Studies on serological cross-reaction of Neospora caninum with Toxoplasma gondii and Hammondia heydorni

The enzyme-linked immunosorbent assay (ELISA) was used to examine cross-reactivity of Neospora caninum with Toxoplasma gondii and Hammondia heydorni. Anti-T. gondii mouse and cat sera cross-reacted with N. caninum soluble antigen (NLA), but not with the recombinant surface antigen (NcSRS2). Anti-H. heydorni dog sera showed no cross-reactivity with either the NLA antigen or the NcSRS2. Lack of cross-reactivity between anti-H. heydorni sera and N. caninum antigens, and the cross-reactivity of anti-T. gondii sera with the NLA suggest that N. caninum has common antigens to T. gondii except for NcSRS2 based on serology. In light of several studies suggesting a closer relationship between N. caninum and H. heydorni than with T gondii, examination of serological cross-reactivity with N. caninum may be necessary to further classify the parasites in addition to molecular and morphological studies and clarification of the life cycle.     

Neospora caninum NcSRS2 is a transmembrane protein that contains a glycosylphosphatidylinositol anchor in insect cells

We investigated the terminal location of NcSRS2, a surface antigen of Neospora caninum that has potential use for diagnosis, and demonstrated its importance as a vaccine component against neosporosis, in an insect-baculovirus expression system. To examine the role of the hydrophobic C-terminal tail in NcSRS2, four types of recombinant baculoviruses were constructed. Immunoblotting and N-terminal amino acid analysis revealed cleavage of a 6 kDa of the N-terminal signal peptide in the mature NcSRS2 protein. The recombinant NcSRS2 (rNcSRS2) lacking 25, and 62 amino acids from the termination codon were detected in supernatants from recombinant virus-infected cells, but not in recombinants with truncated 147 amino acids from the termination codon, and intact NcSRS2 gene (401 amino acids). By flow cytometric and confocal laser scanning microscopic analyses, the truncation of the hydrophobic C-terminal tail in NcSRS2 was shown to result in the reduction of protein expression on the cell surface relative to intact rNcSRS2. Except for the recombinant lacking the 147 C-terminal residues, three other rNcSRS2 were detected in the supernatants after treatment with phosphatidylinositol-specific phospholipase C. Our results demonstrate that the N. caninum NcSRS2 is a transmembrane protein that contains a glycosylphosphatidylinositol-anchor molecule in insect cells, and that the hydrophobic C-terminal domain is an essential component for GPI-membrane attachment. We have likewise shown the usefulness of the insect-recombinant baculovirus system in the expression of rNcSRS2.     

Novel polymorphism of the canine dopamine receptor D4 gene intron II region

Various dog breeds are remarkably different from each other not only in their sizes and shapes but also in behavioral traits, suggesting that some of these characteristics are under genetic control. However, little is known about genes related to behavioral traits in canine species. In humans, it has been reported that the dopamine receptor D4 gene (DRD4) includes polymorphism at several regions that relate to personality or psychiatric disorders. In an earlier study by the authors of the present study, the polymorphisms in canine DRD4 exon III and exon I regions were reported. In the present study, a novel polymorphism in canine DRD4 intron II was found based on a 17 base pair insertion/deletion, and the two alleles detected were named P (shorter allele) and Q (longer allele). The allelic distribution in 28 breeds of dog, including a total of 1114 unrelated individuals, were then investigated. Both P and Q alleles were detected in most of the breeds investigated; however, the frequencies of P and Q differed greatly between breeds. With respect to classification based on breed origin, P and Q alleles were frequent in Occidental and Oriental breeds, respectively. Furthermore, two subspecies of wolves, the ancestors of dogs, were analyzed for the comparison of allele frequencies with dogs, and the P allele was predominant in both European and Chinese wolves.     

