The Genome of Bifidobacterium longum subsp. infantis YLGB-1496 Provides Insights into Its Carbohydrate Utilization and Genetic Stability.

Bifidobacterium longum subsp. infantis YLGB-1496 (YLGB-1496) is a probiotic strain isolated from human breast milk. The application of YLGB-1496 is influenced by carbohydrate utilization and genetic stability. This study used genome sequencing and morphology during continuous subculture to determine the carbohydrate utilization characteristics and genetic stability of YLGB-1496. The complete genome sequence of YLGB-1496 consists of 2,758,242 base pairs, 2442 coding sequences, and a GC content of 59.87%. A comparison of carbohydrate transport and metabolism genes of Bifidobacterium longum subsp. infantis (B. infantis) showed that YLGB-1496 was rich in glycosyl hydrolase 13, 20, 25, and 109 gene families. During continuous subculture, the growth characteristics and fermentation activity of the strain were highly stable. The bacterial cell surface and edges of the 1000th-generation strains were progressively smoother and well-defined, with no perforations or breaks in the cell wall. There were 20 SNP loci at the 1000th generation, fulfilling the requirement of belonging to the same strain. The presence of genes associated with cell adhesion and the absence of resistance genes supported the probiotic characteristics of the strain. The data obtained in this study provide insights into broad-spectrum carbohydrate utilization, genomic stability, and probiotic properties of YLGB-1496, which provide theoretical support to promote the use of YLGB-1496.

Effect of Thermal Inactivation on Antioxidant, Anti-Inflammatory Activities and Chemical Profile of Postbiotics.

Inactivation is a crucial step in the production of postbiotics, with thermal inactivation being the prevailing method employed. Nevertheless, the impact of thermal treatment on bioactivity and chemical composition remains unexplored. The objective of this study was to assess the influence of heating temperature on the antioxidant, anti-inflammatory properties and the chemical composition of ET-22 and BL-99 postbiotics. The findings revealed that subjecting ET-22 and BL-99 to thermal treatment ranging from 70 °C to 121 °C for a duration of 10 min effectively deactivated them, leading to the disruption of cellular structure and release of intracellular contents. The antioxidant and anti-inflammatory activity of ET-22 and BL-99 postbiotics remained unaffected by mild heating temperatures (below 100 °C). However, excessive heating at 121 °C diminished the antioxidant activity of the postbiotic. To further investigate the impact of thermal treatments on chemical composition, non-targeted metabolomics was conducted to analyze the cell-free supernatants derived from ET-22 and BL-99. The results revealed that compared to mild inactivation at temperatures below 100 °C, the excessive temperature of 121 °C significantly altered the chemical profile of the postbiotic. Several bioactive components with antioxidant and anti-inflammatory properties, including zomepirac, flumethasone, 6-hydroxyhexanoic acid, and phenyllactic acid, exhibited a significant reduction in their levels following exposure to a temperature of 121 °C. This decline in their abundance may be associated with a corresponding decrease in their antioxidant and anti-inflammatory activities. The cumulative evidence gathered strongly indicates that heating temperatures exert a discernible influence on the properties of postbiotics, whereby excessive heating leads to the degradation of heat-sensitive active constituents and subsequent diminishment of their biological efficacy.

Lactobacillus paracasei ET-22 Suppresses Dental Caries by Regulating Microbiota of Dental Plaques and Inhibiting Biofilm Formation.

Dental caries is a common and multifactorial biofilm disease that is associated with dietary habits and microbiota. Among the various pathogens inducing caries, S. mutans is the most extensively studied. Promoting oral health with probiotics has gained considerable attention. Lactobacillus paracasei (L. paracasei) strains were reported to modulate the gut microbiota and enhance host resistance to disease. Our previous research has found that L. paracasei ET-22 (ET-22) could inhibit S. mutans biofilms in vitro. However, the preventive effect in vivo and functional mechanism of ET-22 on dental caries were unclear. In this study, the preventive effects of ET-22 on dental caries in mice were checked. Meanwhile, the functional mechanism of ET-22 was further investigated. Results showed that the supplementation of ET-22 in drinking water significantly improved the caries scoring of mice. The microbiota of dental plaques revealed that the live and heat-killed ET-22 similarly regulated the microbial structure in plaque biofilms. Functional prediction of PICRUSt showed that the addition of live and heat-killed ET-22 may inhibit biofilm formation. By the in vitro trials, the live and heat-killed ET-22 indeed inhibited the construction of S. mutans biofilms and EPS productions of biofilms. This evidence suggests that ET-22 can restrain dental caries by regulating the microbiota of dental plaques and inhibiting biofilm formation, which may be partly mediated by the body components of ET-22.

