Divergent evolution of wild and cultivated subspecies of <Emphasis Type="Italic">Triticum timopheevii</Emphasis> as revealed by the study of <Emphasis Type="Italic">PolA1</Emphasis> gene

Triticum timopheevii (genome symbol AAGG) comprises two subspecies, cultivated ssp. timopheevii, and wild ssp. armeniacum. These two subspecies are considered as allotetraploids of AA genome from Triticum diploid species and SS genome from Aegilops species. The difference in genome symbol (G vs. S) is due to wide genetic variations among four SS genome species, Ae. bicornis, Ae. longissima, Ae. searsii, and Ae. speltoides. In order to study the origin of T. timopheevii, we compared 19th intron (PI19) sequence of the PolA1 gene, encoding the largest subunit of RNA polymerase I. Two different sized DNA fragments containing PI19 sequences (PI19A and PI19G) were amplified both in ssp. timopheevii and ssp. armeniacum. Shorter PI19A (112 bp) sequences of both subspecies were identical to PI19 sequences of two AA species, T. monococcum and T. urartu. Interestingly, the longer PI19G (241–243 bp) sequences of ssp. armeniacum showed more similarity to PI19 sequences of Ae. speltoides whereas ssp. timopheevii showed more similarity to PI19 sequences of other three SS genome species. The results indicated that two subspecies of T. timopheevii, ssp. armeniacum or ssp. timopheevii, might have arisen independently by allotetraploidization of AA genome with Ae. speltoides or one of the remaining three Aegilops species, respectively.     

Technical note: viability and motility of vitrified/thawed primordial germ cell isolated from common carp (Cyprinus carpio) somite embryos

The feasibility of cryopreserving common carp (Cyprinus carpio) primordial germ cells (PGC) by vitrification of whole embryos at the 22- to 28-somite stage was investigated. Green fluorescent protein (GFP)-labeled PGC were cooled rapidly using liquid nitrogen after exposure to a pretreatment solution containing 1.5 M cryoprotectant (ethylene glycol or dimethyl sulfoxide, 30 or 50 min) and a vitrification solution containing 3 M cryoprotectant and 0.5 M sucrose (5, 10, 20, or 30 min). Embryonic cells that were pretreated for 30 min and vitrified for 20 min with ethylene glycol had the greatest rate of survival of embryonic cells (68.6%; P < 0.01), an optimal highest percentage of viable PGC (73.8 to 74.9%; P < 0.05), and no evidence of ice formation after thawing. The vitrified/thawed PGC were transplanted into blastula-stage embryos from goldfish (Carassius auratus). The PGC maintained their motility and moved to the gonadal ridge of the host embryo. Thus, the combination of vitrification and transplantation to produce germ-line chimeras is a powerful tool for the artificial production of next-generation offspring.     

Suppression of Fusarium solani f. sp. phaseoli on Bean by Aluminum in Acid Soils

ABSTRACT The severity of bean root rot caused by Fusarium solani f. sp. phaseoli in vitro was studied with regard to exchangeable soil aluminum for 25 soil samples collected from northeastern Honshyu island, Japan. Of these, 24 were Andosols, typically acidic and of volcanic ash origin. Disease severity was assessed based on the number of lesions produced by the pathogen on a 6-cm section of bean stem buried and incubated for 8 days at 25 degrees C in artificially infested soil samples. The number of lesions differed considerably among soil samples. In all soils in which disease incidence was very low, macroconidial germination was strongly inhibited. The inhibition was observed in all soil samples with exchangeable aluminum contents of at least 0.4 meq/100 g of soil, although it is unclear if this concentration is the lowest limit for inhibition. When soil pH was 5.6 or lower, higher amounts of exchangeable aluminum were detected from soils in which the major clay mineralogy was chloritized 2:1 minerals, while no or limited amounts of aluminum were detected from soils in which the major clay mineralogy was allophane/imogolite. Macroconidial germination and disease incidence are thus closely related to clay mineralogy, which regulates the behavior of exchangeable aluminum.     

Relationship between development of intramuscular connective tissue and toughness of pork during growth of pigs

We investigated changes in structures and properties of the endomysium and perimysium during development of semitendinosus muscle in relation to the increase in toughness of pork using samples from neonates to 55-mo-old pigs. The shear force value of pork increased linearly until 6 mo of age, and the rate of increase slowed down thereafter. The secondary perimysium thickened owing to an increase in the number and thickness of perimysial sheets consisting of collagen fibers, which became thicker and wavy with the growth of the pigs. This increase in thickness of the secondary perimysium was correlated significantly with the increase in the shear force value (r = .98). The endomysial sheaths became thicker and denser in the muscle of 6-mo-old pigs. Maturation of the endomysium was accompanied by hypertrophy of muscle fibers. The amount of heat-soluble collagen decreased almost linearly, indicating that nonreducible cross-links between collagen molecules were formed throughout chronological aging. We conclude that thickening of the perimysium is closely related to an increase in the toughness of pork during growth of pigs.     

