• Journal of Sericultural and Entomological Science
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• v.41 no.2
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• pp.94-101
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• 1999

Twelve pure silkworm lines identified based in higher G.C.A values from a line${\times}$Tecter crossing programme, were crossed with twelve breeds showing cocoon shell ratio>22% and hybrids prepared, evaluated in a Multiple index method. Seven hydrids showing average index value>50 in all the 10 economic characters were seclcted and evaluated in the laboratory. However, two hybrids viz., A3${\times}$935E and A3${\times}$916B were finally selected based on the superiority of the breeds in one day shorter larval duration and with and with higher reeling characters compared to control KA${\times}$NB4D2. The breeding procedure involed in evolution hybrids are discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1405-1411
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• 2010

Calpastatin (CAST), an endogenous inhibitor of the calpains, plays an important role in post-mortem tenderization of meat. The objectives of this study were to investigate single nucleotide polymorphisms (SNPs) in the bovine CAST gene and association with carcass and meat quality traits. A total of 212 cattle from commercial herds were tested in this study including 2 pure introduced breeds, 4 cross populations, and 3 pure Chinese native breeds. Five SNPs were identified at position 2959 (A/G), 2870 (G/A), 3088 (C/T), 3029 (G/A) and 2857 (C/T) in the CAST gene (GenBank Accession No. AF159246). Allele frequencies of SNP2959 and SNP2870 were 0.701 (A) and 0.462 (A), respectively. A general linear model was used to evaluate the associations between the two markers and 7 traits. The results showed that both SNP2959 and SNP2870 were significantly (p<0.01) associated with the Warner-Bratzler shear force (WBSF), while they had no significant association with the other 6 traits in the whole population. However, in Chinese native pure breeds, only SNP2870 had significant association with WBSF (p<0.05). The simultaneous analysis of two-marker genotype effects indicated animals containing the A/G haplotype (A for SNP2959 and G for SNP2870) tended to have lower shear force than those containing the G/A haplotype, and, especially, animals homozygous for the A/G haplotype had approximately 2 kg lower shear force than those homozygous for the G/A haplotype (p<0.01). These results suggested that both markers may be effective for the marker-assisted selection of meat quality traits in Chinese commercial herds, especially SNP2870 which can be used for Chinese native cattle.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.735-742
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• 2004

This study was conducted for the identification of pure Landrace, Large White and Duroc breeds which are mainly maintained in Korea using DNA markers. We used known KIT and MC1R mutations, which were related coat color in pigs, and pig mitochondrial DNA variations. The KIT mutation was used to distinguish white and colored animals. Duroc breed could be discriminated from other colored breeds using the MC1R mutation N121D. Discriminating Landrace and Large White was possible using the l l-bp duplication of D-Ioop region and alternative initiation codon of ND2. In conclusion, identification of Landrace, Large White and Duroc breeds was might be possible using the procedure designed in this study.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.807-816
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• 2011

The present study evaluated the difference in objective and subjective meat quality properties among the pure-breed boars of Duroc, Berkshire and Yorkshire. Ten longissimus lumborum (LD) muscles were collected from each breed after 24 h slaughtering. The breed type showed a significant effect on intramuscular fat content, moisture (p<0.01), pH, sarcoplasmic protein solubility and color (p<0.05), whereas cooking loss and Warner Blazer shear force (WBsf) did not differ among the breeds. The Yorkshire breed showed significant (p<0.05) lower sarcoplasmic protein solubility, pH and CIE $a^*$ value when compared with other breeds. The sensory panels identified Duroc as having greater overall acceptability and higher rating values than other breeds. The oleic acid content was significantly lower in the Berkshire (29.85 %) than in the Duroc (40.19 %) and Yorkshire breeds (38.18 %, p<0.05). The Yorkshire breed showed the most desirable ratio of polyunsaturated and saturated fatty acids (0.31) than the Berkshire (0.16) and Duroc breeds (0.15, p<0.05). 40 volatile compounds have been identified and quantified, while aldehydes were the most abundant among flavor substances. Aldehydes were negatively correlated with oleic acid content (p<0.05). Current data indicated that each breed had their own merits and deficiencies in terms of meat qualityThe Yorkshire breed showed a greater number of weak points. Furthermore, this study indicated that individual fat-driven flavor components were greatly influenced by fatty acid composition. The polyunsaturated fatty acids did not show any negative effects on meat flavor if cooked meats were consumed soon after cooking.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.931-937
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• 2006

