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2011年  第32卷  第5期

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We investigated the complete mitochondrial genome (mitogenome) of Argyreus hyperbius. The 15 156 bp long genome harbored the gene content (13 protein coding genes, 22 tRNA genes, 2 rRNA genes and an A+T-rich region) and the gene arrangement was identical to all known lepidopteran mitogenomes. Mitogenome sequence nucleotide organization and codon usage analyses showed that the genome had a strong A+T bias, accounting for A+T content of 80.8%, with a small negative AT skew (−0.019). Eleven intergenic spacers totaling 96 bp, and 14 overlapping regions totaling 34 bp were scattered throughout the whole genome. As has been observed in other lepidopteran species, 12 of the 13 protein-coding genes (PCGs) were initiated by ATN codons, while the COI gene was tentatively designated by the CGA codon. A total of 11 PCGs harbored the complete termination codon TAA, while the COI and COII genes ended at a single T residue. All of the 22 tRNA genes showed typical clover structures except that the tRNASer(AGN) lacks the dihydrouridine (DHU) stem which is replaced by a simple loop. The intergenic spacer sequence between the tRNASer(AGN) and ND1 also contained the ATACTAA motif, which is conserved in all other lepidopterans as well. Additionally, the 349 bp A+T-rich region was not comprised of large tandem repetitive sequences, but harbored a few structures common to other lepidopteran insects, such as the motif ATAGA followed by a 20 bp poly-T stretch, a microsatellite-like (AT)9 element preceded by the ATTTA motif, and a 5 bp poly-A site present immediately upstream of tRNAMet. The mitochondrial genomic sequence features found in this study not only contribute to genetic diversity information of the group, but also are useful in future studies of the endangered nymphalid butterfly in population genetic dynamics, species conservation, phylogeography and evolution.
Tetrahymena has a high genetic polymorphism of metallothionein proteins. These protein isoforms can be divided into subfamilies 7a and 7b. We used real-time quantitative PCR to test the expression levels of Tetrahymena thermophila metallothionein genes MTT2 and MTT4 after exposure to different inducers, including Hg, Cu, Cd, Zn and H2O2. Both genes were most efficiently induced by Cu and secondly by Hg. Their expression was slightly up-regulated after exposure to Cd and Zn, but down-regulated by H2O2. The expression pattern differed from those reported in the 7a subfamily, but was consistent with 7b subfamily members. However, the induced expression level of MTT4 was much higher than that of MTT2, which might be due to differences in their upstream regulatory elements (AP-1, MRE). The high similarities in gene structures and functions indicate that MTT2 and MTT4 were generated by recent gene duplication following the dosage balance model.
Accumulated evidence indicates that the activating transcription factor 4 (atf4) is a developmentally relevant gene. Here, we report on the characterization of atf4 in Xenopus embryos, which is differentially expressed in the central nervous system, eyes, blood, and the pronephros, as well as in developing endodermal organs such as the stomach, duodenum, liver, and pancreas. Ectopic expression of atf4 in the animal hemisphere of Xenopus embryos had no obvious effects on the induction of neural progenitors, but suppressed neurogenesis and eye formation without promoting apoptosis. Our data suggest that tightly controlled atf4 activities may be crucial for normal neurogenesis and early eye patterning.
Coagulation factor X (FX) plays an important role in the immune response of mammals. In this study, the full length cDNA sequence of the ayu FX gene, 1817 bp in length excluding 3'-polyA tail, was determined for the first time. The sequence contained an open reading frame, which encoded a protein of 453 amino acids with a molecular weight of 5.07 × 104. The predicted protein had motifs typical of animal FX, and its N-terminal 24 residues were the signal peptides. Sequence comparison showed that ayu FX shared 53% amino acid sequence identity with zebrafish FX. In healthy ayu, FX mRNA was expressed mainly in the liver and weakly in the brain and gill. After Listonella anguillarum infection, liver FX transcriptions significantly increased, and peaked at 16 h post infection. The serine protease motif of ayu FX was expressed in Escherichia coli and was subsequently used for antiserum preparation. Western blotting analysis revealed that serum FX significantly increased in bacterially infected ayu fish. In conclusion, the ayu FX gene expression was significant in the progress of bacterial infection, which suggests FX’s role in fish immune response.
