Sugar catabolism in Aquaspirillum gracile

Aquaspirillum (Spirillum) gracile is one of the few spirilla that cause acidification of the medium when cultured with sugars. Acidic reactions have been reported only for d-glucose, d-galactose, and l-arabinose, and the mode of attack of these sugars has not been previously investigated. The soluble portion of extracts of glucose-cultured cells of A. gracile ATCC 19624 was found by spectrophotometric methods to contain enzyme activities characteristic of the Entner-Doudoroff and Embden-Meyerhof-Parnas pathways. No activity for 6-phosphogluconate dehydrogenase (EC 1.1.1.44) was detected. Pyridine nucleotide-linked dehydrogenase activities for l-arabinose and d-galactose (EC 1.1.1.46 and EC 1.1.1.48) occurred in the soluble fraction of cells cultured with either sugar. Glucose-cultured cells contained not only glucokinase (EC 2.7.1.2) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) activities but also glucose dehydrogenase (EC 1.1.1.47) activity. Enzymes capable of oxidizing gluconate were not detectable, but gluconokinase (EC 2.7.1.12) activity was present. Paper chromatographic analysis of the spent culture supernatant media from glucose-cultured cells indicated an accumulation of gluconic acid, and this was confirmed by enzymatic methods. Evidence is presented for the production of d-galactonic and l-arabonic acids in cultures containing d-galactose or l-arabinose, respectively.     

细风轮菜种子化学成分研究

对细风轮菜种子化学成分的研究表明,种子含大量脂肪油(23.25%),油中含大量不饱和脂肪酸:亚麻酸(66.929%)、亚油酸(21.813%)、油酸(4.596%),总量达93.338%。此外,种子还含18种氨基酸和18种矿质元素。因此,种子和种子油具有较高营养价值和药用保健功效。     

Identification of penile inputs to the rat gracile nucleus

Neurons in the medullary reticular formation (MRF) of the rat receive a vast array of urogenital inputs. Using select acute and chronic spinal cord lesions to identify the location of the ascending neural circuitries providing either direct or indirect inputs to MRF from the penis, our previous studies demonstrated that the dorsal columns and dorsal half of the lateral funiculus convey low- and high-threshold inputs, respectively. In the present study, the gracile nucleus was targeted as one of the likely sources of low-threshold information from the penis to MRF. Both electrophysiological recordings and neuroanatomical tracing [injection of cholera toxin B subunit (CTB) into a dorsal nerve of the penis] were used. After discrimination of a single neuron responding to penile stimulation, testing for somatovisceral convergence was done (mechanical stimulation of the distal colon and the skin over the entire hindquarters). In 12 rats, a limited number of neurons (43 in total) responded to penile stimulation. Many of these neurons also responded to scrotal stimulation (53.5%, dorsal and/or ventral scrotum) and/or prepuce stimulation (46.5%). Histological reconstruction of the electrode tracks showed that the majority of neurons responding to penile stimulation were located ventrally within the medial one-third of the gracile nucleus surrounding obex. This location corresponded to sparse innervation by CTB-immunoreactive primary afferent terminals. These results indicate that neurons in the gracile nucleus are likely part of the pathway that provides low-threshold penile inputs to MRF, a region known to play an important role in mating processes.     

Ultrastructural changes in the gracile nucleus of alloxan-induced diabetic rats

The present study reports ultrastructural changes in the gracile nucleus of male Wistar rats after alloxan-induced diabetes. During the acute phase (3-7 days) degenerating electron-dense dendrites and axon terminals were dispersed in the neuropil. Degenerating dendrites were characterized by an electron-dense cytoplasm, swollen mitochondria, dilated endoplasmic reticulum and randomized ribosomes. Degenerating axon terminals were characterized by an electron-dense cytoplasm and clustering of small spherical agranular vesicles. Degenerating axon terminals may form the central element or part of a synaptic glomerulus. Macrophages were present in the neuropil and in the process of engulfing neuronal elements. During the medium phase (1-6 months), most of the degenerating dendrites and axon terminals had been engulfed or removed by macrophages. During the late phase (9-12 months), a second wave of degeneration occurred in the gracile nucleus, similar to the acute phase.     

Two New Oleanane-Triterpenoid Saponins from Clinopodium gracile

Two new oleanane-triterpenoid saponins, clinograsaponins A ( 1 ) and B ( 2 ), together with twelve known ones ( 3 – 14 ), were isolated from the whole herb of Clinopodium gracile (Bentham) Matsumura. Their structures were determined by spectroscopic analysis and chemical method. All the isolated compounds were evaluated for their activities against ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB).     

