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2001年  第22卷  第5期

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研究论文
Fragments of about 360 base pairs of the mitochondrial cytochrome b gene from 7 species of Rana and 2 species of Pelophylax were amplified and sequenced.Phylogenetic analyses reveal that:1)The DNA sequence variations between Gansu population and Northeastern population of Rana chensinensis are notable,but the data are insufficient to judge whether the two populations are two different subspecies or species.2)Rana chensinensis is most closely related to Rana amurensis,and is most alienated from R.huanrenensis among the 7 species of Rana studied.3)The molecular evidences support to place R.zhenhaiensis,R.omeimo ntis,R.chaochiaoensis and R.longicrus into Rana japonica species group.
Under constant and alternating temperature conditions oosperms of Rana chensinensis were cultivated till the completion of metamorphosis.The study was done on the development of sexual gland during the embryo stage,the beginning and ending periods of sexual differentiation and the relationship between temperature and sexual differentiation of Rana chensinensis.The results showed:1)In the 24[th] period of embryo development,a genital ridge began to appear,and in the 25[th] period there had been a few PGCs moved to the genital ridge.PGCs together with the genital ridge developed into a sexual gland.2)In the 31st period of embryo development,the sexual gland began to differentiate;the initial differentiation stage of an ovary was easy to recognize while the differentiation of a testis was not so obvious.3)The differentiation of the ovary completed at the 37[th] period,while the differentiation of the testis completed after metamorphosis,and the left and the right sides of the sexual glands were the same size.4)In the 30[th] period of the embryo,sex differentiation began to be impressible to temperature,and lower temperature was favorable for feminization,while higher temperature was favorable for masculinization.5)In alternating temperature conditions the impressible temperature range for the sex ratio was 15-20 ℃;slow rise of temperature would increase the male ratio,while slow drop of temperature would increase the female ratio.
According to the relative parameters,the population dynamics of the black bears in Wolong Nature Reserve were simulated by a simulation modal-Vortex 8.21,and the factors affecting the population were also analyzed.The results showed as follows:without inbreeding depression and catastrophes,the population would gradually increase,otherwise it would decrease.Some recommendations on conversation ac-tion are put forward based on the ananlyses.
A Brown Eared Pheasant Crossoptilon mantchuricum is a rare pheasantsspecies and endemic to China.From November 1998 to February 1999,the social hierarchy and its affected factors on a captive population of Brown Eared Pheasants were studied in Luyashan Nature Reserve of Shanxi Province,China.The dominance hierarchy was ranked with the Batchelder-Bershad-Simpson (BBS) Scaling Method.It was found that the dominance hierarchy of the captive Brown Eared Pheasants was a near-linear.The hierarchy ranks of adults were significantly higher than that of subadults while the males were significantly higher than females .There were statistically significant correlations between the hierarchy scale values and the body weight,wattle size,ear-tuft length.Statistically significant correlations were found between the body weight and body length,wattle size,ear-tuft length.Body weight was the indicator of the fighting ability while the body length,wattle size and ear-tuft length were the exterior signals of the fighting ability.It is suggested that the face might be the center of the fighting display in Brown Eared Pheasants.
Males and females of the oriental garden lizard (Calotes versicolor) from a population in Tongshi,Hainan,southern China,differ in head size at hatchlings,with males having larger heads than females.This sexual dimorphism is slightly more pronounced in adults than in hatchlings.Embryos of C.versicolor allocate relatively more resources to the growth of ecologically significant morphological characters than do characters less directly tied to early survival and growth of hatchlings.As a consequence of this allocation pattern,hatchlings have larger heads but shorter tails relative to snout-vent length (SVL) than do juveniles and adults.Adults do not show a sexual dimorphism in SVL,but male adults attain longer tails than do female ones at the same SVL.An isometric growth pattern with SVLs increase is showed in the head length of both sexes and the head width of females during ontogeny.However,an allometric growth pattern with SVLs increase is showed in the head width of males,which the growth rate becomes increasingly fast with the ontogeny.The food niche width and overlap differ in the different age and sex groups to a certain extent.However,no direct evidence has been found to show a noticeable contribution of the divergence in head size to the food niche segregation between males and females.
In order to explain the genesis and development of the digestive system,we studied the embryonic development of the swimming crab,Portunus trituberculatus,by histological section.The results showed that the foregut,mid-gut and hind gut arised in the gastrulating stage.The foregut differentiated an esophagus and a stomach in the egg zoea Ⅰ.The stomach opened to the yolk sac.The hind gut epithelial cell did not arrange in order during the egg naupliusⅠand Ⅱ.The epithelial cell formed hind gut cavity in the egg zoea Ⅰ.The hind gut touched with the midgut in the egg zoea Ⅱ.The mid-gut developed to a cup-like structure in the egg zoea Ⅱ.The digestive system formed when the mid-gut touched with foregut before hatching.
