Identification of Facklamia sourekii from a lactating cow

A gram-positive, catalase-negative, facultatively anaerobic coccus was isolated from a lactating cow with hematuria and urodynia in Japan. The isolate was identified by 16S rRNA gene sequence analysis as Facklamia sourekii. The biochemical and culture characteristics of the isolate were well consistent with those of F. sourekii type strain. Since all F. sourekii strains reported so far were isolated from human clinical specimens, this is the first reported case of F. sourekii isolated from veterinary clinical specimen.     

Rice false smut pathogen, Ustilaginoidea virens, invades through small gap at the apex of a rice spikelet before heading

Ustilaginoidea virens, the false smut pathogen of rice, produces false smut balls on spikelets after heading. To clarify how the fungus invades spikelets during the booting stage, we developed a fungal strain that expresses a green fluorescent protein gene and injected conidia from this strain into rice sheaths. Observations at 48?h post-inoculation showed many conidia were present on spikelet surfaces, and the conidia had germinated and the hyphae have gradually grown by 120?h post-inoculation. By 144?h, hyphae had invaded spikelets through their apices, via the small gap between the lemma and palea and had already reached all floral organs.     

Identification and functional analysis of alleles for productivity in two sets of chromosome segment substitution lines of rice

Using two sets of chromosome segment substitution lines (CSSLs) of crosses between cvs. ‘Koshihikari’ and ‘Kasalath’ (Ko/Ka) and between ‘Koshihikari’ and ‘Nona Bokra’ (Ko/NB), respectively, we have identified alleles for ten traits related to productivity (e.g., harvest index and biomass) in rice (Oryza sativa L.). A total of 43 chromosome regions affecting traits (CRATs) in Ko/Ka CSSLs and 40 in Ko/NB CSSLs were detected. Among them, ten and 18 CRATs in Ko/Ka and Ko/NB CSSLs, respectively, had positive effects. A CRAT for harvest index (HI) with a positive allele from ‘Kasalath’ on chromosome 6 (tentatively named HI6) increased the HI by 25 % relative to ‘Koshihikari’, raising it to the theoretical upper limit in rice (0.6). Functional analysis using CSSLs with HI6 indicated that HI6 reduced the size of the lower parts of the plant, which is not important for production, while maintaining the size of the other organs related to production (e.g., flag leaf and panicle), resulting in improved nitrogen (N) use efficiency. These results suggest an ‘ideal plant type’ with improved N use efficiency that can sustain higher yields. A CRAT for the SPAD (soil plant analysis development) value, which is a chlorophyll meter value commonly used as an indicator of leaf N content and strongly associated with the source ability of a leaf, with a ‘Nona Bokra’ allele on chromosome 4 increased the value by 13 % relative to ‘Koshihikari’ with no loss of leaf area. These CRATs can be used for the improvement of rice productivity.     

Development of EST-SSR markers of Ipomoea nil

Although Japanese morning glory (Ipomoea nil (L.) Roth.) has been used intensively for genetic studies, DNA markers have not been developed in Ipomoea nil sufficient to cover all chromosomes. Therefore, we conducted microsatellite (simple sequence repeats, SSR) marker development in I. nil for future genetic studies. From 92,662 expressed sequence tag (EST) sequences, 514 unique microsatellite-containing ESTs were identified. Primer pairs were designed automatically in 326 SSRs. Of 150 SSRs examined, 75 showed polymorphisms among strains. A phenogram based on the SSR genotypes revealed the genetic relation among seven Japanese morning glories from five different regions of the world and an ivyleaf morning glory (I. hederacea Jacq.). The developed SSR markers might be applicable for genetic studies of morning glories and their relatives.     

Induction of feline immunodeficiency virus from a chronically infected feline T-lymphocyte cell line

The infection of the feline T-lymphocyte cell line FeT-J with the feline immunodeficiency virus (FIV) Petaluma strain led to the establishment of nonvirus-producing cells. One clone (C15) obtained by limiting dilution was found to express FIV in response to chemical inducers of retroviruses. The chemical treatment of C15 cells led to not only FIV protein synthesis but also an augmentation of viral production. Examination of the C15 cell derivatives obtained by recloning revealed that 10-40% of treated cells constitutively expressed FIV antigens, whereas 100% with expressed FIV antigen in response to the inducer. Chemical induction resulted in more than a 100-fold increase in infectious viral production. The results suggest that a majority of FeT-J cells that are infected with FIV exist in a non-productive state. Establishing a cell line that can be non-productively infected by FIV may help determine the mechanisms of FIV latency.     

