Organization of diencephalon of the sturgeons. Posterior tubercular area. Periventricular and rostral parts

Cytoarchitectonics of periventricular and rostral parts of the posterior tubercular area of diencephalon was studied in four species of the cartilaginous ganoids by using routine Nissl staining and Bielschowski impregnation technique in Viktorov’s modification. The posterior tubercular area in the giant sturgeon Huso huso L., the Kura sturgeon Acipenser güldenstädtii persicus n. Kurensis Belyaeff, the stellate sturgeon Ac. stellatus Pall., and the barbel sturgeon Ac. nudiventris Lov. was shown to have similar structure. Six structures were identified in these areas: the periventricular nucleus, paraventricular organ, nucleus of the paraventricular organ, and posterior tuberal nucleus in the periventricular region and preglomerular medial and lateral nuclei in the rostral region. Both nuclei of the rostral zone are migrated nuclei. Out of nuclei of the posterior tubercle regions, the posterior tuberal and medial preglomerular nuclei are characterized by polymorphism of cellular elements. A conclusion is made that these parts of the posterior tubercular area in the sturgeons considered to be the lower ray-finned fish are comparable with those of the higher teleosts, and even are more differentiated according to some parameters.     

Organization of diencephalon of the sturgeons. External nuclei of the pretectal area

Cytoarchitectonics of the external nuclei of the pretectal area was studied in four species of the sturgeons: great sturgeon, Huso huso L., Kura sturgeon, Acipenser gueldenstaedtii persicus n. Kurensis Belyaeff, stellate sturgeon, Ac. stellatus Pall. and barbel sturgeon, Ac. nudiventris Lov. Study of morphological organization of the structures was carried out using routine Nissl staining and Bilschowski impregnation technique in Viktorov’s modification. Similar structure of this pretectal area was found in the species. Five nuclear formations were described in this pretectal area: parvocellular and magnocellular external pretectal nuclei, laminiform nucleus of pretectum, dorsal pretectal nucleus, and the accessory optic nucleus. Comparison of the obtained data with the literature revealed a high level of differentiation of the area of pretectum in the sturgeons. Also, a general conclusion is given on the organization of the whole pretectal area in the sturgeons.     

Organization of diencephalon of the sturgeons. Dorsothalamic and epithalamic areas

Cytoarchitectonics of the dorsal part of diencephalon and epithalamus was studied in four species of the true sturgeons: the great sturgeon Huso huso L., the Kura sturgeon Acipenser gƅlden-st∂dtii persicus n. Kurensis Belyaeff, the starred sturgeon Ac. stellatus Pall., and the barbel sturgeon Ac. nudiventris Lov. Material was processed using routine Nissl and Bielschowski staining techniques (the latter in Viktorov’s modification). The described areas are the smallest among diencephalic regions. Dorsal thalamus is exceeded by the ventral one both in length and in the number nuclear structures. It includes four nuclear structures, three of which are periventricular: the anterior, posterior dorsal, and central nuclei, while the subhabenular nucleus is a migrated one. Epithalamic area has a pronounced right-left asymmetry that consists both in the external appearance of these structures and in their internal organization. Three types of neurons were revealed in epithalamic structures: granular cells, rounded neurons with poorly expressed processes, and bipolar neurons with clearly seen processes. In the epithalamic area, a sufficiently large nervous structure designated as the central habenular nucleus consisting of relatively large rounded neurons was described. A conclusion is made about a unique organization the studied areas in the true sturgeons, which distinguishes them markedly among both other actinopterygian fish and the higher organized vertebrates.     

Periventricular and central nuclei of the pretectal area of diencephalon of the sturgeons

Cytoarchitectonics of periventricular and central nuclei of the pretectal area was studied in four species of the sturgeons: the great sturgeon Huso huso, L., the Russian sturgeon Acipenser gъldenst?dti persicus n. kurensis, Belyaeff, the starred sturgeon Ac. stellatus, Pall., and the barbel sturgeon Ac. nudiventris, Lov.; this pretectum part has a similar structure. Study of these parts of the pretectal area was carried out by methods of Nissl and Bielshowskii modified by Viktorov. In this part of the pretectal area, nine nuclear structures were described, eight of them—nuclear; these are ventral periventricular pretectal nucleus and its dorsal component, dorsal periventricular pretectal nucleus, nucleus of medial longitudinal bundle, subcomissural organ, medial and lateral intercalate nuclei, and central and posterior pretectal nuclei. The main attention has been paid to the issue of the evolutional progression of this part of the pretectal area in the sturgeons as compared with other Actinopterygii.     