The full-length cDNA of the porcine SMPX gene was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequences and the predicted protein sequences share high sequence identity with both human and mouse. The promoter of SMPX was sequenced and then analyzed to find the promoter binding sites. The reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that SMPX has a high level of expression in heart and skeletal muscle, a very low expression in lung and spleen and no expression in liver, kidney, fat and brain. Moreover, SMPX has a differential expression level in skeletal muscle, the expression in 65-day embryos being higher than other stages. The porcine SMPX was mapped to SSCXp24 by using a somatic cell hybrid panel (SCHP) and was found closely linked to SW1903 using the radiation hybrid panel IMpRH. An A/G single nucleotide polymorphism (PCR-RFLP) in the 3'-untranslated region (3'-UTR) was detected in eight breeds. The analysis of allele frequency distribution showed that introduced pig breeds (Duroc and Large White) have a higher frequency of allele A while in the Chinese indigenous pig breeds (Qingping pig, Lantang pig, YushanBlack pig, Large Black-White pig, Small Meishan) have a higher frequencies of allele G. The association analysis using an experimental population (188 pigs), which included two cross-bred groups and three pure-blood groups, suggested that the SNP genotype was associated with intramuscular fat content.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.77-88
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• 2016

To establish a new synthetic Korean meat chicken breed, we tested $5{\times}5$ diallel cross mating experiment with domestic chicken breeds. Comparing stress responses among diallel crossed chicken breeds, we analyzed telomere length, DNA damage and expressions of heat shock protein genes (HSPs) as the markers of the stress response. The telomere length was measured by quantitative fluorescence in situ hybridization on the nuclei of lymphocytes. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes were analyzed by quantitative real-time polymerase chain reaction in lymphocytes. The DNA damage rate of lymphocytes was quantified by the comet assay known as the single cell gel electrophoresis. In results, there were significant differences in the values of the stress markers such as telomere length, HSPs and DNA damage rate, and also were significant differences in viabilities and body weights among the $5{\times}5$ diallel crossed chicken breeds. The telomere shortening rate, expression values of HSPs and DNA damage rate were significant low in W and Y crossed chickens compare to the others, but GG pure breed showed the highest values in the 25 crossed chickens. Estimating correlation coefficient, the survival rate positively correlated to telomere length, but negatively correlated to the expression levels of HSP-70, $HSP-90{\alpha}$, $HSP-90{\beta}$ genes and to the value of % DNA in tail as DNA damage rate. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes of dead chickens had significantly higher than those of survival chickens. According to the results on the stress marker analysis, it would be considered that the crossed breeds had more stress resistant than the pure breeds, and the crossed chickens with a light strain such as W or Y were relatively resistant to stress, but the crossed chickens with a heavy strain such as G, H, F were susceptible to stress.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.39-48
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• 1999

This study was carried out to investigate the difference and genetic similarity at the level of molecular genetics. Genomic DNA was extracted from blood of Holstein, Korean cattle, Charolais, and hybrid between Korean cattle and charolais and RAPD(random amplified polymorphic DNAs) was analyzed by PCR(polymerase chain reaction). After genetic similarity value from different breeds are analyzed, genetic similarity was estimated by UPGMA(unweighted pair-group method using average). The results obtained from this study can be summarized as follows: 1. When genomic DNA which was extracted from different breeds was subjected to electrophoresis on 1.5% agarose gel, bigger than 12.2kb was appeared. Ratio by absorbance of $A_{260}/A_{280}$ was 1.75~2.10, indicating that genomic DNA was quite pure for RAPD analysis. 2. Different band patterns by RAPD were appeared according to the breeds in cattle. The best primer used to distinguish Holstein from other breeds was 5'-GAC CGC TTG T-3'. 3. A 340bp fragment was amplified in $33.0^{\circ}C$ of annealing temperature for the Holstein and Charolais breeds, but any amplification was not occurred in this annealing temperature for Korean cattle and hybrid. In addition, a 340bp fragment was amplified in $37.5^{\circ}C$ of annealing temperature for the Holstein and Korean cattle, but any amplification was not occurred in this annealing temperature for Charolais and hybrid. For the reaction of PCR. $37.5^{\circ}C$ and $33.0^{\circ}C$ of annealing temperature was shown to be best for genetic marker identification from Holstein, Charolais, and hybrid between Korean cattle and Charolais. 4. When genetic similarity from different breeds are analyzed at the both temperature of $33.0^{\circ}C$ and $37.5^{\circ}C$, the genetic similarity value of Holstein and Korean cattle, Holstein and Charolais, Korean cattle and Charolais, and Korean cattle and hybrid were 0.666~0.777, 0.615~0.666, 0.400~0.461 and 0.857~0.888, respectively. 5. It could be concluded that different breeds are capable of distinguishing by RAPD used random primer 5'-GAC CGC TTG T-3', genetic similarity from different breeds was appeared the higher genetic similarity value of Korean cattle and Charolais than that of Holstein between Korean cattle and Charolais by UPGMA.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.139-143
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• 2005

