Histo-and Cytochemical Studies on the Distribution of Acetylcholinesterase-positive Nerve Fibers in the Goat Adrenal Gland

The distribution patterns of acetylcholine esterase positive nerve fibers in the goat adrenal gland is described. Some positive cells are observed within the capsule. Terminals were identified in both the medulla and the cortex of the gland.     

Caprine somatic cell nuclear transfer using in vivo matured oocytes collected by laparoscopic follicular aspiration

In vivo matured oocytes collected by laparoscopic follicular aspiration (LFA) from hormone treated female goats were used as recipient ooplasts for somatic cell nuclear transfer (SCNT). Japanese native (Shiba) goats were used as donor females and some donor females were used repeatedly (two or three times) at intervals of a few months. To induce synchronization of estrus, a sponge containing 0.5 g of progesterone was inserted into the vagina of each goat for 14 days. These animals were also treated with follicle stimulating hormone (FSH) in a series of 8 injections over 4 days. The first FSH injection was administered on the morning of day 9 of sponge insertion. On the morning of day 13, 50 µg of gonadotropin‐releasing hormone (GnRH) was injected into each animal. Twenty‐nine hours after GnRH injection, LFA was performed. After removal of cumulus cells, collected oocytes with the first polar body were selected and enucleated for nuclear transfer. Anterior pituitary cells isolated from an adult male Shiba goat were transfected with a DNA fragment containing the enhanced green flourescent protein gene and the puromycin resistance gene. A single donor cell was inserted into the perivitelline space of each enucleated oocyte and fusion was induced with one electric pulse of 20 V for 10 µs. The SCNT goat eggs were cultured in chemically defined medium at 38.5°C in 5% CO₂, 5% O₂, 90% N₂ for 9 days. By LFA, 396 oocytes were collected from a total of 30 females. After removal of cumulus cells, 64% of them extruded the first polar body. The percentage of SCNT goat eggs produced using in vivo matured oocytes which developed to the blastocyst stage (20–21%) was significantly higher (P < 0.05) than that produced with in vitro matured oocytes (3–8%).     

Novel plasmodesmata association of dehydrin-like proteins in cold- acclimated Red-osier dogwood (Cornus sericea)

Dehydrins are proteins associated with conditions affecting the water status of plant cells, such as drought, salinity, freezing and seed maturation. Although the function of dehydrins remains unknown, it is hypothesized that they stabilize membranes and macromolecules during cellular dehydration. Red-osier dogwood (Cornus sericea L.), an extremely freeze-tolerant woody plant, accumulates dehydrin-like proteins during cold acclimation and the presence of these proteins is correlated with increased freeze tolerance (Karlson 2001, Sarnighausen et al. 2002, Karlson et al. 2003). Our objective was to determine the location of dehydrins in cold-acclimated C. sericea stems in an effort to provide insight into their potential role in the freeze tolerance of this extremely cold hardy species. Abundant labeling was observed in the nucleus and cytoplasm of cold-acclimated C. sericea stem cells. In addition, labeling was observed in association with plasmodesmata of cold-acclimated vascular cambium cells. The unique association of dehydrin-like proteins with plasmodesmata has not been reported previously.     

Distribution of boron in wood treated with aqueous and methanolic boric acid solutions

The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)₃] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)₃ was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution. PGA confirmed that B(OH)₃ was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than the methanolic solution. Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281     

Long-term growth analyses of Japanese cedar trees in a plantation: neighborhood competition and persistence of initial growth deviations

The individual growth of tree diameter at breast height (dbh) is analyzed in an even-aged plantation of Cryptomeria japonica from stand age of 45 to 94 years, to examine how the growth of individual trees has been affected by the changes in spacing resulting from thinning operations. At any age, a significant proportion (0.37–0.46) of the variation in dbh growth during a 5–11-year period was explained by dbh at the beginning of the period, probably due to greater leaf mass of larger trees. Next, either one-sided or two-sided competition was added to the model, by calculating the basal area (BA) of neighboring trees around each tree within a given radius or BA for trees having larger dbh than the focal tree within the radius. After preliminary analyses, a radius of 8 m was selected as the critical range for tree competition. Although both types of competition explained a significant proportion (0.09–0.43) of growth variation, one-sided competition was not significant at ages greater than 54 years. Based on the model at 45 years of age, the initial deviation of growth rate for each tree from the predicted rate was calculated and added to the models as a third variable. This raised the coefficient of determination up to 0.50–0.74. These findings have practical significance for forest plantation management, particularly for controlling the growth of standing trees via thinning, to produce high-quality timber in the future.     

Seasonal and yearly variations in light use and nitrogen use by seedlings of four deciduous broad-leaved tree species invading larch plantations

Several deciduous broad-leaved tree species, differing in leaf phenology, invade larch (Larix kaempferii (Lamb.) Carrière) plantations in Japan. The understory light environment of larch forests changes drastically between the leafy and leafless periods. To determine how the invading seedlings exploit the changing light environment, and if phenological differences reflect the light- and nitrogen-use traits of the seedlings, we measured leaf phenology, seasonal changes in light-saturated photosynthetic rate (P(sat)), leaf nitrogen (N) content (N(area)), chlorophyll/nitrogen ratio (Chl/N), specific leaf area (SLA) and N remobilization rate (NRMR) over 3 years. The mid-successional or gap-phase species, Magnolia hypoleuca Siebold & Zucc., had a short leafy period and high P(sat) and NRMR. In contrast, two late-successional tree species, Prunus ssiori Friedr. Schmidt, which undergoes leaf flush before larch, and Carpinus cordata Blume, which maintains green leaves until frost, both had low P(sat) and NRMR but exploited the opportunity for growth during the period when the larch canopy trees were leafless. Quercus mongolica Fisch. ex Ledeb. var. crispula (Blume) Ohashi, a mid-late-successional species that underwent leaf flush at the same time as the overstory larch, had values of photosynthetic parameters between those of the gap-phase and late-successional species. Among species, M. hypoleuca and Q. mongolica had higher photosynthetic rates and photosynthetic N-use efficiencies. In all species, the relationship between N(area) and P(sat) showed species-specific yearly fluctuations; however, there was no yearly fluctuation in the relationship between N(area) and P(sat) at CO2 saturation. Yearly fluctuations in the N(area)-P(sat) relationship appeared to be induced by changes in SLA and N-use characteristics, which in turn are affected by climatic variations.