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2001年  第22卷  第4期

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研究论文
24 individuals from five different gynogenetic strains of silver crucian carp (Carassius auratus gibelio Bloch) were analyzed using 8 microsatellite markers of the poly (CA) type isolated from common carp (Cyprinus carpio L.) by Crooijmans et al.(1997).Electrophoretogram patterns showed that 7 pairs of microsatellite primers reproducibly produced the well-identifiable and homologous DNA fragments except the primers of MFW28.The number of alleles per marker varied from 1 to 14,and the size of alleles ranged from 100 bp to 506 bp.Nearly identical banding patterns occurred among intra-strain individuals,although subtle polymorphism was occasionally detected in the five strains.It was suggested that each strain might possess specific pattern owing to its gynogenesis.On other hand,the five strains differed from each other in electrophoretogram patterns.A total of 23 polymorphic fragments were scored from 5 pairs of primers after excluding bands that were monomorphic for the five strains.The electrophoretogram pattern clearly indicated their intra-strain homogeneity,inter-strain heterogeneity,and their phylogenetic relationships.Strain P is same to strain A,and strain F originates from strain E.Strains A,D and E may originate from different multiple events of hybridization respectively.The microsatellite markers produced by this study will be of benefit to further studies on the evolutionary genetics and provide useful tools for marker-assisted selection breeding or genetic map.
Phylogenetic relationships among three strains of Tetrahymena (I.e.T.shanghaienisis,T.thermophila Ⅱ and T.thermophila Ⅵ) were investigated using sequences of the first internal transcribed spacer region (ITS-1) of ribosomal DNA (rDNA).Amplified rDNA sequences consisted of 221 bases of the flanking 18S and 5.8S regions,and the entire ITS-1 region (169 or 172 bases).There were 5 variable bases among three strains in the 18S region and 16 variable bases in the ITS-1 region.The affiliation of them were assessed using both Neighbor-joining (NJ) and maximum parsimony (MP) analyses.Variations do exist in the phylogenies created by the two methods.However,the basic tree topologies are consistent.In both the NJ and MP analyses,T.shanghaienisis diverge from the ancestor of Tetrahymena earlier than T.thermophila Ⅱ and T.thermophila Ⅵ,which show that the selfer might be primitive.
Expression of TGF-β mRNA and protein in mouse placenta was detected using in situ hybridization and immunohistochemistry.The results showed that TGF-β mRNA and protein were mainly detected in the deciduas between D7.5 and D9.5 of pregnancy and the expression gradually decreased.The data indicate that TGF-β might be involved in regulation of trophoblast invasion during this period and may act through inhibiting the activity of two types of extracellular proteinase,Pas and MMPs.On D10.5 of pregnancy,trophoblast giant cells expressed TGF-β mRNA and protein.This was consistent with the fact that the trophoblast giant cells stoped to proliferate and invade at this time.On D9.5,spongiotrophoblast cells began to express TGF-β mRNA,while its protein was detected in these cells on D10.5,and the expression of TGF-β mRNA reached the peak level between D11.5 and D12.5 indicating it maybe also involved in regulation of the formati on of fetal vasculature during this period.Furthermore,the maternal tolerance to fetal semi-allograft was partly attributed to the expression of TGF-β,because TGF-β could inhibit the maternal immune system.
The results of the previous studies seem to show the crustaceans can secrete growth hormone,which regulate their growth.However,more evidences are needed to determine it.So the following research was conducted.The extract of thoracic ganglia (TGE) of adult Macrobrachium rosenbergii was applied to a Sephadex G-50 column,the resulting second peak was further isolated by HPLC,and 9 fractions were obtained.Among the fractions only the second fraction significantly increased the protein synthesis of the abdomen muscle of the juvenile M.rosenbergii that was injected TGE.The increasing effects were related to the protein concentration of the injecting fractions.The molecular weight of the substance in the second fraction isolated by HPLC was below 3.4 kDa.The results indicate that the thoracic ganglia of M.rosenbergii could secrete a peptide hormone,which stimulates the muscle protein synthesis of prawn,and the hormone might be the growth hormone of the prawn.