The novel polymorphism of the beta 3-adrenergic receptor gene and its distribution in domestic pigs and wild boars in Asia

The beta 3‐adrenergic receptor (ADRB3) is a G protein‐coupled receptor that is involved in regulating energy homeostasis. We have studied DNA sequences of porcine ADRB3 to find candidate genetic polymorphisms for economically important growth and performance traits in pigs. Five novel haplotypes derived from the three In/dels and 44 SNPs were identified among domestic pigs and wild boars. Three of them encode non‐synonymous amino acid sequences by five missense polymorphisms and a frameshift by a thymine insertion. The amino acid polymorphic sites were distributed as follows: one substitution was in extracellular loop 1, three substitutions were in intracellular loop3 and one substitution and the deletion of two amino acids were at the carboxyl‐terminal. There was no polymorphism in the transmembrane domains. In addition, we surveyed the allelic frequency of the thymine insertion that cause frameshift in South‐east Asian local pigs, including some commercial breeds and wild boars. This thymine insertion was distributed widely in the domestic pigs and wild boars. The frequencies of this allele were relatively low in Western improved breeds, while they were very common in Asian breeds and wild boars in Asia. This result indicates that this insertion originally occurred in ancient Asian wild boars and then circulated among Asian domestic pigs. This allele also spread over Western breeds, probably through the introgression of Asian pigs into European stocks during the 18th and 19th centuries.     

Comparative observations of the growth changes of the histochemical properties and collagen architecture of the iliotibialis lateralis muscle from Silky, layer and meat type cockerels

Growth‐related changes in the histochemical property and collagen architecture of the iliotibialis lateralis muscle were compared among Silky, layer and meat cockerels. Histochemical and immunohistochemical methods were employed to observe the collagen architecture. The total intramuscular collagen was also determined. The muscle consisted of type IIA, IIB and IIC myofibers, of which type IIB occurred at the highest frequency. The diameter of type IIB myofibers in each week was largest in the layer, followed by the meat, and was smallest in the Silky. The total amount of collagen reached 3.38 mg/g in the meat bird, 3.03 mg/g in the layer and 2.71 mg/g in the Silky by 30 weeks of age, respectively. In the perimysium, the collagen bundles increased in size and density of fibrils with growth. At 30 weeks of age the layer had compact collagen platelets while the Silky had loose collagen bundles. In the meat bird, the collagen bundles were moderately compact. The endomysial collagen network had a large mesh size at 1 week and thereafter accumulated many collagen fibrils to form a felt‐like fabric of fibrils at 30 weeks of age. From these results it appears that growth‐related changes in the iliotibialis lateralis muscle are not necessarily causally affected by the different growth rates of chicken breeds.     

Determination of the distribution and reaction of polysaccharides in wood cell walls by the isotope tracer technique VIII: Selective radiolabeling of xylan in mature cell walls of magnolia (Magnolia kobus DC.) and visualization of its distribution by microautoradiography

To radiolabel xylan in mature cell walls selectively, magnolia (Magnolia kobus DC.) was administered withmyo-inositol-[2-³H] and allowed to metabolize for 1 month. The radiolabeled xylem tissue was then submitted to sulfuric acid hydrolysis and nitrobenzene oxidation. A large amount of radioactivity was found mainly in xylose, although slight activities were detected in glucose and in vanillin and syringaldehyde. The labeled tissue was submitted to a preparation of holocellulose followed by treatment with 24% potassium hydroxide (KOH). Radioactivity was distributed mainly in the KOH-soluble part of the holocellulose. These results indicate that most radioactivity was incorporated into xylan in the cell walls. The distribution of the incorporated radioactivity in the xylem tissue was visualized by microautoradiography. Radioactivities were distributed in the xylem more than 400 m from the cambium; and an inner layer of a secondary wall had formed at the labeled xylem. Consequently, selective radio-labeling of xylan was visualized in mature cell walls.Part of this report was presented at the 47th annual meeting of the Japan Wood Research Society, Kouchi, April 1997     

Relationship between body temperature and ovarian cycle in Asian and African elephants

