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Q X Yu

Publications and source records attributed to Q X Yu.

At least 19 recordsLinked to original sources
PubMed2003

Molecular cytogenetic detection of paternal chromosome fragments in allogynogenetic gibel carp, Carassius auratus gibelio Bloch.

In gynogenesis, sperm from related species activates egg and embryonic development, but normally does not contribute genetically to the offspring. In gibel carp, Carassius auratus gibelio Bloch, however, gynogenetic offspring often show some phenotypes apparently derived from the heterologous sperm donor. This paternal effect of allogynogenesis is outstanding in an artificial clone F produced by cold treatment of clone E eggs after insemination with blunt-nose black bream (Megaloabrama amblycephala Yin) sperm. Karyotype analysis revealed 5-15 supernumerary microchromosomes in different individuals of clone F in addition to 156 normal chromosomes inherited from the maternal clone E. A painting probe was prepared from the microdissected microchromosomes, and used to investigate the origin of these microchromosomes. Strong positive signals were detected on each microchromosomes of clone F and on 4 pairs of chromosomes in blunt-nose black bream, whereas no signals were detected on the chromosomes of clone E. This result indicates that some paternal chromosome fragments of blunt-nose black bream have been incorporated into the artificial clone F. Therefore, the manipulation of allogynogenesis may provide a unique method to transfer DNA between diverse species for fish breeding.

Animals↗
PubMed2003

Ag-staining pattern, FISH and ISH with rDNA probes in the rice field eel (Monopterus albus Zuiew) chromosomes.

The present paper reports the Results of rice field eel (Monopterus albus Zuiew) chromosomal analysis by Ag-staining techniques, FISH and ISH with 18S rDNA. Both the Ag-NORs and the hybridization signals were observed on the pericentromeric region of chromosome pairs 3 and 7. The Ag-NORs and the hybridization signals on homologous chromosomes 3 and 7 were corresponding to each other. And rDNA genes were mapped to bivalents 3q12-q24 and 7q14-q26. No heteromorphic sex chromosome pair was identified. The Results obtained were discussed with respect to the feature of Ag-NORs and the position of rDNA genes on chromosome pairs 3 and 7.

Animals↗
PubMed2002

Sex chromosomes in the spiny eel (Mastacembelus aculeatus) revealed by mitotic and meiotic analysis.

Lower vertebrates like fish exhibit tremendous diversity in sex determination. There are wide interplays between environment-dependent sex differentiation ranging from natural hermaphroditism to sex reversal and genetic sex determination. Diverse systems of male and female heterogamety coexist in fish and sex chromosomes are rarely distinguishable in morphology. Here we show that the spiny eel ((Mastacembelus aculeatus) of the Perciformes, has evolved highly heteromorphic X and Y chromosomes. The metacentric X and Y chromosomes are the largest among 24 homologous pairs, differ from each other in size and morphology, and become distinct after C-banding because of conspicuous heterochromatin blocks which exhibit alternate distribution around the centromeric region. Chromosome painting using probes from the microdissected X chromosome revealed sequence homology between X and Y. During the pachytene stage of meiosis the X and Y form a bivalent. However, their synapsis is delayed which is particularly evident in one terminus. Therefore, the X and Y have resulted from a pericentric inversion in the Y. We conclude that M. aculeatus represents an example of a highly advanced stage of sex chromosome evolution in fish.

Animals↗
PubMed2001

[Painting the chromosomes of fishes with human sex chromosome-specific DNA probes].

Chromosome painting is one of the effective methods in studying the evolution of genomes. The chromosomes of the species of fishes--M. aculeatus, M. albus and D. rerio were painted respectively with human X and Y chromosome-specific DNA probes. The results showed that some homologous segments of human X chromosome were found in the genomes of all the three kind of fishes, all the segments were scattered on several pairs of homologous chromosomes in each kind of fish. But no homologous segment of the human Y chromosome was found.

Animals↗
PubMed2000

[The conservative region sequence analysis of PdSox9 in Paramisgurnus dabryanus].

