Mobility of the forearm skeleton in the Asiatic black (Ursus thibetanus), brown (U. arctos) and polar (U. maritimus) bears

In several primates and carnivores, pronation/supination angles of the forearm skeleton were examined, and it is thought that a larger angle is useful to acquire dexterous behaviors in feeding and/or life style, including climbing. In this study, the pronation/supination angles in Asiatic black, brown and polar bears were nondestructively examined. These specimens were classified as adult or non-adult. Three or four carcasses of each group of Asiatic black and brown bears were used for CT analysis, whereas only one adult polar bear was used. The forearms were positioned within the gantry of a CT scanner in both maximally supinated and pronated states. Extracted cross-sectional CT images of two positions were superimposed by overlapping the outlines of each ulna. The centroids of the radii were detected, and then the centroid of each radius and the midpoint of a line which connects between both ends of the surface of each radius facing the ulna, were connected by lines to measure the angle of rotation as an index of pronation/supination. In adult brown and polar bears, the angles were smaller as compared with the other groups (Asiatic black and non-adult brown bears). Asiatic black and non-adult brown bears can climb trees, whereas adult brown bears and polar bears cannot. This suggests that the pronation/supination angle is related to arboreal activity in Ursidae.     

Seed formation in triploid loquat (Eriobotrya japonica) through cross-hybridization with pollen of diploid cultivars

As the fruits of loquat (Eriobotrya japonica, 2n = 2x = 34) carry large seeds, the breeding of seedless loquat has long been a goal. The recent creation of triploid cultivars (2n = 3x = 51) and the application of gibberellins allow commercial production of seedless loquat, but the possibility of seed formation in triploid loquats has not been carefully investigated. Through crossing experiments and cytological observations of meiosis and pollen tube growth, we found that the triploid line 3N-N28 was essentially self-sterile, but developed seeds on pollination with pollen from diploid cultivars at rates of up to 5.5%. Almost half of the seedlings survived to 5 months, and carried diploid (2n = 34), tetraploid (2n = 68), or aneuploid chromosome numbers. Our results suggest that triploid loquat cultivars might retain the risk of seed formation. Protection from pollination by diploid cultivars or the development of new triploid cultivars will be necessary to ensure the production of seedless loquat fruits.     

γ-HCH-Decomposing ability of several strains of Pseudomonas paucimobilis

Abstract

Extract

We succeeded in isolating a γ-HCH (γ-1,2,3,4,5,6-hexachlorocyclohexane)-decomposing aerobic bacterium from an upland field where γ-HCH had been repeatedly applied for more than 10 years. The bacterium was identified as Pseudomonas paucimobilis (Oyaizu and Komagata, 1983; Senoo and Wada 1989; Wada et al. 1989). We assumed that P. paucimobilis was able to thrive in the upland field by acquiring the γ-HCH-decomposing ability (Tu 1975, 1976) based on the following mechanism:     

Genomic variations among Bartonella henselae isolates derived from naturally infected cats

The purpose of this study was to understand the mechanisms of persistent infection with Bartonella henselae in cats. Blood samples were collected from three naturally infected cats for 24 months. These cats were confirmed to be persistently infected with B. henselae by serological and bacteriological examination. Relapsing bacteremia was found in all three cats with intervals of 3-19 months. Following the peaks of bacteremia, increases of specific antibody titer were observed in these cats. To examine the genetic differences among the isolates derived from the first and following bacteremia, the genome DNA patterns of the restriction enzyme fragment length polymorphism (RFLP) of the isolates were examined by pulsed field gel electrophoresis. The isolates derived from the first bacteremia showed an identical RFLP pattern in each of the three cats. The isolates derived from the following peaks, however, showed 1-3 of different RFLP patterns in these cats. Furthermore, the isolates showing different RFLP patterns from those of the first bacteremia were also detected at the following bacteremic peaks in all three cats examined. The 16S ribosomal RNA (rRNA) gene type of all isolates was found to be 16S rRNA type I. The emergence of genetically distinct organisms at various peaks of bacteremia may contribute to the establishment of persistent infection in the naturally infected cats.     

Characteristic computed tomographic myelography findings in 23 Thoroughbred horses

The purpose of this observational study was to determine the characteristic computed tomographic (CT) myelography findings of cervical vertebral stenotic myelopathy (CVSM) lesions in Thoroughbred horses. A total of 23 Thoroughbred horses (age range, 155–717 days on CT examination; mean, 410.9 days) were analyzed. All 23 Thoroughbred horses underwent unenhanced radiography, radiographic myelography, and CT myelography. Unenhanced radiographs were observed the presence of cervical vertebral malalignment and osseous lesions. Radiographic myelograms were observed for signs of cervical spinal cord compression; additionally, CT myelograms were used to detect cervical vertebral osseous lesions. Ventral compressions were frequently observed in the cranial cervical vertebrae (C2–C4), whereas dorsal compressions were frequently observed in the caudal cervical vertebrae (C5–C7). Furthermore, osseous lesions of the caudal articular process developed more frequently than those of the cranial articular process. CT myelography in Thoroughbred horses is a useful method for detecting CVSM changes.     

