Sex differences in gallbladder bile acid composition and hepatic steroid 12 alpha-hydroxylase activity in hamsters

The gallbladder bile acid composition and the activity of the hepatic steroid 12 alpha-hydroxylase were determined in male and female hamsters. Cholic acid, chenodeoxycholic acid, and deoxycholic acid were the major bile acids in both sexes; in addition, 7-ketodeoxycholic acid and lithocholic acid were present. A sex-linked difference in the ratio of cholic acid (plus its metabolites) to chenodeoxycholic acid (plus its metabolite) was observed. The ratio was 1.93 +/- 0.39 in males and 2.74 +/- 0.54 in females. Another sex-linked difference was found in the activity of the 12 alpha-hydroxylase. The extent of the 12 alpha-hydroxylation of 7 alpha-hydroxycholest-4-en-3-one to yield 7 alpha, 12 alpha-dihydroxycholest-4-en-3-one was about two times greater in the microsomal suspension obtained from the liver of female hamsters than in that of male hamsters. A positive correlation between the 12 alpha-hydroxylase activity and the ratio of cholic acid/chenodeoxycholic acid was also observed. These results strongly support the proposal that the activity of the 12 alpha-hydroxylase is the major factor in determining the relative proportion of cholic acid and chenodeoxycholic acid formed from cholesterol in the liver.     

Synaptic localization of growth‐associated protein 43 in cultured hippocampal neurons during synaptogenesis

Growth‐associated protein 43 (GAP‐43), a novel axonal phosphoprotein, is originally identified as a growth‐cone‐specific protein of developing neurons in vitro. The expression of GAP‐43 is also shown to be up‐regulated concomitant with increased synaptic plasticity in the brains in vivo, but how GAP‐43 is concerned with synaptic plasticity is not well understood. In the present study, therefore, we aimed to elucidate subcellular localization of GAP‐43 as culture development of rat hippocampal neurons. Western blotting showed that the expression of GAP‐43 in the cerebral and hippocampal tissues was prominently high at postnatal days 14 and 21 or the active period of synaptogenesis. Double‐labelling immunohistochemistry with an axonal marker Tau revealed that the immunoreactivity of GAP‐43 was seen throughout axons of cultured hippocampal neurons but stronger at axonal puncta of developing neurons than axonal processes. Double‐labelling immunohistochemistry with presynaptic terminal markers of synapsin and synaptotagmin revealed that the immunoreactivity of GAP‐43 was observed mostly at weak synapsin‐ and synaptotagmin‐positive puncta rather than strong ones. The quantitative analysis of immunofluorescent intensity showed a clear inverse correlation between GAP‐43 and either synapsin or synaptotagmin expression. These data indicate that GAP‐43 is highly expressed at immature growing axonal terminals and its expression is decreased along with the maturation of synaptogenesis. Copyright © 2012 John Wiley & Sons, Ltd.     

Mate-searching behavior of the black chafer <Emphasis Type="Italic">Holotrichia kiotonensis</Emphasis> (Coleoptera: Scarabaeidae): identification of a sex pheromone,and male orientation behavior controlled by olfactory and visual cues

In the black chafer Holotrichia kiotonensis Brenske (Coleoptera: Scarabaeidae), mating behavior was observed between 1940 and 2010 hours at < 0.1 lx in both the laboratory and the field. In the laboratory, an ether extract of female abdominal glands induced a series of pre-mating behaviors such as short-distance orientation and abdominal bending. When the extract was fractionated by silica gel column chromatography, the active fraction was eluted with 50% ether in hexane and 100% ether. Gas chromatography–mass spectrometry analysis revealed that both active fractions contained anthranilic acid (2-amino-benzoic acid) as a major compound. The amount of this compound was determined to be ca. 600 ng/female by high performance liquid chromatography analysis with a fluorescence detector. In the field, male chafers were observed to land on cotton balls impregnated with 10 mg of authentic anthranilic acid. When a white ball treated with anthranilic acid was placed 2–10 cm away from an untreated black ball, males were observed to land significantly more frequently on the latter. These results suggest that males could recognize white balls below 0.1 lx and landed on black balls. When a treated black ball was placed beside an untreated black ball, more males landed on the former. The difference was significant when the distance between the two lures was 5 or 10 cm, but not significant when it was 2 cm. These observations demonstrated that anthranilic acid was the sex-attractant pheromone for the black chafer H. kiotonensis and that the males located and landed on a pheromone source by using olfaction in conjunction with visual orientation. The importance of visual orientation in this nocturnal species is discussed in comparison with the congeneric diurnal species Holotrichia loochooana loochooana.     

