26 research outputs found
Regularities in simple sequence repeat variations induced by a cross of resynthesized Brassica napus and natural Brassica napus
Interspecific hybridization can induce extensive variation in genome sequences, including simple sequence repeat (SSR) regions. To determine the characteristics of SSR variation induced by interspecific hybridization and the possible effect of SSR variation on gene function, we constructed a Brassica napus doubled-haploid (DH) population from a cross between natural B. napus and resynthesized B. napus (B. oleracea × B. rapa) and identified, located, sequenced and functionally annotated SSR variants.The results showed that novel SSR variants were generated in the F generation and maintained in the introgressed DH population. Elimination of sequences carrying SSRs also occurred in the F hybrids, with three times as many sequences lost in the introgressed DH population compared to in the F hybrids, probably due to non-homologous recombination. The degree of SSR variation observed depended primarily on the number of SSR repeats and secondarily on the nucleotide composition of the SSR motifs.In the introgressed DH population, many genes containing SSRs exhibited frameshift mutations (62.5%) due to the expansion or contraction of the SSR motifs following deletion deletion (25%) or insertion (12.5%) mutations.Most genes harboring SSR variants were associated with vital metabolic processes, such as protein or DNA metabolic processes. The SSR variation induced by interspecific hybridization reflects an intrinsic property of species adaptability post-hybridization through variation. This study is beneficial to understanding the origin of SSRs and the effects of SSR mutation on polyploid genomes
Horizontal gene transfer in plants
Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries. HGT often occurs in microbic and eukaryotic genomes. However, the pathways by which HGTs occur in multicellular eukaryotes, especially in plants, are not well understood. We systematically summarized more than ten possible pathways for HGT. The intimate contact which frequently occurs in parasitism, symbiosis, pathogen, epiphyte, entophyte, and grafting interactions could promote HGTs between two species. Besides these direct transfer methods, genes can be exchanged with a vector as a bridge: possible vectors include pollen, fungi, bacteria, viruses, viroids, plasmids, transposons, and insects. HGT, especially when involving horizontal transfer of transposable elements, is recognized as a significant force propelling genomic variation and biological innovation, playing an important functional and evolutionary role in both eukaryotic and prokaryotic genomes. We proposed possible mechanisms by which HGTs can occur, which is useful in understanding the genetic information exchange among distant species or distant cellular components
Cross-cultural color-odor associations
Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e., an inherent mapping between color and odor), statistical reasons (i.e., covariance in experience), and/or semantically-mediated reasons (i.e., stemming from language). The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents), using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience
Cross-cultural color-odor associations
Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e., an inherent mapping between color and odor), statistical reasons (i.e., covariance in experience), and/or semantically-mediated reasons (i.e., stemming from language). The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents), using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience
Can You Get a Ticket? Adaptive Railway Booking Strategies by Customer Value
This paper integrates a customer segmentation method with a discrete event simulation model to bridge the gap between identifying customer behaviors and using this knowledge to respond to customers and make the best use of resources. Three strategies are proposed and examined to improve the operation efficiency of a ticket-booking system. Their objective is to assist high-value customers in obtaining the tickets they want and/or reduce cancellations and failure-to-pays from low-value customers. Our simulation results demonstrate that the high-value, customer-friendly strategy beats all in assisting high-value customers and simultaneously improves railway operation performance. Additionally, the indirect, low-value customer abandonment strategy also has improved slightly in all aspects. Applying these strategies is expected to result in a decrease in complaints regarding booking system rejections and an increase in high-value customer satisfaction. On the other hand, the direct abandonment strategy to reject all low-value customers does not make any improvement
The Effect of Sex Differences on Endothelial Function and Circulating Endothelial Progenitor Cells in Hypertriglyceridemia
Background. Men have a higher risk and earlier onset of cardiovascular diseases compared with premenopausal women. Hypertriglyceridemia is an independent risk factor for the occurrence of ischemic heart disease. Endothelial dysfunction is related to the development of ischemic heart disease. Whether sex differences will affect the circulating endothelial progenitor cells (EPCs) and endothelial function in hypertriglyceridemia patients or not is not clear. Methods. Forty premenopausal women and forty age- and body mass index (BMI)-matched men without cardiovascular and metabolic disease were recruited and then divided into four groups: normotriglyceridemic women (women with serum triglycerides level <150 mg/dl), hypertriglyceridemic women (women with serum triglycerides level ≥150 mg/dl), normotriglyceridemic men (men with serum triglycerides level <150 mg/dl), and hypertriglyceridemic men (men with serum triglycerides level ≥150 mg/dl). Peripheral blood was obtained and evaluated. Flow-mediated dilatation (FMD), the number and activity of circulating EPCs, and the levels of nitric oxide (NO), vascular endothelial growth factor (VEGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in plasma and culture medium were measured. Results. The number and activity of circulating EPCs, as well as the level of NO in plasma or culture medium, were remarkably increased in premenopausal females compared with those in males both in the hypertriglyceridemic group and the normotriglyceridemic group. The EPC counts and activity, as well as the production of NO, were restored in hypertriglyceridemic premenopausal women compared with those in normal women. However, in hypertriglyceridemic men, the EPC counts and activity, as well as levels of NO, were significantly reduced. The values of VEGF and GM-CSF were without statistical change. Conclusions. The present study firstly demonstrated that there were sex differences in the number and activity of circulating EPCs in hyperglyceridemia patients. Hypertriglyceridemic premenopausal women displayed restored endothelial functions, with elevated NO production, probably mediated by estradiol. We provided a new insight to explore the clinical biomarkers and therapeutic strategies for hypertriglyceridemia-related vascular damage
