Identification of potential sex-related genes in Siniperca chuatsi

Mandarin fish(Siniperca chuatsi)is an economically important freshwater fish cultured in China.In this species,females grow faster than males.However,due to the lack of available genomic and transcriptome information,the mechanisms of sex differentiation remain poorly understood.In this study,Illumina high-throughput sequencing technology was used to sequence four cDNA libraries;the tissues examined included hypothalamus,pituitary gland,ovary,and testis.A total of 134124 high-quality unigenes were obtained on average length of 1361 bp and N50 of 3312 bp.A search of all-unigene sequences against NR,NT,SwissProt,KOG,KEGG,GO,and InterPro databases resulted in 59688(44.50%),76329(56.91%),50432(37.60%),45741(34.10%),48760(36.35%),5241(3.91%),and 46099(34.37%)annotations,respectively.In a comparison of ovarian and testicular libraries,15289 ovary-biased genes and 10035 testis-biased genes were identified,including a series of genes related to sex determination and differentiation,such as cyp19a1a,foxl2,sox9,dmrt1,amh,and others.In addition,49495 SSRs and 85899 SNPs were detected in transcriptome data.Quantitative real-time PCR results of 15 sex-related functional genes indicated that RNA-seq data was reliable.This study will contribute to a better understanding of the molecular mechanisms of sex differentiation and development in Mandarin fish.

Production of XX neo-male mandarin fish, Siniperca chuatsi, after sexual differentiation by oral administration of 17α-methyltestosterone

A well-known fact about mandarin fish(Siniperca chuatsi)is that females grow faster than males.Mandarin fish that have all-female populations have economic advantages,but traditional neo-male fish are difficult to produce.In this study,indirect feeding of 500 mg/kg 17α-methyltestosterone(MT)to XX mandarin fish(60 dpf,days post fertilization)with completely differentiated ovaries induced secondary sex reversal.At 40 days after MT treatment,14.7%of mandarin fish with complete reversal was produced,which showed for the first time that XX mandarin fishes with differentiated ovaries still have potentially bisexual germ cells and the plasticity of sex reversal.In the MT treatment group,there was no significant difference in survival compared to the control group.The body weight of the MT treatment group was significantly lower than that of the control group 40 days after treatment(dat)(P<0.05).During MT treatment,serum 11-KT and T concentrations increased and serum E2 concentration decreased in the MT treatment group,but there was no significant difference in hormone levels between the MT treatment group and the control group.A masculinization of mandarin fish was also confirmed by the expression patterns of sex-specific genes sox9,dmrt1,cyp19a1a and foxl2.A significant amount of sox9 and dmrt1 was expressed in the fish gonads of the MT treatment group,whereas cyp19a1a and foxl2 were minimally expressed in the fish gonads.

Soil bacterial communities respond differently to graphene oxide and reduced graphene oxide after 90 days of exposure

Graphene-based nanomaterials(GBNs)are likely to be entering the soil environment in increasing amounts via consumer products.However,the disturbance of bacterial communities and their associated ecological functions by GBNs remains elusive.We performed a soil incubation experiment with the addition of graphene oxide(GO)and reduced graphene oxide(RGO).The Illumina sequencing technique was used to investigate changes in bacterial communities,and the functional groups of the communities were analyzed using the functional annotation of prokaryotic taxa database.After 90 days of exposure,RGO induced a lower bacterial richness than GO.However,GO induced larger changes in community composition and functions than RGO.After exposure to GBNs,some of the functional groups associated with organic matter degradation and biogeochemical cycling of nitrogen and sulfur decreased.However,the functional group associated with aromatic compound degradation increased,possibly because GBNs contain rich aromatic hydrocarbon structures,which are tolerated by this functional group.