Control of cell polarity and motility by the PtdIns(3,4,5)P3 phosphatase SHIP1

Proper neutrophil migration into inflammatory sites ensures host defense without tissue damage. Phosphoinositide 3-kinase (PI(3)K) and its lipid product phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) regulate cell migration, but the role of PtdIns(3,4,5)P(3)-degrading enzymes in this process is poorly understood. Here, we show that Src homology 2 (SH2) domain-containing inositol-5-phosphatase 1 (SHIP1), a PtdIns(3,4,5)P(3) phosphatase, is a key regulator of neutrophil migration. Genetic inactivation of SHIP1 led to severe defects in neutrophil polarization and motility. In contrast, loss of the PtdIns(3,4,5)P(3) phosphatase PTEN had no impact on neutrophil chemotaxis. To study PtdIns(3,4,5)P(3) metabolism in living primary cells, we generated a novel transgenic mouse (AktPH-GFP Tg) expressing a bioprobe for PtdIns(3,4,5)P(3.) Time-lapse footage showed rapid, localized binding of AktPH-GFP to the leading edge membrane of chemotaxing ship1(+/+)AktPH-GFP Tg neutrophils, but only diffuse localization in ship1(-/-)AktPH-GFP Tg neutrophils. By directing where PtdIns(3,4,5)P(3) accumulates, SHIP1 governs the formation of the leading edge and polarization required for chemotaxis.     

Cloning of the Microcystis aeruginosa M228 lectin (MAL) gene

We have cloned and characterized the gene encoding Microcystis aeruginosa (strain M228) lectin (MAL). The gene contains 1551 nucleotides and an open reading frame for a protein of 517 amino acids with a predicted molecular weight of 55,159 Da. The carboxy-terminal region of MAL has three tandemly repeated homologous domains composed of 61 amino acids. These regions show similarity to the corresponding regions of the alpha-amylase of Clostridium beijerinckii (23% identity). The mal gene lies adjacent to an ORF that display homology to cytochrome P-450 and polyketide synthase. Southern hybridization showed that the genomic DNA of the strain M228 contained, in addition to MAL gene (mal), at least two other mal like gene.     

Water-Soluble Glycoconjugates of Vegetables I. Isolation and Properties of Arabinogalactan-Proteins from Cabbage

We present a new method for isolating and purifying water-soluble arabinogalactan-proteins from cabbage and give their chemical properties. The water-soluble nondialyzable material from fresh cabbage was separated into three fractions (A-I, II, and III) by gel filtration on Sepharose CL-4B. A-I and A-II can be purified by HPLC. Borate is necessary to avoid formation of insoluble aggregates during isolation and purification. The molecular weights of A-I, II, and III were estimated to be 4.0×10⁵, 1.0×10⁵, and 1.0~4.0×10⁴, respectively. A-I and A-II are arabinogalactan-proteins with different carbohydrate/protein ratios: 5.5/1 for A-I and 11.4/1 for A-II. The carbohydrate moieties of A-I and A-II were both arabino-3,6-galactans having d-galactose/l-arabinose ratios of 1.9/1 and 1.5/1, respectively. The amino acid composition indicates an abundance of hydroxyproline, serine, threonine and alanine, the sum of which amounted to about 50% of the total amino acids. A-I contained 1.5 times more hydroxyproline (20%) than A-II (14%), while A-II contained higher proportions of serine, glycine, and alanine. A-III was not a glycoprotein but was a mixture of carbohydrate and polypeptides.     

Variation in storage alpha-glucans of the Porphyridiales (Rhodophyta)

Storage glucans were analyzed in the Porphyridiales which include the most primitive and phylogenetically diverged species in the Rhodophyta, to understand early evolution of the glucan structure in the Rhodophyta. The storage glucans of both Galdieria sulphuraria and Cyanidium caldarium consisted of glycogen, while those of Rhodosorus marinus, Porphyridium purpureum, P. sordidum and Rhodella violacea could be defined as semi-amylopectin. X-ray diffraction analysis of the glucans demonstrated variation in the crystalline structure: the patterns in P. purpureum and R. violacea were of A- and B-types, respectively, while alpha-glucans of R. marinus and P. sordidum displayed structures with lower crystallinity. Electron microscopic observations indicated that the alpha-glucans of P. sordidum consisted of two kinds of granules; a minor component of more dense granules with crystalline leaflets and a major component of softer ones without crystalline structure. Gel permeation chromatography showed that all the species containing the semi-amylopectin-type glucans also contained amylose, although the relative amounts of this fraction were different depending on the species. Our results are consistent with two distinct evolution scenarios defined either by the independent acquisition of semi-crystalline starch-like structures in the different plant lineages or more probably by the loss of starch and reversion to glycogen synthesis in cyanidian algae growing in hot and acid environments.     

Gonadal sex differentiation and expression of Sox9a2, Dmrt1, and Foxl2 in Oryzias luzonensis

Oryzias luzonensis is closely related to the medaka, O. latipes. The sex of both species is determined by an XX‐XY system. However, the testis determining gene (DMY/Dmrt1bY) found in O. latipes does not exist in O. luzonensis. Instead, a different gene is thought to act as a testis determining gene. In this study, we focused the gonadal sex differentiation process in O. luzonensis under different testis determining gene. First, we observed the gonadal development of O. luzonensis histologically. We then analyzed the expression of Sox9a2/Sox9b, Dmrt1, and Foxl2 during early development. Our results suggest that the sexual differentiation of germ cells in O. luzonensis is initiated later than in O. latipes. However, the timing of the sexual differentiation of the supporting cell linage is similar between the species. genesis 47:289–299, 2009. © 2009 Wiley‐Liss, Inc.