Nausea and Vomiting during Early Pregnancy among Chinese Women and Its Association with Nutritional Intakes.

Nausea and vomiting in pregnancy (NVP) is one of the most common uncomfortable symptoms of women in early pregnancy. A total of 303 Chinese pregnant women from 10 urban cities in their first trimester were recruited in this study to collect their sociodemographic characteristics and their NVP occurrence. Their dietary nutrient and food intakes were also collected by a 24 h dietary recall and a semi-quantitative food frequency questionnaire (SFFQ). Using the univariate analysis and multiple linear regression analysis to estimate the correlation between NVP and dietary intake, we found that 255 (84.1%) pregnant women experienced NVP during their first trimester. The intake of energy, protein, fat, vitamin A, thiamin, riboflavin, vitamin E, phosphorus, potassium, iron and zinc was lower in women with NVP than in those with no NVP. Additionally, women with NVP were more likely to have insufficient intake of protein, riboflavin, calcium, phosphorus and selenium. In terms of specific food groups, the average daily intake of mushrooms, algae, nuts and seeds, meat, eggs and dairy products in the NVP group was lower. Women in the severe NVP group even had insufficient gestational weight gain. We should pay more attention to women who experience nausea and vomiting during pregnancy and provide them with targeted nutritional support.

Sleep quality, antepartum depression and self-harm thoughts in pregnant Chinese women.

BACKGROUND: Previous literature has shown a significant association between sleep and depression, whereas limited studies have examined the association of sleep quality with self-harm ideation in pregnant Chinese women. METHODS: A total of 898 pregnant women (first to third trimester) from the Young Investigation Study were enrolled in this study. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess sleep quality. Antepartum depression and self-harm ideation were evaluated using the Edinburgh Postnatal Depression Scale (EPDS). Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs). RESULTS: In this sample, the prevalence of poor sleep quality and antepartum depression was 44.3 % and 24.4 %, respectively. Furthermore, 12.8 % of women were considered as having self-harm ideation. Individuals in different trimesters reported similar prevalence of self-harm thoughts. Women were more likely to report self-harm thoughts if they were categorized as poor sleep quality or antepartum depression. And women with moderate or severe depression had higher risk of self-harm ideation and poor sleep, compared with those with mild depression. Although sleep quality indirectly influenced self-harm thoughts through the mediation effect of depressive symptoms, poor sleep quality was still associated with a 2.62-fold increased odds of self-harm ideation among women in the second trimester (OR = 2.62; 95 % CI: 1.11-6.21), after adjustment for depression. LIMITATIONS: Causality cannot be inferred. Results should be generalized carefully. Depression was evaluated by a screening tool rather than clinical interviews. CONCLUSIONS: The prevalence of poor sleep quality, depressive symptoms and self-harm ideation in pregnant Chinese women were noteworthy and high. Besides, a direct effect was also found between sleep quality and self-harm thoughts among women in the second trimester. Our findings suggest the need to identify and intervene when sleep disturbances are observed in women during pregnancy.

[Effects of the timing of complementary food on infant physical development].

OBJECTIVE: To analyze the timing of supplementary food and its effect on the development of infants at 6-8 months of age. METHODS: A total of 168 breastfed healthy infants in Beijing and Chenzhou were selected and followed up from birth to 8 months of age. According to the time of the first supplementary food addition, the survey subjects were divided into a reasonable supplementary food group and an unreasonable supplementary food group. Repeated measures analysis was used to compare the differences in the Z scores of the two groups of infants. RESULTS: Infants who added complementary food between 4-6 months accounted for 80.4%(n=135). There were 6.0%(n=10) of infants who added complementary food for more than 8 months of age(added too late), and the timing was earlier than 4 months old infants accounted for 6.5%(n=11). The result of repeated measurement analysis showed that the body mass index for age Z score(BAZ) of infants whose complementary foods were added at an unreasonable time was different from that of infants with reasonable complementary food addition(P=0.046). Infants whose complementary food was added at an unreasonable time had higher BAZ at the age of 6 months(ß=0.615, 95%CI 0.053-1.178). CONCLUSION: Few infants add complementary foods too early or too late, and the timing of complementary foods for most infants was between 4-6 months of age. Unreasonable complementary food addition time might have a short-term impact on the infants' BAZ.

Perinatal depression and serum vitamin D status: A cross-sectional study in urban China.

