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Age-related deterioration in the reproductive capacity of women is directly related to the poor developmental potential of ovarian follicles. Although telomerase plays a key role in female fertility, TERT-targeting therapeutic strategies for age-related female infertility have yet to be investigated. This study elucidated the effect of Telomerase activation on mice ovaries and more specifically on Klb (β-Klotho) gene expression, which is linked to ageing, female hormonal regulation, and cyclicity. The homology-based 3D model of hTERT was used to predict its binding mode of Cycloastragenol (CAG) using molecular docking and molecular dynamics simulations. Based on docking score, simulation behavior, and interaction with hTERT residues it was observed that CAG could bind with the hTERT model. CAG treatment to primary cultured mouse granulosa cells and activation of telomerase was examined via telomerase activity assay (Mouse TE (telomerase) ELISA Kit) and telomere length by quantitative fluorescence in situ hybridization. CAG mediated telomerase also significantly improved β-Klotho protein level in the aged granulosa cells. To demonstrate that β-Klotho is telomerase dependent, the TERT was knocked down via siRNA in granulosa cells and protein level of β-Klotho was examined. Furthermore, CAG-mediated telomerase activation significantly enhanced the level of Klb and recovered ovarian follicles in the D-galactose (D-gal)-induced ovarian ageing mouse model. Moreover, Doxorubicin-induced ovarian damage, which changes ovarian hormones, and inhibit follicular growth was successfully neutralized by CAG activated telomerase and its recovery of β-Klotho level. In conclusion, TERT dependent β-Klotho regulation in ovarian tissues is one of the mechanisms, which can overcome female infertility.

An eggshell is a complex and highly ordered structure which composed of several mineralized layers. The quality of eggshell is very important factor for food safety and marketing. It is well known that the eggshell quality decreases with increasing hen age. This study was to investigate the changes of eggshell structure and shell composition according to hen age. In the microscopic observations of the uterus endometrium, histological deformation, fibrosis, atrophy and elimination of micro-villi were found with increasing hen age. The concentration of blood-ion components such as Ca(2+), Na(+), K(+), and Cl(-) ions did not change with age. As the results from ultrastructure analysis of eggshell, the palisade layer ratio and the density of mammillary knobs significantly decreased with increasing hen age. In addition, a number of type B mammillary knobs were observed in shell with increasing hen age. In the mineral element assay from eggshell, Ca(2+), S(2-) and Co(2+) significantly decreased with increasing hen age, whereas Na(+), K(+) and V(2+) significantly increased. Decreasing mammillary knob density and palisade layer ratio causes cracking of the egg shell and facilitates bacterial invasion. The high incidence of type B mammillary knobs, which are a type of broken crystal debris, weaken the egg shell and cause to easily egg break. Decreasing the major transport ions such as Ca(2+), S(2-) and Co(2+) causes negatively affect eggshell crystallization. Therefore, endometrial tissue damages inhibit the processes of ion transmission and crystallization for eggshell formation and causing a large and non-uniform mammillary knob formation. It means the damage of endometrial cells due to aging affects the formation of poor eggshell structure. In conclusion, aging of the hen reduces the quality of the eggshell.

Prediction of growth patterns of commercial chicken strains is important. It can provide visual assessment of growth as function of time and prediction body weight (BW) at a specific age. The aim of current study is to compare the three nonlinear functions (i.e., Logistic, Gompertz, and von Betalanffy) for modeling the growth of twenty five commercial Korean native chicken (KNC) strains reared under a battery cage system until 32 weeks of age and to evaluate the three models with regard to their ability to describe the relationship between BW and age. A clear difference in growth pattern among 25 strains were observed and classified in to the groups according to their growth patterns. The highest and lowest estimated values for asymptotic body weight (C) for 3H and 5W were given by von Bertalanffy and Logistic model 4629.7 g for 2197.8 g respectively. The highest estimated parameter for maturating rate (b) was given by Logistic model 0.249 corresponds to the 2F and lowest in von Bertalanffy model 0.094 for 4Y. According to the coefficient of determination (R2) and mean square of error (MSE), Gompertz and von Bertalanffy models were suitable to describe the growth of Korean native chicken. Moreover, von Bertalannfy model was well described the most of KNC growth with biologically meaningful parameter compared to Gompertz model.

