Antimicrobial resistance has become a global problem that poses great threats to human health.  Antimicrobials are widely used in broiler chicken production and consequently affect their gut microbiota and resistome.  To better understand how continuous antimicrobial use in farm animals alters their microbial ecology, we used a metagenomic approach to investigate the effects of pulsed antimicrobial administration on the bacterial community, antibiotic resistance genes (ARGs) and ARG bacterial hosts in the feces of broiler chickens.  Chickens received three 5-day courses of individual or combined antimicrobials, including amoxicillin, chlortetracycline and florfenicol.  The florfenicol administration significantly increased the abundance of mcr-1 gene accompanied by floR gene, while amoxicillin significantly increased the abundance of genes encoding the AcrAB-tolC multidrug efflux pump (marA, soxS, sdiA, rob, evgS and phoP).  These three antimicrobials all led to an increase in Proteobacteria.  The increase in ARG host, Escherichia, was mainly attributed to the β-lactam, chloramphenicol and tetracycline resistance genes harbored by Escherichia under the pulsed antimicrobial treatments.  These results indicated that pulsed antimicrobial administration with amoxicillin, chlortetracycline, florfenicol or their combinations significantly increased the abundance of Proteobacteria and enhanced the abundance of particular ARGs.  The ARG types were occupied by the multidrug resistance genes and had significant correlations with the total ARGs in the antimicrobial-treated groups.  The results of this study provide comprehensive insight into pulsed antimicrobial-mediated alteration of chicken fecal microbiota and resistome.

In January 2022, we received ant specimens collected from three field colonies from Shantou City, Guangdong Province, China.  They were identified as the little fire ant, Wasmannia auropunctata, through morphological and molecular analyses.  Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union for Conservation of Nature (IUCN) and has spread from its native range in South America to every continent except Antarctica.  DNA analysis of mitochondrial cytochrome c oxidase subunit I (COI) in nine specimens of W. auropunctata found that they had a close genetic relationship with specimens from Argentina.  This study represents the first formal record of the establishment of W. auropunctata outdoor in Chinese mainland.  However, the invasion stage and occurrence degree of W. auropunctata in China are not clear to date.  The implementation of quarantine measures, investigation of the occurrence and distribution, and development of monitoring and control strategies are needed to actively respond to the threat posed by this highly invasive ant.

Financial support is a crucial part of China’s poverty alleviation effort.  Thus, it is vital to understand how formal credit impacts income growth in rural households.  In 2012, 2015, and 2018, a survey was conducted to obtain a panel dataset of 592 rural households from 6 poverty-stricken counties in western China, including counties in Guizhou, Yunnan, and Shaanxi provinces.  We use the data to examine the effect of formal credit on rural household income and the mechanism that underlies this effect.  We find that formal credit can significantly increase rural households’ income in deprived areas in western China.  Furthermore, formal credit promotes the reallocation of household labor from the agricultural sector to the non-agricultural sector and changes rural households’ decisions about investment-consumption behavior.  These are the drivers of changes in the amount and structure of household income.  Further analyses show that formal credit may widen income inequality among rural households in western China’s deprived areas.  The individual characteristics of rural households, such as different levels of material capital, human capital, and social capital, bring about differences in the effects of formal credit on income growth.  This study emphasizes that the implementation of formal credit is an essential strategy for poverty alleviation in underdeveloped areas, but policymakers should not excessively interfere with the financial market.

   In the rice cytoplasmic-genetic male sterility (CMS) system, the combination of a CMS line, maintainer line and restorer line carrying the restorer gene to restore fertility, is indispensable for the development of hybrids. However, the process of screening for the trait of fertility restoration is laborious and time-consuming. In the present study, we analyzed the nucleotide sequence of the Rf4 gene, which is the major locus controlling fertility restoration, to identify allele-specific variation. A single nucleotide polymorphism (SNP) A/C at +474 in the coding sequence (CDS) was found to be capable of strictly distinguishing groups of alleles Rf4 (A) and rf4 (C). Using KASP genotyping, this valuable SNP was converted to an allele-specific PCR marker. We evaluated and validated the marker among three-line parents with different backgrounds, and the results revealed a complete correlation between SNP alleles and the fertility restoration phenotype. Molecular screening was subsequently carried out for the presence of alleles of Rf4 and Rf3 among 328 diverse rice cultivars with worldwide distribution. The results demonstrate that this SNP marker could be the optimal choice for the molecular identification of potential restorers.

Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 (st18). At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay (RIA) at 30 wk. The results showed that body weight and shank length of sexreversed females were not significantly different between low-dose groups (0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively) and high-dose groups (1.0 and 1.3 mg for F4 and F5, respectively) (P>0.05). Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group (P<0.05). While the gonad weight of treatment groups were less than that in male control (P<0.05), oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group (P<0.05). Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups (P<0.05). Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups (P<0.05), but significant lower compared with male control (P<0.05). While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups (P<0.05). In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at sex maturity.