BACKGROUND: Although vitamin D has been found to be associated with perinatal depression, the results are inconsistent. The aim of this cross-sectional study was to examine the association between vitamin D and PND in Chinese pregnant women and lactating women. METHODS: A total of 1773 participants were included, including 907 lactating women and 866 pregnant women. The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for PND, and those with scores ≥13 were considered to have PND. Serum 25-hydroxyvitamin D concentrations were assessed with high-performance liquid chromatography. RESULTS: The prevalence of postpartum depression (PPD) and antenatal depression (AD) were 15.9 % and 9.8 %, respectively. Compared with individuals with sufficient vitamin D, those with vitamin D deficiency were associated with a higher prevalence of PPD in lactating women (OR = 1.71, 95%CI: 1.01-2.88, p = 0.044). The serum 25(OH)D of lactating women was inversely associated with the scores of the factor "depressive mood" of the EPDS (ORper 5 ng/mL = -0.10, 95%CI: -0.19 to -0.01, p = 0.032). No significant association between serum 25-hydroxyvitamin D and AD was observed. LIMITATIONS: First, this study is a cross-sectional design, which can only determine associations but not causality. Secondly, this study only included participants from urban areas. Thirdly, there are still some possible confounding factors that have not been considered. CONCLUSION: In conclusion, this study suggested a significant association between vitamin D status and PPD; however, the association between vitamin D status and AD was not significant.

Dietary Diversity, Micronutrient Adequacy and Bone Status during Pregnancy: A Study in Urban China from 2019 to 2020.

Diet quality during reproduction is crucial to maternal and infant health. However, the association between dietary diversity and bone health of pregnant women remains unclear. We aimed to evaluate the dietary quality of Chinese urban gravidas using the dietary diversity score (DDS), and to explore the relationship of the DDS with micronutrient adequacy and bone health. In this cross-sectional study, we analyzed data from 775 pregnant women aged 18 years or older in urban China. Dietary diversity was assessed using the Minimum Dietary Diversity for Women (MDD-W) indicator. A 24-h dietary recall was used to collect diet data and to calculate the MDD-W and the nutrient intake. Bone health was measured using quantitative ultrasound and assessed by the speed of sound (SOS). Pearson's correlation coefficients between the DDS and the nutrient adequacy ratio (NAR) were calculated. A multivariable linear regression model was used to estimate the effect size of the DDS on the SOS. The mean DDS was 6.61 ± 1.53 points and 91.0% of participants reported the consumption of five or more food groups. Women in the diverse diet subgroup (DDS ≥ 7 points) were more likely to consume all kinds of food except starchy staples and had higher NARs. Pearson's correlation coefficients between the DDS and the NAR ranged from 0.161 to 0.484. For participants in the second trimester, those with a diverse diet had a higher SOS. A multivariable linear regression analysis showed that the DDS was positively and significantly associated with the SOS (ß = 17.18, 95% CI = 5.97-28.39, p = 0.003), but this was not the case for women in the first and third trimesters. Urban Chinese women had good dietary diversity during pregnancy. A higher dietary diversity was associated with a higher NAR. From the point of view of bone, a diverse diet was positively correlated with better bone status, suggesting the importance of improving diet diversity for pregnant women, especially from mid-pregnancy.

Consumption of Added Sugar among Chinese Toddlers and Its Association with Picky Eating and Daily Screen Time.

