Genetic mapping of a dwarfing gene found inSolanum phureja clone 1.22     

Takafumi Kimura  Kazuyoshi Hosaka 《American Journal of Potato Research》2002,79(3):201-204

Dwarf plants were obtained in an F₂ population of a cross betweenSolanum chacoense (clone chc 525-3) andS. phureja (clone 1.22). Segregation analyses in F₂ and backcross populations suggested that the dwarfism was controlled by a single recessive gene transmitted fromS. phureja clone 1.22. The dwarf plants responded to treatment with gibberellic acid, which recovered normal growth. We named this gene‘ga ₂’. Linkage analysis of the genega ₂ with RFLP and RAPD markers indicated that the genega ₂ was located on the most or near distal end of chromosome 7.  相似文献   

Distribution of the 241 bp deletion of chloroplast DNA in wild potato species     

Kazuyoshi Hosaka 《American Journal of Potato Research》2002,79(2):119-123

The common potato (Solanum tuberosum L. ssp.tuberosum) has T-type chloroplast DNA characterized by a 241 bp deletion. To explore the maternal ancestry of the common potato, a total of 566 accessions of 35 wild species, collected mostly from central Bolivia to northern Argentina, were determined for presence or absence of the deletion by a simple PCR assay using primers flanking the deleted region of chloroplast DNA. Sixteen out of 80 accessions ofS. tarijense, S. berthaultii, andS. neorossii showed a shorter PCR amplified fragment. Sequencing of these fragments revealed that the same 241 bp was deleted at the same position in these accessions. This strongly suggests that the deletion event had occurred in wild species.  相似文献   

Species relationships between a wild tetraploid potato species,Solanum acaule bitter, and its related species as revealed by rflps of chloroplast and nuclear DNA     

Kumi Nakagawa  Kazuyoshi Hosaka 《American Journal of Potato Research》2002,79(2):85-98

Solanum acaule Bitter is a wild, disomic tetraploid potato species widely distributed in the South America. In this study, species relationships between eight accessions ofS. acaule and 108 accessions of 27 morphologically closely related species were investigated using chloroplast and nuclear DNA RFLPs. Chloroplast DNA types were determined for most of the accessions based on restriction digestion patterns of entire chloroplast DNA. C type chloroplast DNA was common inS. acaule andS. albicans (a hexaploid derivative fromS. acaule), which was also found inS. megistacrolobum, S. sanctae-rosae,S. raphanifolium, and several other Peruvian species in seriesTuberosa. Nuclear DNA was analyzed by Southern hybridization with 31 single-copy RFLP probes. One hundred and thirty-four bands were scored, from which a UPGMA dendrogram was constructed to show overall similarities among accessions.Solanum acaule andS. albicans (andS. demissum) formed a cluster with a high similarity, and then, this group was clustered withS. megistacrolobum andS. sanctae-rosae. The resulting cluster was well separated from other clusters. Thus, we suggest that an initial tetrasomic tetraploid arose from eitherS. megistacrolobum orS. sanctae-rosae. Interestingly, a Mexican hexaploid speciesS. demissum showed the closest similarity toS. acaule andS. albicans, suggesting that they shared a common ancestry.  相似文献   

Nosological study of Borna disease virus infection in race horses.     

Katsuro Hagiwara  Minoru Okamoto  Wataru Kamitani  Shiki Takamura  Hiroyuki Taniyama  Nobuo Tsunoda  Hidetoshi Tanaka  Hiroshi Iwai  Kazuyoshi Ikuta 《Veterinary microbiology》2002,84(4):367-374

To investigate the prevalence of diseases in the Borna disease virus (BDV) antibody positive race horses, we undertook seroepidemiological studies of BDV infection on 125 culled race horses in Hokkaido, Japan. The serological study disclosed the presence of antibodies only to BDV-p40 or -p24 in 19.2% (24/125) and 3.2% (4/125) of culled horses, respectively. Antibodies to both BDV-p40 and -p24 were found in 24.0% (30/125) of these horses. Of particular note was the finding that locomotorium disorders were detectable at a significantly higher rate in BDV antibody positive horses than that in the seronegative horses. These results imply that BDV infection may possibly contribute to an increase in the incidence rate of locomotorium disorders in race horses.  相似文献   

Concentrations of ketone body and antidiuretic hormone in cerebrospinal fluid in response to the intra‐ruminal administration of butyrate in suckling calves     

Tsunenori IRIKI  Kazuyoshi TAMURA  Mana ISHII  Hiroyuki TANAKA  Tsuyoshi MIYAMOTO  Ken ONDA 《Animal Science Journal》2009,80(6):655-661