Degenerate primers within HMG-box analyzed the Sox genes of P. dabryanus. Three amplification bands with the length 220, 550 and 1500 bp respectively were observed. A novel gene was obtained from the 550 bp band. The identity of possible amino acid sequence to Sox9 of human, mouse and chicken is 94%. The similarity to HSOX10, MSox10, HSRY, MSry is 87%, 55%, 40% and 47% respectively. So, it was named PdSox9. Northern blotting result showed that it overexposes in adult testis and brain.

Amino Acid Sequence↗
PubMed2000

[The chromosome mapping of PdSox8 and PdSox9 in two kinds of loaches].

With the Dig-labelled PdSox8 and PdSox9 as probes, the chromosome mapping of Sox8 and Sox9 in Paramisgurnus dabryanus and Misgurnus anguillicaudatus were analyzed by chromosome in situ hybridization technique. In P. dabryanus, the PdSox8 and PdSox9 were successfully localized in the No. 4 and No. 2 telocentric chromosome respectively, the relative distance to centromere is 40.2% and 67.5%; In M. anguillicaudatus, they were localized in the No. 9 and No. 6 telocentric chromosome respectively, the relative distance to centromere is 58.3% and 30.8%.

Animals↗
PubMed1998

[Px gene of rice-field eels primed in situ labeling].

Peroxidase (Px) gene of rice-field eels (Monopterus albus) was successfully localized to the segments of two bivalents, 8q15-q26 and 11q32-q37 with digoxigenin labeled primed in situ labeling (PRINS) technique, which is utilized for localization of single copy gene of fish for the first time. Our results demonstrated the possibility of mapping genes in fish by the DNA probes of other species and PRINS technique.

Animals↗
PubMed1996

[Effects of NA and 5-HT on the spontaneous and evoked activities of Purkinje cells in cerebellar slice].

Effects of NA and 5-HT perfusion on the spontaneous activity and evoked responses of the Purkinje cells (PCs) to stimulation of white matter were studied in the rat cerebellar slices. The results were as follows: (1) Perfusion with NA could elicit inhibitory, excitatory or biphasic responses of the spontaneously discharging PCs, with inhibitory response in dominance (79.8%). 5-HT perfusion could also exert either excitatory or inhibitory effect on PC spontaneous activity. (2) When NA and 5-HT were perfused successively, NA tended to inhibit while 5-HT tended to excite in 53.8% of the tested cells. (3) Most of the complex spike (CS) and simple spike (SS) responses evoked by white matter stimulation could be potentiated by NA (68.2%, 57.1%) or depressed by 5-HT (60.0%, 68.2%). (4) On the same cell under successively perfusion with NA and 5-HT, the evoked CS and SS responses of most cells (60.0%, 52.9%) showed a tendency to be facilitated by NA and suppressed by 5-HT. These results suggest that aminergic afferent fibers, by releasing NA and 5-HT, may affect PC's excitability and responsiveness to synaptic inputs from mossy and climbing fibers, thus playing an important role in the cerebellar function.

Afferent Pathways↗
PubMed1996

[Effects of dorsal raphe stimulation on activities of cerebellar nuclear neurons in the rat].

The effects of stimulating dorsal raphe nucleus (DR) on activities of three deep cerebellar nuclei (DCN) (medial, interposed and lateral nuclei) were investigated. The results were as follows: (1) Stimulation of DR elicited three types of responses, inhibition, excitation, and biphasic response (excitation-inhibition or inhibition-excitation) from DCN cells with responsive latencies ranging from 10 to 84 ms. The majority of responsive cells showed an inhibitory response (76%-90%) with a latency less than 30 ms. (2) The spontaneous discharge frequencies of the DCN cells were 5 to 120 Hz. The cells with higher spontaneous discharge frequencies showed low responsive rates to the DR stimulation, as compared with lower firing frequency cells. (3) The depressive effect of DR stimulation could be blocked by injection of 5-HT2/1c antagonist methysergide (66.7%-83.3%). These results suggest that raphe-cerbellum serotonergic afferent fibers may be involved in the cerebellar sensorimotor integration process by exerting some modulatory effects on the DCN cell's activities.

