Genome-wide identification and skin expression of immunoglobulin superfamily in discus fish (Symphysodon aequifasciatus) reveal common genes associated with vertebrate lactation.

Discus Symphysodon spp. employs an unusual parental care behavior where fry feed on parental skin mucus after hatching. Studies on discus immunoglobulin superfamily (IgSF) especially during parental care are scarce. Here, a total of 518 IgSF members were identified based on discus genome and clustered into 12 groups, unevenly distributing on 30 linkage groups. A total of 92 pairs of tandem duplication and 40 pairs of segmental duplication that underwent purifying selection were identified. IgSF genes expressed differentially in discus skin during different care stages and between male and female parents. Specifically, the transcription of btn1a1, similar with mammalian lactation, increased after spawning, reached a peak when fry started biting on parents' skin mucus, and then decreased. The expression of btn2a1 and other immune members, e.g., nect4, fcl5 and cd22, were up-regulated when fry stopped biting on mucus. These results suggest the expression differentiation of IgSF genes in skin of discus fish during parental care.

Distinct skin morphological and transcriptomic profiles between wild and albino Oscar Astronotus ocellatus.

Oscar Astronotus ocellatus is an important ornamental fish, including albino and wild varieties. Albino individuals attract aquarium hobbyists due to their unique body color, but studies on the species' albinism mechanism are currently scarce. Here, we investigated the morphological and transcriptomic profiles of the skin of albino and wild Oscar. The results showed that the albino type had fewer oval-shaped melanophores and immature melanosomes but that the wild type contained more stellate-shaped melanophores and mature melanosomes. Albino Oscar had a degenerative pigment layer without obvious melanin deposition and content, while the wild type contained more concentrated melanin within the pigment layer. A total of 272,392 unigenes were detected, 109 of which were identified as differentially expressed genes (DEGs) between albino and wild Oscar. Pathways of DEGs, including those involved in complement and coagulation cascades, novobiocin biosynthesis, Th1 and Th2 cell differentiation, and tropane, piperidine and pyridine alkaloid biosynthesis, were significantly enriched. DEGs, including upregulated Sfrp5 and Tat, and downregulated Wnt-10a, Ppp3c, Notch1 and Trim27 involved in the Wnt signaling pathway, Notch signaling pathway, tyrosine metabolism, MAPK signaling pathway and melanogenesis, might be associated with the albinism of Oscar. This study characterized the difference in melanophore morphology between wild and albino Oscar and identified some albinism-related candidate genes and signaling pathways, helping to understand the genetic mechanism of fish albinism.

Exposure to microplastics impairs digestive performance, stimulates immune response and induces microbiota dysbiosis in the gut of juvenile guppy (Poecilia reticulata).

Microplastics (MPs) are widely distributing in aquatic environment. They are easily ingested by aquatic organisms and accumulate in digestive tract especially of intestine. To explore the potential effects of MPs on intestine, here we, using juvenile guppy (Poecilia reticulata) as experimental animal, investigated the response characteristics of digestion, immunity and gut microbiota. After exposure to 100 and 1000 µg/L concentrations of MPs (polystyrene; 32-40 µm diameters) for 28 days, we observed that MPs could exist in guppy gut and induce enlargement of goblet cells. Activities of digestive enzymes (trypsin, chymotrypsin, amylase and lipase) in guppy gut generally reduced. MPs stimulated the expression of immune cytokines (TNF-α, IFN-γ, TLR4 and IL-6). Through high throughput sequencing of 16S rRNA gene, decreases in diversity and evenness and changed composition of microbiota were found in guppy gut. PICRUSt analysis revealed that MPs might have effects on intestinal microbiota functions, such as inhibition of metabolism and repair pathway. Our findings suggested that MPs could retain in the gut of juvenile guppy, impair digestive performance, stimulate immune response and induce microbiota dysbiosis in guppy gut. The results obtained here provide new insights into the potential risks of MPs to aquatic animals.

[Health damage assessment due to PM2.5 exposure during haze pollution events in Beijing-Tianjin-Hebei region in January 2013].

OBJECTIVE: To assess the human health damage due to particulate matter ≤ 2.5 µm (PM2.5) exposure during the haze pollution events in 12 cities of Beijing-Tianjin-Hebei region in January 2013. METHODS: The data were collected for urban population, ambient air quality, baseline mortality rate and emergency visits in Beijing, Tianjin, Shijiazhuang, Baoding, Chengde, Handan, Langfang, Hengshui, Qinhuangdao, Tangshan, Xingtai and Zhangjiakou. Then the exposure-response relationship was constructed between short-term PM2.5 exposure and mortality and emergency room visits with meta-analysis. Thus the excess deaths and emergency room visits due to PM2.5 exposure were estimated during the haze pollution events using city-specific exposure population, PM2.5 daily concentration and exposure-response coefficients. RESULTS: Three serious PM2.5 pollution events occurred on January 12, January 19 and January 27 in Beijing-Tianjin-Hebei region respectively. From January 10 to January 31, the 24 h mean concentrations of PM2.5 in Beijing, Tianjin, Shijiazhuang, Tangshan, Qinhuangdao, Handan, Xingtai, Baoding, Zhangjiakou, Chengde, Langfang, Hengshui were 705, 411, 675, 506, 255, 598, 698, 667, 231, 178, 718 and 405 µg/m(3). Xingtai, Shijiazhuang, Handan, Baoding, Langfang and Beijing were the more polluted areas. And there were 17 days (77.3%), 13 days (59.1%), 12 days (54.5%), 11 days (50.0%), 10 days (45.5%) and 8 days (36.4%) of Air Quality Index reaching the serious level respectively. The short-term PM2.5 exposure caused 2725 excess death including 846 excess deaths duo to respiratory disease and 1878 excess deaths due to circulatory disease in Beijing-Tianjin-Hebei region from January 10 to January 31. CONCLUSIONS: The haze pollution events led to serious public health damage. And it is imperative to take actions of controlling PM2.5 pollution.

