Shuichi Tsuchida

The teleost Oryzias latipes shows telomere shortening with age despite considerable telomerase activity throughout life.

Previous studies of telomeres and telomerase have focused mostly on mammals, and data for other vertebrates are limited. We analyzed both telomere length (terminal restriction fragment length) and telomerase activity in a small freshwater teleost fish, the medaka (Oryzias latipes), and found that the telomeres shorten during ageing despite the fact that a considerable amount of telomerase activity is ubiquitously detectable throughout the life of the fish. Since the telomere attrition rate during development was greater than that in adulthood, telomere length is inversely correlated with the increase in body length. The difference in telomere length among medaka individuals was similar to that in humans, and the individual specific differences were evident even at the earliest embryonic stage. Telomerase activity was ubiquitously detectable not only in the body of the embryo but also in the systemic organs of mature individuals throughout their entire life span. These data suggest that telomere attrition during ageing in medaka, which is similar to that in humans, may be a major factor determining their mortality, and that telomere maintenance through strong telomerase activity may be required for the characteristic lifelong continuous growth of this fish.

Concentration of Radiocesium in the Wild Japanese Monkey (Macaca fuscata) over the First 15 Months after the Fukushima Daiichi Nuclear Disaster

Following the massive earthquake that struck eastern Japan on March 11, 2011, a nuclear reactor core meltdown occurred at the Fukushima Daiichi Nuclear Power Plant, operated by Tokyo Electric Power Company, and was followed by the release of large amounts of radioactive materials. The objective of this study was to measure the concentration of radiocesium 134Cs and 137Cs in the muscle of Japanese monkeys (Macaca fuscata) inhabiting the forest area of Fukushima City and to determine the change in concentration over time as well as the relationship with the level of soil contamination. Cesium concentrations in the muscle of monkeys captured at locations with 100,000–300,000 Bq/m2 were 6,000–25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000–3,000 Bq/kg in some animals during and after December 2011 before returning to 1,000 Bq/kg in April 2012, after which it remained relatively constant. This pattern of change in muscle radiocesium concentration was similar to that of the change in radiocesium concentration in atmospheric fallout. Moreover, the monkeys feed on winter buds and the cambium layer of tree bark potentially containing higher concentrations of radiocesium than that in the diet during the rest of the year. The muscle radiocesium concentration in the monkeys related significantly with the level of soil contamination at the capture locations.

Xanthine urolithiasis in a cat: A case report and evaluation of a candidate gene for xanthine dehydrogenase

Xanthine urolithiasis was found in a 4-year-old spayed female Himalayan cat with a 10-month history of intermittent haematuria and dysuria. Ultrasonographs indicated the existence of several calculi in the bladder that were undetectable by survey radiographic examination. Four bladder stones were removed by cystotomy. The stones were spherical brownish-yellow and their surface was smooth and glossy. Quantitative mineral analysis showed a representative urolith to be composed of more than 95% xanthine. Ultrasonographic examination of the bladder 4.5 months postoperatively indicated the recurrence of urolithiasis. Analysis of purine concentration in urine and blood showed that the cat excreted excessive amounts of xanthine. In order to test the hypothesis that xanthinuria was caused by a homozygote of the inherited mutant allele of a gene responsible for deficiency of enzyme activity in purine degradation pathway, the allele composition of xanthine dehydrogenase (XDH) gene (one of the candidate genes for hereditary xanthinuria) was evaluated. The cat with xanthinuria was a heterozygote of the polymorphism. A single nucleotide polymorphism analysis of the cat XDH gene strongly indicated that the XDH gene of the patient cat was composed of two kinds of alleles and ruled out the hypothesis that the cat inherited the same recessive XDH allele suggesting no activity from a single ancestor.

Identification of microphthalmia-associated transcription factor isoforms in dogs

Microphthalmia-associated transcription factor (MITF) belongs to the basic helix-loop-helix leucine zipper (bHLH-LZ) family of transcription factors, and plays an important role in the development and differentiation of melanocytes, mast cells, and osteoclasts. To investigate canine MITF isoforms, cDNA cloning with 5-rapid amplification of cDNA ends was performed. Three canine isoforms, the counterparts of human MITF-M, MITF-H, and MITF-A, were determined. Canine MITF-M, MITF-H, and MITF-A were highly homologous to the nucleotide sequences in isoform-specific 1M, 1H, and 1A with 100%, 98%, and 97% identity in humans, respectively. When scanning of the canine genome was performed to identify the homologous regions to human MITF isoforms, in addition to MITF-M, MITF-H, and MITF-A isoforms, the homologous sequences to all the other isoforms observed in humans existed in the canine genome sequence of chromosome 20. Comparison of the homologous sequences for MITF isoforms among dogs and humans suggested that MITF-D, MITF-E and MITF-J may be expressed in canine adult tissues in addition to canine MITF-M, MITF-H, and MITF-A. However, RT-PCR showed that canine MITF-E and MITF-J, but not canine MITF-D were expressed. Although the mRNAs encoding canine MITF-H and MITF-A were expressed widely, MITF-M, MITF-E and MITF-J were expressed in tissue-specific patterns. Two types of mRNAs with and without an 18-base insert were detected for five MITF isoforms in canine tissues. MITF-M distal enhancer (MDE) was also located upstream from canine exon 1M.