Objectives: This study aimed to examine the relationship between daily screen time, picky eating, and consumption frequency of sugared foods and sugar-sweetened beverages (SSBs). Methods: The research data came from the Young Investigation (YI) study conducted in 10 cities in China. This study used sociodemographic information, feeding behavior, picky eating reported by parents, and the consumption frequency of sugared foods and SSBs of 879 toddlers aged 1−3 years. The relationship between daily screen time and picky eating behavior was assessed using logistic regression. The zero-inflated negative binomial (ZINB) model was used to fit the consumption frequencies of sugared foods and SSBs. Results: In all, 13.1% (n = 115) of toddlers did not have sugared foods 1 month before the survey, while 73.3% (n = 644) of toddlers did not have SSBs 1 month before the survey. The consumption rate of sugared foods was relatively higher than SSBs (χ2 = 661.25, p < 0.001). After adjusting for social demographic information, no relationship was found between daily screen time and picky eating (OR = 1.437; 95% CI: 0.990,2.092). The ZINB model showed that, among children who ate sugared foods, children who were picky eaters ate them more often (IRR = 1.133; 95% CI: 1.095,1.172), but no association was found between picky eating and the chance of avoiding sugared foods (OR = 0.949; 95% CI: 0.613,1.471). Children who were picky eaters were less likely not to drink SSBs (OR = 0.664; 95% CI: 0.478,0.921). However, among children who consumed SSBs, picky eaters drank them less frequently (IRR = 0.599; 95% CI: 0.552,0.650). Children with a screen time of no less than 1 h/d ate sugared foods more frequently (IRR = 1.383; 95% CI: 1.164,1.644), and they were less likely to avoid sugared foods (OR = 0.223; 95% CI: 0.085,0.587). The longer the screen time per day was, the less likely children did not have SSBs (<1 h/d: OR = 0.272; 95% CI: 0.130, 0.569; ≥1 h/d: OR = 0.136; 95% CI: 0.057, 0.328). Conclusions: The consumption rate of sugared foods was higher than that of SSBs. Picky eating and daily screen time were related to the consumption frequency of added sugar among Chinese toddlers aged 1−3 years. Picky eaters consumed sugared foods more frequently and were more likely to drink SSBs. Children whose daily screen time reached 1 h/d were more likely to eat sugared foods and drink SSBs.

The Association between Postpartum Practice and Chinese Postpartum Depression: Identification of a Postpartum Depression-Related Dietary Pattern.

Conflicting results of Chinese traditional postpartum practices have aroused concerns over their health effects. The role of postpartum practices in postpartum depression (PPD) is still a matter of discussion, especially from a dietary practice point of view. The current study was designed to (1) explore the association between postpartum practices and PPD, (2) to identify the dietary pattern related to PPD, and (3) to identify the possible pathways among postpartum practices and PPD. This study is part of the YI Study, which was a cross-sectional study conducted in 10 cities in China. Data for 955 postpartum women were used in the current analysis. The Edinburgh Postnatal Depression Scale (EPDS-10) was used to evaluate PPD with a cutoff value of 9. Postpartum practice was based on the participants' self-reported practices. Individual practices were recorded and categorized as dietary and non-dietary practices. The dietary pattern was identified based on the food intake frequencies of 25 food groups using the method of reduced rank regression. Structural equation modeling was used to explore the potential pathways between postpartum practices and PPD. The current study observed significant associations between postpartum practices and PPD (Adjusted OR = 1.41, 95% CI: 1.04-1.90). A similar trend was also found between dietary postpartum practices and PPD (Adjusted OR = 1.39, 95%CI: 1.03-1.88) but not for non-dietary practices and PPD (Adjusted OR = 1.26, 95%CI: 0.92-1.75). A PPD-related dietary pattern was identified with the characteristics of a high intake of meat and eggs and a lower intake of vegetables, mushrooms, and nuts. This dietary pattern was significantly associated with a higher chance of adhering to postpartum practice (Adjusted OR = 1.26, 95% CI: 1.10-1.44). Based on the pathway analysis, this study also observed the association between postpartum practices and PPD, and the association between dietary practices and PPD were both mediated by sleep quality. In conclusion, this study demonstrated that a substantial proportion of women in modern China experience traditional postpartum Chinese practices and that either overall or dietary-related postpartum practices are associated with a higher risk of PPD. The current dietary practices in postpartum rituals may play an important role in developing PPD. A culturally embedded, science-based dietary guideline is required to help women to achieve both physical and psychological health in the postpartum period.

Association between Milk Intake and All-Cause Mortality among Chinese Adults: A Prospective Study.

BACKGROUND: Little is known about the effect of milk intake on all-cause mortality among Chinese adults. The present study aimed to explore the association between milk intake and all-cause mortality in the Chinese population. METHODS: Data from 1997 to 2015 of the China Health and Nutrition Survey (CHNS) were used. A total of 14,738 participants enrolled in the study. Dietary data were obtained by three day 24-h dietary recall. All-cause mortality was assessed according to information reported. The association between milk intake and all-cause mortality were explored using Cox regression and further stratified with different levels of dietary diversity score (DDS) and energy intake. RESULTS: 11,975 (81.25%) did not consume milk, 1341 (9.10%) and 1422 (9.65%) consumed 0.1-2 portions/week and >2 portions/week, respectively. Milk consumption of 0.1-2 portions/week was related to the decreased all-cause mortality (HR: 0.59, 95% CI: 0.41-0.85). In stratified analysis, consuming 0.1-2 portions/week was associated with decreased all-cause mortality among people with high DDS and energy intake. CONCLUSIONS: Milk intake is low among Chinese adults. Consuming 0.1-2 portions of milk/week might be associated with the reduced risk of death among Chinese adults by advocating health education. Further research is required to investigate the relationships between specific dairy products and cause-specific mortality.

