[Analysis of effect of microsatellite markers on Escherichia coli F4 (K88) receptor in different swine breeds].

Four microsatellite markers linked with Escherichia-coli F4 receptor gene were selected from chromosome 13 of pig (authorization) to analyze difference in hereditary between the genotype and F4 receptor adhesive appearance. Results showed that the microsatellite markers were highly polymorphic and the heterozygosities ranged from 0.6117 to 0.

[Effect of five genetic Loci related to pig litter size].

To compare the effect of different genes on litter size, we used PCR-RFLP to test the genotypic frequencies of 5 genes related to litter size, i. e. ESR, FSHbeta, PRL, PRLR and NCOA1 and analyzed the effect of various genotypes on total number born (TNB) and number born alive (NBA) within the same populations of Large White (n=158) and Landrace (n=224) pigs.

[Progress in the study on diacylgycerol acyltransferase (DGAT)-related genes].

Diacylgycerol Acyltransferase (DGAT) plays an important role in the formation of lipid in different tissues of biological body. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycerol. This enzyme is coded by both DGAT1 and DGAT2.

[Experimental results on enterotoxigenic E.coli F18 receptor genotypes].

A total of 158 pigs of Yorkshire, Landrace and Duroc were selected from some swine breeding farms in Hunan province. The genotypes of enterotoxigenic E.coli F18 receptor were tested by PCR-RFLP.

[Screening genes related to 'black' character in wu-ding chicken by delta differential display].

The 'black' character is a cardinal character of black chicken that is very important to the medical value and economical value of black chicken. The study compared gene expression between black chicken and non-black chicken by delta differential display method, and obtained twenty-nine expressed sequence tags(ESTs) by extraction, amplification, purification, northern blotting, cloning and sequencing of gel-embedded DNA. Of twenty-nine ESTs, eight ESTs have high similarity rate with known gene in chicken-beta-trepomyosin gene, cardiac myosin alkali light chain gene, insertionally activated c-Ha-ras oncogene, fra-2 oncogene, 16S rRNA gene and mitochondrion genome sequence, respectively, with similarity rate 97%,100%, 98%, 98%, 98%, 99%, 99% and 97%.

[The genetic variation of two microsatellite markers of Escherichia coli F4(K88) receptor in different swine breeds].

The genetic variation of ETEC F4 receptor in Shaziling and Yorkshire breeds were studied using two micro-satellite markers(S0223 and S0068). The results showed that there were polymorphisms in the two markers, and there were great variations of the gene heterozygosity and Shannon information index in the two breeds. It was also reported that there were differences in K88ab and K88ac receptors in Chinese native breeds and foreign breeds, so the two markers might be the genetic markers of F4 receptor gene.

[Progress in Attractin(mahogany/ATRN) gene].

Attractin is an autosomal recessive gene and received great attention within the last few decades. Attractin in different lines has been identified attractin to have multiple roles in regulating physiological process. It affects the balance between agonist and antagonist at receptors on melanocytes, modifies behaviour and basal metabolic rate, intervenes developing the central nervous system and its function, and modulates an interaction between activated T cell and macrophages.

[Genetic linkage between Atrn gene and microsatellite markers and the effects to some economic traits in pigs].

The genetic polymorphisms of Atrn gene, which were from 174 F0-F5 Danish resource family pigs (DRF) that has undergone five successive generations of inbreeding and 129 F9 Hunan yellow pigs (HY) that were developed by crossbreeding, were tested by PCR-RFLP method, and the effects to carcass and growth traits were also analyzed. The results showed that: (1) Three genotypes of AA, AB, BB were detected by Taq I-RFLP in the two pig breeds, and highly significant differences (P<0.01) in genotype frequencies were found between the two breeds; (2) Based on the linkage analysis of resource family pigs using CRI-MAP V2.

Polymorphism of E. coli F18 receptor gene in different pig breeds.

The genetic variation of E. coli F18 receptor(ECF18R) loci in 867 pigs including Large Yorkshire, Landrace, Duroc, Ningxiang pig, Shaziling pig and Daweizi pig was detected by PCR-RFLP with Hin6 I. The results showed as follows: The three exotic breeds including Large Yorkshire, Landrace and Duroc were proved to be polymorphic at the Hin6 I-RFLP site.

[A search for chromosome 13 QTL in a complex pig family].

A search for chromosome 13 QTL was carried out in a pig family of complex pedigree. The results indicated that a significant QTL on chromosome 13 was segregating in pig family. The QTL significantly affected body weight and average daily gain (P < 0.