Organization of diencephalon of the sturgeons. Preoptic area

Cytoarchitectonics of preoptic area of diencephalon of chondroid ganoid fish (the sturgeons) was studied in serial sections using Nissl and Bilschowski techniques, the latter in Viktorov’s modification). The preoptic area of the hausen, Huso huso L., Kura sturgeon, Acipenser guldenstaedtii persicus n. kurensis Belyaeff, Caspian sturgeon, Acipenser stellatus Pall. and the sturgeon Acipenser nudioventris Lov. was shown to be one of the largest parts of diencephalon. It is located along the rostral excess of the third ventricle and the anterior third of the ventricle thalamic part. Eight nuclei are identified in the preoptic area: (1) anterior microcellular preoptic nucleus, (2) suprachiasmatic nucleus, (3) accessory preoptic nucleus, (4) intrachiasmatic nucleus, (5) magnocellular preoptic nucleus, (6) posterior microcellular preoptic nucleus, (7) caudal preoptic nucleus, (8) entopeduncular nucleus. Besides, microcellular, magnocellular, and gigantocellular parts are identified in the magnocellular preoptic nucleus. The obtained results indicate high differentiation of this area of the sturgeons among Actinopterygii.     

Organization of the diencephalon ventrothalamic area in the sturgeons

Cytoarchitectonics of ventrothalamic area of the diencephalon of the sturgeons was studied in four species of the sturgeons, the great sturgeon Huso huso L., the Kura sturgeon Acipenser guelden-staedtii persicus n. Kurensis Belyaeff, the Caspian sturgeon, Ac. stellatus Pall., and the barbel sturgeon Ac. nudioventris Lov. using Nissl staining and Bilschowski impregnation techniques in Viktorov’s modification. The ventral thalamus of the sturgeons was found to include seven nuclei: ventromedial, ventrolateral, intermediate and ventral thalamic nuclei, thalamic eminence, and nuclei of ventral and medial optic tracts. The main attention was paid to comparative analysis of this area in the sturgeons and other actinopterygian fish. The structures common to all ray-finned fish or only to the lower teleosts and ganoids as well as characterizing only the sturgeons.     

Organization of hypothalamic area of diencephalon in the sturgeons

Cytoarchitectonics of hypothalamic area of diencephalon of the sturgeons was studied in serial sections by techniques of Nissl staining and Bielschowski impregnation in Viktorov’s modification. The hypothalamus was shown to be the most expanded area of diencephalon and forms its the most ventral part. The hypothalamic area of four studied sturgeons, the hausen, Huso huso L., Kura sturgeon, Acipenser guldenstaedtii persicus n. Kurensis Belyaeff, Caspian sturgeon, Ac. stellatus Pall. and the barbel sturgeon Ac. nudioventris Lov. was found to have similar structure. Eleven nerve structures are identified and described in the hypothalamic area: dorsal, ventral, and caudal periventricular zones, rostral and dorsal hypothalamic nuclei, ventral and ventrolateral hypothalamic nuclei, diffuse and central nuclei of the inferior lobes, nucleus of the vascular sac, and mammillary nucleus. Peculiarities and common features of organization of four major parts of hypothalamus of the sturgeons are considered in comparison with those of other ray-finned fish. The performed analysis indicates a high level of development of hypothalamus of the sturgeons.     

Outer nuclei of the diencephalon pretectal area of the sturgeons

Cytoarchitectonics of outer nuclei of the pretectal area was studied in four species of the sturgeons: the great sturgeon Huso huso, L., the Russian sturgeon Acipenser güldenst?dti persicus n. kurensis, Belyaeff, the starred sturgeon Ac. stellatus, Pall., and the barbel sturgeon Ac. nudiventris, Lov. Morphological organization of these structures was studied by methods of Nissl and Bielshowskii modified by Viktorov. In this part of the pretectal area, five nuclear structures were described: parvicellular and magnocellular outer pretectal nuclei, lamellar pretectal nucleus, and dorsal pretectal nucleus, as well as accessory optic nucleus. Comparison of the obtained results with literature data has revealed a sufficiently high level of differentiation of this pretectum part of the sturgeons. Besides, a general conclusion is presented on organization of their entire pretectal area.     

Periventircular and central nuclei of the diencephalon pretectal area of the sturgeons

Cytoarchitectonics of periventricular and central nuclei of the pretectal area was studied in four species of the sturgeons: the great sturgeon Huso huso, L., the Russian sturgeon Acipenser güldenst?dti persicus n. kurensis, Belyaeff, the starred sturgeon Ac. stellatus, Pall., and the barbel sturgeon Ac. nudiventris, Lov.; this pretectum part has a similar structure. Study of these parts of the pretectal area was carried out by methods of Nissl and Bielshowskii modified by Viktorov. In this part of the pretectal area, nine nuclear structures were described, eight of them--nuclear; these are ventral periventricular pretectal nucleus and its dorsal component, dorsal periventricular pretectal nucleus, nucleus of medial longitudinal bundle, subcomissural organ, medial and lateral intercalate nuclei, and central and posterior pretectal nuclei. The main attention has been paid to the issue of the evolutional progression of this part of the pretectal area in the sturgeons as compared with other Actinopterygii.     