Maternal diet associated with infants' intestinal microbiota mediated by predominant long-chain fatty acid in breast milk.

Introduction: Long-chain fatty acids in breast milk are affected by the mother's diet and play an important role in the growth, development, and immune construction of infants. This study aims to explore the correlation between maternal diet, breast milk fatty acids (FAs), and the infant intestinal flora. Methods: We enrolled 56 paired mothers and their infants; both breast milk samples and infants' fecal samples were collected to determine the long-chain FA content of breast milk by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS), and metagenomic technology was applied to determine the microbial composition of infant feces. The maternal diet was also investigated using a 24-h dietary recall. Results: The results indicated that the fat contribution rates of edible oils in the maternal diet are significantly positively correlated with the contents of certain long-chain fatty acids (C16:0, C18:1, C16:1, and C22:4) in breast milk, which mainly regulate the abundance of Lacticaseibacillus rhamnosus, Lacticaseibacillus fermentum, and Lacticaseibacillus paracasei in the infant gut. Through KEGG pathway analysis, our data revealed that the long-chain FAs in different groups of breast milk were significantly correlated with the pathways of biotin metabolism, glycerolipid metabolism, and starch and sucrose metabolism. Discussion: The results of this study suggest a pathway in which the diets of lactating mothers may affect the composition of the infant intestinal microbiota by influencing breast milk FAs and then further regulating infant health.

Feeding Difficulty Among Chinese Toddlers Aged 1-3 Years and Its Association With Health and Development.

Feeding problems are biopsychosocial in nature and have a great influence on children's growth. The aim of this study was to profile the status and possible influencing factors of feeding difficulty among normal Chinese toddlers, and to investigate its association with health and development. This study is a part of the Young Investigation (YI study) conducted in 10 cities in China. Data from 924 children aged 1-3 years were analyzed. Data on socio-demographic factors, feeding behaviors, self-reported diseases, and anthropometry parameters were collected. Blood samples were drawn to determine hemoglobin levels. Feeding difficulty was evaluated by the Montreal Children's Hospital Feeding Scale (MCH-FS). Ages and Stages Questionnaires, Third Edition (ASQ-3) were used to assess developmental progress. Multivariable analyses were performed to explore the potential associations. The mean total score of the MCH-FS was 35.21 ± 12.90 and the highest scored item was "acting up/making a big fuss during mealtimes." Feeding difficulty occurred more often among children with picky eating behavior or whose caregivers once used the strategy of pre-mastication. Children with feeding difficulty had lower intakes of cereals, vegetables, and fruits, and were more likely to suffer from diarrhea (OR, 2.04; 95%CI: 1.32, 3.11) or constipation (OR, 2.04; 95%CI: 1.27, 3.24), but not anemia. Feeding difficulty was also negatively associated with weight, height, head circumference and mid-upper-arm circumference-related Z-scores (P all < 0.05). In addition, it was related to poorer fine motor skills, personal and social skills, and total scores of ASQ-3 (ß, -9.00; 95%CI: -15.11, -2.89). Feeding difficulty assessed by MCH-FS showed a negative association with children's health and development, supporting the need for early identification.

Fruit and vegetable consumption and serum vitamin A in lactating women: A cross-sectional survey in urban China.

During the lactation period, healthy eating behavior is essential to maternal and child health. However, Chinese lactating women may have some traditional food restrictions. Our aims were to evaluate the fruit and vegetable consumption of Chinese lactating women and to examine the associations between fruit and vegetable consumption and serum vitamin A concentrations. A total of 885 participants were included. Dietary intakes were assessed during the same time frame as blood collection via a one-time 24-h dietary recall (24HDR) and a semiquantitative food frequency questionnaire (SFFQ), respectively. Serum vitamin A concentrations were assessed with high-performance liquid chromatography. Based on 24HDR, 64.7% and 85.5% of lactating women did not consume the appropriate amount of fruits and vegetables, respectively. New mothers who adopt zuo yuezi behavior during the first month were negatively associated with fruit consumption. The median (25th to 75th) dietary vitamin A intake was 349.5 (202.5-591.4) µg RAE/day. Vegetable contributed 24.9% and fruit 4.8% of the dietary vitamin A intake. The median (25th to 75th) serum vitamin A concentration was 1.92 (1.61-2.30) µmol/L. 24HDR assessments of total fruit and vegetable consumption, and fruit consumption were positively associated with higher serum vitamin A concentrations, respectively (ß = 0.200, 95%CI = 0.077, 0.323, p = .001; ß = 0.241, 95%CI = 0.008, 0.474, p = .044). These positive associations were replicated in the SFFQ assessments (ß = 0.102, 95%CI = 0.016, 0.188, p = .020; ß = 0.215, 95%CI = 0.088, 0.341, p = .001). Chinese lactating women had inappropriate fruit and vegetable consumption. Fruit and vegetable consumption was associated with serum vitamin A concentrations.

