The Effects Of Temperature And Light On The Growth Of Procambarus Clarkii And The Rhythmic Expression Of Clock And Cryptochrome Genes

Procambarus clarkii is an important aquatic economic animal in China.Currently,the main problems in the aquaculture of crayfish are: insufficient breeding of seedlings,poor breeding mode,and low output per unit area etc.The circadian rhythm of the organism's physiology and behavior is regulated by the circadian clock,and the periodicity of the generated internal rhythm is about 24 hours.Core clock genes such as clock(Clk),timeless(Tim),period(Per),and cryptochrome(Cry)etc.,participate in the internal regulation mechanism,allowing organisms to allowing organisms to adapt the change of external environment.In addition,temperature and light are both important exogenous environmental factors that shifting or driving the biological clocks of organisms.Therefore,the circadian clock gene of P.clarkii was used as an entry point to explore the relationship between the rhythmic oscillation of the circadian clock gene of P.clarkii and its growth and development under different light and temperature modes.These results are expected to provide ideas and theoretical basis for exploring new models of healthy and efficient breeding.1.Sequence and functional analysis of Pc Clk and Pc Cry1 genes of P.clarkiiA partial c DNA sequence of Pc Clk was obtained,containing a 183 bp 3'end untranslated region(UTR)and an open reading frame(ORF)of 1182 bp,encoding393 amino acids.The predicted molecular weight of the protein is 45.054 k Da.The full-length sequence of Pc Cry1 gene was 2006 bp,including ORF 1650 bp,which could encode 549 amino acids,5' UTR 116 bp,3' UTR 240 bp.The predicted molecular weight of the protein was 63.167 k Da.Pc CLK protein analysis revealed that the amino acid sequence contains an HLH domain and a PAS domain.Pc CRY1 contained a DNA photolyase domain and a FAD binding site domain.The partical sequence of Pc Clk c DNA had the highest similarity with that of Pacifastacus leniusculus and the full length sequence of Pc Cry1 c DNA was most similar to Eurydice pulchra and Talitrus saltator.2.Analysis of tissue expression characteristics of Pc Clk and Pc Cry1 genes of P.clarkii under different lights and temperaturesQuantitative Real-time PCR technology was used to detect the expression of Pc Clk and Pc Cry1 gene m RNA in different tissues of P.clarkii under different lightsand temperatures.The results showed that Pc Clk was expressed in the brain,eyestalk,hepatopancreas,and gonads.Regardless of changes in light or temperature conditions,the 24-hour oscillation cycle was basically followed in the brain,eyestalk,and hepatopancreas.Pc Clk was an endogenous rhythm gene,and oscillation was not affected by changes in external environmental factors.Pc Cry1 was also expressed in the brain,eyestalk,hepatopancreas,and gonads.No matter how light and temperature change,the Pc Cry1 gene also basically had a 24-hour circadian oscillation rhythm in all tissues.Under the change of light,the expression of Pc Cry1 gene m RNA was significantly different.Pc Cry1 expression changes are endogenous and regulated by light.3.Probing into the growth of P.clarkii under different breeding modesSix groups of culture modes were selected to measure the growth index of P.clarkii.The results showed that under relatively low temperature conditions,P.clarkii grew slowly,but the survival rate was high.When the temperature increased,its survival rate decreased,but to a certain extent,it promoted the growth of shrimp.At three different illumination modes at the same temperature,natural light significantly improved the growth status of P.clarkii,and the set natural condition group(12LD,25?)was a relatively ideal breeding mode.