Successful induction of lactation in a barren thoroughbred mare: growth of a foal raised on induced lactation and the corresponding maternal hormone profiles

The purpose of this study was to demonstrate that a barren parous Thoroughbred mare with lactation induced by hormonal treatment can be introduced to an orphan foal at the same farm and that the mare can become pregnant after the end of the hormonal treatment. An additional purpose was to investigate the changes in the plasma concentrations of prolactin, estradiol-17β, progesterone, follicle-stimulating hormone, and luteinizing hormone before, during, and after hormonal treatment. The difference in body weight between the adopted foal and the control foals, which were at the same farm and raised by their natural mothers, was 17 kg at 24 weeks old, when the foals were weaned. However, the adopted foal and the control foals had almost the same weight at 35 weeks old and later. The first ovulation after hormonal treatment was confirmed 10 days after the end of hormonal treatment and then the normal estrous cycle resumed. Furthermore, the changes in plasma progesterone, estradiol-17β, follicle-stimulating hormone, and luteinizing hormone showed regular patterns after the first ovulation. Conception was confirmed in the fifth ovulation. Meanwhile, another study demonstrated that conception was confirmed in the first ovulation after hormonal treatment. The present study is the first to demonstrate the hormonal profiles during and after induction of lactation in a Thoroughbred mare. This approach is useful for solving the economic and epidemic problems of introducing a nurse mare to an orphan foal.     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Both stem and crown mass affect tree resistance to uprooting

To examine the hypothesis that both stem and crown mass affect the resistance of a tree to uprooting and that tree resistance increases with increasing crown mass, we conducted tree-pulling experiments on three Picea glehnii plantations (stands A, B, and C: 27–32 years old) that differed in tree density and slenderness ratio. Allometries between crown and stem masses and between the critical uprooting moment and stem mass differed significantly among the three stands, with the crown mass and critical moment significantly larger in stand C than in stands A or B, despite the same stem mass. These results quantitatively verified our hypothesis. Allometries between crown and stem masses and between critical uprooting moment and stem mass were highly significant in each stand but were stand specific. Therefore, these allometries can be used to estimate tree resistance to uprooting in a given stand but not for data compiled from stands of various conditions and tree shapes. The allometry between critical moment and aboveground mass did not differ among the three Picea stands; thus, it is not stand specific and is generally appropriate to use for estimating tree resistance. To increase tree resistance to uprooting, we recommend light management for Picea glehnii plantations and probably other coniferous plantations as well.     

Distribution of photoperiod-insensitive allele Ppd-A1a and its effect on heading time in Japanese wheat cultivars

The Ppd-A1 genotype of 240 Japanese wheat cultivars and 40 foreign cultivars was determined using a PCR-based method. Among Japanese cultivars, only 12 cultivars, all of which were Hokkaido winter wheat, carried the Ppd-A1a allele, while this allele was not found in Hokkaido spring wheat cultivars or Tohoku-Kyushu cultivars. Cultivars with a photoperiod-insensitive allele headed 6.9–9.8 days earlier in Kanto and 2.5 days earlier in Hokkaido than photoperiod-sensitive cultivars. The lower effect of photoperiod-insensitive alleles observed in Hokkaido could be due to the longer day-length at the spike formation stage compared with that in Kanto. Pedigree analysis showed that ‘Purple Straw’ and ‘Tohoku 118’ were donors of Ppd-A1a and Ppd-D1a in Hokkaido wheat cultivars, respectively. Wheat cultivars recently developed in Hokkaido carry photoperiod-insensitive alleles at a high frequency. For efficient utilization of Ppd-1 alleles in the Hokkaido wheat-breeding program, the effect of Ppd-1 on growth pattern and grain yield should be investigated. Ppd-A1a may be useful as a unique gene source for fine tuning the heading time in the Tohoku-Kyushu region since the effect of Ppd-A1a on photoperiod insensitivity appears to differ from the effect of Ppd-B1a and Ppd-D1a.     

Effects of photoperiod on secretory patterns of growth hormone in adult male goats

The aim of the present study was to clarify the effect of photoperiod on secretory patterns of growth hormone (GH) in male goats. Adult male goats were kept at 20°C with an 8‐h or 16‐h light photoperiod, and secretory patterns of GH secretion were compared. In addition, plasma profiles of prolactin (PRL), insulin‐like growth factor‐I (IGF‐I) and testosterone (T) were also examined to characterize GH secretion. GH was secreted in a pulsatile manner. There was no significant difference in pulse frequency between the 8‐h and 16‐h photoperiods. However, GH pulse amplitude tended to be greater in the group with the 16‐h photoperiod (P = 0.1), and mean GH concentrations were significantly greater in the 16‐h photoperiod (P < 0.05). The GH‐releasing response to GH releasing hormone was greater in the 16‐h than 8‐h photoperiod (P < 0.05). Plasma PRL and IGF‐I levels were higher in the 16‐h than 8‐h photoperiod (P < 0.05). In contrast, plasma T levels were lower in the 16‐h photoperiod (P < 0.05). These results show that a long light photoperiod enhances the secretion of GH as well as PRL and IGF‐I, but reduces plasma T concentrations in male goats.