The aim of the present study was to investigate whether changes in body temperature are related to the ovarian cycle in elephants. Rectal, tongue or fecal temperature was measured for 2 Asian and 5 African elephants using an electric thermometer. Evaluation of ovarian cycles was based on the changes in serum or fecal progestin. The mean +/- SD values of the rectal, tongue, and fecal temperatures were 36.3 +/- 0.3 (2 Asian), 36.2 +/- 0.5 (1 African) and 36.5 +/- 0.3 C (4 African), respectively; the fecal temperature was the highest of the 3 temperatures (P<0.01). The longitudinal changes in body temperatures correlated with the ovarian cycle, with higher temperatures occurring during the luteal phase. The fecal temperatures of one acyclic African elephant did not change cyclically. These results suggest that measurement of body temperature can be used to easily evaluate the ovarian cyclicity of an individual animal, although it might not be able to determine the ovarian cycle length.     

M. Ichinari,M. Masuko,H. Takenaka,R. Hasegawa,T. Ichiba,Y. Hayase and R. Takeda, ‘Structure and fungicidal activities of methoxyiminophenylacetamide derivatives’. Pesticide Science 55(3) 1999, 347–349

The original article to which this Correction refers was published in Pesticide Science 55 (3) 1999, 347–349. © 1999 Society of Chemical Industry     

A database for poplar gene co-expression analysis for systematic understanding of biological processes,including stress responses

Reforestation in the humid tropics and arid zones, where trees are often subject to stresses, is an effective approach for mitigating global warming. Forestation with Populus species that are tolerant to the stresses in such regions has been conducted. The selection of poplar trees with higher stress tolerance leads to more efficient reforestation. The genome-wide bioinformatics approaches of gene function have been used for revealing the mechanisms of biological processes, including such stress tolerance. The decoding of the poplar genome has been followed by the genome-wide identification of genes and then the inference of gene function for systematic understanding of biological processes. To predict gene function in poplar, we analyzed poplar gene expression data using DNA microarray datasets obtained from the Gene Expression Omnibus database and developed a database for poplar gene co-expression analysis. Using the database, we illustrate the steps to retrieve two groups of co-expressed genes that are specifically expressed in experiments of hypoxic stress response in gray poplar, a flooding-tolerant tree species. Our database allows users to extract genes involved in biological processes, such as stress reaction, and then is useful for understanding such mechanisms in tree species.     

Genetic and morphological evidence of hybridization between <Emphasis Type="Italic">Nematalosa japonica</Emphasis> and <Emphasis Type="Italic">N. come</Emphasis> (Clupeiformes: Clupeidae) off Okinawa Island,Ryukyu Archipelago,Japan

Two morphologically similar species of gizzard shad, Nematalosa japonica Regan and N. come (Richardson), sympatrically distributed off Okinawa Island, Japan, were examined using an allozyme locus (SOD*) and two nuclear polymerase chain reaction (PCR)-based DNA markers (ITS-1 and CaM), which provided diagnostic identification of each species. In addition, a multiplex PCR-based mitochondrial DNA (mtDNA) marker (16S) was used to characterize the distribution of mtDNA haplotypes among specimens. The species composition of sympatric and allopatric population samples from Tungkang, southern Taiwan, to Okinawa and the Shikoku Islands, Japan, were also examined. Gizzard shad with hybrid genotypes were detected in three populations from Okinawa Island, with hybrid frequency ranging from 1 to 67%. A backcross level of 2% was detected in the dominant hybrid frequencies of one population sample only. Morphological examination of hybrids showed intermediate forms, with hybrid indices of three meristic characters falling between those of the parental species (range 39–53; mean 45). Although principal component analysis showed differences between N. japonica and N. come based on the first principal component scores, hybrids were difficult to identify. Accordingly, satisfactory identification of species and hybrids could be achieved only using genetic tools. We also discuss the cause of hybridization and its relationship with recently conducted reclamation on Okinawa Island.