鲟致病性类志贺邻单胞菌的鉴定及药物敏感性

【目的】2012年夏季北京地区多地养殖的鲟鱼发病,主要临床症状为肛门红肿、伴有黄色分泌物,腹腔内有大量腹水,腹腔内壁有出血点,肝脏点状出血,脾脏肿大等,累计死亡率达60%。本文目的为研究其病原。【方法】从具有临床症状的濒死鱼中分离病原菌,分析病原菌的形态特征、理化特性、分类地位及药物敏感性等特性,经过人工感染及引起的组织病理确认致病性。【结果】结果显示病原菌的16S rDNA序列构建的进化树,与类志贺邻单胞菌同源性最高,在99%以上;结合其生理生化特征和API细菌鉴定系统的结果,确认为类志贺邻单胞菌。该菌对鲟鱼的半致死量LD50为1.0×105.8CFU/mL,引起肝、肾和脾组织病变。胞外产物不具有淀粉酶、蛋白酶、脂肪酶和明胶酶活性,也无溶血性,推测其毒性可能来源于内毒素。该菌对恩诺沙星、盐酸多西环素、氟苯尼考和甲枫霉素敏感,药物敏感浓度均小于2μg/mL;而对试验的其它抗菌药物不敏感。【结论】确认类志贺邻单胞菌是引起北京地区鲟鱼发生上述临床症状疾病的主要致病菌,可优选盐酸多西环素、氟苯尼考和恩诺沙星进行防治。     

Neuronal Organization of the Telencephalon in the Chum Salmon Onchorhynchus keta

This paper presents original data on the neuronal composition of various regions of the pallium of the telencephalon in Oncorhynchus keta. This study was carried out using routine neurohistologic techniques. Four basic areas were distinguished within the pallium: medial, dorsal, central, and lateral. The central pallium exhibited the most complicated cytoarchitectonics. In the central and lateral areas, pyramidal-like neurons with a well-developed dendritic spine apparatus were found. These were allodendritic cells, which appeared to be comparable to the pyramidal neurons of higher vertebrates in a number of features. Horizontal neurons and isodendritic radial neurons were also encountered. These cell types occurred in the ventral part of the central area and in the lateral area.     

Immunohistochemical demonstration of contractile proteins in astrocytes,marginal glial and ependymal cells in rat diencephalon

Summary Actin and myosin were located in astrocytes, marginal glial and ependymal cells in rat diencephalon by using antibodies against highly purified chicken gizzard actin and myosin. On the basis of these findings it is suggested that glial cell motility in vivo and in vitro is due to the presence of an intracellular actin/myosin system.Supported by grants from Deutsche Forschungsgemeinschaft     

Organization of the replication control region of plasmid ColIb-P9.

We identified a 1,845-base-pair sequence that contains essential information for the autonomous replication and regulation of the 93-kilobase-pair IncI alpha group ColIb-P9 plasmid. Biochemical and genetic analyses revealed that this sequence specifies at least two structural genes, designated repZ and inc. The repZ gene encodes a protein with a molecular weight of 39,000, which probably functions as an initiator for the ColIb-P9 replicon. The inc gene that phenotypically governs the incompatibility encodes an RNA with a size of about 70 bases. This small RNA acts in trans to repress the expression of repZ, thereby functioning to maintain a constant copy number of the ColIb-P9 replicon in host cells.     

Organization and expression of the E4 region of adenovirus 2.

The E4 region of Adenovirus 2 is a leftward transcribed part of the viral genome. Its nucleotide sequence has already been analysed. From this sequence several open reading frames were defined, which could be used in the coding of the E4 proteins. Using S1 digestion of mRNA-DNA hybrids a precise mapping of donor and acceptor sites was done. Their use in various combinations allows the synthesis of mRNAs, able to direct the synthesis of at least 7 polypeptides, ranging in size from 9K to 34K. Comparison of the sequences of the different acceptor sites indicates that they all conform to the consensus sequence. Analysis of the ATG surrounding sequence shows that initiator ATG may be positively selected according to Kozak's rule.     

Organization of the GAL1-GAL10 intergenic control region chromatin.

A defined, "far upstream" promoter element, the Upstream Activator Sequence (UAS), which mediates the galactose dependent induction of expression of the GAL10 gene in yeast, is the locus of an anomalous, mainly expression independent chromatin structure. The UAS chromatin shows three symmetrical DNase I hypersensitive sites in brief digests, a loss of the 10 bp DNase I ladder pattern in more extensive digests and an enhanced staphylococcal nuclease sensitivity. This anomalous structure is confined to a small region of the UAS. The surrounding chromatin, including the TATA box regions shows a more typical, but expression dependent nucleoprotein, probably nucleosomal, organization. Such an arrangement may be a common feature of eukaryotic genes.