Schizophrenia is a common and complex psychiatric disorder. Significant evidence has suggested that genetic factors play pivotal roles in the etiology of schizophrenia. More than 100 schizophrenia candidate genes have been reported; however, many of them do not have satisfactory replications among different populations. Among these genes, RELN is thought to be associated with schizophrenia in many populations, suggesting it is a real risk gene for this disorder. Identified in the GWAS study, single nucleotide polymorphism (SNP) rs7341475, located in intron 4 of RELN, has been successfully replicated in subsequent investigations, implying its potential contribution to schizophrenia susceptibility. To investigate the association of rs7341475 with schizophrenia in Chinese populations, a case-control association analysis was conducted with samples from Yuxi (400 cases and 400 controls) in southwestern China. The results do not indicate any association of rs7341475 with schizophrenia, which suggests it is not a risk SNP for schizophrenia in Han Chinese.
Previous research on gene expression analysis and association tests have suggested that RELN is a risk gene for schizophrenia in world populations. Based on the reported down-regulation of RELN in schizophrenia patients compared with normal subjects, we speculated that variants in the RELN promoter region may confer risk for schizophrenia. In this study, we investigated the associations of three SNPs in the promoter region of RELN with schizophrenia in a case-control sample from southwestern China (940 cases and 1 369 controls). The results suggested that none of the SNPs showed significant associations in our sample, indicating the risk variants for schizophrenia in RELN may not be located in the promoter region. We also performed meta-analysis by combining our data with previously reported data on the Chinese population with a total sample size of 2 843 individuals, and the result remained non-significant. Collectively, our results suggested variants in the RELN promoter may not harbor risk SNPs associated with schizophrenia in the Chinese population.
The BRCT domain (after the C-terminal domain of a breast cancer susceptibility protein) is an important signaling and protein targeting motif in the DNA damage response system. To clarify possible interaction mechanisms between the BRCT domain, which contains phosphate binding pocket and its phosphorylated ligand, we analyzed the structural conservation and electrostatic surface potentials of XRCC1 BRCT1, PTIP BRCT4, ECT2 BRCT1 and TopBP1 BRCT1. The results showed common structurally conserved and positively charged grooves located around the phosphate binding pockets of these domains. These grooves possibly act as functional sites in the four BRCT domains due to the extensive existence of similar grooves in the BRCT domains containing phosphate binding pocket. The two sides of the groove were composed of positively charged and hydrophilic residues and the bottom was composed of hydrophobic and hydrophilic residues, suggesting that the groove binds to BRCT domain ligand mainly through electrostatic and hydrophobic interactions. The groove was mainly located in individual BRCT domains and differences in shape and charge distribution among the four BRCT domain grooves were observed, indicating that ligand binding specificity was predominantly determined by individual BRCT domains. The groove was centered by the phosphate binding pocket, implying that the groove interacted with residues located at both the N-terminal and C-terminal sides of the phosphorylated residue.
To investigate population structure and marker assisted breeding, fast isolation by AFLP of sequences containing repeats (FIASCO) and GenBank database mining were used to develop novel microsatellite markers for sea perch (Lateolabrax japonicus). Genomic DNA fragments containing SSR sequences were captured by hybridization to (GT)13 biotin-labeled probe and were ligated to PMD18-T vector. Among 150 randomly chosen clones from the SSR-enriched library, 66 sequences contained microsatellite motif over five repeats. In addition, 540 cDNA sequences and 132 ESTs of Lateolabrax japonicus were downloaded from GenBank and screened for di-, tri- and tetra-nucleotide repeats, while 22 sequences were found to contain microsatellites. As a result, 15 microsatellite loci were shown to be polymorphic in 30 Lateolabrax japonicus individuals, with the alleles ranging from two to ten, the observed heterozygosities from 0.6000 − 1.0000, and the expected heterozygosities from 0.5079 − 0.8890. Four loci (SP17, SP52, SP94 and SP468) were deviated from HWE in the sampled population after Bonferroni’s correction, and no linkage disequilibrium was found among all loci (P<0.003), whereas null alleles were detected at locus SP52 ( P<0.05). Among 15 polymorphic loci, the PIC values, which can be used for related population genetics analysis, were all above 0.5, with the exception of SP17 and SP468.
