Delay in Cleavage of Porcine Embryos after Intracytoplasmic Sperm Injection (ICSI) Shows Poorer Embryonic Development

In pigs, the embryonic developmental ability after intracytoplasmic sperm injection (ICSI) is inferior to that resulting from in vitro fertilization (IVF). We evaluated the timing of cell division up to blastocyst formation on embryonic development after ICSI using either whole sperm (w-ICSI) or the sperm head alone (h-ICSI) and IVF as a control. At 10 h after ICSI or IVF, we selected only zygotes, and each of the zygotes/embryos was evaluated for cleavage every 24 h until 168 h. We then observed a delay in the 1st and 2nd cleavages of h-ICSI embryos and also in blastocoele formation by w-ICSI embryos in comparison with IVF embryos. The rate of blastocyst formation and the quality of blastocysts in both ICSI groups were inferior to those in the IVF group. In conclusion, the delay in cleavage of porcine ICSI embryos shows poorer embryonic development.     

Seasonal variation in docosahexaenoic acid content in horse mackerel caught in the East China Sea

ABSTRACT:   The fatty acid composition in horse mackerel caught off Nagasaki, off Tsushima Island, and in the middle of the East China Sea was investigated. The ratios of monoenoic and polyenoic acids to the total fatty acids in the Nagasaki and bull trawl catch specimens had a negative correlation. The docosahexaenoic acid (DHA; 22:6n-3) ratios of total fatty acids in summer-caught specimens were lower than those in winter-caught specimens, and this tendency was significantly clearer in smaller-sized fish, while DHA levels in tissues varied little throughout the year. Consistently high levels of DHA were found in various fishing areas, which suggests that horse mackerel offers a stable source of DHA.     

Carbon dynamics of rhizodeposits, root- and shoot-residues in a rice soil

A laboratory incubation experiment was conducted to investigate the fates of plant-derived C during the simulated fallow period in a rice soil. The ¹³C labelled soil and plant materials were used to follow the residue decomposition and its effect on soil organic C (SOC) dynamics under the conditions of either incorporation into soil or intact root systems. The soils were incubated at 15 °C for 240 d and destructive sampling was conducted at 60, 150 and 240 d. To observe the temperature effect, one batch of incubation was shifted from 15 to 25 °C during the last 45 d (between 195 and 240 d). The results showed that the decomposition of the incorporated residues could be divided into two phases: an initial rapid phase followed by a slower phase of decomposition. The decomposition of straw residues was faster than root residues: with 73% of the straw residue being decomposed, compared with 56% of the root residue over 240-d incubation at 15 °C. The water-soluble organic C and microbial biomass C significantly increased after residue incorporation. The total SOC contents, however, slightly decreased, although significant amounts of straw C (14.2%) and root C (8.7%) were found in SOC at the end of incubation, suggesting that the degradation of native SOC occurred concomitantly. Similar to decomposition of the incorporated residues, the organic substances derived from rhizodeposition of the previous season were mineralized rapidly at first and then slowly. The decomposition of the intact root system, however, was extremely slow. This result suggested that the intact root system conserved more organic C in soils compared with the incorporation of fresh residues. Increase of temperature from 15 to 25 °C during the last 45-days of incubation significantly promoted the residue decomposition.     

Effect of Long-term Fertilizer Application on the Concentration and Solubility of Major and Trace Elements in a Cultivated Andisol

The concentrations and solubility of major and trace elements in soils collected from a field for long-term experiments maintained for more than 60 years and the neighboring area were investigated in order to reveal the influence of soil management on their behavior in soils. No obvious differences in the element concentrations in soils were observed except for P and U, whose concentrations were elevated in the surface soils of the experimented field because of the long-term application of phosphate fertilizers. Soil acidification associated with the successive applications of potentially acid fertilizers had changed the solubility of many elements as follows: the solubility of Li, Be, Al, Mn, Co, Zn, Y, Cd, Ba and rare earth elements increased, while the solubility of P, As, Se, Nb, Sb, Mo and V increased by liming. In the uncultivated soils, the concentrations of Fe, Zr, Nb, Hf and Th in the water extracts were relatively high, and a certain amount of these elements in the water extracts may occur in colloidal forms.     

Production and analysis of reciprocal hybrids between <Emphasis Type="Italic">Asparagus officinalis</Emphasis> L. and <Emphasis Type="Italic">A. schoberioides</Emphasis> Kunth

The genus Asparagus (Asparagaceae) encompasses 100–300 species, including the important vegetable crop, A. officinalis (garden asparagus). Previous attempts to hybridize garden asparagus with A. densiflorus (Kunth) Jessop, with the aim of introducing disease resistance, were unsuccessful because of the failure of endosperm development. In the present study, reciprocal interspecific hybrids between garden asparagus and A. schoberioides Kunth were generated by hand pollination. The F1 hybrids were analyzed by using both morphological and molecular techniques. This is the first report describing the production of an interspecific hybrid between garden asparagus at the diploid level (2n = 2x = 20) and its diploid (2n = 2x = 20) wild relative, A. schoberioides. Morphological characteristics of candidate hybrids were a mixture of those found in the parents, and cytological and RFLP analyses confirmed that morphologically intermediate plants were indeed diploid hybrids of those two species. In other words, post-zygotic isolation is not complete between phylogenetically distinct these two species. Our results suggest that other Asparagus species may be capable of hybridizing with A. officinalis and that introducing wild characters through interspecific hybridization may offer advantages for breeding for novel traits. Takuro Ito and Toshinori Ochiai authors are contributed equally to this work     

Atmospheric Deposition of Acidifying Components to a Japanese Cedar Forest

One-year field measurements were conducted in a Japanese cedar (Cryptomeria japonica) forest, located in Gunma Prefecture, Japan. On the basis of the meteorological and atmospheric concentration data, the dry deposition of SO₂, HNO₃, NO₂ and HCl was estimated using the inferential method. The annual dry deposition of H⁺ was estimated at 721 eq ha^?1yr^?1, which was 40% larger than the measured annual wet deposition of H⁺ (514 eq ha^?1yr^?1). Therefore, dry deposition is an important pathway for the atmospheric input of H⁺ to the forest in the study site. The contribution of each gas to the dry deposition of H⁺ was as follows: SO₂, 25%; HNO₃, 32%; NO₂, 10%; and HCl, 33%. The extremely high contribution of HCl appeared to be caused by the high emission intensity of HCl due to waste incineration in the site region. The differences between estimated deposition and throughfall and stemflow measurements indicated that about 80% of the total deposition of H⁺ was taken up by the canopy.