Polymerase chain reaction primers for highly selective detection of algicidal Proteobacteria     

Ryuji Kondo  Ichiro Imai 《Fisheries Science》2001,67(2):364-366

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Reproductive biology of the female Japanese mantis shrimp Oratosquilla oratoria (Stomatopoda) in relation to changes in the seasonal pattern of larval occurrence in Tokyo Bay, Japan     

Keita  KODAMA  Takamichi  SHIMIZU  Takashi  YAMAKAWA  Ichiro  AOKI 《Fisheries Science》2004,70(5):734-745

ABSTRACT:   The reproductive traits and the monthly larval abundance of the mantis shrimp Oratosquilla oratoria were investigated in Tokyo Bay, Japan, in 2002. The goal of the study was to elucidate the cause of changes in the monthly pattern of larval abundance from the 1980s to the 1990s as these changes relate to variation in the stock size of the adult shrimp. Oogenesis was divided into 10 stages by histological observation. The developmental stage of oocytes in an individual's ovary was synchronous, suggesting that almost all the oocytes in an ovary are spawned at the same time. The size at first maturity was estimated to be 7 ≤ body length ( BL ) < 8 cm. Fecundity was expressed as a function of BL , ranging from 19 300 eggs for 8 cm BL to 92 100 eggs for 14 cm BL . Small female shrimps (<10 cm BL ) spawned around August. Most large female shrimps (≥10 cm BL ) spawned around May, and some large female shrimps also spawned until September. Although most large female shrimps spawned in spring, the larval abundance was low before July and high from August onwards. The results suggest that a substantial decrease in the stock size of large individuals causes the low larval abundance before July.  相似文献   

Quantitative capillary reversed passive latex agglutination test for C-reactive protein (CRP) in the dog     

K. Tagata  S. Yokoyama  T. Ginbo  M. Honda  T. Okimura  M. Odakura  M. Nomura  S. Yamamoto 《Veterinary research communications》1996,20(1):21-30

A capillary reversed passive latex agglutination test (capillary RPLA) was developed which allows quantification of serum C-reactive protein (CRP) within approximately 15 min. The logarithmic regression line (calibration curve) obtained after measuring each CRP concentration three times in twofold dilutions of a standard canine serum containing 222 g/ml of CRP was y=6.394+0.030x (r=0.995). Capillary RPLA permitted quantification of CRP in the range 6.9–222 g/ml. The coefficients of variation ranged from 10.28% to 12.40%. The recovery rates (percentage recovery) of CRP by capillary RPLA were within the range 87% to 106%. On measuring the CRP concentrations in sera from 78 dogs by capillary RPLA, single radial immunodiffusion (SRID) and enzyme-linked immunosorbent assay (ELISA), close correlations were demonstrated between SRID and capillary RPLA (y=7.250+1.109x, r=0.978), between SRID and ELISA (y=3.042+1.059x, r=0.967), and between capillary RPLA and ELISA (y=1.778+0.929x, r=0.962). Capillary RPLA may be considered useful as a routine biochemical technique for measurement of serum CRP concentration in the dog.Abbreviations CRP C-reactive protein - ELISA enzyme-linked immunosorbent assay - RPLA reversed passive latex agglutination test - SRID single radial immunodiffusion  相似文献   

Monitoring of genetic diversity in the Japanese Black cattle population by the use of pedigree information     

T. Honda  T. Nomura  Y. Yamaguchi  F. Mukai 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2004,121(4):242-252

The gene pool of the Japanese Black cattle has been completely closed to foreign breeds during the last 100 years. Genetic diversity of the Japanese Black cattle from 1960 to 2000 was monitored with three estimates of effective number of ancestors. Founder genome equivalent (N_ge) accounts for all the causes of reduction of diversity. Effective number of founders (N_ef) and non‐founders (N_enf) explain reduced diversity because of unequal genetic contributions of founders and random genetic drift in non‐founders, respectively. Further examination using gene dropping simulation was conducted to obtain information on survival of founder alleles. Unique founder alleles were dropped down along the actual pedigree with Monte Carlo procedure following Mendelian segregation rules, and generated genotypes of all the current live animals (612 959 heads). Pedigree records consisted of 2 075 188 animals was used for these analysis. The estimates of three effective numbers (N_ef, N_ge, and N_enf) decreased from 418.6 to 50.3, 86.6 to 7.3, and 109.2 to 8.5, respectively, during the period 1960–2000. The increasing differences between two kinds of genetic diversity indices derived from N_ge and N_ef showed that large part of the reduced diversity from 1980 was attributed to genetic drift caused by the intensive use of particular limited number of sires. In gene dropping analysis, probabilities of extinction of founder alleles were derived from their distributions of frequency in the current animals. Several founders showed low probabilities of allele extinction, irrespective of their relatively low genetic contributions. This suggests that these founders have lineages through which their alleles are surely transmitted to the current breed. The use of these founders as a strategy for recovering the genetic diversity was discussed.  相似文献   