Successful crossbreeding between Oreochromis niloticus and Sarotherodon melanotheron to produce a commercial hybrid has been difficult. The karyotypes and isoenzyme of these two species and their reciprocal hybrids (O. niloticus ♀ × S. melanotheron ♂, S. melanotheron ♀ × O. niloticus ♂, the last not included in the isoenzyme study) were investigated via metaphase chromosomes obtained from head kidney cells and electropherogram of lactate dehydrogenase (LDH) isoenzymes from the liver, kidney, white muscle, heart, and eye balls. The diploid chromosome number (2n=44) and the fundamental number (NF=50) of the four tilapia genotypes were the same. However, the karyotype of O. niloticus had three pairs of sub-metacentric (sm), twelve pairs of sub-telocentric (st), and seven pairs of telocentric (t) chromosomes, while S. melanotheron had one pair of metacentric (m), two pairs of sm, 12 pairs of st, and seven pairs of t chromosomes. The reciprocal hybrids both showed a mixed karyotype range between their parents: 0.5 pair of m, 2.5 pairs of sm, 12 pairs of st, and seven pairs of t chromosomes. In view of the electropherogram of isozymes, only the LDH of the kidney showed significant clear bands, with five bands in O. niloticus, three bands in S. melanotheron, and duplicated six bands in the hybrids. The bands varied depending on their activities and mobilities. We considered that the differences in karyotype and isoenzyme were related to the genetic mechanism for post-mating isolation, and provided some additional basic genetic background of their taxonomy.
In the present study, the differences between addictive memory and ordinary memory were investigated by morphine-induced and food-induced conditioned place preference (CPP) in adolescent and adult mice. The result showed that: 1) morphine-induced CPP could be established in adult mice but not in adolescent mice. 2) food-induced CPP could be established both in adolescent and adult mice. This study indicated that between adolescent and adult mice, there was no difference in ordinary memory, but for addictive memory, they were quite different. Our data suggested that the development of addictive memory and ordinary memory system in mouse brain might not be paralleled.
Psychophysical experiments on human and animal subjects have proven that aged individuals show significantly reduced visual contrast sensitivity compared with young adults. To uncover the possible neural mechanisms, we used extracellular single-unit recording techniques to examine the response of V1 (primary visual cortex) neurons as a function of visual stimulus contrast in both old and young adult cats (Felis catus). The mean contrast sensitivity of V1 neurons to visual stimuli in old cats decreased significantly relative to young adult cats, consistent with findings reported in old primates. These results indicate that aging can affect contrast sensitivity of visual cortical cells in both primate and non-primate mammalian animals, and might contribute to the reduction of perceptual visual contrast sensitivity in aged individuals. Further, V1 cells of old cats exhibited increased responsiveness, decreased signal-to-noise ratio, and enlarged receptive field (RF) size compared with that of young adult cats, which indicated that decreased contrast sensitivity of V1 neurons accompanied a reduction of intracortical inhibition during senescence.
The shallow lake wetlands in the middle and lower Yangtze River ?oodplain are important wintering and stopover habitats for migratory waterbirds on the East Asia-Australia Flyway. With increasing fishery practices in recent years, however, the wetlands have deteriorated significantly and now threaten wintering waterbirds. To gain insight into the influence of deteriorating wetlands on waterbirds, we conducted a survey of wintering waterbird species, population size, and distribution across 11 belt transects in Caizi Lake and Shengjin Lake, two shallow lakes along the Yangtze River in Anhui Province from November 2007-April 2008 and from November 2008-April 2009, respectively. The impacts of different fishery patterns on the distribution of waterbirds were also analyzed. A total of 43 waterbirds species belong to 7 orders of 12 families were counted during the surveys, of which 38 were found in Caizi Lake with a density of 8.2 ind./hm2, and 42 in Shengjin Lake with a density of 3.5 ind./hm2. Geese (Anser cygnoides), bean geese (Anser fabalis), tundra swan (Cygnus columbianus), and dunlin (Calidris alpina) were the dominant species in the two shallow lakes. Species number and individual assemble reached maximum at the end of December and in early January of the following year, without coincidence of the largest flock for different ecological groups. Based on waterbird diversity across the 11 belt transects and the fishery patterns, habitats could be divided into three groups. Gruiformes, Anseriformes and Charadriiformes had relatively higher densities in the natural fishery zones and lower densities in the cage fishery zones; whereas, the density of Ardeidae showed little change across all lake zones. It is important to develop sustainable fishery patterns in shallow lakes along the middle and lower Yangtze River floodplain to better protect resources of wintering waterbirds.
