Identification of a quantitative trait locus (QTL) related to a chronic respiratory disease such as Mycoplasmal pneumonia of swine (MPS) and immune-related traits is important for the genetic improvement of disease resistance in pigs. The objective of this study was to detect a novel QTL for a total of 22 production, respiratory disease, and immune-related traits in Landrace pigs. A total of 874 Landrace purebred pigs, which were selected based on MPS resistance, were genotyped using the Illumina PorcineSNP60 BeadChip. We performed single nucleotide polymorphism (SNP)-based and haplotype-based genome-wide association studies (GWAS) to detect a novel QTL and to evaluate the possibility of a pleiotropic QTL for these traits. SNP-based GWAS detected a total of six significant regions in backfat thickness, ratio of granular leucocytes to lymphatic cells, plasma concentration of cortisol at different ages, and complement alternative pathway activity in serum. The significant region detected by haplotype-based GWAS was overlapped across the region detected by SNP-based GWAS. Most of these detected QTL regions were novel regions with some candidate genes located in them. With regard to a pleiotropic QTL among traits, only three of these detected QTL regions overlapped among traits, and many detected regions independently affected the traits.

The widely used porcine artificial insemination procedure involves the use of liquid‐stored semen because it is difficult to control the quality of frozen–thawed porcine sperm. Therefore, there is a high demand for porcine semen. The control and enhancement of sperm function are required for the efficient reproduction of pigs. We previously reported that gamma‐aminobutyric acid (GABA) enhanced sperm capacitation and acrosome reaction in mice. In this study, we demonstrated the presence of GABA A receptors in porcine sperm acrosome. Furthermore, we investigated the GABA effects on porcine sperm function. We did not detect any marked effect of GABA on sperm motility and tyrosine phosphorylation of sperm proteins. However, GABA promoted acrosome reaction, which was suppressed by a selective GABA A receptor antagonist. GABA binds to GABA A receptors, resulting in chloride ion influx. We found that treatment with 1 μM GABA increased the intracellular concentration of chloride ion in the sperm. In addition, the GABA concentration effective in the acrosome reaction was correlated with the porcine sperm concentration. These results indicate that GABA and its receptors can act as modulators of acrosome reaction. This study is the first to report the effects of GABA on porcine sperm function.

Pleomorphic B cell lymphoma was detected in a small number of lymph nodes in an 8-year-old Holstein cow with persistent lymphocytosis associated with bovine leukemia virus (BLV). Necropsy showed enlargement of the left superficial inguinal and right deep inguinal lymph nodes. Large numbers of BLV copies were detected by real-time polymerase chain reaction analysis in the enlarged nodes, whereas little BLV was found in normal-sized lymph nodes. Histologically, the enlarged lymph nodes were occupied by diffusely growing pleomorphic cells. In a few other lymph nodes, in contrast, extensive areas of neoplastic mantle cells showing a transition to more malignant pleomorphic cells were observed. These virological and histological findings indicate that large numbers of viral copies may be closely related to transformation from neoplastic mantle cells to pleomorphic lymphoma cells. The current study supports the view that nodal pleomorphic B cell lymphoma is of mantle cell origin.

Although sperm head-to-head agglutination has been reported in many mammalian species, the biological significance of this unique sperm–sperm interaction remains largely unknown. Here, we aimed to examine the functional characteristics of agglutinated bovine sperm to determine the possible role of sperm agglutination in the fertilization process. We initially examined temporal changes to the degree of head-to-head agglutination in culture, and found that bovine sperm agglutinated despite the lack of sperm agglutination inducers in medium. Sperm viability and motility were evaluated by SYBR14/PI and JC-1 staining, respectively, to identify the relationship between sperm agglutination and fertilizing ability. Agglutinated sperm had increased motility, viability, and intact mitochondrial function compared with unagglutinated sperm. Furthermore, we found that heparin significantly increased the percentage of unagglutinated sperm, but did not affect viability of both agglutinated and unagglutinated sperm, suggesting that sperm agglutination dictated the viability. In conclusion, agglutinated bovine sperm maintained viability and motility for a longer time than unagglutinated sperm. Thus, we propose that the head-to-head agglutination is a crucial sperm–sperm interaction to ensure the fertilizing ability of sperm.

An outbreak of Akabane virus (AKAV) was observed in the Tohoku area, including Miyagi prefecture, in 2010. Sixty anomaly calves infected with AKAV were provided for pathological examination and for detection of the viral gene from their central nervous systems. Non-suppurative encephalomyelitis and spinal curvature were observed in 14 of 15 calves between September and October 2010. Serious muscular atrophy was found in 22 calves between November and December 2010. Hydranencephaly was observed in 10 of 12 calves between February and April 2011. A slight presence of AKAV antigens was detected in a glial cell in the cervical spinal cord of a calf born in September 2010. The AKAV gene was detected in the midbrain, the medulla oblongata, and in several parts of the spinal cords of calves born in or before December 2010, but was not detected in calves born from February 2011. AKAV was not isolated from calves born in any period. The present study showed that RThnested PCR analysis of the midbrain, medulla oblongata, and spinal cord could detect the viral gene for long periods, and is imperative in diagnosing the disease.