The aim of the present study was to elucidate the mechanism by which ketone bodies increase antidiuretic hormone (ADH) secretion. Four male Holstein calves (5 weeks of age) were utilized. Four levels of butyrate (0 g, 11 g, 22 g and 44 g) were administrated intra‐ruminally in a 4 × 4 Latin square design and cerebrospinal fluid (CSF, six‐position lumbar puncture), blood plasma and urine were collected. The concentration of total plasma and CSF protein was 5.5–5.6 g/dL and 27.5–28.3 mg/dL, respectively. CSF concentrations of a specific ketone body, 3‐hydroxybutyric acid, were significantly higher in the 22 g and 44 g butyrate groups than in the control group. CSF concentrations of ADH in the 11 g and 44 g butyrate groups were significantly higher than in the control group. Plasma concentration of 3‐hydroxybutyric acid was increased by intraruminal administration of butyrate within 15 min in a dose‐dependent manner, and it was higher in the 22 g and 44 g butyrate group than in the control group from 15 min to 4 h. With the exception of the 11 g butyrate group, plasma concentrations of ADH also increased in response to butyrate treatment, and it was higher in the 44 g butyrate group than in the 22 g butyrate group from 15 min to 1.5 h. The duration of the elevated plasma concentrations of ADH was shorter than that of the plasma concentration of 3‐hydroxybutyric acid. The relationship between the plasma concentrations of ADH and 3‐hydroxybutyric acid was statistically significant but the correlation between the two concentrations was not high. Butyrate treatment elevated the plasma concentration of ADH and also resulted in reduced urine volume and increased urine osmolality. Haematocrit (Ht) values, and the osmolality of CSF and plasma were not different among the groups. Our results suggested that the increased ADH secretion observed in suckling calves fed dry feeds was caused by butyrate‐derived ketone body that crossed the blood‐brain barrier rapidly.  相似文献   

Migration and spawning behavior of the greater amberjack Seriola dumerili in eastern Taiwan     

Kazuki Tone  Yosuke Nakamura  Wei-Chuan Chiang  Hsin-Ming Yeh  Sheng-Tai Hsiao  Chun-Huei Li  Kazuyoshi Komeyama  Masanori Tomisaki  Takamasa Hasegawa  Takashi Sakamoto  Itsumi Nakamura  Yoshitaka Sakakura  Ryo Kawabe 《Fisheries Oceanography》2022,31(1):1-18

Greater amberjack (Seriola dumerili) is an important fishery resource with a circumglobal distribution from tropical to temperate waters. Here, we investigated the spawning migration and habitat utilization of S. dumerili in the East China Sea (ECS). Archival tags were attached to 22 adult fish to examine their horizontal and vertical movements and estimate the spawning ground. S. dumerili were captured and released in the coastal waters of eastern Taiwan on November of 2016 and 2017. Information from seven pop-up satellite archival tags and seven depth–temperature recorders was recovered. Almost all of the fish stayed in the Taiwanese exclusive economic zone. Most individuals moved from released site to the southern edge of the ECS and showed behavior associated with the topographic features in winter (November to December). These phenomena may be related to foraging and be driven by oceanographic features such as the seasonal monsoon and the Kuroshio. The fish then migrated to the south offshore area of Taiwan in January and February. During their southward migration, the fish experienced a slowly elevated water temperature regime (SETR), which is one of the environmental factors that induce final oocyte maturation. In the spawning season (February to April), tagged females exhibited continuous diel vertical movements (DVMs) after experiencing the SETR. These continuous DVMs were observed over a wide geographic range from north to south in the Kuroshio off eastern Taiwan. Our study demonstrated that the putative spawning ground of S. dumerili must extend further in a north–south direction than predicted in a previous study.  相似文献   

Use of acceleration loggers in aquaculture to determine net-cage use and field metabolic rates in red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis>     

Tohya Yasuda  Kazuyoshi Komeyama  Keitaro Kato  Yasushi Mitsunaga 《Fisheries Science》2012,78(2):229-235

We investigated the usefulness of acceleration loggers in aquaculture by examining net-cage use and metabolic rates in red sea bream, Pagrus major. First, the fish’s metabolic rate (mg O₂ kg⁻¹ min⁻¹) was measured with the logger in a swim tunnel at designated water velocities. We found that metabolic rate could be expressed by using a linear regression model of the activity rate index (unitless min⁻¹) derived from acceleration data. Using this equation, the field metabolic rates of three fish in a net cage were monitored and were estimated at 14.1–15.0 kcal kg⁻¹ day⁻¹. The results suggested that 15–19% of energy from satiation feeding ration was consumed for metabolism and activity in the net cage. The loggers showed orderly net-cage use by the fish. Tagged individuals used the whole cage from surface to bottom, but individual fish that preferred the surface area rarely used the bottom, and vice versa. Metabolic rate increased significantly with distance of the fish from their preferred depths. The logger provided information on the physiological and behavioral responses of fish in a given breeding system, and its use should contribute to the design of practical aquaculture systems.  相似文献