[A pre-conception cohort study of fertility and its related factors among couples with the intention of conception]

Objective: To describe fertility and explore factors associated with it among pre-conception couples of childbearing age. Methods: Based on the pre-conceptional offspring trajectory study of the School of Public Health of Fudan University, couples of childbearing age who participated in the pre-conception physical examination in Shanghai Jiading District from 2016 to 2021 were recruited and followed up. Couples' time to pregnancy (TTP) was analyzed and Cox proportional hazards regression model was used to explore the factors associated with TTP. Kaplan-Meier was used to calculate each menstrual cycle's cumulative pregnancy rate. Results: A total of 1 095 preconception couples were included in the analysis, the M(Q₁,Q₃)of TTP was 4.33 (2.41, 9.78) menstrual cycles. Age of women (FR=0.90, 95%CI: 0.85-0.95, P<0.001), women who were overweight or obese before pregnancy (FR=0.36, 95%CI: 0.24-0.55, P<0.001), women who were exposed to second-hand smoking (FR=0.63, 95%CI: 0.44-0.92, P=0.016), women whose home or office had been renovated in the past 2 years and had a particular smell (FR=0.46, 95%CI: 0.26-0.81, P=0.008) were risk factors for impaired fertility. Regular menstrual cycles (FR=1.64, 95%CI: 1.16-2.31, P=0.005), females who often drank tea/coffee (FR=1.55, 95%CI: 1.11-2.17, P=0.011) and males who took folic acid before conception (FR=2.35, 95%CI: 1.38-4.23, P=0.002) were associated with better fertility. The cumulative pregnancy rate of 3, 6, and 12 menstrual cycles was 37.6%, 64.4%, and 78.4%, respectively. Conclusion: Older couples, overweight or obesity before pregnancy, irregular menstruation, exposure to secondhand smoke and decoration pollutants in females are associated with impaired fertility. Frequent tea/coffee drinking before pregnancy in females and taking folic acid before pregnancy in males are associated with shortened conception time.

Genome-Wide Identification, Evolution and Expression Analysis of the Glutathione S-Transferase Supergene Family in Euphorbiaceae

Euphorbiaceae, a family of plants mainly grown in the tropics and subtropics, is also widely distributed all over the world and is well known for being rich in rubber, oil, medicinal materials, starch, wood and other economically important plant products. Glutathione S-transferases (GSTs) constitute a family of proteins encoded by a large supergene family and are widely expressed in animals, bacteria, fungi and plants, but with few reports of them in Euphorbiaceae plants. These proteins participate in and regulate the detoxification and oxidative stress response of heterogeneous organisms, resistance to stress, growth and development, signal transduction and other related processes. In this study, we identified and analyzed the whole genomes of four species of Euphorbiaceae, namely Ricinus communis, Jatropha curcas, Hevea brasiliensis, and Manihot esculenta, which have high economic and practical value. A total of 244 GST genes were identified. Based on their sequence characteristics and conserved domain types, the GST supergene family in Euphorbiaceae was classified into 10 subfamilies. The GST supergene families of Euphorbiaceae and Arabidopsis have been found to be highly conserved in evolution, and tandem repeats and translocations in these genes have made the greatest contributions to gene amplification here and have experienced strong purification selection. An evolutionary analysis showed that Euphorbiaceae GST genes have also evolved into new subtribes (GSTO, EF1BG, MAPEG), which may play a specific role in Euphorbiaceae. An analysis of expression patterns of the GST supergene family in Euphorbiaceae revealed the functions of these GSTs in different tissues, including resistance to stress and participation in herbicide detoxification. In addition, an interaction analysis was performed to determine the GST gene regulatory mechanism. The results of this study have laid a foundation for further analysis of the functions of the GST supergene family in Euphorbiaceae, especially in stress and herbicide detoxification. The results have also provided new ideas for the study of the regulatory mechanism of the GST supergene family, and have provided a reference for follow-up genetics and breeding work.

