Active loss of DNA methylation in two-cell stage goat embryos.

Early mammalian embryos are thought to gain nuclear totipotency through DNA methylation reprogramming (DMR). By this process, DNA methylation patterns acquired during gametogenesis that are unnecessary for zygotic development are erased. The DMR patterns of various mammalian species have been studied; however, they do not seem to have a conserved pattern. We examined early goat embryos to find conforming rules underlying mammalian DMR patterns. Immunocytochemical results showed that the overall level of DNA methylation was not greatly changed during the pronucleus stage. At the two-cell stage, active demethylation occurred and simultaneously affected both parental DNAs, resulting in a global loss of 5-methylcytosine. The level of DNA methylation was lowest in the four-cell stage, with increased de novo methylation during the eight-cell stage. Histone H3-lysine 9 was gradually trimethylated in the sperm-derived chromatin, continuing from the pronucleus stage through the two-cell stage. This goat DMR pattern is novel and distinct from the DMRs of other mammalian species. The more mammalian species we included for DMR analysis, the more multifarious patterns we obtained, adding an extra diversity each time to the known mammalian DMR patterns. Nevertheless, the evolutionary significance and developmental consequence of such diverse DMR patterns are currently unknown.

A case of perosomus elumbis in a Holstein calf.

Perosomus elumbis is an occasionally found congenital anomaly of unknown etiology and is characterized by partial or complete agenesis of lumbar, sacral and coccygeal vertebrae and ankylosis of the hindlimbs. A 2-day-old female Holstein calf presented nearly normal forelimbs but flexure and ankylosis of the hindlimbs. The vertebrae and pelvic malformations and agenesis were radiographed and then necropsied. Mild ankylosis of the hindlimbs, absence of cauda equina, left scoliosis in state of fusion of T11 and T12 and complete fusion of L4 and L5, narrowed pelvic canal and misshapen ilium were confirmed. However, abnormal development or agenesis was not observed in the urogenital and intestinal system in this calf.

Harlequin ichthyosis in a HanWoo calf.

Ichthyosis (fish scale disease) is a rare hereditary disease and characterized by excessive cutaneous scale formation. A male HanWoo calf born by natural service was found with fissures and thickened, scaly, cutaneous plates covering over 90% of its body. Histopathological feature was excess compact orthokeratotic hyperkeratosis involving surface of the epidermis and follicular epithelia. The calf had small malformed ears, ectropion, eclabium and an abnormal nose. Gross and histopathologic findings in calf were consistent with those of harlequin ichthyosis, and it was the first observed harlequin ichthyosis in HanWoo cattle.

Ultrasonic measurement of fetal parameters for estimation of gestational age in Korean black goats.

The objective of this study was to determine relationship of gestational age with measurement of diameter of head, orbit, trunk, long and short axis of heart, aorta, placentome, umbilical cord and umbilical vein in Korean black goats. In this study, ten pregnant Korean black goats (Capra hircus aegagrus) were used. Pregnancy diagnosis was performed with a 5 MHz linear transducer and ultrasonographic scan were performed at 60, 75, 90, 105, 120 and 135 days after mating with a 4-9 MHz convex transducer. For accurate measurement, all fetal organs were measured at least 3 times. The diameter of head, orbit, trunk, long and short axis of heart, aorta, placentome, umbilical cord and umbilical vein were significantly increased with the gestational age (p<0.05). Of these parameters, trunk (r=0.8876; p<0.001), long axis of heart (r=0.9168; p<0.001) and short axis of heart (r=0.8819; p<0.001) proved to be the more effective measurements than other parameters, as it correlated well with gestational age. Results indicate that ultrasonic measurements of these parameters were useful methods to estimate gestational age in Korean black goat.

Recurrence quantification analysis of sleep electoencephalogram in sleep apnea syndrome in humans.

The aim of this study is to elucidate whether the results of recurrence quantification analysis (RQA) of sleep EEGs in sleep apnea syndrome are valuable for analyzing sleep EEGs in sleep apnea syndrome. We investigated the ability of RQA to discriminate sleep stages and to characterize the different behaviors of sleep EEGs in sleep apnea syndrome. RQA was applied to EEG signals during sleep stages 1, 2, slow wave sleep (SWS), REM and the stage 'awake.' The sleep EEG signals were obtained from the MIT-BIH polysomnographic database. To examine the differences in the RQA measures for all sleep stages, one-way analysis of variance (ANOVA) and post hoc analysis were performed. From the results, all sleep stages could be distinctly discriminated by means of the RQA measure of %RATIO. We observed that stage 1 and REM had fewer recurrences, and that stage 2 was more autocorrelated than the other stages. The different dynamic behaviors of wakefulness and sleep EEG were also observed. Of significant interest was the observation that RQA was able to distinguish stage 1 from REM. In conclusion, we suggest that the information obtained from RQA of sleep EEGs in sleep apnea syndrome is valuable for its analysis, and that RQA constitutes a useful tool for analyzing sleep EEGs in subjects with sleep apnea syndrome.