Phospholipase Cζ (PLCζ) versus postacrosomal sheath WW domain‐binding protein (PAWP): Which molecule will survive as a sperm factor?

During mammalian fertilization, sperm is fused with the oocyte's membrane, triggering the resumption of meiosis from the metaphase II arrest, the extrusion of the second polar body, and the exocytosis of cortical granules; these events are collectively called 'oocyte activation.' In all species studied to date, the transient rise in the cytosolic level of calcium (in particular, the repeated calcium increases called 'calcium oscillations' in mammals) is required for these events. Researchers have focused on identifying the factor(s) that can induce calcium oscillations during fertilization. Sperm‐specific phospholipase C, i.e., PLC zeta (PLCζ), is a strong candidate of the factor(s), and several research groups using different species obtained evidence that PLCζ is a sperm factor that can induce calcium oscillations during fertilization. However, postacrosomal sheath Tryptophan‐Tryptophan (WW)—domain‐binding protein (PAWP) was recently shown to have a pivotal role in inducing calcium oscillations in some species. In this review, we focus on PLCζ and PAWP as sperm factors, and we discuss this controversy: Which of these two molecules survives as a sperm factor?     

Mycoplasma ovis detected in free-living Japanese serows, Capricornis crispus

Nineteen blood samples collected from free-ranging wild Japanese serows, Capricornis crispus, between 2006 and 2008 in Iwate prefecture were examined for the hemoplasma infection by real-time PCR targeting the 16S rRNA gene. Five (26.3%) out of the 19 samples were positive in real-time PCR with an average melting temperature at 85.18 °C. The positive samples in the real-time PCR were reconfirmed by conventional PCR, and one of them was successful for direct DNA sequencing. The nucleotide sequence of the 16S rRNA gene of the representative stain was identical to that of Mycoplasma ovis. This was the first demonstration of hemotropic mycoplasma infections among the free-living Japanese serows in Japan.     

Search for low-mass exoplanets by gravitational microlensing at high magnification

Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which the peak magnification was over 500, the highest yet reported. Continuous observations around the peak enabled a sensitive search for planets orbiting the lens star. No planets were detected. Planets 1.3 times heavier than Earth were excluded from more than 50% of the projected annular region from approximately 2.3 to 3.6 astronomical units surrounding the lens star, Uranus-mass planets were excluded from 0.9 to 8.7 astronomical units, and planets 1.3 times heavier than Saturn were excluded from 0.2 to 60 astronomical units. These are the largest regions of sensitivity yet achieved in searches for extrasolar planets orbiting any star.     

Changes in serum vitellogenin levels and immunohistochemical localization of vitellogenin in hepatic cells during ovarian development in the Japanese eel

ABSTRACT: The present study was designed to quantify changes in serum vitellogenin (VTG) levels and to localize VTG in hepatic cells immunohistochemically during artificial maturation of the Japanese eel Anguilla japonica . Hormone treatment resulted in a gradual rise in serum VTG levels, in which the highest values were attained at the migratory nucleus stage. Hepatocytes responded to hormone treatment by increased immunoreactivity; both staining area and intensity were enhanced with ongoing gonadal development. Moreover, cytoplasmic vacuoles increased in number during artificial maturation, occupying large areas inside hepatocytes. The unusual appearance of hepatocytes may reflect the effect of artificial maturation.     

Identification, purification and classification of multiple forms of vitellogenin from white perch (Morone americana)

Three forms of female-specific plasma protein (FSPP 1-3) were purified from blood plasma of estrogen-treated white perch (Morone americana) by combining several types of ion-exchange chromatography including a novel, fast flow, strong anion exchanger (POROS media), followed by gel filtration. Native FSPP 1, FSPP 2 and FSPP 3 had molecular masses of 532 kDa, 532 kDa and 426 kDa, respectively. The apparent mass of purified FSPP 1 and FSPP 2 after SDS-PAGE under reducing conditions was ∼ 180 kDa, while FSPP 3 appeared as a major ∼ 148 kDa band. All of the FSPPs resembled one another with respect to amino acid composition but each appeared to be immunologically distinct. In double immunodiffusion using anti-total FSPP (antiserum raised against vitellogenic female plasma pre-absorbed by male plasma), each FSPP formed one precipitin line that crossed those produced by both others. A rabbit antiserum was raised against each FSPP and absorbed with combinations of the other two FSPPs to ensure specificity. Using the antisera, each FSPP was detected by immuno-electrophoresis in plasma from vitellogenic females or estrogen-treated male or immature fish, but no FSPP was detected in normal male plasma. Endoprotease (Asp-N) digests of the FSPPs were subjected to HPLC separation for N-terminal sequencing and mapping of isolated peptides to published vitellogenin (Vg) sequences. Results of these analyses indicate that white perch FSPP 1, FSPP 2, and FSPP 3 can be classified into three Vg groups identified in previous studies: VgA, VgB, and VgC-like protein, respectively. This is the first report, of which we are aware, on isolation of more than two Vg proteins from any species of vertebrate except the chicken. This revised version was published online in July 2006 with corrections to the Cover Date.     

