Development of CAPS markers and their application in breeding for mango, Mangifera indica L.

To develop cleaved amplified polymorphic sequence (CAPS) markers for the identification of true hybrids in F1 progeny, we cloned sucrose synthase (SS) and sucrose phosphate synthase (SPS) genes from 19 mango cultivars. Through comparison of amino acid sequences in a BLASTX search, cloned SS and SPS genes were found to be homologs of Citrus unshiu CitSUS1 (AB022092) and CitSPS1 (O22060), respectively. Therefore, we designated the SS and SPS genes as MiSUS1 and MiSPS1, respectively. There were 11 genotypes in MiSUS1 and 10 in MiSPS1 sequences. In the MiSUS1 nucleotide sequences, 46 SNPs and 5 in/dels were detected. Twenty-six out of the 46 SNPs mapped on the restriction enzyme recognition sites were successfully converted to 25 CAPS markers. In the MiSPS1 nucleotide sequences, 99 SNPs and 6 in/dels were detected. Thirty out of 99 SNPs and 2 out of 6 in/dels mapped on the recognition sites were also converted to 32 CAPS markers. By using two CAPS markers, SS-2798 and SPS-5745, we identified 37 true hybrids that had different genotypes to ‘Irwin’ from 82 F1 progeny obtained through a cross between ‘Irwin’, the maternal parent, and paternal parents by using flies as pollinators. The method developed here to identify true hybrids is a simple, rapid and highly reliable tool for efficient mango breeding.     

Larval molting and growth of the Japanese spiny lobster Panulirus japonicus under laboratory conditions

ABSTRACT:   Ten newly hatched phyllosoma of Panulirus japonicus were cultured individually to monitor body length ( BL ) and intermolt period, and 2000 were cultured in groups to sample specimens for measurement of body weight. Phyllosoma were fed with Artemia and mussel gonad; the culture seawater temperature was 24–26°C. The individually cultured phyllosoma showed an increment in body length by the first molt of approximately 0.5 mm, and the molt increment increased to approximately 1 mm at 5 mm BL ; it was constant to 15 mm BL . Thereafter, the molt increment increased exponentially. The duration of the first instar was 6–7 days. Instar duration increased with development up to approximately 2 weeks at the 20th instar (∼16 mm BL ) and then became constant. Of the 10 larvae reared individually, five metamorphosed to the puerulus stage. The entire phyllosoma life ranged from 245–326 days (mean 289.0 days), and the number of instars ranged from 22–29 (mean 26.2). Body length in the final instar ranged from 28.50–33.10 mm (mean 30.280 mm). For the phyllosoma cultured in groups, relationships between BL and wet/dry body weights ( WW / DW , mg) were expressed as exponential equations: WW  = 0.0686 BL ^2.2023 and DW  = 0.0209 BL ^2.1905.     

An econometric estimation of Japanese shrimp supply and demand during the 1990s

Abstract

A simultaneous‐equation model of the supply and demand of shrimp in Japan is constructed, and sensitivity analyses are conducted to measure the effects of changing exchange rates and the stock holdings of shrimp. Using monthly statistics from January 1990 to December 1997, the Japanese own‐price elasticity of supply is found to be inelastic and has a less important effect than the beginning stocks factor. The Japanese demand for shrimp is also found to be price‐and income‐inelastic. The beginning of stock holdings is more sensitive to Japanese shrimp demand than the import price and income. The result of seasonality analyses shows that Japanese shrimp demand also depends on cultural factors.     

Connective tissue-type mast cell leukemia in a dog

An unusual case diagnosed as connective tissue-type mast cell leukemia with marked mastocyte infiltration into visceral organs in a seven-year-old female Curly-Coated retriever is presented. Acute circulatory collapse, emesis, diarrhea, abdominal enlargement, icterus, cyanosis, dyspnea, pulmonary edema, hepatomegary, ascites, and right ventricular enlargement were observed. Hematologic and biochemical examinations revealed mast cell leukemia, mature neutrophilia, monocytosis, thrombocytopenia, hemolytic hyperbilirubinemia, hyperhistaminemia, renal and hepatic injuries. Mast cells were distributed systemically, but predominantly in the diaphragm and liver with a large mass among the serosa of ileum, cecum and colon. Mast cells were stained intensely by both safranin and berberine sulfate.     

Expression of monocarboxylate transporter 1 (MCT1) in the dog intestine

In this study, the expression and distribution of monocarboxyolate transporter 1 (MCT1) along the intestines (duodenum, jejunum, ileum, cecum, colon and rectum) of dogs were investigated at both the mRNA and protein levels. The expression of MCT1 protein and its distribution were confirmed by Western blotting and immunohistochemical staining using the antibody for MCT1. We identified mRNA coding for MCT1 and a 43-kDa band of MCT1 protein in all regions from the duodenum to the rectum. Immunoreactive staining for MCT1 was also observed in epithelial cells throughout the intestines. MCT1 immunoreactivity was greater in the large intestine than in the small intestine. MCT1 protein was predominantly expressed on the basolateral membranes along intestinal epithelial cells, suggesting that MCT1 may play an important role in lactate efflux and transport of short-chain fatty acids (SCFAs) to the bloodstream across the basolateral membranes of the dog intestine.     

