Publications by authors named "Shin-ichi Kawakami"

Identifying the genes responsible for quantitative traits remains a major challenge. We previously found a major QTL on chromosome 4 affecting several innate fear behavioral traits obtained by an open-field test in an F2 population between White Leghorn and Nagoya breeds of chickens (Gallus gallus). Here, an integrated approach of transcriptome, haplotype frequency, and association analyses was used to identify candidate genes for the QTL in phenotypically extreme individuals selected from the same segregating F2 population as that used in the initial QTL analysis.

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Testosterone (T) is known to induce aggressive behavior, particularly in male animals. However, our recent results showed that a certain kind of aggressive behavior is T-independent; moreover, the role of T in chicken territorial and isolation-induced aggressive behavior has not yet been investigated. In addition, castration alone is insufficient to evaluate the role of T in aggressive behavior because we found that non-testicular T concentration, probably derived from the adrenal gland, in the blood of castrated chicks was low, but not zero.

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Testosterone (T) is known to induce aggressive behavior, mainly in male animals. Subcutaneous implantation of T-filled silastic tubes, rather than intramuscular injection of T, is generally recommended for long-term treatment using exogenous T. However, the effect of T implantation on chicken aggressive behavior has not been investigated.

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Traditional morphology-based taxonomy of dictyostelids is rejected by molecular phylogeny. A new classification is presented based on monophyletic entities with consistent and strong molecular phylogenetic support and that are, as far as possible, morphologically recognizable. All newly named clades are diagnosed with small subunit ribosomal RNA (18S rRNA) sequence signatures plus morphological synapomorphies where possible.

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Chicken agonistic behavior, a type of social behavior related to threatening and fighting, is among the most serious problems in the poultry industry. However, due to luck of effective models for investigating the brain mechanisms of the behavior, no effective measures have been taken. This study, therefore, aimed to select the behavioral tests available for monitoring chicken agonistic behavior.

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The aim of this study is to elucidate whether insulin acts differentially within the central nervous system (CNS) of two types of commercial chicks to control ingestive behavior. Male layer and broiler chicks (4-day-old) were intracerebroventricularly (ICV) injected with saline or insulin under satiated and starved conditions. Feed intake was measured at 30, 60 and 120 min after treatment.

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Feeding behavior is managed by various neuropeptides and/or neurotransmitters within the central nervous system in vertebrates. It is proposed that central insulin acts as the negative-feedback regulator of appetite via the central melanocortin system in neonatal chicks. The present study investigated the localization of insulin receptors in the chick hypothalamus using immunohistochemistry.

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Adipocytes derived from different anatomical sites vary in the expression of adipocytokines and growth factor genes. Adipogenesis is tightly associated with angiogenesis, although the regional variation of angiogenic growth factor gene expression in adipose tissues remains unclear. In this experiment, we studied the fat depot-specific differences (subcutaneous, intramuscular, intermuscular, renal, and mesenteric) in the expression of angiogenic growth factor mRNA [vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), fibroblast growth factor-10 (FGF-10), hepatocyte growth factor (HGF), and leptin], as well as the relationship between angiogenic growth factor mRNA level and adipocyte size in bovine adipose tissues.

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Polysphondylium multicystogenum, a new heterothallic species of dictyostelids, is described based on three isolates collected from soils in Sierra Leone, West Africa. This species is characterized by sorophores with a combination of clavate base and ovoid to oblong tip cell, smaller spores and abundant microcyst production under the usual culture conditions for sorocarp formation at 20 C. This is the first report of Polysphondylium producing such abundant microcysts.

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To reevaluate two dictyostelid species, namely, Polysphondylium pallidum and P. album, 92 isolates of the P. pallidum complex from their type localities were examined based on mating relationships and morphological characteristics.

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Two hundred and seventy-five accessions of cultivated Asian rice and 44 accessions of AA genome Oryza species were classified into 8 chloroplast (cp) genome types (A-H) based on insertion-deletion events at 3 regions (8K, 57K, and 76K) of the cp genome. The ancestral cp genome type was determined according to the frequency of occurrence in Oryza species and the likely evolution of the variable 57K region of the cp genome. When 2 nucleotide substitutions (AA or TT) were taken into account, these 8 cp types were subdivided into 11 cp types.

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1. Although microtubule-associated protein (MAP) 1B and its phosphorylation have been suggested to be important for synapse formation among cortical neurons, the localization of MAP1B in synapses has not yet been confirmed. In this report, we examine the localization of MAP1B in synaptic regions.

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