An update on the role and potential mechanisms of clock genes regulating spermatogenesis: A systematic review of human and animal experimental studies.

Circadian clocks can be traced in nearly all life kingdoms, with the male reproductive system no exception. However, our understanding of the circadian clock in spermatogenesis seems to fall behind other scenarios. The present review aims to summarize the current knowledge about the role and especially the potential mechanisms of clock genes in spermatogenesis regulation. Accumulating studies have revealed rhythmic oscillation in semen parameters and some physiological events of spermatogenesis. Disturbing the clock gene expression by genetic mutations or environmental changes will also notably damage spermatogenesis. On the other hand, the mechanisms of spermatogenetic regulation by clock genes remain largely unclear. Some recent studies, although not revealing the entire mechanisms, indeed attempted to shed light on this issue. Emerging clues hinted that gonadal hormones, retinoic acid signaling, homologous recombination, and the chromatoid body might be involved in the regulation of spermatogenesis by clock genes. Then we highlight the challenges and the promising directions for future studies so as to stimulate attention to this critical field which has not gained adequate concern.

Evaluating and forecasting the associated main flavor components in Baijiu (Chinese distilled spirits) with alcohol metabolism and hangover symptoms through mice acute withdrawal model.

Over the past few decades, more alcohol-problem concerns focused on reducing the risk of hangover caused by the alcoholic beverages over-consumption. Chinese distilled spirits (Baijiu) is one of the most favorite alcoholic beverages. The intention of this study is to explore the associations of main flavor components in Baijiu and hangover symptoms using mice acute alcohol withdrawal model. The behaviors of each mouse were assessed by open-field tests using separate groups of mice with the treatment of sauce-aroma Baijiu, light-aroma Baijiu, strong-aroma Baijiu, pure alcohol, and distilled water, respectively. The behavioral data including total move distance and immobile time were used as indicators for the evaluation of the liquor intoxicating effects. Alcohol and acetaldehyde concentrations in mice plasma and the neurotransmitter contents of GABA and Glu in mice cerebellum were detected afterward. The results showed that the mice with the treatment of Baijiu samples displayed unusual exciting behaviors including increased alcohol metabolization with alleviating drunken and hangover symptoms, compared with that of pure alcohol control groups after 2-4 h. Moreover, the sauce-aroma Baijiu treatment group showed lessening intoxicated symptoms than those of light-aroma Baijiu and strong-aroma Baijiu. In addition, there were significant differences between Baijiu and pure alcohol treatment groups at the inhibitory neurotransmitter GABAergic levels and its receptor GABA-AR1 activating levels in the mice neuron cells. Furthermore, the Principal Component Analysis (PCA) analysis inferred that the flavor compounds acetic acid, ethyl acetate, ethyl lactate, and 1-propanol in the sauce-aroma Baijiu were played the major roles in the drunk behaviors that caused by the hangover. While, the acetic acid in the sauce-aroma Baijiu was speculated as a major flavor component to accelerate the alcohol metabolism and retard hangover symptoms.

The prevalence of male rotating shift work correlates with reduced total fertility rate: an ecological study of 54,734 reproductive-aged males in 35 European countries between 2000 and 2015.

Europe has the lowest fertility rate in the world, and 19 European countries are already experiencing negative population growth. Previous studies have shown that light-dark cycle misalignment induces damages to semen quality in animals, but whether shift work impairs male human fertility remains controversial. The diverse types of shift work, which may have distinct health impacts, have not been differentiated in the few previous studies. The present study aims to assess the impact of different male shift work types, i.e., rotating shift work (RSW), permanent shift work (PSW), and daily split shifts (DSS), on male fertility in European countries, based on the European Working Conditions Survey of 54,734 men and 52,457 women of reproductive (15-49 years) age from 35 countries conducted between 2000 and 2015. Year-specific total fertility rate (TFR) for each country was obtained from the World Bank. Mixed linear model was used to analyze the association between the prevalence of shift work types and TFR among the countries during the 15 years span, with adjustment for latitude, per capita GDP, working duration, working frequency, median age of men or women engaged in shift work, education level of men or women, and female shift-work condition in reproductive aged participants. The results showed that the average prevalence of RSW declined from 15.6% in 2000 to 9.8% in 2010, and then rose to 11.1% by 2015, while TFR went up from 1.45 in 2000 to 1.60 in 2010, and then decreased to 1.56 in 2015. A 10% increase of RSW prevalence was associated with a 0.114 decrease of TFR (95% CI: -0.167, -0.061, P < .001), indicating 11.4 fewer births per 100 women throughout lifetime. The association remained significant (ß = -0.088, 95% CI: -0.160, -0.015, P = .020) after adjusting for confounding factors. However, no association was observed between TFR and the prevalence of male PSW (ß = -0.011, 95% CI: -0.094, 0.073, P = .801) or DSS (ß = 0.357, 95% CI: -0.171, 0.884, P = .189). In conclusion, male RSW, rather than PSW and DSS, may reduce TFR. Further studies are needed to validate our findings.

Intelligent microbial cell factory with genetic pH shooting (GPS) for cell self-responsive base/acid regulation.

BACKGROUND: In industrial fermentation, pH fluctuation resulted from microbial metabolism influences the strain performance and the final production. The common way to control pH is adding acid or alkali after probe detection, which is not a fine-tuned method and often leads to increased costs and complex downstream processing. Here, we constructed an intelligent pH-sensing and controlling genetic circuits called "Genetic pH Shooting (GPS)" to realize microbial self-regulation of pH. RESULTS: In order to achieve the self-regulation of pH, GPS circuits consisting of pH-sensing promoters and acid-/alkali-producing genes were designed and constructed. Designed pH-sensing promoters in the GPS can respond to high or low pHs and generate acidic or alkaline substances, achieving endogenously self-responsive pH adjustments. Base shooting circuit (BSC) and acid shooting circuit (ASC) were constructed and enabled better cell growth under alkaline or acidic conditions, respectively. Furthermore, the genetic circuits including GPS, BSC and ASC were applied to lycopene production with a higher yield without an artificial pH regulation compared with the control under pH values ranging from 5.0 to 9.0. In scale-up fermentations, the lycopene titer in the engineered strain harboring GPS was increased by 137.3% and ammonia usage decreased by 35.6%. CONCLUSIONS: The pH self-regulation achieved through the GPS circuits is helpful to construct intelligent microbial cell factories and reduce the production costs, which would be much useful in industrial applications.