Comparison of DNA extraction methods for genotyping equine histidine-rich glycoprotein insertion/deletion polymorphisms using oral mucosa swabs and feces.

Previously, we demonstrated unique insertion/deletion polymorphisms of equine histidine-rich glycoprotein with five genotypes composed of 45-bp or 90-bp deletions in the histidine-rich region of in Thoroughbred horses. Although leukocytes are typically used to collect DNA for genotyping, blood sampling from animals is sometimes difficult and invasive. Moreover, the method for extracting DNA from blood leukocytes involves complicated steps and must be performed soon after blood sampling for sensitive gene analysis.

Unique insertion/deletion polymorphisms within histidine-rich region of histidine-rich glycoprotein in Thoroughbred horses.

Histidine-rich glycoprotein (HRG) is abundant plasma protein with various effects on angiogenesis, coagulation, and immune responses. Previously, we identified the base and amino acid sequences of equine HRG (eHRG) and revealed that eHRG regulates neutrophil functions. In this study, we first conducted a large-scale gene analysis with DNA samples extracted from 1700 Thoroughbred horses and identified unique insertion/deletion polymorphisms in the histidine-rich region (HRR) of eHRG.

Period of excretion of equine herpesvirus 3 (EHV-3) from a stallion before showing clinical signs of equine coital exanthema and the effect of acyclovir treatment on the duration of EHV-3 excretion.

In 2017, two Thoroughbred stallions, A and B in Farms A and B, respectively, in Hokkaido in Japan showed clinical signs of equine coital exanthema (ECE). In 2020, stallion C in Farm B showed clinical signs of ECE. Eighteen mares were mated within five days before stallion A developed ECE.

Isolation of an Equine Foamy Virus and Sero-Epidemiology of the Viral Infection in Horses in Japan.

An equine foamy virus (EFV) was isolated for the first time in Japan from peripheral blood mononuclear cells of a broodmare that showed wobbler syndrome after surgery for intestinal volvulus and the isolate was designated as EFVeca_LM. Complete nucleotide sequences of EFVeca_LM were determined. Nucleotide sequence analysis of the long terminal repeat (LTR) region, and genes revealed that EFVeca_LM and the EFV reference strain had 97.

Evaluation of the chemiluminescent enzyme immunoassay system for the measurement of testosterone in the serum and whole blood of stallions.

Testosterone (T) concentration is a useful indicator of reproductive function in male animals. However, T concentration is not usually measured in veterinary clinics, partly due to the unavailability of reliable and rapid assays for animal samples. In this study, a rapid chemiluminescent enzyme immunoassay system (CLEIA system) that was developed for the measurement of T concentration in humans use was validated for stallion blood samples.

Isolation of equine herpesvirus 3 (EHV-3) from equine coital exanthema of two stallions and sero-epidemiology of EHV-3 infection in Japan.

In the spring of 2015, two stallions reared in Farms A and B in Hokkaido in Japan showed symptoms of equine coital exanthema. Equine herpesvirus 3 (EHV-3) was isolated from penis swab samples of both stallions, and the isolates from each stallion in Farms A and B were designated as SS-1 and YS-1 strains, respectively. BamHI restriction profiles of SS-1 and Japanese reference strain Iwate-1 were indistinguishable, but the BamHI-A fragment of YS-1 was larger than those of SS-1 and Iwate-1 by 1.

Occurrence of equine coital exanthema (ECE) in stallions in Japan and effectiveness of treatment with valacyclovir for ECE.

Equine coital exanthema (ECE) has been reported in many countries, but equine herpesvirus 3 (EHV-3) has been isolated only once in Japan. In 2015, symptoms of ECE were found, and EHV-3 was isolated in two stallions. Valacyclovir, an anti-herpesvirus agent, was administered orally.

PATHFAST, a novel chemiluminescent enzyme immunoassay for measuring estradiol in equine whole blood and serum.

A novel chemiluminescent enzyme immunoassay system, PATHFAST, for the measurement of estradiol in horses was evaluated. The concentrations of estradiol in the whole blood and serum of mares were measured using PATHFAST and the estradiol concentrations measured by PATHFAST were compared with those measured by a time-resolved fluoro-immunoassay (FIA). To monitor physiological changes, serum estradiol concentrations in mares were measured using PATHFAST throughout the gestation period.

Evidence for a PGF2α auto-amplification system in the endometrium in mares.

In mares, prostaglandin F2α (PGF2α) secreted from the endometrium is a major luteolysin. Some domestic animals have an auto-amplification system in which PGF2α can stimulate its own production. Here, we investigated whether this is also the case in mares.

Evaluation of the PATHFAST Chemiluminescent Enzyme Immunoassay for Measuring Progesterone in Whole Blood and Serum of Mares.

Evaluation of a new chemiluminescent enzyme immunoassay, the PATHFAST assay system (PATHFAST), for measurement of circulating progesterone in mares was performed. Five mares at the mid-luteal stage were administrated a single i.m.

Annual Changes in Day-length, Temperature, and Circulating Reproductive Hormones in Thoroughbred Stallions and Geldings.

Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor (IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings were studied. The correlations of day-length with changes in the concentrations of these hormones were also studied. Five stallions and thirteen geldings were employed to draw blood samples in monthly basis and radioimmunoassay was performed to measure these hormones.