Depression of the xylanase-encoding cgxA gene of Chaetomium gracile in Aspergillus nidulans

Regulation of the Chaetomium gracile xylanase A gene (cgxA) was investigated using Aspergillus nidulans as an intermediate host. Deletion of a 185 bp DNA fragment from its promoter region led to higher levels of the cgxA gene expression, indicating that the 185 bp DNA fragment contains an element involved in repression of the gene. A nuclear extract was assayed for proteins which bind to the 185 bp DNA fragment. A protein designated AnRP bound sequence specifically to the DNA fragment. The minimum sequence required for AnRP binding, 5'TTGACAAAT-3', was determined by means of gel mobility shift assays with various double-stranded oligonucleotides. Furthermore, this sequence repressed the expression of the cgxA gene when inserted at the 5' end of the cgxA gene on pXAH, which was deleted for the repressive element from the promoter region.     

Ultrastructural changes in the gracile nucleus of the spontaneously diabetic BB rat.

The present study describes the structural changes in the gracile nucleus of the spontaneously diabetic BB rat. At 3-7 days post-diabetes, axons, axon terminals and dendrites showed electron-dense degeneration. Degenerating axons were characterized by swollen mitochondria, vacuolation, accumulation of glycogen granules, tubulovesicular elements, neurofilaments and dense lamellar bodies. Degenerating axon terminals consisted of an electron-dense cytoplasm containing swollen mitochondria, vacuoles and clustering of synaptic vesicles. These axon terminals made synaptic contacts with cell somata, dendrites and other axon terminals. Degenerating dendrites were postsynaptic to normal as well as degenerating axon terminals. At 1-3 months post-diabetes, degenerating electron-dense axons, axon terminals and dendrites were widely scattered in the neuropil. Macrophages containing degenerating electron-dense debris were also present. At 6 months post-diabetes, the freshly degenerating neuronal elements encountered were similar to those observed at 3-7 days. However, there were more degenerating profiles at 6 months post-diabetes compared to the earlier time intervals. Terminally degenerating axons were vacuolated and their axoplasm appeared amorphous. It is concluded that degenerative changes occur in the gracile nucleus of the spontaneously diabetic BB rat.     

Reanalysis of the biogeographical hypothesis of range expansion between robust and gracile capuchin monkeys

The data used by Lynch Alfaro et al. (2012a, Journal of Biogeography, 39 , 272–288) and the biogeographical hypothesis postulated by these authors to explain the current distribution of capuchin monkeys were reanalysed including additional cytochrome b data from Sapajus xanthosternos and Sapajus flavius. Our reconstructed phylogeny placed S. xanthosternos in a monophyletic clade representing the most basal lineage of this genus. All analyses indicated polyphyletic arrangements for several capuchin species, suggesting that incomplete lineage sorting has occurred during their evolution. These results also suggest that available molecular data lack adequate variation for accurately resolving species relationships. These results suggest that the divergence of capuchin monkey genera may have occurred in the Atlantic Forest. However, a more conclusive scenario and better resolution of the species tree requires correct identification of species, data from several unlinked nuclear loci from a higher number of individuals per species, and careful analysis of ancient DNA data from museum specimens.     

Paralytic Shellfish Poisoning Toxin-Producing Cyanobacterium Aphanizomenon gracile in Northeast Germany

