番茄核雄性不育系大107果实硬度杂种优势及遗传效应的研究

以温敏型核雄性不育系大107为母本,以6个优良自交系(东圣3号、牛番茄、美丽莎、1439、12、A3)为父本进行杂交,配制成6个番茄杂交组合,分析果实硬度的杂种优势及遗传效应。结果表明:6个杂交组合中,果实硬度表现为负向杂种优势;果实硬度性状一般配合力与特殊配合力分别为58.56%和41.44%;广义遗传力和狭义遗传力分别为52.76%和50.31%;果实硬度的同亲相关系数为0.8479,达到显著水平;可作为生产优良果实硬度的杂种一代的亲本有大107、东圣3号、美丽莎、牛番茄;果实硬度以大107×牛番茄为最高。     

CRYSTALLIZATION OF SE POLYOMA VIRUS

Crystals have been obtained from purified preparations of SE polyoma virus. Specific infectivity measurements of the mother liquor, wash fractions, and the dissolved crystals indicate the viral nature of the crystals.     

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.     

Transmission of extended-spectrum cephalosporin-resistant Salmonella harboring a blaCMY-2-carrying IncA/C2 plasmid chromosomally integrated by ISEcp1 or IS26 in layer breeding chains in Japan

Dissemination of extended-spectrum cephalosporin (ESC)-resistant Salmonella is a public health concern in the egg production industry. ESC-resistant Salmonella often acquires the bla gene via insertion sequences (ISs). Therefore, this study aimed to assess antimicrobial resistance in Salmonella from Japanese layer breeding chains and egg processing chains, and determine the genetic profiles of IS-like elements in ESC-resistant Salmonella. Antimicrobial susceptibility testing was performed on 224 isolates from 49 facilities involving layer breeder farms, hatcheries, pullet-rearing farms, and layer farms in breeding chains along with egg processing chains. ESC-resistant Salmonella strains were whole-genome sequenced. Among them, 40 (17.9%) were resistant to at least streptomycin, tetracycline, ampicillin, chloramphenicol, cefpodoxime, nalidixic acid, ciprofloxacin, and/or kanamycin despite lacking resistance to azithromycin and meropenem. Moreover, 15 were ESC-resistant Salmonella harboring bla_CMY-2 (Salmonella enterica serovar Ohio, n=12; S. Braenderup, n=1; untypeable with O7:b:-, n=1) and bla_CTX-M-14 (S. Cerro, n=1). IncA/C₂ plasmids containing ISEcp1, IS26, and multiple antimicrobial resistance genes (including bla_CMY-2) were identified in S. Ohio isolates from pullet-rearing and layer farms belonging to the same company. Chromosomal integration of partial or whole IncA/C₂ plasmids was seen with two S. Ohio isolates via ISEcp1 or IS26, respectively. Antimicrobial resistance genes such as bla_CMY-2 might be transmitted among the upper and the lower levels of layer breeding chains via the replicon type IncA/C₂ plasmids containing ISEcp1 and IS26.     

Immunohistochemical detection of virus antigen in the nasal planum of rabid dogs

The rabies virus is one of the most neurotropic of all viruses infecting mammals. During the terminal phases of infection, the virus spreads to peripheral tissues, including the skin. The external skin of the nose, called the nasal planum, is a sensory organ where numerous nerve bundles and terminal nerves are distributed. Therefore, the nasal planum is expected to serve as a postmortem diagnostic material. However, the distribution of rabies virus antigens in the nasal planum in rabid animals has not yet been studied. In this study, the nasal planum was obtained from 45 rabid dogs. In all rabid dogs, the viral antigen was detected in the peripheral nerve tissues, Merkel cells, and squamous cells. The viral antigen in the epidermis exhibited three patterns: first, a diffuse positive pattern from the basal layer to the squamous layer; second, a reticular positive pattern along the cell membrane in the squamous layer; and third, a basal layer pattern of the epidermis. In the dermis, viral antigens were detected more often in lamellated corpuscles just beneath the rete pegs. These results suggest that the nasal planum could serve as a useful alternative source for postmortem diagnosis in rabies endemic countries.     

Detection of granzyme B in CD3-positive cells infiltrated in lesional skin of a dog with erythema multiforme associated with zonisamide

In human erythema multiforme (EM), cytotoxic T lymphocytes (CTLs) play an essential role in the pathogenesis. In canine EM, immunohistochemical staining with anti-CD8 antibody using frozen sections has shown the involvement of CTLs; however, CTL infiltration has never been quantitatively analyzed. We herein quantitatively analyzed CTL infiltration by immunohistochemical staining with granzyme B and CD3 antibodies using paraffin sections of a dog with EM associated with zonisamide. The present results indicated approximately 70% of cells at the border between the epidermis and dermis consisted of CTLs. Detection of granzyme B and CD3 using paraffin sections employed in this study can be a clinically applicable method for detecting CTLs.     

Prevalence of amyloid deposition in mature healthy chickens in the flock that previously had outbreaks of vaccine-associated amyloidosis

Avian amyloid A (AA) amyloidosis is commonly observed in adult birds with chronic inflammation, such as that caused by bacterial infection. We previously described vaccine-associated AA amyloidosis in juvenile chickens. In this study, the prevalence of amyloid deposition was measured in mature healthy chickens that survived a previous outbreak of avian AA amyloidosis while they were juveniles. Herein, we analyzed the amyloid deposition in mature chickens and compared the prevalence of amyloid deposition with juvenile chickens obtained in our previous study (Murakami et al., 2013). We found that: 1) amyloid deposition in the liver was absent in mature chickens, while juvenile chickens had a rate of 24%; 2) amyloid deposition in the spleen was observed in 36% of juvenile chickens and in 40% of mature chickens; 3) amyloid deposition in the pectoral muscle of mature chickens (43.75%) was approximately half that of juvenile chickens (88%). These results suggest that additional amyloid deposition in chickens previously exposed to AA amyloidosis may not worsen with age. Further, amyloid deposition in chickens may tend to regress when causative factors, such as vaccinations and/or chronic inflammation, are absent.     

Developmental capacity and implantation potential of the embryos with multinucleated blastomeres

The presence of multinucleated blastomeres (MNBs) in embryos is associated with poor developmental competence in assisted reproductive technologies. This phenomenon is observed not only in humans but also in other animal species. The purpose of the present study was to investigate the characteristics of embryos with MNBs (MNB embryos) that could be utilized in embryo transfer. The developmental rate of MNB embryos to the blastocyst stage (50.8%) was significantly lower than that of normal embryos (73.3%) (P < 0.05). The clinical pregnancy rates of fresh embryo transfer (ET) using day 2 or day 3 embryos were significantly lower in MNB embryos (5.1%) compared with normal embryos (24.0%) (P < 0.05). In the case of frozen-thawed ET using a single vitrified/warmed blastocyst, however, the clinical pregnancy rate of MNB embryos was close to that of normal embryos (59.1% vs. 52.8%). Thus, the findings of the present study suggest that the frozen-thawed ET of MNB embryos might improve the potential for implantation followed by successful pregnancy.