Economic loss due to viral endothelial cell necrosis of eel (VECNE) of Anguilla japonica is a serious problem for the cultured Japanese eel market. However, the viral genome responsible for VECNE is unknown. We recently developed a rapid determination system for viral nucleic acid sequences (RDV) to determine viral genome sequences. In this study, viral DNA fragments were obtained using RDV, and approximately 15-kbp circular full genome sequences were determined using a next-generation sequencing system, overlapping PCR, and Southern blot analysis. One open reading frame (ORF) was homologous to the large T-antigen of polyomavirus; other ORFs have no homology with any nucleic or amino acid sequences of polyomavirus. Therefore, as this DNA virus might comprise a novel virus family, we provisionally named it Japanese eel endothelial cells-infecting virus (JEECV). JEECV was detected in both naturally and experimentally infected eels, suggesting that JEECV potentially causes VECNE.

ABSTRACT. The phenotype of high K (HK) red blood cells, which is an autosomal recessive, was found in dog groups from 10 of 13 breeds or populations in Japan. The incidence of HK was 26 to 38% in the San'in-Shiba, Shinshu-Shiba and Akita breeds, and the gene frequencies of HK ranged from 0.513 to 0.612. The highest incidence (42%) was found in the Jindo breed from Korea, and the gene frequency was 0.652. Two other groups from Korea also possessed this HK variation. However, although HK cells were not found in dogs from Taiwan, Indonesia, Mongolia and Sakhalin, Russia, the HK phenotype is clearly distributed now throughout Japan and Korea. -KEY WORDS: canine, potassium, red blood cell.

Although information regarding morphogenesis of the hepatitis C virus (HCV) is accumulating, the mechanism(s) by which the HCV genome encapsidated remains unknown. In the present study, in cell cultures producing HCV, the molecular ratios of 3’ end- to 5’ end-regions of the viral RNA population in the culture medium were markedly higher than those in the cells, and the ratio was highest in the virion-rich fraction. The interaction of the 3’ untranslated region (UTR) with Core in vitro was stronger than that of the interaction of other stable RNA structure elements across the HCV genome. A foreign gene flanked by the 3’ UTR was encapsidated by supplying both viral NS3-NS5B proteins and Core-NS2 in trans. Mutations within the conserved stem-loops of the 3’ UTR were observed to dramatically diminish packaging efficiency, suggesting that the conserved apical motifs of the 3´ X region are important for HCV genome packaging. This study provides evidence of selective packaging of the HCV genome into viral particles and identified that the 3’ UTR acts as a cis-acting element for encapsidation.

Goat diarrheal feces were subjected to metagenome analysis by the next-generation sequencing. Nucleotide sequences with homology to enteroviruses were obtained. Primers for RT-PCR were designed based on the nucleotide sequence of these sequences at the 5'-untranslated region, and we determined 563 bp nucleotide sequences that showed homology to bovine-like and ovine enteroviruses (77-87 %). We named the virus detected in this study goat enterovirus G1 (GEV-G1). In the phylogenetic analysis, GEV-G1 belonged to a cluster containing ovine enteroviruses. To our knowledge, this is the first report on nucleotide sequences of an enterovirus infecting Japanese goats.

Abstract.Our previous studies have demonstrated that prenatally administered diethylstilbestrol (DES) impairs testicular endocrine function in male offspring. The present study examined whether maternal DES treatment influences testicular steroidogenesis and spermatogenesis. DES was injected subcutaneously at 0.5 or 1.5 μg/kg/day (DES 0.5 and 1.5 groups, respectively) into pregnant SD rats on days 7-21 of gestation. Male offspring in the DES 0.5 and 1.5 groups were autopsied at 1, 3, 6 and 15 weeks after birth. At 1 week, DES treatment did not lead to a change in the volume of P450scc-positive cells (Leydig cells), suggesting that DES has no inhibitory effect on the development of Leydig cells. DES administration disrupted luteinizing hormone receptor (LHr) expression and exerted inhibitory effects on signal transduction from LHr to steroidogenic acute regulatory protein (StAR) in testicular steroidogenesis (P<0.05), although there were no changes in the mRNA expression levels of steroidogenic enzymes, such as P450scc, 3β-hydroxysteroid dehydrogenase (3β-HSD) and P45017α, which may have caused a decrease in the plasma testosterone level. DES treatment did not disrupt the cycle of spermatogenesis but did upregulate the expression levels of androgen receptor (AR) mRNA in both DES groups at 15 weeks (P<0.05). These results indicate that maternal DES treatment disrupts steroidogenesis but induces a high level of AR mRNA expression to counteract the low levels of testosterone during spermatogenesis. uring embryonic development, rat primordial germ cells appear in the yolk sac on embryonic day 10, and the gonadal primordium begins to develop as the genital ridge around embryonic day 11. Primordial germ cells begin to reach the genital ridge on embryonic day 12 [1]; thereafter, Sertoli and Leydig cells in the male differentiate from genital ridge cells, leading to a series of differentiation events. The duration of pregnancy is generally divided into periods of embryonic development (first trimester), organogenesis (second trimester) and organ maturation (third trimester).Diethylstilbestrol (DES), a synthetic non-steroidal estrogen, exhibits strong estrogenic activity by binding to estrogen receptors (ERs). It has been shown that the treatment of pregnant rats with DES dose-dependently (range: 10 to 300 μg/kg) suppresses testosterone levels in the blood and testes of male fetuses [2-4]. We administered doses of DES much lower (1.5 μg/kg) than those previously applied to pregnant rats at 7-21 days of gestation (in the second and third trimesters) and demonstrated that DES suppresses plasma testosterone levels in adolescent male offspring (6 weeks after birth) [5].Androgen plays an important role in the development and function of the testis and male reproductive tract via the androgen receptor (AR). Similarly, since ERs have been found in these tissues [6][7][8][9][10], estrogen may be involved in development of the male reproductive system. Nevertheless, it is apparent that male ER-or aromatase-knockout mice initially ...