Transferrin and antioxidants partly prevented mouse oocyte oxidative damage induced by exposure of cumulus-oocyte complexes to endometrioma fluid
Abstract Background Exposure of oocytes to the endometrioma fluid has an adverse effect on embryonic quality. To determine whether adding transferrin and antioxidants to culture medium could counteract detrimental effects on mouse cumulus-oocyte complexes (COCs) induced by exposure to endometrioma fluid or not, we conducted an in vitro cross-sectional study using human and mouse COCs. Methods Eighteen women who had their oocytes exposed to endometrioma fluid during oocyte retrieval were enrolled. COCs from superovulated ICR female mice were collected. They were first exposed to human endometrioma fluid and then treated by transferrin and/or antioxidants (cysteamine + cystine). Subsequently, COCs function was assessed by molecular methods. Results This study observed that human COCs inadvertently exposed to endometrioma fluid in the in vitro fertilization (IVF) group led to a lower good quality embryo rate compared to intracytoplasmic sperm injection (ICSI) group. Exposure of mouse COCs to endometrioma fluid accelerated oocyte oxidative damage, evidenced by significantly reduced CCs viability, defective mitochondrial function, decreased GSH content and increased ROS level, associated with the significantly higher pro-portion of abnormal spindles and lower blastocyst formation (p < 0.05, respectively). This damage could be recovered partly by treating COCs with transferrin and antioxidants (cysteamine + cystine). Conclusions Transferrin and antioxidants could reduce the oxidative damage caused by COCs exposure to endometrioma fluid. This finding provides a promising new possibility for intervention in the human oocyte oxidative damage process induced by endometrioma fluid during oocyte pick-up
Smoking-Induced Inhibition of Number and Activity of Endothelial Progenitor Cells and Nitric Oxide in Males Were Reversed by Estradiol in Premenopausal Females
Objectives. The number and activity of circulating EPCs were enhanced in premenopausal women contrast to postmenopausal females and age-matched males. Here, we investigated whether this favorable effect exists in premenopausal women and age-matched men with cigarette smoking. Methods. In a cross-sectional study, the number and activity of circulating EPCs and nitric oxide production (NO) as well as flow-mediated vasodilation (FMD) in both premenopausal women and age-matched men with or without cigarette smoking were studied. Results. Compared with age-matched men with or without smoking, the number and function of circulating EPCs as well as NO level in premenopausal women were obviously higher than that in the former and not affected by smoking. The number and function of circulating EPCs as well as NO level in male smokers were shown to be the most strongly inhibited. Furthermore, there was significant correlation between EPC number and activity, plasma NO level, and NO secretion by EPCs and FMD. Conclusions. Estradiol was deemed to play an important role in enhancing the number and activity of EPCs and NO production in premenopausal women even when affected by smoking, which may be the important mechanisms underlying vascular protection of estradiol in premenopausal women, but not in age-matched men
Characterization and functional annotation of nested transposable elements in eukaryotic genomes
The movement of transposable elements (TE) in eukaryotic genomes can often result in the occurrence of nested TEs (the insertion of TEs into pre-existing TEs). We performed a general TE assessment using available databases to detect nested TEs and analyze their characteristics and putative functions in eukaryote genomes. A total of 802 TEs were found to be inserted into 690 host TEs from a total number of 11,329 TEs. We reveal that repetitive sequences are associated with an increased occurrence of nested TEs and sequence biased of TE insertion. A high proportion of the genes which were associated with nested TEs are predicted to localize to organelles and participate in nucleic acid and protein binding. Many of these function in metabolic processes, and encode important enzymes for transposition and integration. Therefore, nested TEs in eukaryotic genomes may negatively influence genome expansion, and enrich the diversity of gene expression or regulation
Identification and characterization of a curly-leaf locus CL1 encoding an IAA2 protein in Brassica napus
The leaf is the main organ for rapeseed photosynthesis, and its morphology influences photosynthetic efficiency and supports increased planting density and yield. However, the molecular regulatory mechanism of leaf morphology in Brassica napus is poorly understood, restricting progress in breeding for the trait. We describe a novel dominant mutation, curly leaf 1 (cl1), which confers uneven dorsal–ventral axis development, irregular cellular structure and influenced gravitropic response in the seedling stage. The CL1 locus was mapped to a 1.573-Mb interval on chromosome A05 using simple sequence repeat (SSR) markers, and co-segregated with the phenotype of plants in the curly F2 population. A substitution (P62S) was identified in the highly conserved degron motif (GWSPV) of the IAA2 protein in the cl1 mutant, and the P62S substitution impaired the interaction between IAA2 and TIR1 in the presence of auxin, influencing auxin signaling. The P62S substitution-induced curly leaf phenotype was verified by ectopic expression of BnaA05.iaa2 in Arabidopsis and B. napus. Our findings explain the function of IAA2 in rapeseed, providing a foundation for future investigation of auxin signaling and the mechanisms underlying leaf development in B. napus