We report data on growth,sexual dimorphism and female reproduction for bluetailed skinks,Eumeces elegans,from a population in Hangzhou,Zhejiang,eastern China.All the animals were captured from the field and then raised in the laboratory.The body and head sizes of 449 skinks were measured to indicate ontogenetic changes in sexual size dimorphism.The growth of 94 juveniles and 50 adults and the reproductive output of 12 adult females were determined.We pay particular attention to the point during ontogeny at which males and females diverge in body size (SVL) and head size (length and width) and the way through which females increase their reproductive output.Adults were sexually dimorphic in coloration,body size and head size,with male adults being larger in both body and head size than female adults.Newly emerged young did not show sex difference in SVL,and male and female juveniles (SVL <69.3 mm) exhibit isometric growth pattern of SVL.Male and female adults (SVL >69.3 mm) showed allometric growth pattern of SVL,as male adults grew faster than female adults.Therefore,It was concluded that sexual dimorphism in body size of E.elegans occurred only in adults.Our data revealed that male and female juveniles larger than 50 mm SVL began to diverge in head size,with males having larger heads than females.This sexual dimorphism resulted from the greater head growth rate relative to SVL in males when their SVLs were larger than 50 mm SVL,and became increasingly pronounced in adults.The sexual dimorphism in body and head size suggested that the strategy of energy partition of adult males and females was different.Adult males partition relatively more energy into body and head growth so as to improve the reproductive fitness,in contrast,adult females partition relatively more energy into reproductive investment other than body growth.Morever,adult females pa rtition relatively less energy into head growth but more into carcass growth,thereby leaving a larger space for containing more eggs.The smallest reproductive female in our sample is 69.3 mm SVL,and all females larger than this size lay a single clutch of eggs per breeding season.Clutch size,clutch mass and clutch mean egg mass were all positively correlated with maternal SVL,with average 6.4 eggs,2.783 g and 0.554 g,respectively.Females of E.elegans increase reproductive output mainly through increasing clutch size (egg number) and egg size as well.
The resting metabolic rate (RMR),maximal nonshivering thermogenesis (NST[max]),cold induced resting metabolic rate (CIRMR),body mass,body temperature of the tree shrews were measured.The results showed that the body mass and the capacity of heat production in the coldacclimated groups were higher,and body temperature was lower than that in the control.The increase of RMR and CIRMR during cold acclimation was the main pattern of heat production in tree shrews.
Tree Sparrows (Passer montanus) used to be a dominant bird widely distribution in Sichuan Province.It was found that they had disappeared twenty years ago in the farming region,city and town of Sichuan basin,mountainous area around basin and southwest of Sichuan,and this phenomenon continues up to now.Investigation results (Jul.,1995-Oct.,2000) and historical data reveal that the disappearance of Tree Sparrows began in Sichuan basin at the end of the seventies or the beginning of the eighties;in the eighties,it expanded from the basin to mountainous area around basin and southwest of Sichuan ;in the nineties,the distribution pattern had taken shape into the rare,the partial and the extensive distribution region.The discussion indicates that the causing disappearance and geographic distribution change of the Tree Sparrow in S ichuan is a result of abusing Organic Phosphoric Pesticide.
Autumn habitat selection by Houbara bustards in eastern Jungar Basin,Xinjiang was studied in September 2000.It was found that the birds preferred sites were the flat and open places,where were dominated by sparse short xero-halophytic plants with randomly interspersed bushy patches.Vegetative density,plant species richness and phenology were the most important factors that determined the autumn habitat selection of Houbara bustard.Vegetative density,herb species richness,Petrosimonia sp.density,and fruiting plant density and species richness at the autumn habitat sites were all higher than those at the control sites,and the differences were statistically significant (P<0.01);shooting plant,Anabasis sp.and Reaumuria sp.density at the habitats differed significantly from those at the controls (P<0.05),and shooting plant density relatively were high,Anabasis sp.and Reaumuria sp.density low at the habitats respectively.
The present paper deals with a new species of Caridina collected from Kunming,Yunnan Province in 1983.Caridina kunmingensis Wang et Liang,sp.nov.Rostrum reaches to the extremity of 2nd segment of the antennular peduncle.The dorsal border bears 11-19 teeth,6-9 of which are situated on the carapace behind orbital margin.The ventral border bears 2-7 teeth.Ultimate segment of 3rd maxilliped is longer than penultimate segment,pemultimate segment and antepenultimate segment are the same in length.Carpus of lst leg is 1.6-1.8 times as long as wide.Chela is 2-2.1 times as long as wide.Carpus of 2nd leg is 4-4.6 times as long as wide,chela is 2.3-2.6 times as long as wide.Propodus of 3rd leg is 2.6-3.7 times as long as dactylus,which bears 6-7 spinules.Propodus of 5th leg is 3.4-4.5 times as long as dactylus,which bears 29-32 spinules. Endopod of lst male pleopod is ovate.The proximal half of the outer margin bears long plumose setae,and the distal half is armed with longer spinules.The appendix masculina of 2nd pleopod is rodshaped,and bears many large spines in inner margin.Remarks:The present new species closely allied to Caridina shilinica Liang et Cai,2000,but differs from the latter in following features:1)rostrum is shorter;2)carpus and chela of lst and 2nd legs are shorter and thicker;3)carpus of 2nd leg is shorter than merus;4)ultimate segment of 3nd maxilliped is longer than antepenultimate segment;5)the outer-distal angle of endopod of lst maxilliped is round;6)the thorns of appendix masculina are larger and fewer;⑦the shape and structure of endopod of lst male pleopod and appendix masculina are different.
