Sequence And Expression Difference Of ASIP Gene In Youzhou Black Goats And YuDong White Goats

The skin color is not only one of the distinguishing features of the breed but also associated with the growth rate and disease resistance in animals.In mice,the agouti signaling protein(ASIP)gene is one of the main genes that regulate pigmentation.In this study,we cloned and analysed sequence feature of A SIP gene in Youzhou Black goats and Yudong White goats.The expression of ASIP gene in different tissues(muscle,mons pubis,lips,spleen,brain,lung,kidney and heart)between two breeds were detected by semi-quantitative PCR and qPCR.In addition,the expression of ASIP gene and the intramuscular fat(IMF)content in the quadriceps of Youzhou Black goats,Yudong White goats and Boza goats were detected.Results were shown as follows:(1)A total of 21200 bp ASIP gene sequences of Youzhou Black goats and Yudong White goats were obtained.Compared Youzhou Black goats mRNA sequence with Yudong White goats,we found that CDS is located at rsl5410-15569,rsl6886-16950,rs20432-20608.Four promoter candidate regions were predicted to be located at rs7046-rs7296,rs 17973-18223,rs 18330-18080,rs7017-rs6767,two transcription initiation sites were predicted to be located at rs7308,rs6782,respectively.(2)Compared with the ASIP gene sequence of Yudong White goats,there were three mutation sites in rs 16501(G>A);rs 19643(C>A);rs 19858(C>T)and three consecutive base deletions in rs20011-rs20013(delAGG)in Youzhou Black goats.All mutations were located in the intron region of the ASIP,which may be related to the regulation of the ASIP gene.(3)The CDS of ASIP gene was 402 bp.The similarity of goat ASIP nucleotide sequences with those ASIP gene in sheep,cattle,buffalo,yak,pigs,camels was 98%,98%,97%,93%,90%,89%,respectively.These suggest ASIP gene is highly conserved in mammals.(4)ASIP gene mRNA was detected in goats all tissues,but the expression abundance was tissue-specific.Interestingly,the Youzhou Black goats ASIP gene mRNA levels were highest in the heart but lowest in muscle;whereas ASIP gene expression was lowest in the heart of Yudong White goats and highest in the kidney.At the same time,the relative expression of ASIP gene in Youzhou Black goats tissues were significantly lower than that in Yudong White goats(P<0.01).(5)Furthermore,the expression of ASIP gene mRNA in the quadriceps femoris was significantly higher than that in Youzhou Black goats(P<0.01),but there was no significant difference between Boza goats and Yudong White goats(P>0.05).The intramuscular fat content in quadriceps muscle trended to be:Boza goats>Yudong White goats>Youzhou Black goats,and levels of ASIP mRNA tended to be correspongding to the change of IMF value.In conclusion,ASIP gene of Youzhou Black goats and Yudong White goats possibly had two transcription initiate sites.Although ASIP gene CDS sequence highly conserved between species,four mutations were identified in introns.ASIP gene mRNA levels in tissues of Youzhou Black goats were significantly lower than in Yudong White goats.ASIP mRNA levels and IMF values in muscle tissues tended to be correspondingly altered.