Neurotoxic paralytic shellfish poisoning (PSP) toxins, anatoxin-a (ATX), and hepatotoxic cylindrospermopsin (CYN) have been detected in several lakes in northeast Germany during the last 2 decades. They are produced worldwide by members of the nostocalean genera Anabaena, Cylindrospermopsis, and Aphanizomenon. Although no additional sources of PSP toxins and ATX have been identified in German water bodies to date, the observed CYN concentrations cannot be produced solely by Aphanizomenon flos-aquae, the only known CYN producer in Germany. Therefore, we attempted to identify PSP toxin, ATX, and CYN producers by isolating and characterizing 92 Anabaena, Aphanizomenon, and Anabaenopsis strains from five lakes in northeast Germany. In a polyphasic approach, all strains were morphologically and phylogenetically classified and then tested for PSP toxins, ATX, and CYN by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) and screened for the presence of PSP toxin- and CYN-encoding gene fragments. As demonstrated by ELISA and LC-MS, 14 Aphanizomenon gracile strains from Lakes Melang and Scharmützel produced four PSP toxin variants (gonyautoxin 5 [GTX5], decarbamoylsaxitoxin [dcSTX], saxitoxin [STX], and neosaxitoxin [NEO]). GTX5 was the most prevalent PSP toxin variant among the seven strains from Lake Scharmützel, and NEO was the most prevalent among the seven strains from Lake Melang. The sxtA gene, which is part of the saxitoxin gene cluster, was found in the 14 PSP toxin-producing A. gracile strains and in 11 non-PSP toxin-producing Aphanizomenon issatschenkoi, A. flos-aquae, Anabaena planktonica, and Anabaenopsis elenkinii strains. ATX and CYN were not detected in any of the isolated strains. This study is the first confirming the role of A. gracile as a PSP toxin producer in German water bodies.Neurotoxic saxitoxins, also known as paralytic shellfish poisoning (PSP) toxins, as well as neurotoxic anatoxin-a (ATX) and hepatotoxic cylindrospermopsin (CYN), have been detected in several northeast German lakes in the last 2 decades (3, 35). In a survey conducted in 1995 and 1996, ATX was present in 26% of 78 German lakes and PSP toxins were present in 34% of 29 lakes (3). In 2004, a qualitative survey showed that CYN was present in 50% of 127 German lakes investigated (8). Aphanizomenon flos-aquae Ralfs ex Born. et Flah. has been identified as producer of CYN in these lakes (33), but sources of PSP toxins and ATX have yet to be identified in German water bodies.PSP toxins are potent neurotoxic alkaloids produced by marine dinoflagellates and filamentous freshwater cyanobacteria (1, 2, 42). The 21 currently known PSP toxin variants belong to four groups: carbamoyl toxins, decarbamoyl toxins, N-sulfocarbamoyl toxins, and deoxydecarbamoyl toxins (15). Carbamoyl toxins are the most potent PSP toxins, including saxitoxin (STX) and neosaxitoxin (NEO), while deoxydecarbamoyl toxins comprise the least potent PSP toxins (38). PSP toxins block neural sodium ion channels, leading to death through respiratory failure (1).Cyanobacteria belonging to the orders Oscillatoriales and Nostocales, including members of the genera Cylindrospermopsis, Anabaena, and Aphanizomenon, have been identified as PSP toxin producers in freshwater habitats (4). Aphanizomenon gracile Lemmermann and Aphanizomenon flos-aquae strains from China, Portugal, and the United States have been described as PSP toxin producers (9, 23, 31). Both species are abundant members of the Nostocales and are widely distributed in phytoplankton communities in oligotrophic, mesotrophic, and eutrophic water bodies throughout northeast Germany (35).Regarding saxitoxins, Cylindrospermopsis raciborskii (Woloszyńska) Seenayya et Subba Raju strain T3 was recently found to contain a new candidate saxitoxin gene cluster containing around 35 kb of DNA and comprising more than 26 genes (16). This saxitoxin gene cluster was also found in Anabaena circinalis Rabenhorst ex Bornet & Flahault strains from Australia, in Aphanizomenon sp. strain NH5, and in Lyngbya wollei (Farlow ex Gomont) comb. nov. (16).Anatoxin-a, a neurotoxic bicyclic alkaloid, has been detected in freshwater bodies worldwide (4). Anatoxin-a production has been found in Anabaena, Aphanizomenon, Cylindrospermum, Oscillatoria sp., and Phormidium strains (4). Anatoxin-a is a potent agonist for the nicotinic acetylcholine receptor. Its toxic effects include muscle fasciculation, gasping, convulsions, and death by respiratory arrest in vertebrates (2).Cylindrospermopsin is a potent alkaloid hepatotoxin produced by planktonic cyanobacteria of the order Nostocales. It was first detected in Australian Cylindrospermopsis raciborskii strains (12) and is additionally produced by Anabaena bergii Ostenfeld (36), Umezakia natans M. Watanabe (11), Aphanizomenon ovalisporum (Forti) (37), and A. flos-aquae (33). CYN results in liver, kidney, intestinal, and lung damage (13) and inhibits protein synthesis (40).Overall knowledge of the cyanobacterial sources of PSP toxins, ATX, and CYN is scarce. To identify the producers of such toxins, we isolated and investigated 92 Aphanizomenon, Anabaena, and Anabaenopsis strains from five northeast German water bodies dominated by cyanobacteria of the order Nostocales. All strains were morphologically and phylogenetically classified and screened for the presence of toxin-encoding genes and for the ability to produce cyanobacterial toxins using a polyphasic approach including enzyme-linked immunosorbent assay (ELISA) and liquid chromatography with tandem mass spectrometry (LC-MS/MS).     

Morphological and physiological characteristics ofSpirillum gracile sp.n.

Spirilla measuring 0.25 to 0.30 µ in diameter and generally 5 to 10 µ in length were selectively isolated from pond and stream water. The isolation procedure involved the use of cellulose ester filter discs (0.45 µ pore size) which allowed the thin spirilla to migrate onto the surface of culture plates, but retained larger organisms. The spirilla isolated formed distinctive subsurface, spreading, semi-transparent colonies. The organisms exhibited a microaerophilic behavior; however, they did not grow anaerobically. Nutritional studies indicated that amino acids served both as carbon and nitrogen sources for the organisms and that organic acids and carbohydrates were suitable as carbon sources. NH₄Cl was utilized poorly as a nitrogen source and KNO₃ not at all. An exogenous supply of vitamins was not needed for growth. On the basis of their cell diameter, their microaerophilic growth and other physiological characteristics, the spirilla could not be identified with any of the previously described species of the genusSpirillum. It is proposed that these thin spirilla be recognized as a new species to be designatedSpirillum gracile.     