Association Between Dietary Quality and Postpartum Depression in Lactating Women: A Cross-Sectional Survey in Urban China.

Background: Evidence on the effects of dietary quality on the risk of postpartum depression in the Chinese population is limited. This study aimed to examine the association between dietary quality and postpartum depression in Chinses lactating women. Methods: A total of 939 participants from 10 cities were included in this analysis. A one-time 24-h dietary recall was used to obtain the data on food consumption and dietary quality was assessed based on Diet Balance Index. The Edinburgh postnatal depression scale was considered at a cutoff point of 10 to detect postpartum depression. Poisson regression models were used to explore the association of dietary quality with postpartum depression. Results: Depressed women tended to have a more inadequate intake of vegetables and have more insufficient food variety. The median (25th, 75th) of the overall high bound score (HBS), low bound score (LBS), and diet quality distance (DQD) was 9 (5, 14), 30 (25, 37), and 40 (34, 47), respectively. Compared with subjects with the lowest quartile of LBS, those with the highest quartile of LBS had a higher risk of postpartum depression [adjusted prevalence ratio (aPR), 1.08; 95% confidence interval (95% CI), 1.01, 1.15; P for trend, 0.043]. We also observed a significant association between DQD and postpartum depression (Q4 vs. Q1: aPR, 1.07; 95% CI: 1.00, 1.14; P for trend, 0.036). Conclusion: Poor dietary quality was associated with postpartum depression in Chinese lactating women.

Molecular characterization, tissue distribution, subcellular localization and actin-sequestering function of a thymosin protein from silkworm.

We identified a novel gene encoding a Bombyx mori thymosin (BmTHY) protein from a cDNA library of silkworm pupae, which has an open reading frame (ORF) of 399 bp encoding 132 amino acids. It was found by bioinformatics that BmTHY gene consisted of three exons and two introns and BmTHY was highly homologous to thymosin betas (Tß). BmTHY has a conserved motif LKHTET with only one amino acid difference from LKKTET, which is involved in Tß binding to actin. A His-tagged BmTHY fusion protein (rBmTHY) with a molecular weight of approximately 18.4 kDa was expressed and purified to homogeneity. The purified fusion protein was used to produce anti-rBmTHY polyclonal antibodies in a New Zealand rabbit. Subcellular localization revealed that BmTHY can be found in both Bm5 cell (a silkworm ovary cell line) nucleus and cytoplasm but is primarily located in the nucleus. Western blotting and real-time RT-PCR showed that during silkworm developmental stages, BmTHY expression levels are highest in moth, followed by instar larvae, and are lowest in pupa and egg. BmTHY mRNA was universally distributed in most of fifth-instar larvae tissues (except testis). However, BmTHY was expressed in the head, ovary and epidermis during the larvae stage. BmTHY formed complexes with actin monomer, inhibited actin polymerization and cross-linked to actin. All the results indicated BmTHY might be an actin-sequestering protein and participate in silkworm development.

In vivo bioassay of recombinant human growth hormone synthesized in B. mori pupae.

The human growth hormone (hGH) has been expressed in prokaryotic expression system with low bioactivity previously. Then the effective B. mori baculovirus system was employed to express hGH identical to mature hGH successfully in larvae, but the expression level was still limited. In this work, the hGH was expressed in B. mori pupae by baculovirus system. Quantification of recombinant hGH protein (BmrhGH) showed that the expression of BmrhGH reached the level of approximately 890 microg/mL pupae supernatant solution, which was five times more than the level using larvae. Furthermore, Animals were gavaged with BmrhGH at the dose of 4.5 mg/rat.day, and the body weight gain (BWG) of treated group had a significant difference (P < .01) compared with the control group. The other two parameters of liver weight and epiphyseal width were also found to be different between the two groups (P < .05). The results suggested that BmrhGH might be used as a protein drug by oral administration.