Purified Culture Systems for Bovine Oviductal Stromal Cells

Isolated stromal cells from the ampullary and isthmic parts of bovine oviductal tissues were cultured in monolayer and spheroid (cell aggregate) systems. Prostaglandin F2α (PGF) plays a crucial role in oviductal contraction and is produced by oviductal epithelial cells in cattle. Since stromal cells of many organs produce PGF, PGF production by bovine oviductal stromal cells was investigated. After PGF synthesis was confirmed, the utility of isolation and culture methods for oviductal stromal cells was evaluated by PGF production in the present study. The homogeneity of the cells was > 99%. PGF production of the cells was increased by tumor necrosis factor-α. The stromal cells aggregated and formed a spheroid by the treatments with several reagents. PGF production was higher in the spheroid culture than in the monolayer culture. The isolation and culture methods described here will facilitate studies of the physiological function of bovine oviductal stromal cells.     

Oocyte development and serum profiles of vitellogenin and steroid hormone levels in captive female Pacific herring Clupea pallasii during their first maturational cycle

ABSTRACT:   The present study investigates the relationship between oocyte development and serum steroid hormone levels in captive Pacific herring, Clupea pallasii , during the first reproductive cycle. The process of oocyte development in Pacific herring belongs to the group-synchronous type. Maturity of the ovary was divided into six periods based on histological observation (i.e. immature (April to September), onset of vitellogenesis (August to October), progress of vitellogenesis (October to December), completion of vitellogenesis (December to March), maturation and spawning (March to April) and spent (late April)). The pattern of seasonal change in the gonadosomatic index (GSI) well reflected the ovarian maturity. Serum vitellogenin levels showed good correlation with change in GSI, which increased from September to a peak (4.2 ± 0.3 mg/mL) in March. Serum estradiol-17β (E2) levels elevated from September and reached a peak (15.8 ± 4.2 ng/mL) in December, and remained comparatively high until March, suggesting that the active vitellogenin synthesis during vitellogenesis is controlled by the high E2 level. 17,20β-Dihydroxy-4-pregnen-3-one showed a single sharp peak (2.4 ± 0.28 ng/mL) in early April of the second year, suggesting it was a maturation-inducing steroid in this species.     

The formation process of button ulcers in pigs experimentally infected with a subgenotype 2.1 isolate of classical swine fever virus

We evaluated the role of classical swine fever virus (CSFV) in the formation of button ulcers in the mucosa of the gastrointestinal tract. Histopathological and immunohistochemical analyses of pigs experimentally infected with a subgenotype 2.1 isolate of CSFV, which was isolated in Japan in 2019, revealed follicular necrosis in the submucosal mucosa-associated lymphoid tissue and herniation of crypts as factors that contribute to the development of button ulcers during CSFV infection. These findings indicate that CSFV induces follicular necrosis and is one of the causative agents of button ulcers in pigs.     

Distribution of recesses in the olfactory organ of African lungfish Protopterus aethiopicus

In the olfactory organ of lungfish, recesses at the bases of lamellae comprise sensory and nonsensory epithelia. The sensory epithelium of the recesses, the recess epithelium, is distinguished from the olfactory epithelium covering the lamella by the absence of ciliated olfactory receptor cells. Therefore, it has been suggested that the recess epithelium is a primordium of the vomeronasal organ of tetrapods. However, developmental changes in the number and distribution of recesses in the olfactory organ of lungfish were unknown. We examined four Protopterus aethiopicus specimens of body lengths 215–800 mm to determine the localization of recesses in their olfactory organs. Histological examination showed recesses at the bases of lamellae in all individuals examined. The recesses were localized mainly in the medial and caudal parts of the olfactory organs, especially in juveniles. Compared to smaller fish, larger fish had a larger number of recesses, distributed more broadly in their olfactory organs. Significance of the recess localization and its relationship to the function of lungfish olfactory organ warrants further investigation.     

Functional Analysis of Lysosomes During Mouse Preimplantation Embryo Development

Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.     