The genetic association study between polymorphisms in uncoupling protein 2 and uncoupling protein 3 and metabolic data in dogs

BackgroundThe uncoupling proteins (UCPs) in the mitochondrial inner membrane are members of the mitochondrial anion carrier protein family that play an important role in energy homeostasis. Genetic association studies have shown that human UCP2 and UCP3 variants (SNPs and indels) are associated with obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome. The aim of this study was to examine the genetic association between polymorphisms in UCP2 and UCP3 and metabolic data in dogs.ResultsWe identified 10 SNPs (9 intronic and 1 exonic) and 4 indels (intronic) in UCP2, and 13 SNPs (11 intronic and 2 exonic) and one indel (exonic) in UCP3, by DNA sequence analysis of 11 different dog breeds (nu2009=u2009119). An association study between these UCP2 and UCP3 variants and the biochemical parameters of glucose, total cholesterol, lactate dehydrogenase and triglyceride in Labrador Retrievers (nu2009=u200950) showed that none of the UCP2 polymorphisms were significantly associated with the levels of these parameters. However, four UCP3 SNPs (intron 1) were significantly associated with total cholesterol levels. In addition, the allele frequencies of two of the four SNPs associated with higher total cholesterol levels in a breed that is susceptible to hypercholesterolemia (Shetland Sheepdogs, nu2009=u200930), compared with the control breed (Shiba, nu2009=u200930).ConclusionThe results obtained from a limited number of individuals suggest that the UCP3 gene in dogs may be associated with total cholesterol levels. The examination of larger sample sizes and further analysis will lead to increased precision of these results.

Molecular Characterization of the Cytidine Monophosphate-N-Acetylneuraminic Acid Hydroxylase (CMAH) Gene Associated with the Feline AB Blood Group System

Cat’s AB blood group system (blood types A, B, and AB) is of major importance in feline transfusion medicine. Type A and type B antigens are Neu5Gc and Neu5Ac, respectively, and the enzyme CMAH participating in the synthesis of Neu5Gc from Neu5Ac is associated with this cat blood group system. Rare type AB erythrocytes express both Neu5Gc and Neu5Ac. Cat serum contains naturally occurring antibodies against antigens occurring in the other blood types. To understand the molecular genetic basis of this blood group system, we investigated the distribution of AB blood group antigens, CMAH gene structure, mutation, diplotypes, and haplotypes of the cat CMAH genes. Blood-typing revealed that 734 of the cats analyzed type A (95.1%), 38 cats were type B (4.9%), and none were type AB. A family of three Ragdoll cats including two type AB cats and one type A was also used in this study. CMAH sequence analyses showed that the CMAH protein was generated from two mRNA isoforms differing in exon 1. Analyses of the nucleotide sequences of the 16 exons including the coding region of CMAH examined in the 34 type B cats and in the family of type AB cats carried the CMAH variants, and revealed multiple novel diplotypes comprising several polymorphisms. Haplotype inference, which was focused on non-synonymous SNPs revealed that eight haplotypes carried one to four mutations in CMAH, and all cats with type B (n = 34) and AB (n = 2) blood carried two alleles derived from the mutated CMAH gene. These results suggested that double haploids selected from multiple recessive alleles in the cat CMAH loci were highly associated with the expression of the Neu5Ac on erythrocyte membrane in types B and AB of the feline AB blood group system.

Analysis of mitochondrial DNA HVR1 haplotype of pure-bred domestic dogs in Japan

To develop DNA markers for forensic analysis, we examined the hypervariable region 1 (HVR1) sequences of 447 pure-bred domestic dogs (Canis lupus familiaris) that had been bred and raised in Japan. HVR1 is a 660-bp stretch of mitochondrial (mt) DNA. Among the 447 HVR1 sequences examined, we identified 58 haplotypes from 47 single nucleotide polymorphisms (SNPs) and two insertion-deletion (InDel) polymorphisms. The haplotype diversity inferred from inter-breed analysis (N=154, 88 breeds) was 0.929±0.011. Intra-breed analysis showed that the haplotype diversity of Golden Retrievers (N=53), Labrador Retrievers (N=67), Miniature Dachshunds (N=61), Toy Poodles (N=62), and Welsh Corgis (N=50) was 0.624±0.052, 0.722±0.029, 0.922±0.010, 0.877±0.020, and 0.443±0.084, respectively. The results of this genotype analysis were used to construct a dataset consisting of dog mtDNA HVR1 sequences for use in forensic applications in Japan.

Removal of Multiple Free-Floating Iridociliary Cysts by Irrigation with Viscoelastic Material.

左眼の前房内に多数発生した浮遊性虹彩毛様体嚢腫によって視覚障害を示した雌, 8歳齢, 25.3.kgのラブラドール・レトリバーに対して, 眼内手術用の粘弾性物質を用いて前房内から浮遊性の虹彩毛様体嚢腫を押し出す方法によって摘出術を行ったところ, 針を付けた注射器で穿刺し一つ一つ吸引する方法よりもより簡便に嚢腫を摘出することができた。