Major Fatty Acid Compositions and Antioxidant Activity of Cultivated Paeonia ostii under Different Nitrogen Fertilizer Application

Paeonia ostii is now being extensively planted for oil extraction in China, which is recognized as a single oil-use tree peony cultivar and commonly called 'Fengdan'. This study investigated the effects of nitrogen fertilizer on oil yield, fatty acid compositions and antioxidant activity of P. ostii. Oil yield (33.46 %), oleic acid (25.12 %), linoleic acid (29.21 %) and α-linolenic acid (43.12 %) reached the maximum at N450 treatment, with significant differences compared with other treatments (P<0.05). Furthermore, strong antioxidant activity with low DPPH_IC50 value (19.43±1.91 μg mL^-1 ) and large ABTS value (1216.53±30.21 μmol Trolox g^-1 ) and FRAP value (473.57±9.11 μmol Trolox g^-1 ) was also observed at N450. Palmitic acid (5.57 %) and stearic acid (2.02 %) reached a maximum at N375, but not significant with N450 (P<0.05). Nitrogen fertilizer could promote oil yield, fatty acid accumulation and antioxidant activity, and N450 (450 kg ha^-1 ) is recommended as the optimum application for P. ostii.

Major Fatty Acid Profiles and Bioactivity of Seed Oils from Ten Tree Peony Cultivars as a Potential Raw Material Source for the Cosmetics and Healthy Products

As a new woody oleaginous crop, tree peony is now being widely developed and utilized, which attributed to the outstanding oil-use features regarding the fatty acid profiles and bioactivity. The major fatty acid profiles and bioactivity of seed oils in ten tree peony varieties collected from a common garden were investigated in the present study. The results showed that the oil yields, fatty acid profiles, bioactivity of seed oils existed significant variations among ten tree peony varieties (P<0.05). Considered the application value, 'Fengdan' (FD) and 'Ziban' (ZB) was the optimal resources as the high oil yields, rich unsaturated fatty acids especially high α-linolenic acid of 40.46 %, great antioxidant activity with low IC₅₀ values, high ABTS and FRAP values, and strong antimicrobial activity with high DIZ and low MIC/MBC values. The study also confirmed seed oil of tree peony as the potential raw materials sources in functional food, pharmaceuticals and cosmetics for human health.

Phytochemical Profiles and Antioxidant Activity of Rehmannia glutinosa from Different Production Locations

The chemical components and antioxidant activity of 16 Rehmannia glutinosa samples were investigated to reveal the high-quality raw resource for pharmaceutical products. 22 main chemical components were detected with significant content differences (P<0.05). The contents of 14 substances reached the maximum in S1 sample such as catalpol (6.74 mg g^-1 ), rehmaionoside A (1.93 mg g^-1 ) and rehmannioside D (5.13 mg g^-1 ). However, the content distribution of the other eight substances had no obvious change regulation. Three antioxidant evaluation methods commonly showed that S1 sample had strong antioxidant activity with a low IC₅₀ value of 0.022 mg mL^-1 , a high ABTS value of 524.196 μmol equiv. Trolox g^-1 , and a high FRAP value of 200.517 μmol equiv. Trolox g^-1 . Considered the medicinal value, S1 had high quality based on the present phytochemical profiles and antioxidant activity. These results also indicated that the root extracts of R. glutinosa could become useful supplement for pharmaceutical products as new antioxidant agents.

Genetic diversity and structure of the threatened species Sinopodophyllum hexandrum (Royle) Ying