11-ketotestosterone potentiates estrogen-induced vitellogenin production in liver of Japanese eel (Anguilla japonica)

Isolated hepatocytes from male Japanese eel at various stages of human chorionic gonadotropin (HCG)-induced spermatogenesis were cultured in the presence of estradiol-17β (E2). Hepatic vitellogenin (VTG) production in response to E2 increased during testicular development. This indicates that VTG production is influenced by gonadal maturity not only in females but also in males, where serum levels of 11-ketotestosterone (11KT) increase during testicular development. Recently, it has been confirmed that significant levels of 11KT are detected in maturing female eel. Therefore, in a next experiment, effect of 11KT on E2-induced VTG production was examined in vitro. As a result, in both male and female hepatocytes, 11KT enhanced E2-induced VTG production, although 11KT alone failed to induce VTG production.     

In situ measurement of wood moisture content in high-temperature steam

Changes in moisture content of sugi (Cryptomeria japonica D. Don) wood during high-temperature saturated and superheated steam treatments were investigated. A system for in situ weighing of specimens was used, and the reduction of wood substance by heating was taken into consideration. At 160°C the loss of wood substance due to heating was significant and influenced the moisture content values, but it was almost negligible at 120°C. Treatment time and temperature affected the moisture content in saturated steam but not in superheated steam. Excess water in a saturated closed system appears to promote the decomposition of wood and condensation in or on specimens.Parts of this work was presented at the 49th, 50th, and 52nd Annual Meetings of the Japan Wood Research Society in Tokyo, April 1999; Kyoto, April 2000; and Gifu, April 2002     

Advanced backcross QTL analysis reveals complicated genetic control of rice grain shape in a japonica × indica cross

Grain shape is an important trait for improving rice yield. A number of quantitative trait loci (QTLs) for this trait have been identified by using primary F₂ mapping populations and recombinant inbred lines, in which QTLs with a small effect are harder to detect than they would be in advanced generations. In this study, we developed two advanced mapping populations (chromosome segment substitution lines [CSSLs] and BC₄F₂ lines consisting of more than 2000 individuals) in the genetic backgrounds of two improved cultivars: a japonica cultivar (Koshihikari) with short, round grains, and an indica cultivar (IR64) with long, slender grains. We compared the ability of these materials to reveal QTLs for grain shape with that of an F₂ population. Only 8 QTLs for grain length or grain width were detected in the F₂ population, versus 47 in the CSSL population and 65 in the BC₄F₂ population. These results strongly suggest that advanced mapping populations can reveal QTLs for agronomic traits under complicated genetic control, and that DNA markers linked with the QTLs are useful for choosing superior allelic combinations to enhance grain shape in the Koshihikari and IR64 genetic backgrounds.     

Satellite Analysis of Volcanic Clouds and Transport of Acidic Substances from Mt. Aso and Mt. Sakurajima

The satellite images of volcanic clouds in Kyushu, Japan during September–November 1989 were studied in connection with the mountain site measurement of atmospheric qualities at Unzen-Nodake and the SO₂ concentration data at Aso Volcano Museum. The images strongly indicate that many high concentration events of SO₂ were the results of the long-range transport of volcanic gas from Mt. Aso and Mt. Sakurajima to these stations. Brief comments on the 2000 eruption of Miyake-jima volcano are added.     

Determination of spherosomes from lees materials

To evaluate the effectiveness in adsorbing organochlorine compounds such as chloroform, dichloromethane, or benzene by lees materials, the determination of spherosomes from different lees materials was established by using a hemacytometer under an optical microscope. Rice bran, wheat bran, rapeseed, linseed, okara, and sakekasu were used for this investigation, and activated carbon was also used as a standard adsorbent material. The number of spherosomes varied from 1.82 x 10(10) particles/g for sakekasu to 4.95 x 10(10) particles/g for wheat bran. There was a high correlation between the removal efficiency in adsorbing organochlorine compounds such as chloroform, dichloromethane, or benzene by lees materials and the number of spherosomes from different lees materials.