| The gene sequence and polymorphism in arylalkylamine-N-acetyltransferase (AA -NAT) and Hydroxyindole-O-Methyltransferase (HIOMT) of 179 individuals including Xinjiang finewool sheep, Small Tail Han sheep, Aletai sheep and Duolang sheep were analysised by PCR-SSCP, PCR-RFLP and gene sequencing.The objective of this studies is to find the difference of AA-NAT, HIOMT gene sequence between nonseasonal oestrus and seasonal oestrus sheep breeds, to provide marker assisted selection(MAS) for culturing nonseasonal oestrus sheep breeds,and to provide the theory basis for perennial equilibrating reproduction. The main results of our experiments are as follows:1. Partial AA-NAT gene sequence (1142bp) were acquired, which included exon1 (152 bp), intron1 (290bp), exon2 (155bp), intron2 (338bp) and exon3(207bp), the intron1 and intron2 were first obtained. Partial cds sequence (35bp) and 3′flanking region sequence of HIOMT gene were first acquired.2. The results of sequencing indicated there was a mutation(A→G)in exon 3 of AA-NAT gene, which changed Arginine to Glycine. There were three mutations which were C→G(at 120bp position), C→G(at 131bp position), A→G(at 151bp position) in 3′flanking region of AA-NAT gene. The abundant polymorphism were found in 3′flanking region of HIOMT gene(nine gentypes and six mutations).There were five mutations which were T→C(at 94bp position), G→C(at 95bp position), G→A(at 96bp position), T→C(at 201bp position), G→A(at 217bp position) in the amplified fragment of primer HIOMT2, there was a mutation A→G(at 107bp position) in the amplified fragment of primer HIOMT3.3. At the Smaâ… endonuclease site of primer NAT1 amplified products, the analysis of population genetics indicated that there was strong uniformity of gentypes in nonseasonal oestrus sheep breeds(Small Tail Han sheep and Duolang sheep) and seasonal oestrus sheep breeds (Xinjiang finewool sheep and Aletai sheep), but the nonseasonal oestrus sheep breeds and seasonal oestrus sheep breeds are different. The HIOMT genotype distributions were high significantly different (P<0.01) between nonseasonal oestrus sheep (Small Tail Han sheep, Duolang sheep) and seasonal oestrus sheep (Xinjiang finewool sheep, Aletai sheep) in primer HIOMT2 and HIOMT3 products. 4. At the Smaâ… endonuclease site of primer NAT1 amplified products, the frequency of allele A(≥0.8710)was higher than the allele B in nonseasonal oestrus sheep populations, and BB genotype was not found in nonseasonal oestrus sheep populations, which indicated that high frequency of allele A is associated with nonseasonal oestrus in sheep breeds. At the site of primer NAT4 amplified products, allele A was not found in seasonal oestrus sheep populations, and the frequence of allele B in Small Tail Han sheep, Duolang sheep was 0.8276,0.7333, respectively,which indicated the allele B is associated with seasonal oestrus in sheep breeds. At the site of primer HIOMT2 amplified products, the CC genotype was all found in nonseasonal oestrus sheep populations, but all not in seasonal oestrus sheep populations, which indicated allele C is associated with nonseasonal oestrus in sheep breeds. At the site of primer HIOMT3 amplified products, the allele E was protogene in nonseasonal oestrus sheep populations, and the frequence of allele E in Small Tail Han sheep, Duolang sheep was 0.7000,0.7581, respectively;the allele D was protogene in seasonal oestrus sheep populations, and the frequence of allele D in Xinjiang finewool sheep, Aletai sheep was 0.5690,0.6500, respectively; which indicated that allele E is associated with nonseasonal oestrus and allele D is associated with seasonal oestrus in sheep breeds. |
