiple logistic regression was used to examine the association between child and maternal variables, adjusting for mother's education and the child's sex and age. Results. Pradolescents of obese mothers were more likely than preadolescents of mothers with normal weight to engage in less than three days of at least 60 minutes of vigorous PA per week (OR: 6.47: 95% CI: 1.61-26.0). Preadolescents whose mothers did not engage in moderate PA were more likely to engage in less than three days of at least 60 minutes of vigorous PA per week (OR: 2.92, CI: 1.18-7.24); and have elevated BP (OR: 2.50, 95% CI: 1.02-4.53) than preadolescents whose mothers engaged in moderate PA. Discussion. Our results show a negative relationship between maternal obesity and preadolescent PA, and a positive relationship between lower maternal PA and elevated BP and lower PA in Hispanic
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