Effect of relationships among clinical mastitis incidence,reproductive performance,and culling rate on the lifetime of dairy cows at Hiroshima University Farm     

Yuzo Kurokawa  Miki Okita  Hirokazu Kubota  Yoshimasa Tsumiyama  Ichiro Chikamatsu  Akiyoshi Tanaka  Taketo Obitsu  Kensuke Kawamura 《Animal Science Journal》2021,92(1):e13591

Farm managers' decision to cull dairy cows is based on the cows' milk production, history of disorder(s), and reproductive performance, each of which affects dairy cows' lifetime (herd life and productive lifespan). We investigated the relationships among the incidence of clinical mastitis (CM), the reproductive performance, and the culling rate. We also assessed the effects of these relationships on the lifetimes of dairy cows, using the records made before and after the introduction of an automatic milking system (AMS) at Hiroshima University Farm. Milk yield, CM incidence density, and culling rate of dairy cows increased after the AMS introduction. The CM incidence was associated with an elongation of the calving interval in cows with the same parity. CM in the 1st parity might have caused the reductions of the cows' lifetime and their parity at culling. A higher age at first calving (AFC) was associated with an increase in culling rate but did not lead to a significant decrease in lifetime. Investigations of the factors mediating CM in the 1st parity or AFC with CM incidence or culling rate in the later stages might contribute to the control of lifetime of dairy cows.  相似文献   

Glucagon‐related peptides and the regulation of food intake in chickens          下载免费PDF全文

Kazuhisa Honda 《Animal Science Journal》2016,87(9):1090-1098

The regulatory mechanisms underlying food intake in chickens have been a focus of research in recent decades to improve production efficiency when raising chickens. Lines of evidence have revealed that a number of brain‐gut peptides function as a neurotransmitter or peripheral satiety hormone in the regulation of food intake both in mammals and chickens. Glucagon, a 29 amino acid peptide hormone, has long been known to play important roles in maintaining glucose homeostasis in mammals and birds. However, the glucagon gene encodes various peptides that are produced by tissue‐specific proglucagon processing: glucagon is produced in the pancreas, whereas oxyntomodulin (OXM), glucagon‐like peptide (GLP)‐1 and GLP‐2 are produced in the intestine and brain. Better understanding of the roles of these peptides in the regulation of energy homeostasis has led to various physiological roles being proposed in mammals. For example, GLP‐1 functions as an anorexigenic neurotransmitter in the brain and as a postprandial satiety hormone in the peripheral circulation. There is evidence that OXM and GLP‐2 also induce anorexia in mammals. Therefore, it is possible that the brain‐gut peptides OXM, GLP‐1 and GLP‐2 play physiological roles in the regulation of food intake in chickens. More recently, a novel GLP and its specific receptor were identified in the chicken brain. This review summarizes current knowledge about the role of glucagon‐related peptides in the regulation of food intake in chickens.  相似文献   

Effect of fungicide thiram on microbial communities of rice seed surface estimated by culture-dependent and culture-independent (PCR-RFLP) methods     

Guang-Hua Wang  Yasunori Nakajima  Ichiro Shaku  Makoto Kimura 《Soil Science and Plant Nutrition》2013,59(2):303-314

Coating of rice seeds with fungicide Thiram improved the seed germination capability over a long period of time (11 weeks) under low temperature conditions (4 and 8°C), which simulated the sowing of rice seeds in the winter season (the farmer's slack season). To analyze the effect of Thiram on the community structure of microorganisms on the rice seed surface, culture-dependent and culture-independent (PCR-RFLP) methods were applied. PCR-RFLP patterns of 16S rDNA showed that the bacterial communities on the rice seed surface were different between coated and uncoated treatments under 8°C conditions, but that they were very similar under 4°C conditions. PCR-RFLP patterns of 18S rDNA revealed the remarkable effect of Thiram on the fungal community structure under both 4 and 8°C conditions. Although the fungal communities were quite different between coated and uncoated seeds at the beginning of incubation, the fungal communities on the coated seed surface became similar to those of uncoated seeds along with the duration of the incubation period. As the dominance percentage of Fusarium spp. among the isolates increased with the duration of the incubation period for both coated and uncoated seeds, Fusarium was considered to be a responsible for the poor germination of rice seeds that were sown in the winter season.  相似文献   

Analysis of mesh breaking loads in cotton gill nets: Possible solution to ghost fishing     

Yoshiki Matsushita  Shusuke Machida  Haruyuki Kanehiro  Fumio Nakamura  Naoto Honda 《Fisheries Science》2008,74(2):230-235