Reduction of urinary nitrogen excretion and ammonia emission from slurry by feeding a low protein diet supplemented with apple pomace to growing pigs

An experiment was conducted to determine the effects of supplementing a reduced crude protein (CP) diet with apple pomace on the urinary nitrogen excretion and ammonia emission from slurry in the growing pigs. Four barrows (35 kg bodyweight) were assigned to one of two diets. Each pig was placed in a metabolism cage and fed a low CP, amino acid-supplemented diet (CP 11.33%; low CP diet) or a low CP, amino acid-supplemented diet containing 23.08% dried apple pomace (CP 9.47%; apple pomace diet) for two 14-day experimental periods. After the completion of the first period, the pigs were switched to the other diet. Urine and feces were quantitatively collected daily for 5 days after a 9-day adaptation period. The daily nitrogen intake for the low CP diet and the apple pomace diet was 17.76 g/pig and 18.64 g/pig, respectively. The pigs fed the apple pomace diet excreted more fecal nitrogen (6.86 g/day) than the pigs fed the low CP diet (3.63 g/day) ( P  < 0.001), but urinary nitrogen excretion with the apple pomace diet was 3.11 g/day, which was much lower than that for the low CP diet (5.95 g/day) ( P  < 0.001). The daily ammonia emission from the mixture of urine and feces determined by an in vitro method was much lower for pigs fed the apple pomace diet (120 mg) than that for pigs fed the low CP diet (603 mg) ( P  < 0.01). The addition of apple pomace to a reduced CP, amino acid-supplemented diet reduces urinary nitrogen excretion and thereby ammonia emission.     

Relationship between adipose maturity and fatty acid composition in various adipose tissues of Japanese Black,Holstein and Crossbred (F1) steers

The amount of monounsaturated fatty acid (MUFA) is intimately related to adipose softness, melting point (MP) and flavor in beef. Stearoyl‐CoA desaturase (SCD) is a main gene involved in MUFA synthesis. Mature adipose tends to be highly saturated, whereas immature or maturing adipose is highly unsaturated when chronologically based, so the degree of non‐saturation can be an index of adipose maturity. In this study, three different adipose tissues (coelomic (CL), perirenal (PR), and subcutaneous (SC)) from three beef breeds with differing slaughter ages (Japanese Black (29.5 months), Holstein (20.1 month), and F1 crossbreed (25.6 months)) were examined to: (i) determine adipose maturity level as indexed by MUFA %; and (ii) determine SCD and other lipogenic gene messenger RNA (mRNA) expression levels in relation to unsaturated fatty acid content. Fatty acid composition was significantly different between adipose tissues (P < 0.05). MUFA amount was high in the following order: SC > CL > PR. This pattern corresponded to SCD mRNA expression profile showing higher expression in SC than CL and PR. However, Japanese black cattle are an exception with CL adipose containing similar UFA % as SC adipose, yet having the lowest SCD mRNA expression level among all adipose tissues tested. Therefore, SCD mRNA expression and MUFA % appear to be directly related; however, differences in SCD mRNA expression among three adipose tissues may reflect differences in the fat development characteristics affected by chronological age of the cattle breeds.     

Predominant expression of growth hormone secretagogue receptor in the caudal lobe of chicken pituitary and parallel developmental increase in expression of pituitary GH and proventriculus ghrelin mRNA

To examine the involvement of ghrelin in growth hormone (GH) synthesis in the chicken pituitary, the regional distribution of GH secretagogue receptor (GHS‐R)/ghrelin receptor was investigated. Quantitative real‐time polymerase chain reaction (Q‐PCR) analysis revealed that the expression levels of GHS‐R and GH mRNA in the caudal lobe were about fourfold and sevenfold higher in the cephalic lobe of 7 day‐old chickens, respectively. Immunohistochemical analysis showed that GHS‐R immunoreactivity was more abundant in the caudal lobe than in the cephalic lobe, as was the case for GH immunoreactivity. By Q‐PCR, parallel increases were observed in the expression levels of ghrelin mRNA in the proventriculus and GH mRNA in the pituitary from embryonic day 17 to day 7 after hatching, whereas no significant change was found in the expression levels of GHS‐R mRNA in the pituitary during this period. These results suggest that proventriculus‐derived ghrelin may participate in pituitary GH synthesis by acting on its receptor during late embryonic development and the early post‐hatching period in chickens.     

Evaluation of the transmission risk of foot-and-mouth disease in Japan

The transmission risk of foot-and-mouth disease (FMD) in Japan was evaluated using a mathematical FMD transmission model. The distance-based transmission rate between farms, which was parameterized using the FMD epidemic data in 2010 in Japan, was used to calculate the local-level reproduction numbers—expected numbers of secondary infections caused by one infected farm—for all cattle and pig farms in the country, which were then visualized as a risk map. The risk map demonstrated the spatial heterogeneity of transmission risk in the country and identified risk areas with higher possibility of disease spread. This result suggests that, particularly in high-risk areas, it is important to prepare for the smooth and efficient implementation of control measures against FMD outbreaks.