35 EFFECTS OF THAWING TEMPERATURE OF FROZEN SEMEN ON VIABILITY OF REFROZEN AND THAWED CHICKSO (KOREAN BRINDLE CATTLE) AND KOREAN ALBINO CATTLE SPERMATOZOA

Germplasm cryopreservation from a desired species with agricultural and genetic importance would protect them from the risk for extinction. Semen freezing from Korean native cattle would be a good approach for protecting genetic resources due to their limited numbers. It has been known that sperm could resist cryo-damages by freeze-thaw cycles. Thus, we performed 2 refreezing experiments with different initial thawing temperatures using frozen Korean native cattle semen. A total of 5 Hanwoo, Korean Albino, and brindle cattle were used as semen donors. After thawing by using 5°C/2 min or 37°C/40 s with cooling rates, the semen was diluted with the same volume of cryo-media in the first thawing temperature and refrozen. Sperm motilities were determined and compared between animals and groups after rethawing. The mean sperm concentration and motility was 45 × 106 mL–1 (range 2.3 to 89 × 106 mL–1) and 40% (range 13 to 55%). Mean values of motility and viability of sperm that underwent second preservation were significantly higher in 5°C than in 37°C (P < 0.01). However, the activity of viable sperm thawed at 5°C was significantly decreased before refreezing. It is estimated that refreezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa. The higher motility and viability of refrozen semen could be obtained with 5°C thawing procedure for reuse of frozen semen.

215 PRODUCTION OF PROGENY WITH SEXED WHITE HANWOO (KOREAN NATIVE ALBINO CATTLE) SEMEN

The aim of the study was to produce sexed progeny of the genetically confined White Hanwoo (albinism). A White Hanwoo bull was selected as the semen donor. The X-bearing sperm were sorted by MoFlo XDP cell sorter from Korea Sexing Biotech (Daegu, South Korea). To compare pregnancy and birth rates as well as semen quality, a Korean proven bull (KPN) was used as control. Total number of nonsorted sperm was 20 × 106 per straw. Double insemination of 2 or 4 × 106 sexed and frozen X-bearing sperm were performed on Hanwoo heifers. The abnormality of nonsorted albino spermatozoa (5 ejaculates) was 24.9 ± 7.31% (but 18.7 ± 6.2% C in KPN 768, derived from 5 straws) with a higher number of distal reflex abnormality in midpiece (11.7% compared with that of KPN 768, 5.6%). There were no differences in pregnancy and birth rates when 2 or 4 × 106 X-bearing sperm were inseminated but nonsorted semen had higher pregnancy rates (P < 0.05). The pregnancy rates of KPN 768, 2 × 106 cells, and 4 × 106 cells X-bearing sperm of White Hanwoo cattle were 85.0% (17/20), 26.3% (5/19), and 50% (7/14), respectively. The birth rates were 80.0% (16/20), 15.8% (3/19), and 21.4% (3/14), respectively. The female offspring rates were 43.8% (7/16), 100% (3/3), and 100% (3/3) (P < 0.05). These results indicated that sex-sorted albino Hanwoo semen could be used for the production of wanted progeny with 2 × 106 cells/straw for AI to heifers.

50 ESTIMATION OF CHROMATIN ABNORMALITY OF OGYE ROOSTER SEMEN WITH Diff-Quik STAINING

The abnormality of Ogye rooster sperm chromatin could be detected by simple sperm staining. In this abstract, a Diff-Quick staining kit was tested for assessment of chicken sperm quality. Using a standard bright-field microscope, Diff-Quik stains can be reproducibly, easily, and routinely monitored with simple staining. The presence of abnormal chromatin staining of rooster sperm was determined by darker stain in head. In the fresh semen, the viabilities of 3 tested Ogye spermatozoa were 93.53, 82.42, and 90.63%, and normal chromatin rates were 87.96, 74.25, and 85.10%, respectively. However, after cryopreservation, the rates of viability of thawed semen were reduced to 69.58, 61.98, and 72.20%, and normal chromatin rate also reduced to 58.91, 48.49, and 63.34%. A significant correlation between live sperm and normal sperm nuclei was 0.875 in fresh semen and 0.513 in frozen semen. After incubation of sperm at 37°C for 5 min, the rates of viability, chromatin normality, and sperm head activity were shown as 90.63 ± 1.28%, 82.44 ± 8.09%, and 66.68 ± 10.29% in fresh semen. However, the rates of thawed semen were reduced to 67.92 ± 7.55%, 56.92 ± 12.15%, and 47.32 ± 5.02%, respectively. The relationship between chromatin normality and sperm head movements in fresh and thawed semen were 0.564 and 0.540, respectively. With these results, the chicken sperm normality could be assessed by the Diff-Quik staining, which could be used for chromatin status of sperm head and activated morphology of live spermatozoa, as a simple and rapid staining method.