A gracile hominid cranium from upper member G of the Shungura Formation,Ethiopia

A fragmentary hominid cranium with teeth, specimen L.894-1, dating from 1.84 m.y. BP in the Shungura Formation at Omo, is described. From its dental and cranial morphology and because of similarities to Olduvai Hominids 24 and 13 and Sangiran 4, among others, it is concluded that the specimen represents a member of an early species of the genus Homo (Homo habilis or Homo modjokertensis). The specimen shows approximal grooving on the premolars, pre-mortem chipping of the molar enamel, foramina ovale and spinosum divided by the sphenosquamosal suture, limited pneumatization of the mastoid region, and a possible interparietal bone. Sedimentological, ostracod, pollen, macrofloral, and taphonomic data indicate that the paleo-environmental context was a savanna/grassland or savanna woodland on the margin of a saline lake.     

Behavioral study on the gracile axonal dystrophy (GAD) mutant mouse.

We investigated motor function and pain sensation in the gracile axonal dystrophy (GAD) mutant mouse, using the tail-flick test and the rotarod test. GAD (gad/gad) and normal sib mice (gad/+ or +/+) were used between 5 and 11 weeks of age, during which time the behavioral signs of GAD mice shifted from sensory ataxia (about 4 to 8 weeks of age) to paresis (after about 9 weeks of age). In the tail-flick test, significant shortening of latency was observed at 6 and 8 weeks of age in female GAD mice, in comparison with normal female mice. This may be related to dysfunction or degeneration of axons in the fasiculus gracilis, whose collaterals are thought to control the transmission of nociceptive information. In the rotarod test, a cumulative chi 2 test showed significant reduction in the performance times of GAD mice beginning at 5 and 6 weeks of age in males and females, respectively, indicating that the rotarod test can detect the development of motor incoordination as early as these ages. The performance times of GAD mice dropped sharply from 9 weeks of age onwards, and this is believed to reflect the progression of paresis. The rotarod test therefore appears to be a good method of quantifying behavioral changes in GAD mice and to be applicable both to objective selection of GAD mice before 8 weeks of age and to evaluation of drugs to treat ataxia or paresis.     

Reduced fertility in gracile axonal dystrophy (gad) mice

Mean litter size in gad/gad females was significantly lower than in normal females (+/+ and gad/+) in intra- and inter-strain crosses. The reduction in litter size was not dependent on the genotypes of the males, but could be attributed to the gad/gad females themselves. The numbers of corpora lutea and implants in gad/gad females were slightly reduced as compared with those in the controls, but the number of live fetuses was significantly lower than that in normal females 14 days after copulation (P less than 0.02). Hence, reduced litter size in gad/gad females was accounted for mostly by embryonic and fetal death after implantation, which was inferred to be due to impaired uterine function.     

A new pelvic fragment from swartkrans and the relationship between the robust and gracile australopithecines

A recently discovered hominid pelvic fragment from Swartkrans (SK 3155) is described in detail with particular reference to the relationship of the two presently recognized forms of australopithecines in South Africa. Results of this examination and metrical analysis indicate that the acetabulum and iliac blade of the early hominids are similar to Homo sapiens except for a unique pattern of traits: a relatively small sacral articular surface, a relatively small acetabulum, a relatively large iliac fossa, and wide lateral splaying of the iliac blades. The new Swartkrans fossil expresses these traits more strongly than does the gracile australopithecine (Sts 14) and is therefore somewhat less similar to Homo sapiens but it is very unlike any pongid.     

Localization of the pituitary lactotropes and thyrotropes within Ambystoma gracile by histochemical and immunochemical methods

Summary The prolactin-producing cells are the first hormone-producing cells of the pars distalis to be differentiated within Ambystoma gracile. They first appear when the larvae attain a length of approximately 3.0 cm snout to vent length (SVL). Thyrotropes are observed as the next chromophilic cells to appear, and they occur when the larvae are approximately 4.5 cm SVL. Both thyrotropes and lactotropes increase in numbers until metamorphosis. Gonadotropes begin to appear when larvae attain a size of 5.0 cm SVL and become extremely abundant when larvae are in excess of 7.0 cm SVL. Animals, generally, exhibit the greatest number of thyrotropes just prior to the mean size for metamorphosis, and metamorphosing animals exhibit a dramatic reduction in the number of thyrotropes. Neotenous larvae have an abundant number of thyrotropes which are mainly located along the caudal periphery of the pituitary.