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2012年  第33卷  第3期

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研究论文
Copulation patterns are important to understanding male mating strategies and stabilization strategies of social organizations in primates. However, information on copulation patterns of Asian primates is relatively rare. This study was undertaken to collect data on mating behavior and birth seasonality of Black-and-white Snub-nosed monkeys (Rhinopithecus bieti) using all occurrence sampling and Focal animal-scan sampling methods at Mt. Lasha, between January and December, 2011. Our study focused on observing mating frequency and birth rates. Snub-nosed monkeys mate year round, with two observable peaks: one reproductive peak during the mating season, roughly from August to October, and a second non-breeding peak during the birth season. It is unclear what biological significance this non-reproductive mating peak has. During our observation, we noted a lower ratio of mount to ejaculation and rare ejaculatory copulations, which indicated that every mating would not result in ejaculation. This study corroborates the previous view that the Rhinopithecus bieti’s copulatory pattern is likely multiple-mount ejaculation (MME) or at the upper part of mating continuum of single-mount ejaculation (SME) toward MME. More ejaculatory copulations initiated by males than females indicate that MME is not only a mating strategy of males, but that males can influence the position of their copulatory pattern on the continuum between SME and MME. The mating frequencies significantly correlated with the birth rates with a delay of 6 to 7 months. Monkeys gave birth within a strict seasonality with a birth peak of March, which confirms the previous view. Infants were born with a certain degree of synchronization, but different populations displayed different modes of synchronizations.
Bird song has two key functions: attraction and competition. The structures of these songs have been shaped by both intra- and intersexual selection. Accordingly, there are ome species that appear to use different parts of song to attract females and repel males. Alongside this functional separation, the structure of song can also have significant divergence. We studied the songs from 32 individuals of Phoenicurus auroreus, recorded in Beijing Xiaolongmen forest Park during the 2011 breeding season. The song of Phoenicurus auroreus consists of two distinct parts, a stereotyped and variable part. Significant differences between these two parts were observed between all the variables we measured. Based on the stereotyped part, the rate of correct individual identification is satisfactory, and most of songs can be correctly classified.
Based on four surveys of eggs and larvae in the Yangtze estuary in 2005 (April and November) and 2006 (April and September), combined with the historical data of the wetland in 1990 (September) and 1991 (March), we analyzed seasonal changes in fish species composition and quantity of ichthyoplankton. Thirty-six species of egg and larvae were collected and marine fish species were the highest represented ecological guild. Average fish species and average abundance in spring were lower than in autumn for every survey. The total number of eggs in brackish water was higher than in fresh water, but the total number of larvae and juveniles in brackish water was lower. The abundance of eggs and larvae during from 2005 to 2006 in both spring and autumn was higher compared to those from 1990 to 1991. Obvious differences in species composition in September between 1990 and 2006 were found, especially for Erythroculter ilishaeformis and Neosalanx taihuensis. Fish species composition and quantity within the ichthyoplankton community has obviously changed in the Yangtze estuary over the last 20 years.
The Siberian sturgeon (Acipenser baerii Brandt), a chondrostean, occupies an important position in the evolution of the electroreceptor. In order to more fully understanding the evolution of these receptors, we examined the development of the lateral line system during early ontogeny of the Siberian sturgeon by using light and scanning electron microscopes. We detected four major events in this process: the lateral line placodal development, the sensory ridge formation, the receptor formation and the canal formation. On day 1 of post hatching, all six lateral line placodes are present and the posterior lateral line placode starts actively migrating posteriorly along the mid-line of the trunk, depositing neuromasts at intervals on the way of migration. The other lateral line placodes elongate to form sensory ridges according to its destination line pattern over the head, all containing primordial neuromasts. By day 7, ampullary organs rise from the lateral zones of the ventral of the head, though this may lag up to one week behind of that of the neuromasts. On day 9, the epidermis under the neuromast slowly invaginates, and the bony lateral line canals begin to form. Towards day 29, the epidermal cells surrounded some single openings of the ampullary organs at the ventral surface of the head, begin to migrate, and then transform into 3 to 4 aggregate openings. By this point, abundant microvilli are visible on the surface of the receptor epithelium, similar to the structure in elasmobranches and other sturgeons. On the day 57 of post hatching, the trunk canal is fully embedded into the lateral scutes. By then, the majority of ampullary organs are highly concentrated on the ventral rostrum, arranged in clusters of 3?4, distributing closely such as the shape of quincunx, thus completing the formation of the lateral line system.