Time-series analysis of the relationship between air quality, temperature, and sudden unexplained death in Beijing during 2005 - 2008.

BACKGROUND: There is a yearly increase in the rate of sudden unexplained death (SUD), even through extensive physical examination and the testing of a large number of biomarkers, the cause of sudden death in patients previously in good health cannot be fully determined. During clinical practice, a spatial aggregation phenomenon has been observed in the incidence of sudden unexplained death. Previous research has shown that environmental factors, such as air pollution, weather conditions, etc., have a significant impact on human health. In the wake of the continuous environmental damage, the relationship between environmental factors and sudden unexplained death still needs to be studied. To study the relationship between sudden unexplained death and air quality and temperature, commonly used markers such as particulate matter of aerodynamic diameter < 10 µm (PM(10)), daily average concentration of the gaseous pollutants sulfur dioxide (SO2) and nitrogen dioxide (NO2), and the daily average temperature were investigated. METHODS: The methods include collecting the data of sudden unexplained death; air quality monitoring; meteorological monitoring from January 1, 2005 to December 31, 2008; utilizing generalized additive models (GAM); controlling the influential factors such as secular trend, seasonal trend, and Sunday dummy variable; and analyzing the correlation between daily inhalable particle concentration, daily average temperature, and the number of daily SUD. RESULTS: There was no statistical significance between the daily inhalable particle and daily incidence of sudden unexplained death. Incidence rate of sudden unexplained death had nonlinear positive correlation with daily temperature. When the temperature was 5°C above the daily average temperature, the daily incidence of sudden unexplained death went up with the rising temperature. CONCLUSION: Temperature may be one of the key risk factor or precipitating factor of SUD.

[Time-series analysis on the association between gaseous air pollutants and daily mortality in urban residents in Tianjin].

OBJECTIVE: To study the association between sulphur dioxide, nitrogen dioxide and daily mortality in urban population from Tianjin. METHODS: Data on daily concentration of inhalable particulate matter, sulphur dioxide and nitrogen dioxide, daily mean temperature and relative humidity, daily cause-specific death counts were collected. Generalized additive models was used to explore the relationship between sulphur dioxide, nitrogen dioxide and daily mortality, after adjusting the effects of long-term and seasonal trend, weather conditions, and to analyze the potential effect of particulate matter and model parameters on relative risk estimates. RESULTS: Results showed that the daily concentrations of SO(2) and NO(2) were significantly associated with daily non-accidental and cardiovascular mortality but not associated with daily respiratory mortality. An increase of 10 µg/m(3) in SO(2) was associated with 0.56% (95%CI: 0.23% - 0.89%) non-accidental morality, 0.49% (0.06% - 0.93%) cardiovascular morality, respectively. An increase of 10 µg/m(3) in NO(2) was associated with 0.94% (95%CI: 0.17% - 1.70%) non-accidental morality, 1.29% (0.29% - 2.30%) cardiovascular morality, respectively. CONCLUSION: Our findings suggested that exposure to SO(2) and NO(2) was significantly associated with daily cardiovascular and respiratory mortality in urban population in Tianjin.

[Time-series analysis of association between inhalable particulate matter and daily mortality among urban residents in Tianjin].

OBJECTIVE: To study the association between particulate matter less than 10 micron in aerodynamic diameter (PM(10)) and daily mortality among urban population in Tianjin. METHODS: We collected data of air quality, daily mean temperature and relative humidity, and daily cause-specific death counts, and used generalized additive models to explore the relationship between ambient particulate matter and daily mortality, after adjusting the effects of long-term and seasonal trend, weather conditions and other gaseous pollutants, such as sulfur dioxide and nitrogen dioxide. RESULTS: An increase of 10 µg/m(3) in PM(10) was associated with 0.45% (95%CI: 0.21 - 0.69) non-accidental morality, 0.60% (0.29 - 0.91) circulatory morality and 0.82% (0.04 - 1.61) respiratory morality, respectively. CONCLUSION: Our findings indicated that the extent of exposure to PM(10) was significantly associated with daily mortality in urban population in Tianjin, especially with the mortality rates on circulatory and respiratory diseases.