The present paper deals with two new species of the family Anthomyiidae from Yunnan Province,China,namely Delia nigriabdominis sp.nov.and Chirosia fortipispatula sp.nov.All the type specimens are deposited in Institute of Entomology,Shenyang Normal University,Shenyang.
A new genus and two new species from the family Tenebrionidae of the order Coleoptera of China are reported in this paper,namely Neoblaps gen.nov.,N.huizensis sp.nov.,Dila bomiana sp.nov.The type specimens are preserved in the Museum of Hebei University.
Microsatellites are tandem repeats of short nucleotide motifs (1-5 bp long) dispersing widely and relatively evenly in eukaryotic genomes.The high degree of allelic diversity at each microsatellite locus provides ideal Mendelian markers for population and pedigree analysis.Understanding of microsatellite mutational m echanism will be helpful to appropriately use microsatellite markers for biological studies.Here we introduce the latest progress in microsatellite research,including its mutation,mutational mechanism,application (especially in relationship identification),as well as its pitfalls.
Mitochondrial DNA variation analyses have been extensively used in the past two decades,mainly on tracing the origin and migration pattern of human populations,the molecular mechanism of mitochondrial diseases as well as on forensic identification.In this paper,we reviewed many ordinary methods that were used for hu man mtDNA mutation typing,such as RFLP,SSO,and control region sequencing,with special emphasis on the thoughts on choosing which method to detect mutations.By grouping the recent phylogenetic results about human mtDNA,we listed specific variation sites and corresponding primers for major haplogroups identification in the world.The approach that work with control region data for stable motifs of haplogroups supplemented by additional diagnostic site confirmations by RFLP or sequencing in coding regions should be a main method in the future study about human mtDNA lineages.
The phylogenetic relationships of four species,Bufo melanostictus,Hyla chinensis,Rana limnocharis and Rana guentheri,which belong to three differrent families of Anura,were detected with RAPD technique.The genomic DNA of each species was amplified with 19 random primers.16 primers given clear amplified bands were used for analysis and the genetic distances between four species were calculated.The results show that RAPD bands obtained by all 16 primers evinced different degree polymorphisms.The genetic distance between R.limnocharis and R.guentheri is the nearest,that between B.melanostictus and H.chinensis is the second nearest,and that between B.melanostictus and R.guentheri is the furthest.The different distances also indicated that the relationship between Bufoidae and Hylidae is closer than that between Bufonidae and Ranidae at genomic DNA level.In concordant with the conclusion of the morphology,chromosomal and mitochondrial DNA studies,our results provide a new evidence of the systematic evolution of the three families of Anura at DNA molecular level.
Using a pair of degenerate primers based on the conservative region,HMG-box,of human SRY gene,four different fragments were amplified from both female and male Chinemys reevesii,then cloned by using pGEM-T vector and sequenced.The sequence result indicated their high homology to human Sox genes.The identities to human Sox genes in the DNA sequence and the amino acid sequence are 92%,91%,84%,92% and 100%,93%,98%,98%,respectively.It might be conclud ed that Sox gene was highly conservative in phylogenesis.Our work provides molecular data for the study of sex-determining mechanism of C.reevesii,which might be temperature-dependent sex determination.
In order to investigate glucose metabolism pathways and their changes in Kunming mouse preimplantation 1-,2-,4-,8-cell,and morula embryos,the mRNA level for the genes involved in glucose metabolism was tested by nested RT-PCR on embryos at different development stages in vivo.These genes were glucose 6-phosphate dehydrogenase (G6PDH),phospho-fructokinase (PFK),and phosphoglucomutase (PGM),representing pentose phosphate pathway (PPP),glycolysis,and glycogensis and glycogenolysis respectively.Three sets of inner and outer primers were designed and synthesized based on cDNA sequences of G6PDH,PFK and PGM.RT-PCR results revealed that G6PDH gene transcription was found in Kunming mouse 1-8 cell embryos,and not in morula embryos;it indicated that 1-8 cell embryos may metabolize glucose by pentose phosphate pathway,but morula embryos can not do so.PFK gene transcription was found in 1-8 cell and morula embryos;it is probable that there exists glycolysis in those embryos.PGM gene transcription was not found in 1-8 cell and morula embryos,so glycogenesis and glycogenolysis in these embryos were not present.