Genetic Polymorphisms of the Bovine NOV Gene Are Significantly Associated with Carcass Traits in Korean Cattle

The objective of this study was to investigate single nucleotide polymorphisms (SNPs) in the bovine nephroblastoma overexpressed (NOV) gene and to evaluate whether these polymorphisms affect carcass traits in the Korean cattle population. We resequenced to detect SNPs from 24 unrelated individuals and identified 19 SNPs within the full 8.4-kb gene, including the 1.5-kb promoter region. Of these 19 SNPs, four were selected for genotyping based on linkage disequilibrium (LD). We genotyped 429 steers to assess the associations of these four SNPs with carcass traits. Statistical analysis revealed that g.7801T>C and g.8379A>C polymorphisms in the NOV gene were associated with carcass weight (p = 0.012 and 0.008, respectively), and the g.2005A>G polymorphism was associated with the back fat thickness (BF) trait (p = 0.0001). One haplotype of the four SNPs (GGTA) was significantly associated with BF (p = 0.0005). Our findings suggest that polymorphisms in the NOV gene may be among the important genetic factors affecting carcass yield in beef cattle.

Effects of Dietary Fat Types on Growth Performance, Pork Quality, and Gene Expression in Growing-finishing Pigs

This study was performed to determine the effects of dietary fat sources, i.e., beef tallow, soybean oil, olive oil and coconut oil (each 3% in feed), on the growth performance, meat quality and gene expression in growing-finishing pigs. A total of 72 crossbred pigs (Landrace×Large White×Duroc) were used at 71±1 kg body weight (about 130 d of age) in 24 pens (320×150 cm) in a confined pig house (three pigs per pen) with six replicate pens per treatment. The growing diet was given for periods of 14±3 d and the finishing diet was given for periods of 28±3 d. The fat type had no significant effect either on growth performance or on chemical composition or on meat quality in growing-finishing pigs. Dietary fat type affected fatty acid composition, with higher levels of unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) in the olive oil group. Microarray analysis in the Longissimus dorsi identified 6 genes, related to insulin signaling pathway, that were differentially expressed among the different feed groups. Real time-PCR was conducted on the six genes in the longissimus dorsi muscle (LM). In particular, the genes encoding the protein kinase, cAMP-dependent, regulatory, type II, alpha (PRKAR2A) and the catalytic subunit of protein phosphatase 1, beta isoform (PPP1CB) showed the highest expression level in the olive oil group (respectively, p<0.05, p<0.001). The results of this study indicate that the type of dietary fat affects fatty acid composition and insulin signaling-related gene expression in the LM of pigs.

