| Acrossocheilus fasciatus is a kind of freshwater fish species with high economic value,inhabiting in the fresh water rivers south of Yangtze River in China.In recent years,through the analysis of water,crude fat,crude protein,ash and other general nutrients,it is found that the content of DHA and EPA is high,which is helpful for the prevention and treatment of arteriosclerosis,prevention of cardiovascular and cerebrovascular diseases,prevention of senility dementia,protection of vision and other functions,so the market demand is expanding,with high economic value.Acrossocheilus fasciatus is not very fast,and it is easy to be affected by diseases in the breeding process.Therefore,it is an urgent production problem to cultivate varieties with fast growth and strong resistance to disease.In the process of breeding experiments,we found that there was a huge difference between males and females.The growth rate of females was faster than that of males,and the weight of females at the same age was significantly higher than that of males.It was the key of high-yield breeding technology to obtain all female seedlings.At present,there are few studies on sex determination and gonadal development,and the related genomic information is also lacking,which greatly restricts the breeding and sex control of superior varieties.In order to clarify the genetic background and determine whether there is a unique mechanism of gonadal development in the fish,we used transcriptome information of the fish to screen genes that may be involved in reproduction and gonadal development.In addition,we found that in the process of Acrossocheilus fasciatus breeding,it is easy to break out of Oodinium acidophilum disease,which is caused by the body surface of Oodinium acidophilum parasitic fish.It has fast infection,strong infectivity,long onset period,long treatment period and high mortality,which has caused serious losses to the Acrossocheilus fasciatus breeding industry.Therefore,screening of Oodinium acidophilum resistant seedlings is also a key to high-yield breeding of fish.At present,there are no reports on the immune mechanism and the regulation of related immune genes of the Acrossocheilus fasciatus after suffering from the Oodinium acidophilum disease at home and abroad.For the lack of the background of the immune response mechanism of the Acrossocheilus fasciatus caused by the Oodinium acidophilum disease,this paper studies the disease resistance mechanism of the Acrossocheilus fasciatus,explores the immune mechanism of the Acrossocheilus fasciatus against the Oodinium acidophilum disease,and screens the key immune genes in response to the immune response of the disease,In order to promote the effective prevention and treatment of the disease and the further development of gene breeding and screening.Based on the above research direction for the screening of fast growth,breeding disease-resistant ability,this article from the perspective of the transcriptome and molecular biology to Acrossocheilus fasciatus sex determination and to explore the immune response to two,in order to screening involved in sex determination and Oodinium acidophilum key genetic disease immune response,to enrich the Acrossocheilus fasciatus breeding background of molecular biology.In this study,10 genes were sequenced from gonadal transcriptome of different sexes in the same period,including ABCE1(ATP-binding cassette sub-family E member 1),NOM1(nucleolar MIF4G domain-containing protein 1-like),PKMYT1(protein kinase membrane associated tyrosine/threonine 1),PTGIR(prostacyclin receptor-like),SNPRA(small nuclear ribonucleoprotein A-like),WNT4(Wnt family member 4),DMRT3(doublesex-and mab-3-related transcription factor 3),E2A(E2-alpha-like)and FOXL(winged helix/forkhead transcription factor).The spatiotemporal expression patterns detected by RT-qPCR showed that DMRT3 was significantly up-regulated in males,which may play a key role in sex determination and testicular development.FOXL expression was not significantly increased in females,while NOM1,ABCE1 and PKMYT1 were consistently high.These results indicate that some important sex-determining genes show unique expression patterns in the fish.On the other hand,transcriptome sequencing was performed on samples from infected Oodinium acidophilum and healthy Acrossocheilus fasciatus respectively,and 9 immune-related genes with significant differential expression were screened:antigen-like protein C,IP07(importin 7),IRF1(interferon regulatory factor 1-like),CXCR4(C-X-C chemokine receptor type 4-B-like),SYK(tyrosine-protein kinase SYK-like),DPS(desmoplakin-like),HSP47(serpin H1-like),TLR2(toll-like receptor 2)and IGH(immunoglobulin heavy chain).The results of real-time fluorescence quantification(RT-qPCR)showed that IP07,IRF1,CXCR4 and IGH were significantly upregulated in the infected fish,which may play a key role in the immune response of the fish to Oodinium acidophilum infection.These findings provide a background for the screening of sex-determining genes,the understanding of immune system and immune defense mechanism,and the subsequent intra embryonic manipulation and the breeding of new strains.It provides the research and theoretical basis for screening fast growth and disease resistance lines and gene breeding. |
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