Animals↗
PubMed1995

Cerebellar interpositus nucleus modulates neuronal activity of lateral hypothalamic area.

Effects of stimulating the cerebellar interpositus nucleus (IN) on the neuronal activity of lateral hypothalamic area (LHA) were first observed in the cat. The results showed that (1) IN stimulation could elicit inhibitory, excitatory, inhibitory-excitatory and excitatory-inhibitory responses from LHA neurones, with a majority of inhibitory responses (46.9%); (2) the responsive latencies of LHA neurones to IN stimulation ranged from 5 to 45 ms, while most (83.6%) showed a short latency of < 15 ms; (3) of 67 LHA neurones which responded to the IN stimulation, 42 (62.7%) cells were identified to be glucose-sensitive neurones. These results suggest that IN may be involved in the role of LHA modulating food intake behaviour, as well as other non-somatic functions.

Animals↗
PubMed1994

The microvasculature of human infant oral mucosa using vascular corrosion casts and india ink injection. II. Palate and lip.

The microvasculature of human hard and soft palate and lip originating from four infant males and six females, aged 6 months to 2 years was studied by scanning electron microscopy of vascular corrosion casts and light microscopy of India ink injected specimens. The capillary loops of the hard palate mucosa and vermilion border of the lips were found to be tall, numerous and consisted of primary, secondary and tertiary loops. Those of the soft palatal and labial mucosa were short, few in number and demonstrated a simple hair-pin shape originating directly from the subpapillary vascular network. It was concluded that the configuration of capillary loops is not only determined by the shape of the connective tissue papillae in the lamina propria but also influenced by the functional demands characteristic of the different areas of the oral mucosa.

Carbon↗
PubMed1993

[Effects of stimulating lateral hypothalamic area and ventromedial nucleus of hypothalamus on cerebellar cortical neuronal activity in the cat].

In pentobarbital anaesthetized cat, stimulating lateral hypothalamic area (LHA) and ventromedial nucleus (VMN) of the hypothalamus could elicit inhibitory, excitatory or inhibitory-excitatory responses of cerebellar Purkinje cells (PC) and non-Purkinje cells (NPC) in the loubles VI and VII. The majority of responses are inhibitory (80.4%) usually with a latency of 10-20 ms, or occassionaly as long as 90 ms. Usually stimulation of LHA was more effective and NPC was more responsive. The aforementioned inhibitory response could be blocked by iv. chlorpheniramine. The possible role of the hypothalamo-cerebellar activity was discussed.

Animals↗
PubMed1993

[Effect of stimulation of gigantocellulars reticular nucleus on the spontaneous and evoked activities of cerebellar Purkinje cells in the rat].

In anesthetized and paralyzed rats, the effect of stimulation of Gigantocellulars Reticular Nucleus (Gi) on spontaneous and evoked simple spike discharges of cerebellar Purkinje cells (PCs) was examined. The result were as follows: (1) Stimulation of Gi elicited either inhibitory or excitatory effect on spontaneous simple spikes of PCs with latency less than 20 ms, being inhibitory in the most cases. The inhibitory responses lasted for 40-100 ms, while the excitatory ones were sometimes longer than 200 ms; (2) Injection of 5-HT2 receptor antagonist methysergide could reversibly attenuate or block the inhibitory effect of Gi stimulation on spontaneous simple spike discharges of PCs; (3) The evoked simple spike responses of PCs elicited by stimulating the contralateral cerebral sensorimotor cortex could be markedly suppressed or potentiated by the conditioning Gi stimulation. The results demonstrated that Gi-cerebellar pathways exists, with some fibers being serotonergic. Gi-cerebellar afferent fibers may have certain modulatory effects on PCs through synaptic and/or non-classical chemical synaptic transmission. The Gi-cerebellar afferent fiber projection may play important roles in some cerebellar functions, such as regulating myotonia and posture.