Consumers demand fresh and high-quality eggs. Egg quality may be represented by shell color, shell weight, egg weight, shell thickness, shell density, albumen height, yolk color, albumen pH and viscosity. Various factors such as strain, age of hen, storage temperature, humidity, the presence of CO² and storage time affect egg quality. Therefore, we investigated the effects of storage time and temperature on egg quality to define the freshness of Korean market eggs. A total of 1,800 eggs were used for this experiment and were separated into 45 treatments with 40 eggs in each. The treatments were consisted of 15 storage periods (2 d to 30 d) and 3 storage temperatures (2℃, 12℃, 25℃). Each egg was weighed and broken, and the height of the thick albumen, Haugh units (HU), egg shell color and yolk color were measured by a QCM+system. We also observed the physiochemical properties of eggs such as yolk pH, albumen pH and albumen viscosity. The egg weight, shell weight, albumen height, HU and albumen viscosity significantly decreased with increasing storage time and temperature. However, the albumen and yolk pH significantly increased with increasing storage period and temperature. The interaction effects between the storage period and temperature were significant for shell weight, shell density, egg weight, albumen height, HU, yolk color, yolk pH, albumen pH and albumen viscosity. In the analysis of the correlation with egg quality, the storage temperature exhibited a higher correlation coefficient than the storage period. In conclusion, storage time and temperature are the major factors affecting egg quality, but the storage temperature is a more sensitive determinant of egg quality deterioration compared with the storage period.

The objective of this study was to investigate the result of in vivo embryo collection and pregnancy rate after embryo transfer using sex-sorted sperm of Korean brindle cattle. Donor Korean brindle cattle superovulation treated by decreasing dose of FSH injection. Embryos were recovered on 7 days after the third artificial insemination. Control group semen straw used artificial insemination contained 20 million sperm. Sex-sorted semen straws contained 4 million sperm or 10 million sperm. As for the result of the recovery of the in vivo embryos derived from sex-sorted sperm, the number of transferable embryos was significantly highly recovered to be 6.20±2.28/donor from the control group and was significantly lowly recovered to be 1.57±1.72/donor from the group treated at a sperm concentration of 10×106 (p

Chicken feathers were classified into early-feathering(EF) and late-feathering(LF) depending on the development and patterns of the wing feathers and tail feathers. Currently, the feather-sexing which is based on the differences in the feather developing at hatch is widely used sexing methods of chicks. The industrial application of feather-sexing to Korean native chickens(KNC) has not been reported yet. This study was conducted to investigate the classification of EF and LF in KNC. The developmental patterns of wing and tail feathers of EF and LF were examined on 856 KNC from 1- to 55-day-old. The PCR was performed using K-related gene primers to confirm the match between phenotype and genotype in EF and LF chickens. In the feathering types, 744 EF chickens and 112 LF chickens were identified. The EF chicks had long primaries and coverts, and the length between primaries and coverts was distinctly different. LF chicks had shorter primaries and coverts than EF chicks. The LF chicks could be classified into four types such as LF-less, LF-scant, LF-equal and LF-reverse types according to the shape of wing feathers. In EF chicks, the difference in length between primaries and coverts increased with age. There was no difference in length between primaries and coverts in all four types of LF chicks until 15-day-old. EF chicks had 1.5 times longer in primaries than LF chicks until 15-day-old. The tail feathers of EF chicks were long and distinct at 5-day-old, but the tail feathers of LF chicks were short and unclear. Classifying with primaries lengths, 9 mm or more was regarded as EF and less than 9 mm as LF. Identifying the feathering, PCR results and phenotypes were 99% identical. In conclusion, it is possible to establish the feather-sexing strain of KNC using the sex-linked feathering characteristics. Key Words

Dept. of Animal Science and Biotechnology, the Regional Animal Research Center (RAIC),Gyeongnam National University of Science and Technology, Jinju 52725, Korea,ABSTRACT This study was performed to examine the effects of dietary Acanthopanax senticosus (AS) on growth performance, immune organ weights, blood biochemical parameters and the expression of pro-inflammatory cytokines in broiler chicks. A total of 120 4-day-old birds were given a basal diet (CON) or a basal diet supplemented with 0.5% (AS1) or 1.0% (AS2) AS powder until the birds were 35 days of age. There was no difference in body weight, total gain, feed intake or immune organ weights among the treatment groups. However, the feed conversion ratio in the AS2 group was lower (p