ABSTRACT:   A small number of fishers in Chiba Prefecture of eastern Japan use cotton gill nets to catch Japanese spiny lobster Panulirus japonicus. To examine the advantages of cotton gill nets, we analyzed changes in mesh breaking load of a new cotton gill net used in a fishing operation. A new cotton gill net was also soaked in a seawater tank to simulate ghost fishing conditions. The average mesh breaking load of new cotton mesh was 50.3 N. This value decreased to 19.0 N after 38 days (∼912 h), and after 82 days (∼1968 h) the mesh could be easily torn (breaking load 0.07 N). Under fishing conditions, the cumulative soak time was only 744.4 h over 19 months. The average breaking load at the end of this period was 43.1 N, a strength 86% that of the presoaked mesh. The mesh breaking load of a cotton gill net continuously soaked for 744.4 h was 26.1 N, as estimated from tank experiment data. Thus, a cotton gill net maintains reasonable strength under typical use conditions, but will degrade if lost at sea.  相似文献   

Performance of Bangladesh indigenous rice in a weed infested field and separation of allelopathy from resource competition     

Sheikh Muhammad Masum  Mohammad Amzad Hossain  Hikaru Akamine  Jun‐Ichi Sakagami  Takahiro Ishii  Ichiro Nakamura  Md. Asaduzzaman  Prasanta Chitta Bhowmik 《Weed Biology and Management》2019,19(2):39-50

This study aimed to identify the potential allelopathic indigenous rice (Oryza sativa L. ssp. indica) varieties from Bangladesh using a performance study in a weed‐infested field and to assess the extent of allelopathic interference relative to resource competition in a glasshouse experiment. Six varieties – namely, “Boterswar,” “Goria,” “Biron” and “Kartiksail” as the most allelopathic, “Hashikolmi” as weakly allelopathic and “Holoi” as nonallelopathic – were raised following a nonweed control method. The infestation levels of weed species were calculated using Simpson's Diversity Index (SDI), which ranged from 0.2 to 0.56. However, a significant correlation coefficient (0.87, P < 0.001) was obtained from these field data compared with the root inhibition percentage from the laboratory bioassay, and the “Boterswar” variety was the most allelopathic. The interactions between the allelopathic variety “Boterswar,” weakly allelopathic variety “Hashikolmi” and Echinochloa oryzicola via a target (rice)‐adjacent (E. oryzicola) cogrowth culture were determined in a hydroponic arrangement. The relative competitive intensity (RCI) and the relative neighbor effect (RNE) values showed that the crop–weed interaction was facilitation for “Boterswar” and competition for “Hashikolmi” and E. oryzicola in rice/E. oryzicola cogrowth cultures. The allelopathic effects of “Boterswar” were much higher than the resource competition in rice/E. oryzicola cogrowth cultures. The converse was observed for “Hashikolmi.” Moreover, the mineral content of E. oryzicola was severely affected by “Boterswar”/E. oryzicola cogrowth cultures’ exudate solution. Therefore, the allelopathic potential of “Boterswar” variety might be useful for developing the weed‐suppressing capacity of rice, which will likely have a significant influence on paddy weed control.  相似文献   

Soil properties and the macrofauna community in abandoned irrigated rice fields of northeastern Argentina     

Patricia J. Folgarait  Fabien Thomas  Thierry Desjardins  Michel Grimaldi  Ichiro Tayasu  Pierre Curmi  Patrick M. Lavelle 《Biology and Fertility of Soils》2003,38(6):349-357

This study compared soil physical, chemical, and biological characteristics between natural grassland and recently abandoned rice fields in order to identify those variables that might explain the observed increase of Camponotus punctulatus anthills in abandoned rice paddy fields from Northern Argentina. Mainly due to a reduction of macropores and mesopores, overall porosity decreased by around 6% and bulk density was about 7% greater, in the 0- to 10- and 10- to 20-cm layers of the abandoned rice fields. Carbon and nitrogen content from organic matter increased (29% and 41% respectively for the 0- to 20-cm horizon) during cultivation but decreased (38% and 24%) 2 years after the last rice harvest. Forty percent of natural grassland-organic matter and 30% of abandoned rice-organic matter mineralized in less than 2 years. There was a different community structure between the abandoned rice fields and the undisturbed natural grassland and only a 20.6% (i.e. only 19 species from a total of 92) overlap in species composition. The abundance of macrofauna was greater in abandoned rice fields (2,208 individuals m^–2) in comparison to natural grasslands (288 ind m^–2) due to higher densities of small earthworms and Camponotus punctulatus ants; however, the Shannon index showed lower values in comparison to natural grasslands. Earthworms and C. punctulatus in the abandoned rice fields showed a change in their ¹³C signature indicating a switch in diet from natural grassland organic matter (C4) to organic matter from rice (C3). Our results indicate that the effects of rice cultivation practices did not seem to produce any physical or trophic limitations to recolonization by the macrofauna. It seems that changes in overall soil conditions have favored a change in the construction behavior of C. punctulatus which, in combination with population increases, could explain the explosion in number of anthills.  相似文献