Serovar, pathogenicity and antimicrobial susceptibility of erysipelothrix rhusiopathiae isolates from farmed wild boars (Sus scrofa) affected with septicemic erysipelas in Japan

Six strains of Erysipelothrix rhusiopathiae were isolated from farmed wild boars with acute septicemic erysipelas during the period from 1983 to 1998 in Japan. All isolates belonged to serovar 1a or 2 (predominant serovars in swine). The 50 per cent lethal dose values of those isolates ranged from 10(1.3)to 10(6.2)colony forming units in mice. In swine, all isolates were virulent, capable of inducing localized or generalized urticarial lesions after intradermal inoculation. All of the isolates were resistant to oxytetracycline and/or dihydrostreptomycin. These observations suggest that E. rhusiopathiae strains isolated from wild boars may have aetiological significance in swine erysipelas.     

Feline immunodeficiency virus subtype C is prevalent in northern part of Taiwan

The seroepidemiological survey of cats conducted in northern part of Taiwan in 1998 revealed that the positive rate of feline immunodeficiency virus (FIV)-infection was 21.9% (7/32) and the rate was much higher than those of previous reports. We succeeded in isolation of three strains of FIV from peripheral blood mononuclear cells of the blood samples. Nucleotide sequences of the env variable V3 to V5 region of the strains revealed that the isolates from distinct areas belong to subtype C. These data together with our previous report (Inada et al. 1997. Arch. Virol., 142: 1459-1467) indicate that FIV subtype C is prevalent in northern part of Taiwan.     

Heinz body hemolytic anemia with eccentrocytosis from ingestion of Chinese chive (Allium tuberosum) and garlic (Allium sativum) in a dog

A 4-year-old, intact male miniature schnauzer was presented with anorexia. The dog had ingested some Chinese steamed dumplings 2 days before, which contained Chinese chive (Allium tuberosum) and garlic (Allium sativum). Hematological examinations revealed severe Heinz body hemolytic anemia with eccentrocytosis and an increased concentration of methemoglobin, which was thought to result from oxidative damage to erythrocytes by constituents in these Allium plants. In this case, eccentrocytosis was a hallmark finding and could be detected easily, suggesting that this hematological abnormality is useful in diagnosing Allium plant-induced hemolysis.     

Estrogen inhibits interleukin-18 mRNA expression in the mouse uterus

Interleukin-18 (IL-18) is a proinflammatory cytokine expressed in female reproductive organs in humans, rats and mice. The physiological roles of uterine IL-18 and the regulatory mechanisms of IL-18 gene expression are unclear. The present study aimed to clarify the effects of estradiol-17beta (E2) and progesterone (P4) on IL-18 mRNA expression in the mouse uterus. Distribution and expression levels of IL-18 mRNA were studied using an RNase protection assay. Expression of IL-18 mRNA was observed in all organs studied, including testes, ovaries and uteri. The uterine IL-18 mRNA level of estrous mice was higher than that of diestrous mice. E2 treatment (1, 5, 25 or 250 ng/mouse) decreased uterine IL-18 mRNA levels in ovariectomized mice dose-dependently. E2 treatment acutely decreased IL-18 mRNA levels 3 h after injection, but these levels returned to the initial level after 48 h. P4 treatment (1 mg/mouse) decreased uterine IL-18 mRNA levels after 12 h, but levels returned to the initial level after 48 h. Both uterine IL-18 and IL-18Ralpha mRNAs were detected in cultured endometrial epithelial and stromal cells. These results suggest that uterine IL-18 expression is reduced by sex steroid hormones and that IL-18 acts on endometrial cells in a paracrine or autocrine manner.     

Effect of intramammary injection of RbIL-8 on milk levels of somatic cell count, chemiluminescence activity and shedding patterns of total bacteria and S. aureus in Holstein cows with naturally infected-subclinical mastitis

Summary The effect of intramammary injection of recombinant bovine interleukin-8 (rbIL-8, 1 mg/10 ml of saline) on quarter milk levels of somatic cell count (SCC), chemiluminescence (CL) activity and counts of total bacteria and Staphylococcus aureus (S. aureus) was investigated, using 10 Holstein cows with an early stage or a late stage of subclinical mastitis naturally infected with S. aureus. In the late-stage group, milk SCC and CL activity had significant rises with maximum levels at 6 h, following maintained high levels thereafter post-cytokine injection. The counts in milk total bacteria and S. aureus were insignificantly decreased, being increased back on day 7 post-cytokine injection. Thus, the cytokine was inefficient for the late-stage subclinical mastitis. However, in the early-stage group milk SCC and CL activity declined to under pre-injection levels on day 7 after marked and significant rises at 6 h and day 1 post-cytokine injection. The milk total bacterial count decreased significantly on days 0.25 and 2. Furthermore, the milk S. aureus count was decreased significantly on days 1, 2, 3 and 7 by the cytokine injection. These results suggest that the rbIL-8 has a potential as a therapeutic agent of the subclinical mastitis of dairy cows, if the cytokine is applied at an initial stage of infection.