Effect of farm household income levels and rice-based diet or water hyacinth (Eichhornia crassipes) supplementation on growth/cost performances and meat indexes of growing and finishing pigs in the Mekong Delta of Vietnam

An on‐farm trial was carried out to improve the current low‐income farmers’ diet and to assess farm conditions that could accept the new ingredients using locally available feed resources in the Mekong Delta region. A total of 42 local Large White‐type pigs, comprising 20 barrows and 22 gilts with initial‐to‐final mean live weight of 34.2–93.0 kg, were used. The trial was designed as a 3 × 3 factorial with three agricultural gross income levels of seven farm households and three dietary treatments. The annual income levels were high income (HI; $US2355 on average), medium income (MI; $US1439) and low income (LI; $US1116). The three types of diets were farmers’ common diet (FCD), rice‐based diet (RBD) and water‐hyacinth (Eichhornia crassipes)‐supplemented diet (WHD). A total of 12 pigs, consisting of two barrow–gilt couples in each diet treatment, were slaughtered at the end of the trial. The daily weight gain (DG) was higher and the feed conversion ratio (FCR) was lower in the MI and LI pigs than in the HI pigs over the entire fattening period (P < 0.01). No significant effect of the diet treatments was observed on the aforementioned two parameters, but the backfat thickness was least in WHD (16.8 mm) and next least in RBD (17.1 mm), compared with that of FCD pigs (19.4 mm; P < 0.05). The iodine values of RBD and WHD backfat were lower (P < 0.001) than those of FCD backfat. The cost performance, defined as feed cost per kg weight gain, was lowest for MI, intermediate for LI and highest for HI levels (P < 0.05). Therefore, the benefit was highest at the MI level and lowest at the HI level (P < 0.05). In contrast, cost performance of the diet treatments tended to be higher in FCD, and lower in RBD and WHD (P < 0.1). Then, the benefit tended to be higher in RBD and WHD than in the FCD diet (P < 0.1). Overall, these results suggest that the RBD and WHD diets be recommended especially to households with medium and low agricultural incomes.     

Non‐invasive sampling technique for DNA extraction from captive Japanese Crested Ibis on Sado Island

The Japanese Crested Ibis Nipponia nippon is a critically threatened bird. The post‐hatch eggs of the current captive population of this species on Sado Island have been stored at room temperature for the long‐term. In this study, we investigated the suitability of the vascularized chorioallantois membrane from the eggs as a non‐invasive DNA source. Using microsatellite loci developed for the Japanese Crested Ibis, we performed three experiments for comparison of genotypes obtained among DNA. First, DNA from five different sites of the identical membrane showed the same genotypes at either of two loci examined. Second, DNA from the membrane of each full‐sibling birds and blood of their parents showed the genotypes that were consistent with Mendelian parent–offspring relationships at any of eight loci examined. Third, DNA from the membrane and blood of the same bird showed the matched genotypes at any of eight loci examined. These results indicate that the vascularized chorioallantois membrane from post‐hatch eggs stored at room temperature for the long‐ term can be used as a reliable DNA source of offspring that had hatched from the egg. This study will promote a molecular genetics study on genetic diversity of the current captive Japanese Crested Ibis population on Sado Island.     

Immunohistochemical and histoplanimetrical study on the spatial relationship between the settlement of indigenous bacteria and the secretion of bactericidal peptides in rat alimentary tract

To clarify the regulatory mechanism by bactericidal peptides secretion, the secretion of bactericidal peptides was immunohistochemically and histoplanimetrically compared with the degree of Gram-positive/negative bacterial colonization throughout the rat alimentary tract. In the associated exocrine glands from the oral cavity to the stomach, no comparable differences were observed under the changes of development of indigenous bacterial colonies. In the small intestine, immunopositive granules for lysozyme and secretory phospholipase A2 (sPLA2) were markedly decreased, whereas immunopositive vacuoles in the Paneth cells were more increased at sites with hyper-development of indigenous bacterial colonies in the intervillous spaces than at sites with no or less development. No changes in exocrine glands were observed in the large intestine because of the constant existence of large quantities of bacteria. Gram-positive bacterial colonies on the mucosal surfaces were dominant from the oral cavity to the stomach. Gram-negative bacteria were dominant in the large intestine, and the distributions of both Gram-positive and negative bacteria were intermediate in the small intestine. These findings suggest that lysozyme and sPLA2 secreted from the Paneth cells contribute to the regulation of the proliferation of indigenous bacteria in the intervillous spaces of the small intestine, and that the inversion of distributions of Gram-positive and -negative bacteria in the alimentary tract might be caused by the secretion of lysozyme and sPLA2 in the small intestine.