The Karst mountain area along the Sino-Vietnam border of southwest Guangxi has been designated a “Global Biodiversity Hotspot” since 2003. We conducted a survey of pheasant species in this area, with seven species recorded, namely Chinese Francolin (Francolinus pintadeanus), Bar-backed Partridge (Arborophila brunneopectus), Mountain Bamboo Partridge (Bambusicola fytchii), Chinese Bamboo Partridge (Bambusicola thoracica), Red Junglefowl (Gallus gallus), Silver Pheasant (Lophura nycthemera) and Common Pheasant (Phasianus colchicus). Analysis and comparison of the distribution and spatial niche of these seven pheasant species revealed that Red Junglefowl had the widest spatial niche, while Chinese Francolin had the narrowest. The spatial niche overlap index was high between Chinese Francolin and the Common Pheasant, Chinese Bamboo Partridge, and Red Junglefowl. With narrow distribution range, small population, and lower ecological adaptability, it is likely that the Bar-backed Partridge is the most vulnerable pheasant species in this area. The results suggest more research and conservation measures are required for pheasant habitat protection in the Karst areas of southwest Guangxi.
The winter feeding sites of White-browed Hill Partridge (Arborophila gingica) was investigated in Jiuwanshan National Nature Reserve in Guangxi from November to December 2010. With the 34 found feeding sites, the used sites (n=25) were compared with the control sites (n=25), and 19 parameters were measured at each site. The results showed that White-browed Hill Partridge randomly use broadleaved forest, mixed coniferous-broadleaved forest, mixed broadleaved-bai bamboo (Indosasa shibataeoides) forest and bai bamboo forest, while they rarely occurred in mao bamboo (Phyllostachys edulis) forest and China fir (Cunninghamia lanceolata) forest. The birds prefer to select the southeast-facing slops of 20 − 44 degrees, with smaller bai bamboo-shrub and grass density, lower bai bamboo-shrub and grass coverage, and greater shatter coverage. We found that the main selection factors at the used and control feeding sites, using the Step DA, were the shatter coverage, slope, and bai bamboo-shrub coverage. The veracity to distinguish was 86.0%. The feeding sites selection of White-browed Hill Partridge is associate with food resources and safety index, thus, we suggest that the protection should focus on these two aspects.
Tibetan antelope (Pantholops hodgsoni) are an endemic and endangered species of the Tibetan Plateau. Ex situ conservation may represent an important way to protect Tibetan antelope; however, this process may influence aspects of their behavior. To investigate the ability of these antelopes to adapt to new environments, a study on the vigilance behavior of captive antelope in different seasons was conducted. Using instantaneous scan sampling, focal animal sampling, and all-occurrence recording methods, the vigilance rate and vigilance time of captive male and female Tibetan antelope during cold and warm seasons were recorded and analyzed. Very significant sex differences in vigilance behavior were observed during the warm season, but were not observed in the cold season. Interestingly, vigilance behavior showed seasonal variation as there were significant differences in vigilance time and vigilance rate between cold and warm seasons in both males and females. Specifically, males and females showed more vigilance during the cold than warm season. No interaction between season and sex was found in the vigilance behavior of antelope. Comparing vigilance behavioral characteristic with the Kekexili Tibetan antelope indicated that captive antelope could adapt to a new environment.
A new blind loach of the genus Triplophysa was collected in 2007 from a cave in Leyi village, located near Chuanshan Town, Huangjiang County in the Guangxi Zhuang Autonomous Region of southern China. The new species, Triplophysa huangjiangensis sp. nov, can be distinguished from its congeners by eyes and scales absent; caudal-fin forked; adipose keel present; lips with furrows; distal margin of dorsal-fin truncate, dorsal fin origin much closer to caudal-fin base than snout tip; 8–9 branched dorsal-fin rays; 6–7 branched pelvic-fin rays; 6 branched anal-fin rays; 10–11 branched pectoral-fin rays; 13–14 branched caudal-fin rays; pectoral-fin length 52.3%–70.7% the distance between pectoral-fin origin to pelvic-fin origin; dorsal-fin origin posterior to vertical line of pelvic-fin origin; outer rostral barbel longer than other two pairs of barbels, with 47.0%–73.8% of lateral head length; anterior nostril with elongate barbel-like tip; and posterior chamber of gas-bladder developed, reaching pelvic-fin origin.
A nemacheilid loach not recorded for China so far has been collected during a survey of the Nanxinghe River, Luosuojiang River subbasin, Mekong basin. The specimens could be identified as Schistura porthos Kottelat, 2000. The occurrence in the Luosuojiang River subbasin is a distributional range extension.
A new record species—the woolly-necked stork (Ciconia episcopus)-for China has been detected during a field survey of Shangri-La county, Diqing Tibetan autonomous prefecture, Yunnan province, June 10th, 2011. Ciconia episcopus is the least concern spices according to IUCN.