Granulosa cell tumor in 8 African pygmy hedgehogs (Atelerix albiventris)

A retrospective study involving eight African pygmy hedgehogs histopathologically diagnosed with granulosa cell tumors was conducted. The age at onset was 2.2–4.5 years, with a median age of 3.6 years. The most common clinical signs were hematuria and abdominal distension, which were observed in >50% cases. Exploratory laparotomy was performed in all cases, and ovariohysterectomy or excision of the abdominal mass was performed. Patients with only hematuria survived for >250 days after surgery, whereas those with initial ascites showed recurrence of ascites or tumor growth and survived for approximately 130 days after surgery. Intraperitoneal injection of carboplatin was performed in three recurrent cases. In one of these three cases, the tumor mass disappeared. Hence, carboplatin can be considered a potential antineoplastic drug for the treatment of granulosa cell tumors.     

Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2‐11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low‐marbled and high‐marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2‐11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker‐assisted selection to increase the levels of marbling in Japanese Black beef cattle.     

Morphological and genetic analysis of Vietnamese Sus scrofa bones for evidence of pig domestication

In the present study, we used morphological and genetic analyzes to distinguish bones of domestic boars from those of wild boars. We analyzed 65 Sus bones (cranium, mandible and teeth) stored in three research institutes in Vietnam and in a village in Vietnam. Based on comparison of bucco‐lingual measurements of mandibular parts, the 58 specimens were morphologically classified into two size groups: a large bone group and a small bone group. Analysis of 572‐bp mitochondrial DNA (mtDNA) sequences indicated that the large bones had genetic links to wild boar lineage including Ryukyu, Taiwan and Korean wild boars, and that the small bone group was closely related to East Asian domestic pigs. The phylogenetic analysis and parsimonious networks constructed among mtDNA haplotypes belonging to Ryukyu wild boar lineage showed that the Ryukyu wild boar is closely related to the Vietnamese wild boars, and uniquely miniaturized on their islands after the Ryukyu archipelago became isolated from the Asian continent.     

Ammonia-assimilating microbes in microbial community in a lagoon for wastewater from paddock of dairy cattle

In the present article the distribution and abundance of ammonia‐assimilating microbes among the natural habitants in a lagoon were investigated. In the medium containing lagoon‐extract, about 20% of total 82 isolates showed ammonia‐assimilating ability. By sequencing of 16S ribosomal DNA (rDNA), the highest ammonia‐assimilating isolates at 10°C and 37°C were identified as Janthinobacterium lividum and Bacillus sp., respectively. The structure of the microbial community was analyzed by polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE). Almost of the dominant species that were detected by PCR‐DGGE did not coincide with isolates, which showed the high ammonia‐assimilating ability, but one specie by PCR‐DGGE coincided with ammonia‐assimilating isolate. These results suggested that ammonia‐assimilating microbes existed as non‐dominant species in the microbial community in a lagoon.     

Establishment of a BRAF V595E-mutant canine prostate cancer cell line and the antitumor effects of MEK inhibitors against canine prostate cancer

Canine prostate cancer (cPCa) is a malignant neoplasm with no effective therapy. The BRAF V595E mutation, corresponding to the human BRAF V600E mutation, is found frequently in cPCa. Activating BRAF mutations are recognized as oncogenic drivers, and blockade of MAPK/ERK phosphorylation may be an effective therapeutic target against BRAF-mutated tumours. The aim of this study was to establish a novel cPCa cell line and to clarify the antitumor effects of MEK inhibitors on cPCa in vitro and in vivo. We established the novel CHP-2 cPCa cell line that was derived from the prostatic tissue of a cPCa patient. Sequencing of the canine BRAF gene in two cPCa cell lines revealed the presence of the BRAF V595E mutation. MEK inhibitors (trametinib, cobimetinib and mirdametinib) strongly suppressed cell proliferation in vitro, and trametinib showed the highest efficacy against cPCa cells with minimal cytotoxicity to non-cancer COPK cells. Furthermore, we orally administered 0.3 or 1.0 mg/kg trametinib to CHP-2 xenografted mice and examined its antitumor effects in vivo. Trametinib reduced tumour volume, decreased phosphorylated ERK levels, and lowered Ki-67 expression in xenografts in a dose-dependent manner. Although no clear adverse events were observed with administration, trametinib-treated xenografts showed osteogenesis that was independent of dosage. Our results indicate that trametinib induces cell cycle arrest by inhibiting ERK activation, resulting in cPCa tumour regression in a dose-dependent manner. MEK inhibitors, in addition to BRAF inhibitors, may be a targeted agent option for cPCa with the BRAF V595E mutation.