94 NUCLEAR-CYTOPLASMIC INTERACTION AND DEVELOPMENT OF CLONED EMBRYOS

Although cloned canine offspring have been produced, the efficiency of nuclear transfer (NT) is still far from expectations. The most important factor interfering with the success of NT is the shortage of canine matured oocytes. In the present study, the nuclear-cytoplasmic interaction and in vitro development of porcine oocytes cloned with canine fetal fibroblasts (cFF) and canine mesenchymal stem cells (cMSC) were assessed by examining the developmental rate, embryonic morphology, total cell number, canine genome expression, and in vivo development following the transfer of iNT embryos into the oviducts of surrogate mother. Isolated cMSC from bone marrow were characterized by early transcription factors (Oct3/4, Sox2, and Nanog) and by differentiation into adipogenic, osteogenic, and neuronal cells under controlled in vitro conditions. Porcine cumulus–oocyte complexes (COC) were matured in vitro as described by Kim YS et al. (2005 Mol. Reprod. Dev. 70, 308–313). Porcine NT embryos were used for the control group. Canine MSC showed their characteristic property of attaching to plastic culture flasks and forming a monolayer of spindle-shaped cells. Adherent cells showed moderate expression of Oct3/4, Sox2, and Nanog protein by immunostaining. Following osteogenic cell induction, cMSC transformed into mineralized nodules by von Kossa staining. Oil red O staining revealed that MSC produced lipid droplets after incubation in adipogenic media. Neuronal-like cells with multipolar, round cell bodies organized into a network-like structure were confirmed by immunostaining of neuronal markers (NFM). The tissue-specific mRNA levels were confirmed after differentiation by RT-PCR (osteogenic cell, Osteocalcin; adipogenic cell, PPAR γ; neuronal cell, NFM). The control group blastocysts (porcine oocytes-pMSC) exhibited significantly (P < 0.05) greater development and total cell numbers of than blastocysts of interspecies groups (porcine oocytes-cFF and cMSC). The canine genome GAPDH was detected in cFF, cMSC, and interspecies NT embryos using PCR, whereas there was no detection in porcine oocytes and the negative control. Most of the embryos arrested at the 8- to 16-cell stage and only 5% of embryos developed to blastocyst stage. The interspecies-NT embryos (average 35 embryos/recipient dog) were surgically transferred into the oviducts of 3 recipient dogs. Two of them showed exterior signs of implantation; i.e. a slight thickening of the uterus and small pea-sized lumps. No pregnancies were detected in the recipients after ovariohysterectomy surgery. These results demonstrate the potential of cMSC isolated from bone marrow to differentiate into mesoderm (osteogenic and adipogenic cell) and ectoderm (neuronal cell)-like cells under specific induction conditions. Although interspecies NT embryos could not implant in the canine uterine wall, the results provided valuable information on canine MSC and interspecies NT. This work was supported by Grant No. 20070301034040 from Bio-Organ, Republic of Korea.

271 IDENTIFICATION OF DIFFERENTIALLY EXPRESSED GENES IN A 35-DAY-OLD CLONED PIG FETUS USING THE ANNEALING CONTROL PRIMER SYSTEM

Somatic cell nuclear transfer in pig has limitations due to the high incidence of fetal failure after embryo transfer to recipients. Reasons for the inefficient cloning are assumed to be due to abnormal and poorly developed placenta. Thus, this study was designed to determine possible genetic causes of neonatal deaths and other related abnormalities. Genes expressed specifically or prominently on Day 35 were identified in cloned pig placenta utilizing PCR technology regulated by annealing control primers (ACPs). The RNA was isolated using Trizol reagent. By utilizing 120 ACPs, 53 expressed sequence tags (ESTs) of genes that are differentially expressed in cloned pig placenta compared with normal placenta were cloned and sequenced. The cloned genes or ESTs exhibited significant sequence similarities to known genes or ESTs of other species. Ten of the total known genes, i.e., pregnancy associated glycoprotein, H19, 60S ribosomal protein L12, 20-beta hydroxysteroid dehydrogenase, beta galactosidase precursor, aldehyde reductase, glypican 3 precursor, heme oxygenase 2, granulin precursor, and placenta-expressed transcript protein, were selected and their specific expression levels were confirmed by real-time RT-PCR in the normal and cloned pig placentas in triplicate using beta-actin for determining relative expression. The 60S ribosomal protein L12 and heme oxygenase 2 were highly expressed in the cloned pig placenta, whereas pregnancy associated glycoprotein, H19, 20-beta hydroxysteroid dehydrogenase, beta galactosidase precursor, aldehyde reductase, glypican 3 precursor, granulin precursor, and placenta-expressed transcript protein were low or void. Our data suggest that the ACP system effectively identified tissue-specific genes in cloned pig placenta. Furthermore, identified genes would assist in developing insight into the genetic basis of fetal failure and help in resolving low pregnancy rate in the production of cloned pigs.