We compared the degrees of stress response of 12 domestic purebred chicken strains that have been bred at National Institute of Animal Science, RDA, Korea since 1980. As a physiological marker of stress response, the expression levels of heat shock protein (HSP)-70, HSP-, HSP-, hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) genes and telomere length were measured by quantitative real-time polymerase chain reaction using the lymphocytes of 1,101 chickens. There was significant difference in HSP-70, HSP-, HMGCR expression and telomere length among the strains. There was also significant difference in HSP-, HSP-, and HMGCR expression between male and female chickens. Different age groups of chicken exhibited different expression levels of HSP-70, HSP- and telomere length. The results of the HSPs expression level suggested that, the strains of R, L and Y were highly resistant to stress, whereas the strains of S, O and W were susceptible to stress. Although the statistical differences in some of HSPs gene expression existed between genders, the HSP expression results varied in different strains that some opposed to the others, and there might be interaction between strains and genders, which conclude that there was no difference in stress response between male and female chickens. Moreover, despite of significant difference in some of HSPs expression level, it was considered that there was no difference in stress response between ages due to the inconsistent trends among HSP markers.

In this study, we used two breeds of chicken to identify genomic regions corresponding to necrotic enteritis (NE) resistance. We scanned the genomes of a resistant and susceptible line of Fayoumi and White Leghorn chickens (20 birds/line) using a chicken 60 K Illumina SNP panel. A total of 235 loci with divergently fixed alleles were identified across the genome in both breeds; particularly, several clusters of multiple loci with fixed alleles were found in five narrow regions. Moreover, consensus 15-SNP haplotypes that were shared by the resistant lines of both breeds were identified on chromosomes 3, 7 and 9. Genes responsible for NE resistance were identified in chicken lines selected for resistance and susceptibility. Annotation of the regions spanning clustered divergently fixed regions revealed a set of interesting candidate genes such as phosphoinositide-3-kinase, regulatory subunit 5, p101 (PIK3R5) and inositol 1,4,5-trisphosphate receptor 1 (ITPR1), which participate in immune response. Consensus haplotypes were found in regions containing possibly relevant genes, such as myostatin and myosin, which play important roles in muscle development. Thus, genome scans of divergent selection in multiple chicken lines and breeds can be used to identify genomic regions associated with NE resistance.

Chickens are exposed to the external and internal stressors such as low and high temperature, high stocking density, feed restriction and disease. There have been a few studies on gene expressions through the investigation of chickens under direct exposure to the stress of high stocking density. The objective of the present study was to determine the expressions of genes associated with stress, endoplasmic reticulum (ER)-stress, lipid and glucose metabolism in two strains of chickens, Korean Native Chicken (KNC) and White Leghorn (WL), raised in high stocking density. A total of 164 chickens aged 40 weeks were randomly allotted to a 540 cm 2 /bird stocking density (control), whereas the chickens in a high density group were assigned in a 311 cm 2 /bird stocking density with feeding ad libitum for 10 weeks. Total RNA was extracted from the live for qRT-PCR. The expression levels of hsp70 and hsp90α were higher in WL subjected to stress with high stocking density compared with those genes in control (P

Recently, adipose tissue-derived mesenchymal stem cells (MSCs) were reported to be a valuable cell source for generating induced pluripotent stem (iPS) cells because adipose tissue is readily obtainable and possesses high quantities of MSCs. To date, little research has been conducted to characterize the efficiency of iPS induction in adipose tissue. Human iPS cells were generated from adipose tissue-derived MSCs (AT-MSCs) and stromal cells (AT-SCs) via a retroviral delivery system. The reprogramming efficiency of AT-MSCs and AT-SCs were 0.008 and 0.014%, respectively, in terms of the expression of the TRA-1-60 antibody and 0.023 and 0.041%, respectively, regarding alkaline phosphatase staining. This differential reprogramming capability resulted from different levels of viral infectivity between the two cell types. Viral infectivity using pMXs-IRES-GFP was notably low in AT-MSCs and the quantities of OSKM (OCT4, SOX2, KLF4 and c-MYC) in AT-MSCs were 22.5–31.6% of AT-SCs. In conclusion, the amount of transgenes leads to a higher reprogramming efficiency in AT-SCs compared with AT-MSCs. The present study shows that the induction efficiency of pluripotent cells from somatic or adult stem cells could depend on the viral susceptibility of the target cells. Therefore, non-MSCs could be a more efficient source for reprogramming by retrovirus-mediated iPS induction.

