Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus.

The autotetraploid Carassius auratus (4nRR, 4 n=200, RRRR) is derived from whole-genome duplication of Carassius auratus red var. (RCC, 2 n=100, RR). In the current study, we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin (red in RCC, brownish-yellow in 4nRR). To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR, we performed transcriptome profiling and molecular functional verification in RCC and 4nRR. Results revealed that scarb1, associated with carotenoid metabolism, underwent significant down-regulation in 4nRR. Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration. Subsequently, we identified four divergent scarb1 homeologs in 4nRR: two original scarb1 homeologs from RCC and two duplicated ones. Notably, three of these homeologs possessed two highly conserved alleles, exhibiting biased and allele-specific expression in the skin. Remarkably, after precise editing of both the original and duplicated scarb1 homeologs and/or alleles, 4nRR individuals, whether singly or multiply mutated, displayed a transition from brownish-yellow skin to a cyan-gray phenotype. Concurrently, the proportional areas of the cyan-gray regions displayed a gene-dose correlation. These findings illustrate the subfunctionalization of duplicated scarb1, with all scarb1 genes synergistically and equally contributing to the pigmentation of 4nRR. This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploid fish, substantially enriching our understanding of coloration formation and change within this group of organisms.

Epidemiological analysis of pulmonary tuberculosis among students and teachers in Liangyungang from 2008 to 2017 / 中国学校卫生

Objective@#To understand the prevalence and development of pulmonary tuberculosis(PTB) in students and teachers in Liangyungang over the last ten years, and provide reference for PTB surveillance and control at schools and colleges.@*Methods@#The epidemic information of PTB among students and teachers in Lianyungang during 2008-2017 was collected from Chinese Infectious Disease Report Information Management System and Chinese Tuberculosis Information Management System, and analyzed with quantitative description method.@*Results@#From 2008 to 2017, 1 112 students and teathers with PTB were found in Lianyungang City, the average reported incidence was 14.03/100 000, pathogenic positive incidence was 4.52/100 000. The above two rates both showed a trend of decline year by year (Z=4.55,6.83, P<0.01). The incidence of registered PTB in schools in the second quarter was the highest, especially in April. Guanyun County has the highest incidence. The average age was (20.11±7.54) years old, and the obvious high-incidence age group was 16-21; the sex ratio between men and women was 1.87∶1. Most of the 1 112 patients were Han, accounting for 99.64%, the rest were Hui, Tujia and Uygur. Teachers’ reported incidence was positively correlated with students’ reported morbidity (rs=0.93, P<0.01); there were differences between school population and general population in gender, patient origin, etiological results, treatment classification and positive patients’ treatment outcome (χ2=49.54, 528.27, 63.55, 121.40, 9.80, P<0.05).@*Conclusion@#Overall, the reported incidence of PTB in schools in Lianyungang City has been decreasing year by year, however,it should not be taken lightly. Prevention and control of PTB in schools should be further strengthened.