The objective of this study was to determine the mRNA expression patterns of several putative imprinted genes in in vivo and in vitro fertilized, parthenogenetic, and cloned porcine preimplantation embryos. Both maternally (Dlk1, IGF2, Peg1/Mest and Ndn) and paternally (IGF2r, H19 and Xist) imprinted genes were selected. We have used reverse transcription polymerase chain reaction (RT-PCR) to investigate gene expression patterns in the porcine embryos. IGF2 transcripts were detected in the most of embryos. In nuclear transfer (NT), Peg1/MEST transcripts showed fluctuating pattern. Dlk1 was only expressed partially from the morula and blastocyst stage of NT embryos. Ndn gene expression was started somewhat early for in vivo embryos. However, the expressions of maternally imprinted genes were similar in all types of blastocysts (NT, in vivo and in vitro fertilized, and parthenogenetic embryos). The IGF2R gene expression level was somewhat irregular and varied among samples. However, for the majority samples of all types of embryos, IGF2R expression was diminished after one- to two-cell stages and reappeared at the morulae or blastocyst stage embryos. H19 gene was only expressed early in parthenogenetic and in vivo embryos. For NT embryos, H19 was only expressed in blastocysts. Xist expression was detected in all blastocysts with the earliest being in vivo 8-cell stage embryos and the last one being NT blastocysts. These putative imprinted genes appeared to have stage specific expression patterns with a fluctuating pattern for some genes (Peg/Mest, IGF2r, H19). These results suggest that stage specific presence of imprinted genes can affect the embryo implantation and fetal development.

The objective of present study was to investigate the effect of seasons on reproductive performance of Hanwoo and Holstein heifers. Heat stress in summer or cold stress in winter stress to Hanwoo and Holstein heifers may bring reproduction failure, which would pose an important economic loss, even around Daegwallyeong region located in high mountainous area. Seasonal differences in the serum levels of LH, FSH and progesterone () in response to environmental factors (hot and cold) out of 20 pubertal Hanwoo heifers in Daegwallyeong, Gangwon Province and 20 non-lactating Holstein heifers in Chonan city of Republic of Korea at 2-3 years of age were compared. Blood samples for hormonal analysis were from jugular vein after detection of estrus repeatedly over four seasons within four-week intervals (Spring: May to June, Summer: July to August, Autumn: October to November and Winter: January to February). In Hanwoo heifer population, averages of LH and FSH concentration in spring and in summer were greater compared to those in winter (p<0.05). LH or FSH levels tended to be greater (p=0.06) in spring and less (p=0.09) in winter compared to the levels in autumn. Only in summer, cattle seemed to show lower LH or FSH secretion (p<0.05). Similar to the results in Hanwoo heifers, the serum concentrations of LH and FSH in Holstein heifers decreased further by heat stress in summer when P 4 levels were high during luteal phase. The results demonstrate significant effect of summer heat on reproduction of Hanwoo or Holstein heifers. Although parameters indicating the extent of heat stress were not measured in this study, we suggest that serum hormone levels could be considered as successful indicators of summer heat stress condition for Hanwoo and Holstein heifers even under rather cool summer climate.

The aim of the present recent study was to compare the protein patterns in the vaginal mucus of Hanwoo cattles during spontaneous and CIDR induced-estrus. Ten cattles, who had been observed in estrus, received no treatment and served as the group of cattles with normal spontaneous estrus. Thirteen cattles in the CIDR received an CIDR insert on day 14 were removed and cattles were injected GnRH on day 15. Vaginal mucus samples were collected from all cattles at the same time the single AI in cattles with spontaneous estrus and the AI in cattles with induced estrus. Spontaneous and CIDR-induced estrus vaginal mucus samples were analyzed on two different array surfaces: cation-exchange (CM10), anion-exchange (Q10). In addition, using the NaCl solution by which the proteins combined after washing are 0.5, 1 and 2 M, it was fractionated and a protein was collected successively. The results are summarized as follows: 1) Ionic surfaces chemistries (Q10 and CM10) gave the best results in terms of detectable protein peaks, with more than 100 protein peaks in the two fractions and under each condition. 2) Protein mass spectrometer using 11 different proteins in protein identification of 7 were able to determine the protein. List of identified proteins as follows; Ribosome-binding protein 1, GRIP 1-associated protein 1, Katanin p60 ATPase-containing subunit A-like 1, Protein FAM44A, DUF729 domain-containing protein 1, Prolactin precursor, Dihydrofolate erductase. Conclusively, on the basis of this study, protein expression in the vaginal mucus could be used as an indicator for time of estrus manifestation in order to increase conception rates by applying AI at an optional time.