The aim of this study was to determine the effects of stocking density and strain on the performance and physiological adaptive responses including the plasma corticosterone content and the level of mRNA expression of pro- inflammatory cytokines and antioxidant enzymes in broiler chicks. A total of 300 birds of two strains (150 Ross strain vs. 150 Cobb strain) aged 3-d old were allotted into two stocking densities (standard stocking density, 0.046 m 2 /bird vs. high stocking density, 0.023 m 2 /bird) in battery cages by 2×2 factorial designs with ten replicates until 35 d of age. There was no significant strain effect on body weight, feed intakes and feed to gain ratio and the relative organ weights. However body weight, feed intakes and relative organ weight were found to be significantly (P

Department of Animal Science and Biotechnology, Gyeongnam National University of Science and Technology, Jinju 660-758, KoreaABSTRACT Telomeres are the ends of the eukaryotic chromosomes and consist of a tandem repetitive DNA sequence and shelterin protein complex. The function of telomere is to protect chromosome. Telomere length in somatic cells tends to decrease with organismal age due to the end replication problem. However, several factors at the genetic, epigenetic and environmental level affect telomere length. In this study, we estimated heritability of telomere length and investigated inheritance of telomeres in a chicken. Telomere length of lymphocytes was analyzed by semi-quantitative polymerase chain reaction using telomere primer and quantitative fluorescence in situ hybridization using telomeric DNA probe. In results, heritability of telomere length was estimated 0.9 at birth by offspring-parent regression analysis and was estimated 0.03 and 0.04 at 10 and 30 weeks old, respectively, by parental variance analysis. There was a significant positive correlation in telomere length between father and their offspring (r=0.348), and mother and their offspring (r=0.380). In inheritance patterns of telomere length, the influence of paternal and maternal effect on their offspring was similar. The influence of inherited telomeres on male and female progeny was also roughly alike. These results implicated that imprinting of parental telomere length was regulated by autosomal genes, not sex linked genes. In addition, telomere length of offspring at birth did not differ along with their maternal age. Thus, maternal age does not affects telomere length in their offspring at birth owing to cellular reprogramming at early embryonic stage.(Key words : heritability, telomere length, inheritance, chicken)

Department of Animal Science and Biotechnology, Gyeongnam National University of Science and Technology, Jinju 660-758, KoreaABSTRACT With Single Comb White Leghorn (WL) and Korean Native Chicken (KNC) breeds, we compared the stress response with chicken breeds that were subjected to a high stocking density. Stress response was analyzed by the quantity of telomeric DNA, the rate of DNA damage and the expression levels of heat shock proteins (HSPs) and hydroxyl-3- methyl-glutaryl coenzyme A reductase (HMGCR) genes on tissues and blood. The telomere length and telomere shortening rates were analyzed by quantitative fluorescence in situ hybridization on the nuclei of lymphocytes and tissues. The DNA damage rate of lymphocytes was quantified by the comet assay. The expression levels of HSP70, HSP90-α, HSP90-β and HMGCR genes were measured by quantitative real-time polymerase chain reaction in lymphocytes. There was no significant difference between KNC and WL in body weight, weight gain, telomere shortening rate and DNA damage rate. However, the growth rate significantly decreased in chickens raised under high stocking density conditions, as compared to the control group. The telomere-shortening rate, DNA damage and HSPs expression of the lymphocytes were significantly higher in the high stocking density group than the control. The stress condition and breeds had a significant effect on the expressions of HSP70, HSP90-α and HSP90-β in lymphocytes, except HMGCR. The stress response of WL was higher than that of KNC, as analyzed to the expression of HSP70 and HSP90-α. Therefore, we concluded that the chickens which were exposed to a high stocking density had increased the individual physiological stress response regardless of breeds, and White Leghorns are more susceptible to stress condition than Korean Native Chickens.(Key words : stress response, telomere, DNA damage, HSP, Korean Native Chicken, Leghorn)

The present study was carried out to investigate the effects of dietary antioxidants on pro-inflammatory cytokines, heat shock protein (HSP) and antioxidant status in broiler chicks under summer conditions. A total of 162, 3-d-old broiler chicks were randomly assigned to a basal diet (CON) and the basal diet supplemented with vitamin C (200 mg/kg diet, VCD) or vitamin E (100 mg/kg, VED) until 35 day of age. All birds were exposed to summer diurnal heat stress at average daily fluctuations of temperature between 32 degrees C to 34 degrees C at day to 27 degrees C to 29 degrees C at night for the entire feeding periods. There was no significant difference in body weight, feed to gain ratio and the relative organ weight except the thymus in response to dietary vitamin C or E supplementation. However, the mRNA expression of interleukin (IL)-1 beta, IL-6, interferon (IFN)-gamma, Toll like receptor (TLR)-4 and HSP70 in the liver of birds fed diet containing vitamin C significantly (p