Irradiation history of Itokawa regolith material deduced from noble gases in the Hayabusa samples

Noble gas isotopes were measured in three rocky grains from asteroid Itokawa to elucidate a history of irradiation from cosmic rays and solar wind on its surface. Large amounts of solar helium (He), neon (Ne), and argon (Ar) trapped in various depths in the grains were observed, which can be explained by multiple implantations of solar wind particles into the grains, combined with preferential He loss caused by frictional wear of space-weathered rims on the grains. Short residence time of less than 8 million years was implied for the grains by an estimate on cosmic-ray-produced (21)Ne. Our results suggest that Itokawa is continuously losing its surface materials into space at a rate of tens of centimeters per million years. The lifetime of Itokawa should be much shorter than the age of our solar system.     

Peroxide Concentrations in Fog Water at Mountainous Sites in Japan

Measurements of peroxide concentrations in fog water were conducted near the summit of Mt. Norikura (altitude, 2770m) in central Japan, and at the midslope of Mt. Oyama (altitude, 680m), southwest of the Kanto Plain. The concentrations of peroxide at Mt. Norikura, far from industrial regions, ranged from 3 to 120 µ M during the summer and early autumn in 1993. The potential capacity for SO₂ oxidation appears to be very high near the summit of Mt. Norikura. Analysis of the chemical composition of three-stage size-fractionated fog water samples collected at Mt. Norikura showed that the concentrations of peroxide were apparently independent of droplet size, whereas the concentrations of chemical constituents mainly derived from secondary aerosols and the acidity were higher in smaller droplets. Peroxide concentrations in fog water were low (< 5 µ M) at Mt. Oyama, located near heavy industrial areas, and lower than those in rain water sampled simultaneously (0.2–33 µ M). Especially, peroxide was scarcely detected in strongly acidic fogs (< 0.2 µ M). Peroxide might have been decomposed by SO₂ (S(IV)) oxidation in the aqueous-phase.     

A Case Study on Estimation of Dry Deposition of Sulfur and Nitrogen Compounds by Inferential Method

In order to estimate dry deposition, deposition velocity calculation and concentration measurement were carried out in Niigata, Japan. Deposition velocities of SO₂ and HNO₃ for some surfaces such as coniferous forest, deciduous forest, agricultural land, and water were calculated taking into account diurnal variations of meteorological elements using routine meteorological data. Deposition velocities of fine and coarse aerosols were also estimated respectively. Concentrations of SO₂, HNO₃, sulfate and nitrate in fine and coarse aerosols respectively were measured from July to December in 1998 using filter pack and denuder methods. The results indicate that HNO₃ dry deposition for the high aerodynamic roughness surfaces such as forests is quite large. It is suggested that sulfate and nitrate aerosols depositions as well as the gases depositions should be taken into account to estimate dry deposition of sulfur and nitrogen compounds. It is also indicated that dry depositions of sulfur and nitrogen compounds are unable to ignore compared with their wet depositions.     

Glucocorticoid sensitivity depends on expression levels of glucocorticoid receptors in canine neoplastic mast cells

Glucocorticoid (GC) administration with or without other chemotherapeutic reagents is a commonly used option in the treatment of mast cell malignancies. However, the responsiveness of mast cell tumors to GC treatment varies in individuals, and the regulatory mechanisms determining the GC sensitivity of malignant mast cells remain unclear. Since the expression of the GC receptor (GR) has been reported to be associated with GC sensitivity in human neoplastic lymphocytes, we attempted to investigate the relationship between GR levels and GC sensitivity by using neoplastic mast cells derived from canine mast cell tumors (MCTs). To elucidate the regulatory mechanisms involved in GC responsiveness, we analyzed various canine MCT cell lines and tissue samples from dogs with MCT. While the proliferation of canine MCT cells was suppressed by the addition of GC to the culture, we found that MCT cells derived from humans and rodents, as well as canine lymphoma cells, responded poorly to GC. However, there were also some variations in responsiveness to GC treatment among canine MCT cell lines used in this study. Using real-time polymerase chain reaction and Western blot analysis, we elucidated the relationship between GR expression and responsiveness to GC in canine MCT cells. Furthermore, to assess the involvement of GR expression in GC sensitivity in vivo, clinical investigations were conducted on dogs with cutaneous MCT. Written informed consent was obtained from owners, and the affected dogs were treated with prednisolone (0.5-2.0 mg kg(-1)day(-1), administered orally) 1 or 2 weeks prior to the surgical removal of the tumors. Tumor volume was measured according to WHO criteria both before and after prednisolone treatment, and the GC sensitivity of each MCT was determined on the basis of the reduction in tumor volume. Of the 15 dogs with MCT, 11 responded to treatment with prednisolone completely or partially, whereas 4 dogs showed no response. Examination of clinical samples obtained by surgical removal revealed that GR expression levels were significantly lower in GC-resistant MCT tissues than in GC-sensitive MCT tissues. Thus, these results strongly indicate that GR expression may contribute to GC sensitivity in canine MCT.