The implications of temperature (25, 30 and $35^{\circ}C$) and relative humidity (RH; 60, 70 and $80\%$) on the hatching rhythmicity and hatching parameters (percentage and duration) were studied in the silkworm, Bombyx mori L. under natural photoperiod (LD 12 : 12). Disease free layings (DFLs) of two pure silkworm breeds, Pure Mysore (PM, a multivoltine breed) and $NB_4D_2$ (a bivoltine breed), and their hybrid, $PM{\times}NB_4D_2$ were introduced into the experimental conditions on the $3^{rd}$ day of oviposition till completion of hatching. The hatching rhythm was predominantly diurnal under all temperature and humidity conditions, with peaks just after 'lights-on' phase (6 hrs). Extreme temperature and humidity conditions did not alter the hatching rhythmicity, but prolonged the hatching durations, extending it to the next day, coupled with reduced hatching percentage in PM and $PM{\times}NB_4D_2{\cdot}In\;NB_4D_2$, on the other hand, hatching did not extend to the next day. Hatching percentage in this breed, however, reduced below the economic level under high temperature and low humidity conditions. The high temperature and low humidity together, though did not alter the rhythmicity, seems to exert synergetic effect on the hatching percentage and its duration in the silkworm, B. mori.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.21-25
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• 2003

The implications of temperature $(25, 30 and 35{\times}1^{\circ}C)$ and relative humidity $(60, 70 and 80{\times}2%)$ on the moulting pattern, moulting duration and moulting survival were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB$_4$D$_2$and their hybrid, $PM{\times}NB_{4} D_{2}$ were reared under experimental conditions under natural day photoperiodic (LD 12:12) condition. Two developmental marker events in the fourth moulting, settling for moult (SM) and completion of moult (CM) occurred at or around the middle of the photophase. The computed mean vector (equation omitted), based on the circular statistics also confirmed the above. Temperature and humidity did not alter the moulting rhythmicity much. However, extreme temperature and humidity conditions reduced moulting survival in PM and $PM {\times}NB_{4} D_{2}$. Further, moulting survival reduced below the economic level in $NB_{4} D_{2}$. The temperature and humidity together seem to exert synergic impact on the moulting survival of the silkworm Bombyx mori, at least in $NB_{4} D_{2}$.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.67-71
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• 2002

The implications of temperature (25,30 and 35$^{\circ}C$) and relative humidity (60, 70 and 80%) on the pupation patterns were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB4D2 and their hybrid, PM ${\times}4 NB4D2 were reared under experimental conditions under natural day photoperiodic (LD 12: 12) condition. The three developmental marker events viz., larval ripening, pharate pupal formation and pupal formation occurred at or around the beginning of the photo-phase. The computed of mean vector (equation omitted), based on the circular statistics, also confirmed the above. However, the length of mean vector, r and the mean vector angular variance, s varied according to temperature and humidity conditions imposed; the variations being non-significant. Extreme temperature and humidity conditions, however, resulted in reduction in pupation rate (%) for PM and PM ${\times}4 NB4D2. On the other hand, in NB4D2 pupation percentage reduced below the economic level. The temperature and humidity together seems to exert synergic impact on the pupation rate at least in the silkworm Bombyx mori, L.