99 AMOUNT OF TELOMERIC DNA IN GROWING CLONED CATTLE, THEIR PROGENY, AND THEIR ORGANS

Telomeres are specialized nucleoprotein complexes at the termini of linear chromosomes that are composed of TTAGGG sequences in vertebrates. Telomere lengths in animals vary with species, age, tissue types, environment, and cloning. The experiment conducted emphasized the amount of telomeric DNA in the lymphocytes and organs of growing cloned cattle and their second and third generations. Using somatic cell nuclear transfer (SCNT), 16 cloned (Generation, clone G1) Korean Native cows were obtained from ear skin fibroblasts and 2 cloned bulls from fetal fibroblasts. In addition, 3 females and 2 males (clone G2) were produced from each cloned cow by artificial insemination (AI). A third generation calf (clone G3) was derived from clone G2 by AI. The lymphocytes of all cloned cattle (G1), their offspring (G2), and age-matched controls were examined 3 times at 6-month intervals whereas G3 was examined only once. The amount of telomeric DNA was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) with a human telomeric DNA repeat probe. A minimum of 100 interphase nuclei from each set of harvests was studied to determine the mean and medium percentages of telomeric DNA using MetaMorph Imaging System (Universal Imaging Co, West Chester, PA, USA). The amounts of telomeric DNA in cloned cattle from both ear skin fibroblasts (female, n = 16) and fetal fibroblasts (male, n = 2) were less than those of age-matched controls (P &lt; 0.01). Additionally, irrespective of gender, the telomeres in the clone G2 and G3 calves were lower than in controls (n = 6; P &lt; 0.05). Furthermore, in the cloned cattle, the amount of telomeric DNA was drastically less than that of control animals during growth. Moreover, we examined the internal organs and tissues of a cloned cow at 30 months. The telomeres of leukocytes, cerebrum, spleen, cerebellum, hindbrain, and lung were a little smaller, whereas those of the liver, pituitary, kidney, and heart were slightly larger, than those of an age-matched cow. The results showed a remarkable difference in the amount of telomeric DNA between SCNT cloned cattle and normal cattle. Although the organs and tissues were not correlated, the amount of telomeres rapidly decreased with growth in cloned cattle. Conclusively, the telomeres of a cloned animal and its calves were significantly shorter than those of control cattle, and the short telomeres in calves could be inherited by progeny from their cloned mother.

167 THE SUPPLEMENTATION OF GRANULOCYTE-MACROPHAGE COLONY STIMULATING FACTOR (GM-CSF) PROMOTES THE DEVELOPMENT OF NUCLEAR TRANSFERRED BOVINE EMBRYOS

Granulocyte-macrophage colony stimulating factor (GM-CSF) is secreted by epithelial cells lining the female reproductive tract in mice and several other species. GM-CSF receptors are present in the fertilized oocyte and in all subsequent stages of development, and in blastocysts it is expressed in both inner cell mass and trophectoderm cells. Recent studies suggest that GM-CSF can act as a survival factor for the developing embryo. The purpose of this study was to examine the effect of GM-CSF, as a medium supplement, on the development of nuclear-transferred bovine embryos. Oocytes were enucleated after in vitro maturation in TCM-199 supplemented with 10% fetal bovine serum (FBS), 1 mg/mL FSH, and 1 mg/mL estradiol-17� for 20 h. Enucleated oocytes were fused with bovine ear skin fibroblast cells by a DC pulse of 25 V/150 mm for 20 ms in Zimmerman cell fusion medium. For activation, reconstructed embryos were exposed to 10 mM Ca-ionophore for 5 min, followed by 2 mM 6-dimethylaminopurine for 3 h. NT embryos were subsequently cultured in CR2 medium without or with 10 ng/mL recombinant porcine GM-CSF at 39.0�C in 5% O2, 5% CO2 and 90% N2. After 7 days of culture, blastocyst formation was observed. The number of inner cell mass (ICM) and trophectoderm (TE) cells was examined by differential staining. Apoptotic cells in blastocysts were detected by a terminal deoxynucleotidyl transferase-mediated d-UTP nick-end labeling (TUNEL) assay. Data were analyzed by chi-square and Student's t-test. Addition of GM-CSF to the medium significantly (P < 0.05) increased the proportion of embryos developing to the blastocyst stage (37.6 � 12.0 and 54.7 � 13.9% for control and GM-CSF groups respectively). No differences in the total cell number and the ratio of ICM to total cells were detected between the control group (125.4 � 35.7 and 38.5 � 9.7%) and the GM-CSF group (123.8 � 35.1 and 34.2 � 13.1%). The mean proportion of apoptotic cells in blastocysts was not different between the control (5.4 � 5.4%) and the GM-CSF (5.3 � 3.9%) group. Our results showed the beneficial effect of GM-CSF on the development of NT bovine embryos. These results suggest that GM-CSF might be a useful molecule for increasing development of NT bovine embryos. Further studies are necessary to verify the mechanism of GM-CSF on the development of bovine NT embryos.

