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Korean native chickens are a very valuable chicken population in Korea and their prices are higher than that of commercial broilers. In order to discriminate two commercial Korean native chicken populations (CCP1 and CCP2), single nucleotide polymorphisms (SNPs) from mitochondrial (mt) DNA D-loop sequences and LEI0258 marker polymorphisms in the major histocompatibility complex (MHC) region were investigated. A total of 718 birds from nine populations were sampled and 432 mtDNA sequences were obtained. Of these, two commercial Korean native chicken populations (363 birds) were used for investigation of their genetic relationship and breed differentiation. The sequence data classified the chickens into 20 clades, with the largest number of birds represented in clade 1. Analysis of the clade distribution indicated the genetic diversity and relation among the populations. Based on the mtDNA sequence analysis, three selected SNPs from mtDNA polymorphisms were used for the breed identification. The combination of identification probability (Pi) between CCP1 and CCP2 using SNPs from mtDNA and LEI0258 marker polymorphisms was 86.9% and 86.1%, respectively, indicating the utility of these markers for breed identification. The results will be applicable in designing breeding and conservation strategies for the Korean native chicken populations and also used for the development of breed identification markers.

This work was carried out to investigate the effect of the induced molting with low-protein and energy diet on the postmolt performance of layers. Eighty White Leghorn layers (61-old-wk) with over 80% egg production were used for 12 weeks in this work. Treatments were non-molt control (CO), fasting treatment for 10 days (FW), molt treatment with low-protein and low-energy molting diet for 3 weeks (LO), and molt treatment with standard molting diet for 3 weeks (ST) as 4 treatments (2 replications/treatment and 10 birds/replication). Body weight (BW) loss was 26.5% of initial BW at 2 week in FW treatment, and was 17.3% and 14.2% in both LO and ST treatments (P

The Graduate School of Bio & Information Technology, Hankyong National University, Ansung 456-749, KoreaABSTRACT The chicken major histocompatibility complex (MHC) is known to be associated with disease resistance and susceptibility to several pathogens. The microsatellite marker LEI0258 is physically located between the BG and BF of MHC region and variations near this marker have been well documented. In this report, the LEI0258 marker was used to find specific alleles for the Korean native chicken. The MHC haplotype was analyzed by PCR screening and sequencing of LEI0258 region in four different breeds including black Korean native chicken, brown Korean native chicken, Cornish and Rhode island red. The serologi-cally same MHC haplotypes showed the differences in repeat numbers, a few indels or single nucleotide polymorphisms by sequencing analysis. Even though we could not identify specific alleles for Korean native chickens, the genotypes analyzed in these breeds can give valuable information for the relationships with disease resistance and establishment of breeding strategies for the Korean native chicken. (Key words : genotype, marker, MHC, Korean native chicken)To whom correspondence should be addressed : junheon@cnu.ac.kr

In order to determine the origin and genetic diversity among chicken breeds, mitochondrial (mt) DNA D-loop sequences have been widely used. In this study, 41 individuals from four breeds (Korean native chicken (Black and Brown) and two imported breeds, Rhode Island Red and Cornish) were used for identifying genetic relationships with other chicken breeds. We obtained ten haplotypes and the highest number of haplotype was represented by eight individuals each from haplotype 1 and haplotype 2. Neighbor-joining phylogenetic tree indicates that the black and brown Korean native chicken breeds were mixed in haplotype 2 and they were closely related with the red jungle fowl (Gallus gallus). We also investigated whether the D-loop hypervariable region in chicken mtDNA can be used for the breed identification marker. The results indicated that the combination of the SNPs in the D-loop region can be possibly used for the breed discriminating markers. The results obtained in this study can be used for designing proper breeding and conservation strategies for Korean native chicken, as well as development of breed identification markers.

This work was carried out to investigate the effects of CDDGS (corn distillers dried grains with solubles) colors and phytase levels on the amino acid digestibility of broilers for 7 days. One hundred eight Ross broilers were used in 9 treatment groups with a 3 × 3 factorial design as three colors of DDGSs (DDGS1, DDGS2, and DDGS3) in combination with phytase (0, 500, and 1,000 FTU/kg). The L* values of DDGS1, DDGS2, and DDGS3 were 55.2, 39.8, and 28.3; the a* values, 8.8, 7.5, and 6.1; and the b* values, 41.3, 27.1, and 15.4, respectively. The ileal digestibility of amino acids was decreased as DDGS color was dark, and increased as additive phytase level was increased in the diet. Average digestibilities of essential amino acids were 67.6 80.0%, and those of nonessential amino acids 67.4 77.3. Amino acid digestibility was low in the dark DDGS with no phytase in the diet.