Animals↗
PubMed1992

The microvasculature of human oral mucosa using vascular corrosion casts and India ink injection. I. Tongue papillae.

The microvasculature of human tongue papillae originating from 9 males and 6 females, aged 0.5 to 2 years was studied by scanning electron microscopy (SEM) of vascular corrosion casts and by light microscopy (LM) of India ink injected specimens. All papillae showed a microvasculature characterized by primary, secondary and tertiary capillary loops. In the filiform papillae the loops were generally arranged in a corolla-like pattern with the tertiary loops demonstrating a hair-pin shape. The fungiform papillae showed basically a similar architectural pattern although the loops were somewhat more compact and complex in structure. A small, shallow depression of the tertiary loops at the top of these papillae was found to be occupied by a prominent rete ridge of the surface epithelium. There was a gradual transition from filiform to foliate papillae, the latter appearing as rows of coalesced filiform papillae. The circumvallate papillae easily identified by the surrounding furrow showed a rather complex and compact pattern of capillary loops of which typical hair-pin shaped tertiary loops dominated the periphery of the papilla. Small grooves or depressions in the vascular network were found to be occupied by rete ridges of the overlying mucosal epithelium.

Capillaries↗
PubMed1991

Adenomatoid odontogenic tumor: biologic profile based on 499 cases.

Topographically, the AOT occurs in peripheral and central variants, the latter further in follicular (with embedded tooth) and extrafollicular (no embedded tooth) types. The AOT is slow growing with few or no symptoms. Tumor growth may cause displacement of teeth rather than root resorption. The follicular AOT mimics a follicular cyst, the extrafollicular a residual or "globulo-maxillary" cyst and the peripheral a gingival fibroma. All variants of AOT show identical histologic features. The central variants account for 97.2%, 73.0% of which are follicular. The follicular variant (M:F ratio 1 to 1.9) is three times as frequent as the extrafollicular. The follicular variant is diagnosed earlier in life (mean age 17 yr) than the extrafollicular (mean age 24 yr). 53.1% of all variants occur within the teens (13-19 yr). Follicular AOT is associated with one embedded tooth in 93.2%. Maxillary permanent canines account for 41.7% and all four canines for 60.1% of AOT-associated embedded teeth. Ranking four among the odontogenic tumors the AOT is not a particularly rare tumor. Conservative surgical excision is the treatment of choice. Documented recurrences have not been reported.

Adolescent↗
PubMed1991

[Electron microscopic observation of synaptonemal complexes in spermatocytes of six species of fishes].

The synaptonemal complexes (SCs) in spermatocytes of six species of fishes were detected with a combination of surface spreading and silver staining technique and observed under both light and electron microscopes. These fishes are Tilapia nilotica, T. mossambica and Mastacembelus sinensis of Perciformes. Sarcocheilichthys nigripinnis, Pseudorasbora parva and Hemibarbus maculatus of Gobioninae in Cypriniformes. The formation of SCs started in Zygotene and completed at Pachytene. During the pachytene, each SC was morphologically intact, preferentially stained and attached to the nuclear envelope by a dense terminal plaque. Interlock in SCs frequently occurred in Zygotene. In several cases breakage and disentangling of interlocked lateral elements were observed. SCs disappeared in diplotene. The pairing of the SCs started at telomeres and stretched towards kinetochore. The sex determination of Mastacembelus sinensis was xx/xy. The X and Y chromosomal SCs' axes had a distinctive morphology at pachytene and were clearly distinguishable from autosomal SCs. The X and Y chromosomes begain to pair at early pachytene. The X and Y chromosome axes paired to form a length of SC that is somewhat longer than the unpaired portion at the mid-pachytene. There was a dense substance at unpaired portion. Quantitatine evaluation demonstrated that relative length and arm ratio were distinctive characteristics for each autosomal SC. The consistency of relative length and arm ratio indicates the stability of the techniques. The idiograms of SC karyotypes of three species (Tilapia niloticus, T. mossambicus and Mastacembelus sinensis) have been constructed.

Animals↗