Differences in embryonic development in sensitive and resistant matings to pregnancy block stimuli in mice

Pregnancy block from exposure to foreign male mouse pheromones is sensitive to both male and female mating strain, as well as the foreign male pheromone-producing strain. Incidence of pregnancy block by male pheromones in mice is different depending on the combination of females, stud males and stimulus males. BALB/cA females mated with BALB/cA males showed a 100% pregnancy block when exposed to males of the DDK strain (Chung et al., 1997). In contrast, BALB/cA females mated with males of dissimilar strain show high rates of pregnancy even if they are exposed to DDK males; this difference is thought to be due to the difference in viability of embryos (Chung et al., 1999). The present study investigated how development of BALB/cA and F1 embryos differ under the influence of pregnancy block stimuli. F1 embryos had significantly higher numbers of cells than did the BALB/cA embryos (P<0.05) at day 3 of pregnancy after exposure to DDK males or after bromocriptine (dopamine agonist, 4 mg kg(-1), i.p.) treatment. Histological observation after bromocriptine treatment revealed that: (i) on day 4 of pregnancy, BALB/cA embryos tended to form a large blastocoel, but showed abnormalities such as degeneration of primitive endoderm and depression of the outer trophoblast-distal endoderm layer at the periphery of the inner cell mass (ICM) or detachment of the ICM from the outer layer. In contrast, 60-70% of F1 embryos were normal late blastocysts and incipient egg cylinders, but 28-40% of early blastocysts were degenerating; and (ii) day 5 BALB/cA embryos were in the range from incipient egg cylinder with a large proamniotic cavity to ectoplacental cone only, but their proximal endoderm and trophoblast-distal endoderm layer were degenerating. In contrast, the F1 embryos were mostly at the egg cylinder stage and maintained normal structure except for occasional enlargement of the developing yolk sac cavity. These results indicate that the lining of the inner surface of trophoblast by distal endoderm layer may be more firmly established and that the inner environment for development of F1 embryos may be more effectively maintained, thereby making them more resistant to deleterious influences due to pregnancy block stimuli than are BALB/cA embryos.

20 alpha-Hydroxysteroid dehydrogenase activity in rat placenta

20 alpha-Hydroxysteroid dehydrogenase (20 alpha-HSD) (EC.1.1.1.149) is the enzyme which catabolizes progesterone to 20 alpha-dihydroprogesterone (20 alpha-OHP), a biologically inactive steroid, and is distributed in a variety of tissues including non-steroid-producing tissues. In the present study, changes in cytosolic 20 alpha-HSD activity were investigated in rat placental tissues and its relationship to embryonic mortality was considered; the mesometrial endometrium (including the ectoplacental cone) on days 8-11 of pregnancy (day 0 = estrus), and the chorioallantoic placenta and visceral yolk sac (vitelline membrane) on days 12-21 were separately subjected to measurement of the enzyme activity. 20 alpha-HSD activity was not detected in the chorioallantoic placenta until day 20 and then increased dramatically on day 21. Interestingly, considerable activity of the enzyme was found in the visceral yolk sac from days 14 to 21 and in the mesometrial endometrium from days 8 to 10, whereas it was undetectable in these tissues on days 11 and 12. Analysis of DEAE column chromatography revealed that these tissues contain two different types of 20 alpha-HSD (HSD-1 and HSD-2). By an immunohistochemical method, with polyclonal antiserum to rat 20 alpha-HSD, decidual cells and trophoblastic giant cells adjacent to the ectoplacental cone (day 10), spongiotrophoblasts and visceral yolk sac cells (days 21) were positively stained. The number of fetuses on day 10 of pregnancy was 15.4 and decreased significantly to 12.9 on day 12.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of activities of two 20 alpha-hydroxysteroid dehydrogenase isozymes in rat corpora lutea

The rat ovary contains two isozymes of 20 alpha-hydroxysteroid dehydrogenase (HSD-1 and HSD-2). In this study, the expression of activity of each isozyme was investigated in ovaries that contained a single generation of corpora lutea during pseudopregnancy. This condition was induced by cervical stimulation in rats that had been rendered anovulatory by housing them in a continuously lit environment. The total activity of cytosolic 20 alpha-HSD was lower in the ovaries of these pseudopregnant rats than in ovaries containing multiple generations of corpora lutea. In normal pseudopregnancy, HSD-1 activity was low on days 5 and 9 and increased markedly on day 15, whereas HSD-2 was lower than HSD-1 and did not vary throughout pseudopregnancy. However, on days 5 and 9 of continuous-light pseudopregnancy, low activity of HSD-1 only was detected; by day 15, HSD-1 activity had increased sixfold and HSD-2 activity could be detected. Immunohistochemical methods using a specific antibody recognizing both HSD-1 and HSD-2 revealed that the number of 20 alpha-HSD-positive luteal cells increased by day 15. Thus, the increase in total enzyme activity and appearance of HSD-2 activity observed at late pseudopregnancy was accompanied by an increase in the number of 20 alpha-HSD-positive luteal cells.