This work was conducted to investigate the manure excreta and chemical compositions of layers. Two hundred 1-d-old ISA Brown layers were used in this work, and ten of 200 layers were selected for measurement of manure excreta with feeding phase. Means of the manure excreta per bird, the moisture content of poultry, and the dried manure were 124.7 ± 27.5 g/bird/day, 76.9 ± 1.9%, and 29.1 ± 3.9 g/bird/day, respectively. N, P2O5, and K2O of manure (55 weeks) were 1.39 ± 0.139, 0.62 ± 0.11 and 0.68 ± 0.09%, respectively. pH, BOD5, CODMn, and suspended solids (SS) were 8.19 ± 0.71, 50,266 ± 621 mg/L, 62,832 ± 803 mg/L, and 121,725 ± 16,165 mg/L, respectively. Heavy metal contents in the manure were 0.003 ± 0.0013 ppm for Hg and 0.008 ± 0.0012 ppm for Pb, the latter of which was highly low compared with the standard (150 ppm), but no Cd was detected. The results of this work show the average excretion amounts and chemical compositions of layer's manure, which is used as an organic fertilizer.

There has been great success for making transgenic animals using somatic cell nuclear transfer (SCNT) up to this time. However, the success rates of the production of live transgenic animals are still very low. The current research has been carried out for delineation of differentially expressed genes between SCNT and normal placenta in cattle. In the present observations, high expression has been observed for CTSZ, LOC509426 and ELF1 genes in normal placenta. On the other hand, TIMP2, PAG1B, PAG-21, LOC782894, SERPINB6 and mKIAA2025 protein were highly expressed in SCNT placenta. Five genes, which were highly expressed in SCNT placenta, have been further investigated using semi-quantitative real-time PCR. The results were similar to that we observed using ACP. In the future, all genes affecting the SCNT and normal placenta have to be discovered and their networks will be fully investigated. The genes were identified in this study would be great help for identifying differential gene expressions in SCNT placenta.

Because of high growth rate and large deposition of fat in the abdomen, the chicken has been used as a model organism for understanding lipid metabolism, fattening and growing. In this study, differentially expression of proteins in chicken liver, one of the important organs for lipid metabolism, has been investigated at four different growing stages. After separation of proteins using two-dimensional electrophoresis (2-DE), more than 700 protein spots were detected. Among them, 13 growing stage specific proteins in chicken liver were selected and further investigated by matrix-assisted laser adsorptions ionization-time of flight mass spectrometry (MALDI-TOF MS). Of these, 12 proteins were matched to existing proteins based on a database search. The identified fat-related proteins in this study were fatty acid synthase (FASN) and malic enzyme (ME1). These proteins were more highly expressed at week 32 than at other weeks. In order to confirm the differential expression, one of the proteins, FASN, was confirmed by western blotting. The identified proteins will give valuable information on biochemical roles in chicken liver, especially for lipid metabolism.

The present study was carried out to investigate differentially expressed chicken muscle proteins using proteomics approach. More than 300 protein spots were investigated for the muscle samples in 2DE gels and the differentially expressed protein spots between pectoralis and peroneus longus muscles from Cornish and White Leghorn breeds were characterized by MALDI-TOF. In pectoralis muscles, PGAM1 protein was detected as differentially expressed between White Leghorn and Cornish breeds. On the other hand, 4 protein spots (SP22, nxf-2, SOD1, TNNI2) were differentially expressed between White Leghorn and Cornish breeds in peroneus longus muscles. These proteins assumed to be related with muscle development, growth, stress, and movements in chicken. In this experimental process, 2D reference map of the chicken muscle proteins was needed and 25 proteins, which were commonly expressed in both pectoralis and peroneus longus muscles in both breeds, were selected and characterized. Upon finishing the exact roles of the differentially expressed proteins, the identified 5 proteins will be used as valuable information for the fundamental mechanisms of muscle biology and underline genetics.

Titin-cap (TCAP), one of the abundant transcripts in skeletal muscles, was investigated in this study in cattle because of its role in regulating the proliferation and differentiation of myoblasts by interacting with the myostatin gene. From the 5' and 3' RACE experiments, full-length TCAP coding sequence was identified, comprising 166 amino acids. The amino acid comparison showed high sequence similarities with previously identified human (95.8%) and mouse (95.2%) TCAP genes. The TCAP expression, addressed by northern blot, is limited in muscle tissues as indicated by Valle et al. (1997). The radiation hybrid analysis localized the gene on BTA19, where the comparative human and porcine counterparts are on HSA17 and SSC12. A few muscle-related genetic disorders were mapped on HSA17 and some growth-related QTLs were identified on SSC12. The bovine TCAP gene found in this study opens up new possibilities for the investigation of muscle-related genetic diseases as well as meat yield traits in cattle. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 10 : 1344-1349)

CRABPs (cellular retinoic acid binding proteins) belong to members of a superfamily of lipid-binding proteins (Mansfield et al., 1998) that are thought to act by maintaining tolerable concentrations of intracellular RA (retinoic acid), as modulators of RA catabolism (Gorry et al., 1994) and as intracellular transporters for RA from the cytoplasm to the nuclear receptor (Flagiello et al., 1997). Based on their significance roles in binding lipids, they are thought to be candidate genes for meat quality related traits in domestic animals. The mapping of the porcine CRABP1 and CRABP2 genes are one step towards further investigation on their possible roles in meat quality traits in pig.