Pangolins are unique mammals in that they possess scales that serve a protective biological function. As an important raw material of traditional medicine, illegal trades of these scales are frequent and difficult to investigate or prosecute. We used allometric models of dry weight of scales to compare 35 Chinese pangolins (Manis pentadactyla) and 119 Malayan pangolins (Manis javanica). Our results showed that the dry weight of scales increases significantly faster with the length of head and body in Malayan pangolins (P=0.005), while dry weight of scales is positive (slope=3.725) in Malayan pangolins but isometric (slope=3.105) in Chinese pangolins. The differences in morphology between these species may reflect an evolutionary adaptation to different environments; Malayan pangolins in tropical regions appear to suffer from greater predation pressure than Chinese pangolins in temperate regions. We advise the conversion standards between dry weight of scales and number of individuals as 573.47 g in Chinese pangolins and 360.51 g in Malayan pangolins respectively, and when two are mixed together, average above two parameters of the median at 466.99 g. We propose these measurements be used as judicial evidences in forensic identification of related cases.
This study compares superovulation efficiency during different stages of the estrus cycle in mice by investigating the pudendum appearance, vaginal epithelial cell type, and the follicular development dynamics, in relation to the estrus cycle. We determined the stages of the estrus cycle by observing the pudendum and making vaginal smears of the Kunming mouse, and ascertaining the follicular development by making paraffin sections. Based on the observation, mice in stages of proestrus, oestrus, metoestrus and dioestrus were superovulated respectively, and their follicular developments and embryo collection results were tracked to ascertain the appropriate estrus cycle stage for superovulation. Our data showed that pudendum appearance and vaginal smears could effectively distinguish different stages of the estrus cycle and that ovarian tissue observation showed that follicular development, corpus luteum formation and luteolysis were regular during the estrus cycle. Likewise, during the estrus cycle of the Kunming mouse, pudendum appearance, vaginal epithelial cell type and follicular development were relational to one another. Superovulating mice in different stages of the estrus cycle showed marked differences both in pregnancy rate and average number of embryos collected. Proestrus was significantly better than metoestrus and dioestrus (P<0.05), and better than oestrus, but the difference between them was not significant (P>0.05). We suggest that pudendum appearance and vaginal smears can be used to distinguish estrus cycle stages and that proestrus is the optimal stage of the estrus cycle for superovulation.
Cryopreservation of sperm from Neolissochilus benasi was studied in 2011. The effects of various cryoprotectants of different concentrations, dilution ratios of milt to extender, storage volume and thawing temperature on motility of post-thawing of spermatozoa were examined to optimize cryopreservation procedures. Semen was stored in liquid nitrogen in 1.8 mL cryovial for 24 h, and the intensity of sperm motility was measured before and after cryopreservation. Post-thawing motility of frozen sperm obtained with cryoprotectants 10% MeOH or 15% EG were higher than for others. The most effective dilution ratio of milt to extender is 1:7. The maximal storage volume is 60 μL of 1.8 mL cryovial and the optimal sperm equilibration period in the extender D-15+10% MeOH was between 10-60 min. Thawing was optimal in a 37℃ water bath. When fresh sperm motility is (62.33±2.05)%, this cryopreservation protocol resulted in frozen-thawed semen with 20%-30% motile. The overall effect is not ideal, and cannot achieve extensive application. Different breeding management of different ground protection may have contributed to this result. Therefore, it is necessary to reduce stress capture induced in management of parent fish and provide suitable forming conditions. In the ex situ conservation of rare fish the broodstocks management of males is as important as that for females and the key to obtaining high quality larval fish.
