Relation of reproductive performances and rectal palpation for luteum function of heifers 7 days after estrus

Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP‐based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1 ± 3.1 mm on US and a mean P4 concentration of 8.1 ± 2.3 ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4 ± 5.4 mm, 4.0 ± 2.8 ng/mL) (P < 0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18–25 days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P < 0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7 days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P < 0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post‐estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL.     

First report of ophidiomycosis in Asia caused by Ophidiomyces ophiodiicola in captive snakes in Japan

Ophidiomycosis is an emerging infectious disease caused by the fungus Ophidiomyces ophiodiicola, which has been affecting wild and captive snakes in North America, Europe, and Australia. We report 12 cases of suspected ophidiomycosis in captive colubrid snakes in Japan. Pathological and microbiological examinations were performed, and the results confirmed the diagnosis of ophidiomycosis in two snakes, which indicated that the remaining sympatrically raised snakes also had ophidiomycosis since they exhibited similar lesions. This is the first report of ophidiomycosis in Asia caused by O. ophiodiicola. To prevent the expansion of ophidiomycosis in the natural environment in Japan, there is a need to evaluate the ophidiomycosis carrier status of imported snakes, the pathogenicity of the infection in native snakes, and the prevalence and distribution of O. ophiodiicola in wild and captive snakes. Measures also must be taken to prevent endemicity globally.     

Detection of protease genes in field soil applied with liquid livestock feces and speculation on their function and origin

The origin of soil protease in field soil was estimated using culture-dependent and independent approaches. Overall soil protease activity was much higher in field soils with an annual application of liquid livestock feces (120 t ha⁻¹ year⁻¹ and 600 t ha⁻¹ year⁻¹) compared with the activity recorded in other field soils, and the character of the soil proteases became highly homogeneous (approximately 70% metalloprotease in a 600 t field). Selective incubation studies suggested that bacteria were the most important source of soil protease. There were significantly higher correlations between serratial metalloprotease and the overall soil protease in both feces-applied fields in terms of the effect of inhibitors, and the bacteria, which produced serratial metalloprotease, were suggested to proliferate in both the 120 t and 600 t fields. The gene homologous to serratial metalloprotease gene was amplified in directly extracted DNA from field soils using selective DNA primer and proteolytic Serratia marcescens was certified to be one source of soil protease in these field soils. Proteolytic S. marcescens and its metalloprotease gene have occasionally been isolated and detected in field soils applied with raw feces, and have rarely been isolated or detected from other field soils. Proteolytic S. marcescens is believed to be introduced in the raw feces and subsequently colonizes the field soil and replaces the indigenous bacteria in the soil.     

Element interconnections in Lotus japonicus: A systematic study of the effects of element additions on different natural variants

Lotus japonicus was used to study the distribution and interconnections of 15 elements in plant tissues, including essential and non-essential elements: boron (B), sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), strontium (Sr), molybdenum (Mo), cadmium (Cd) and cesium (Cs). Large amounts of B and Ca accumulated in plant leaves, while Fe, Na, Ni, As and Cd tended to mainly occur in the roots, and Mo was the only element to accumulate in the stems. The elemental compositions within plants were severely disturbed by treatment with toxic elements. Competition between element pairs in the same group (e.g. K and Cs; Ca and Sr) was not found. Iron, Cu and Zn accumulation were induced by Cd and Ni addition. When natural variants grew in a nutrition solution with subtoxic levels of As, Cd, Cs, Ni, Mo and Sr, intriguing relationships between the elements (such as Fe, As and K; Mg and Ni; Mn and Ca) were revealed using principal-component analysis. This study on the plant ionome offers detailed information of element interactions and indicates that chemically different elements might be closely linked in uptake or translocation systems.