Sinopodophyllum hexandrum is an important medicinal plant that has been listed as an endangered species, making the conservation of its genetic diversity a priority. Therefore, the genetic diversity and population structure of S. hexandrum was investigated through inter-simple sequence repeat analysis of eight natural populations. Eleven selected primers generated 141 discernible fragments. The percentage of polymorphic bands was 37.59% at the species level, and 7.66-24.32% at the population level. Genetic diversity of S. hexandrum was low within populations (average HE = 0.0366), but higher at the species level (HE = 0.0963). Clear structure and high genetic differentiation were detected between populations using unweighted pair groups mean arithmetic and principle coordinate analysis. Clustering approaches clustered the eight sampled populations into three major groups, and AMOVA confirmed there to be significant variation between populations (63.27%). Genetic differentiation may have arisen through limited gene flow (Nm = 0.3317) in this species. Isolation by distance among populations was determined by comparing genetic distance versus geographical distance using the Mantel test. The results revealed no correlation between spatial pattern and geographic location. Given the low within-population genetic diversity, high differentiation among populations, and the increasing anthropogenic pressure on this species, in situ conservation measures, in addition to sampling and ex situ preservation, are recommended to preserve S. hexandrum populations and to retain their genetic diversity.

Inhibition of apoptosis by overexpressing Bcl-2 enhances gene amplification by a mechanism independent of aphidicolin pretreatment

To study the effect of apoptosis on gene amplification, we have constructed HeLa S3 cell lines in which the expression of bcl-2 (BCL2) can be controlled by tetracycline in the growth medium. Induction of Bcl-2 expression caused a temporary delay of apoptosis and resulted in roughly a 3-fold increase in the frequency of resistant colonies when cells were selected with trimetrexate. This resistance was due to amplification of the dihydrofolate reductase gene. Cells grown out of the pooled resistant colonies retained the same level of resistance to trimetrexate whether Bcl-2 was induced or repressed, consistent with the theory that Bcl-2 functions by facilitating gene amplification, rather than being the resistance mechanism per se. Pretreating cells with aphidicolin is another method to increase gene amplification frequency. When Bcl-2-expressing cells were pretreated with aphidicolin, the resulting increase in gene amplification frequency was approximately the product of the increases caused by aphidicolin pretreatment or Bcl-2 expression alone, indicating that Bcl-2 increases gene amplification through a mechanism independent of that of aphidicolin pretreatment. These results are consistent with the concept that gene amplification occurs at a higher frequency during drug-induced cell cycle perturbation. Bcl-2 evidently increases the number of selected amplified colonies by prolonging cell survival during the perturbation.

Tetracycline-controlled gene expression system achieves high-level and quantitative control of gene expression

The tetracycline-controlled gene expression system utilizes the control elements of the tetracycline resistance operon encoded in TnlO of Escherichia coli to control gene expression in eukaryotic cells. Here we demonstrate the quantitative control of the expression of the luciferase gene, dihydrofolate reductase gene, and bcl-2 gene in HeLa S3 or Chinese hamster ovary AA8 cells using the tetracycline-controlled gene expression system. Regardless of the host cell lines or the genes being expressed, there is a common range of tetracycline concentration within which the expression of genes is most sensitively regulated. In addition, the maximal gene expression level of the tetracycline-controlled gene expression system is higher than that of the wild-type CMV promoter/enhancer-driven system. Nonetheless, careful selection of stably transfected clones is necessary to achieve the optimally regulated gene expression using this system.

BCL-2 expression delays drug-induced apoptosis but does not increase clonogenic survival after drug treatment in HeLa cells

Apoptosis is a major form of cell death induced by chemotherapeutic drugs. Overexpression of the proto-oncogene bcl-2 can prevent apoptosis in various types of cells. We have constructed a HeLa S3 cell line in which the expression of bcl-2 can be controlled by the concentration of tetracycline in the medium. Using this system, we show that apoptosis induced by various cytostatic treatments could be delayed by the overexpression of bcl-2, as assayed by vital dye exclusion, apoptotic nuclei morphology, DNA histogram shift, and DNA fragmentation. Quantitative analysis revealed a hyperbolic curve when protection from apoptosis was plotted against the amount of Bcl-2. When cells were treated with aphidicolin for 12, 24, or 36 h and then replated in fresh media to assay for colony formation, the majority of cells that did not show apoptotic morphology at the time of drug removal failed to form colonies. Furthermore, Bcl-2 did not increase colony formation after 12-36 h of aphidicolin treatment. Therefore, with aphidicolin treatment, cells were committed to the death program upstream of the point of Bcl-2 action.