The ventri-yellow pigmentation mouse (temporarily named VYSlac) arose spontaneously in the C57BL/6J inbred mouse strain, found and bred by Shanghai SLAC Laboratory Animal Co., Ltd. VYSlac presented a special phenotype marked by yellow coat on the ventral surface of neck and trunk that was without melanin deposition but maintained a normal structure. The number of melanocytes in epidermis and melanin in hair follicle of the abdominal skin of the mutant mouse were less than that of their background strain, while there was no significant difference between the dorsal skins of the two strains. This mutant phenotype was inherited as single-gene dominant inheritance, confirmed by genetic experiment, and there was no significant difference between VYSlac and B6 for other biological parameters such as weight, anatomic and histological structures of major organs and blood physiology. When the linkage relationship between the genomic DNA samples of F2 48 mice (VYSlacD2F12) and mutant phenotype were evaluated, the mutant gene was confirmed on chromosome 2 near D2Mit229. New microsatellite and SNP markers were selected to amplify genomic DNA samples of 196 F2 mice and the mutant gene was narrowed down to 5.3 Mb region between rs13476833 and rs27310903 on chromosome 2. The preliminary results of our phenotype analysis and gene location provides a solid basis for further identification of this mutant gene.
We studied the effects of starvation and re-feeding on the levels of plasma IGF-1, IGFBP-1 and expressions of hepatic IGF-1 mRNA and muscle IGF-1R mRNA in Carassius auratus gibelio. During the two week starvation period, both the levels of plasma IGF-1 and IGFBP-1 decreased and were significantly lower on day 14 (P<0.05). On the first day of re-feeding, the level of plasma IGF-1 increased sharply, to the level of control group, and had no significant changes for the remaining days. While the level of plasma IGFBP-1 was still greatly lower than that of control group at the first day of re-feeding, it increased significantly higher than that of control group by day 14 (P<0.05). During the starvation period, expression of IGF-1 mRNA in liver decreased, but it was not statistically different from that of the control group (P>0.05). During the early period of re-feeding, the abundance of IGF-1 mRNA was still significantly lower than that of control group (P<0.05), then increased to the level of control group on day 7. IGF-1R mRNA showed a decreasing trend after starvation, and reached a significantly low value on day 3 (P<0.05). After re-feeding, the abundance of IGF-1R mRNA increased to peak at day 14. These results indicate that the higher level of IGFBP-1 in serum and IGF-1R mRNA in muscle after re-feeding could improve the promoting growth effect of IGF-1 to participate in the regulation of compensatory growth.
Endogenous green fluorescent proteins (GFPs) have recently been found in amphioxus, where different characteristics of light production in different development stages and between different individuals have manifested. We identified the GFP genes in an amphioxus species Branchiostoma belcheri and monitored real time fluorescence signals of GFPs during different developmental stages to provide an insight on the GFP function in amphioxus. We found there are at least 12 endogenous GFP genes in amphioxus genome, and fluorescent expression changes in body position during different developmental stages. Additionally, GFP expression after metamorphosis development differed significantly among different amphioxus individuals, suggesting that there are multiple GFP homologous genes responsible for fluorescent expression. Expression levels of these genes varied significantly during different developmental stages, indicating that different GFP genes may have their unique functions in the development of amphioxus during specific phases of growth.
