ABSTRACT
Objective To compare the biological characteristics of eyeballs between Zmu-1:DHP and DHP guinea pigs,and to explore the retinal mechanism of myopia in Zmu-1:DHP guinea pigs. Methods To measure the refraction, corneal curvature and axial length of the two guinea pig strains at age of 4-12 weeks. Those spontaneous myopic Zmu-1:DHP guinea pigs were chosen to take the retina for pathological examination. The pathological changes in the retina were determined and compared with the DHP guinea pigs. The expression of RALDH, ALDHTH, TH, TK, iNOS, nNOS, bFGF and TGFβ mRNA in the retina were detected by real time-PCR. Results The myopic rate of 3-week old Zmu-1:DHP guinea pigs was 90.21%,while of the DHP guinea pig was only 18.00%. From 4 to 12 weeks, compared with the DHP guinea pigs,myopia and axial length of the Zmu-1:DHP guinea pigs were significantly increased(P<0.01),and the corneal curvature of Zmu-1:DHP guinea pigs was significantly less than the DHP guinea pigs(P<0.01). The retina outer nuclear layer of Zmu-1:DHP guinea pigs was reduced in thickness,the cell volume was smaller,and the cell number was less compared with the DHP guinea pigs. The choroid of Zmu-1:DHP guinea pigs showed atrophy and became thinner. There were few pigment granules in the pigment epithelium of Zmu-1:DHP guinea pigs,while there were plenty of pigment granules in the DHP guinea pigs. Compared with the DHP guinea pigs,the expression of TH mRNA was significantly down-regulated in the retina of Zmu-1:DHP guinea pigs(P<0.01),and the expression of TK,iNOS,nNOS,bFGF and TGFβ was significantly down-regulated(P<0.01, P <0.05, P <0.05, P <0.05, P <0.05). Conclusions Zmu-1:DHP strain guinea pig has a high rate of spontaneous axial myopia. The retinal mechanism of myopia has a relationship with the regulation of several myopia factors.
ABSTRACT
Objective To breed a guinea pig inbred strain and set up a method for detection of the microsatellite markers of genetic structure in guinea pigs. Method Using inbreeding methods we try to breed the Zmu-1:DHP inbred strain. With 15 pairs of polymorphism microsatellite primers, the genetic homozygosity of Zmu?1:DHP inbred strain,Zmu?1:DHP outbred strain and Zmu?2:DHP inbred strain ( as control) were examined by PCR. Results After breeding for 13 years, 8 sublines of Zmu?1:DHP inbred strain ( >20 generations) were bred. After identification, the gene frequency of the second subline of Zmu?1:DHP inbred strain was 86. 7%,higher than Zmu?1:DHP outbred strain (6. 7%) and Zmu?2:DHP inbred strain (66. 7%). The average number of loci of Zmu?1:DHP inbred strain was 1. 13,lower than that of Zmu?1:DHP outbred strain (2. 47%) and Zmu?2:DHP inbred strain (1. 33%). The genotypic frequency of Zmu?1:DHP in?bred strain was also higher than that of the other strains. The gene types of Zmu?1:DHP inbred strain were included in the genes of Zmu?1:DHP outbred strain, but Zmu?1:DHP inbred strain was short of 2 characteristic genes. The gene homozy?gous rates of 8 sublines of Zmu?1:DHP inbred strain were different with each other,among them, those of the 2nd and 8th sublines were higher than others. Conclusions There are both homozygosity and specificity in the Zum?1:DHP inbred strain and Zum?1:DHP outbred strain. The second Zum?1:DHP subline becomes a new inbred strain guinea pig. It is es?sential that the subline with the characteristic property is screened from these sublines. The guinea pigs of black Zmu?2:DHP inbred strain carrying microsatellite markers not present in the white strains, may carry optimal genes related with hair color properties.
ABSTRACT
Objective To screen microsatellite DNA markers from genome of guinea pigs for further genetic quality control and gene-mapping of this species .Methods Microsatellite sequences were obtained by magnetic bead enrichment and genome database screening , and candidate loci were chosen to design primers .Thereafter , genomic DNA of 5 different guinea pig strains were employed to select polymorphic microsatellite DNA markers based on PCR amplification results .Re-sults A total of 304 microsatellite sequences were analyzed by magnetic bead enrichment and 125 primers were designed . One polymorphic microsatellite DNA marker and 17 specific sites ( no polymorphic was found ) were determined .By gene-mapping , 292 microsatellite sequences were obtained and 178 primers were analyzed , totally 25 polymorphic microsatellite DNA markers and 28 specific sites ( without polymorphics ) were discovered .Conclusions We obtained 26 polymorphic microsatellite DNA markers and 45 potential markers in guinea pigs , and these may lay a foundation for application of mic-rosatellite DNA markers in genetic quality control and gene-mapping of guinea pigs .