Recently, differentiation in phenotypic traits (PST) and differentiation at neutral molecular markers (FST) across populations have been become an important topic in evolutionary biology. The Minjiang River is a key genetic introgression zone between the Chinese mitten crab (Eriocheir sinensis) and the Hepu mitten crab (Eriocheir hepuensis), making it an excellent area to study their genetics and evolutionary mechanisms. We compared and analyzed PST in 14 phenotypic traits and FST in six microsatellite markers from 133 individuals of the mitten crab, sampled in the Minjiang River in 2009 and 2010. The results indicated that 11 phenotypic traits were significantly different (P<0.01) between the 2009 and 2010 populations. The mean expected heterozygosity (HE) of the 2009 populations was significantly higher (P=0.008) than that of 2010 populations, but the mean allele richness (AR), observed heterozygosity (HO) and inbreeding coefficient (FIS) were all not significant between 2009 and 2010 populations (P=0.136-0.675). FST in microsatellite markers was 0.1429 between the two years. In the 14 traits, only one trait (F2) was found with PSTST, suggesting that stabilizing selection is favoring a trait of F2; the other 13 traits were PST>FST, suggesting that directional selection is occurring. This study provides valuable data to the further study and analysis of the molecular evolution of the mitten crab, and contributes a useful reference in comparing PST and FST in other aquatic organisms.
Complete sequences of the COI gene were used to reconstruct the phylogenetic relationship among 56 species from Orthoptera. We also analyzed the reliability of Orthoptera phylogenetic relationship using translated amino acid sequences of the COI genes. The COI sequences were divided into three data sets on the basis of different codon positions to calculate the Partitioned Bremer support (PBS), and to test the phylogenetic signal in different codon positions of protein-coding genes. The result supports the monophyly of Caelifera and Ensifera; but the monophyly of Acrididae, Catantopidae, Oedipodidae, Arcypteridae and Gomphoceridae are not supported. The P-distances among families vary from 0.107 to 0.153, which are smaller than those of other families, being consist with the classification that these 5 families should be merged into one family (Acrididae). Chrotogonidae and Pyrgomorphidae belong to the superfamily Pyrgomorphoidea. Pamphagidae should be a family alone consistent with Otte’s taxonomic system. According to the PBS values, the 3rd and 1st codon positions contribution more for the Phylogenetic tree branches than the 2nd, and longer sequences contain more informative sites. We further demonstrated that it is feasible for phylogenetic studies at family level to use the genetic distances among COI sequences from different species of Orthopera.
研究报告
Pseudosciaena polyactis is an economically important species of marine fish in China that is currently declining due to overexploitation, environmental pollution and related factors. Research in to the genetic structure of Pseudosciaena polyactis populations plays a key role in protecting and promoting sustainable utilization. We collected 53 individuals of Pseudosciaena polyactis from Zhoushan, Zhejiang and sequenced and amplified the mitochondrial DNA (mtDNA) D-loop region using Polymerase Chain Reactions (PCR). The sequence length of the 53 individuals ranged from 795 to 801 bp. The sequences were analyzed by Clustal X1.83, MEGA3.1 and DnaSP4.0. The results showed that the average base content of T, C, A, G was 30.3%, 23.1%, 32.3% and 14.3%, respectively and there were 93 transition or transversion sites, including 53 single nucleotide mutation sites and 40 parsimony informative sites, which accounted for 11.6% of the length of the analyzed sequences. In total, we identified 52 haplotypes and found haplotype diversity (hd) of 0.9993, average number of nucleotide differences were 9.73875 (k), and nucleotide diversity (π) of 0.01233. The average genetic distance of haplotypes was 0.012, and the average transition/transversion was 4.305. Based on mitochondrial DNA D-loop region sequences, these results indicate that the genetic diversity of the Pseudosciaena polyactis population in Zhoushan is currently at a medium level.
综 述
The glioma accounts for half of the central nervous tumors, among which the glioblastoma multiforme (GBM) is one of the most aggressive and lethal brain tumors. The difficulties in glioma therapy indicate the need of appropriate animal models for preclinical studies. Benefiting from the development of molecular biology, genetics, and transgenic technology, variable animal models of glioma have been established. These animal models of human glioma are reviewed in this paper.