The changes of mitochondrial ultrastructure during vitellogenesis in oocytes of Bullacta exarata were investigated by transmission electron microscope method.The results show that mitochondria are the organelles that first involved in the information of yolk granules,their outer and inner morphology differ in different oocyte stages,and the numbers of typical ones decrease during the process of vitellogenesis.At the early stage of vitellogenesis,there are many mitochondria in ooplasm of the oocytes.These are rounded with numerous cristae and electron-dense matrix.Then some mitochondrial cristae and inner membrane begin to degenerate.At the mid-stage,the cristae and inner membrane disappear,there are a great number of small dense masses in the mitochondrial lumen,these masses grow in size and develop into mature yolk granules,many of these granules resemble mitochondria,and a number of transitional stages share both mitochondria and yolk body features.At the end stage of vitellogenesis,there are lots of yolk bodies increasing in the number and diameter,and there are some mitochondria among yolk bodies that supply energy to cell metabolism.Finally,the changes and functions of the mitochondria in vitellogenesis are discussed.
This paper describes the genesis of the digestive system of the redclaw crayfish,Cherax quadricarinatus.The digestive system consists of three parts:fore-gut,mid-gut and hind-gut.The fore-gut and hind-gut origin from the ectoderm,and the mid-gut derives from the mesendodermal cell group.The fore-gut begins to form at the egg-nauplius stage and is made up by stomodaeum,esophagus and stomach;the mid-gut genesis at the egg-metanauplius stage and contains a mid-gut and a pair of hepatic rudiments;the hind-gut starts at the same time as the fore-gut to form the protodaeum which lies in the end of it.
This paper deals with three new species of the subfamily Evacanthinae from Yunnan Province,China:Bundera rufistriana Li et Wang sp.nov.,B.pellucida Li et Wang sp.nov.and Taperus lanpingensis Li et Wang sp.nov.The type specimens are deposited in the Institute of Entomology,Guizhou University. 1 Bundera rufistriana Li et Wang,sp.nov.(Fig.1) Corpus length (incl.teg.):♂6.0-6.2 mm,♀6.2-6.5 mm. This species is similar to Bundera maculata Kuoh in appearance,but can be distinguished from latter by the male gena and outside of lora grey,the posterior area of pronotum pallide-flavens,costal area and middle clava of forewing aurantiacus. Holotype ♂,paratypes 7♂♂,9♀♀,Pianma (26.15°N,98.45°E),Yunnan Province,17-18-Ⅷ-2000,coll.LI Zi-Zhong and YANG Mao-Fa. 2 Bundera pellucida Li et Wang,sp.nov.(Fig.2) Corpus length (incl.teg.):♂5.0-5.2 mm,♀5.2-5.4 mm. This species is related to Bundera venata Distant in appearance,but differs in the outside of lora with a longitudinal spot black,pronotum with 凸-shaped black spot,and anterior margin of forewing also black. Holotyepe ♂,paratypes7 ♂♂,5♀♀,Lanping (26.28°N,99.20°E),Yunnan Province,12-Ⅷ-2000,coll.LI Zi-Zhong and YANG Mao-Fa. 3 Taperus lanpingensis Li et Wang,sp.nov.(Fig.3) Corpus length (incl,teg.)♂6.5 mm. This species is allied to Taperus fasciatus Li et Wang,but can be easily distinguished from latter by the body flavotestaceous,scutellum with four longitudinal stripes fuscous,pygofer side in lateral aspect with caudodorsal process. Holotype ♂,Lanping(26.28°N,99.20°E),Yunnan Province,12-Ⅷ-2000,coll.LI Zi-Zhong.
The total mRNA was prepared and purified from the venom glands of snake Bungarus fasciatus.A cDNA library of the venom glands was then constructed using reverse transcription.Two cDNAs encoding two novel phospholipase A[2],named as Bungarus fasciatus phospholipase A[2]Ⅰ(Bf-PLA[2]Ⅰ) and Bungarus fasciatus phospholipase A[2] Ⅱ(Bf-PLA[2]Ⅱ) respectively,were screened out by polymerase chain reaction and sequenced.Both cDNAs have an open reading frame of 435 bp,encoding a 145 amino acid phospholipase A2 precursor composed of a 27 amino acid signal peptide followed by 118 amino acid mature protein.The two cloned phospholipase A[2] belong to Group Ⅰ phospholipase A[2].Their primary structures are different from known Bungarus fasciatus phospholipase A[2]s.
The present paper summarizes the kinds of molecular information applied in the molecular phylogenetic studies of amphibians and reptiles,and introduces the published articles on molecular phylogenetics of frogs,toads,turtles,lizards and snakes.In these studies mtDNA sequences were mainly used,some nuclear DNA sequences were also applicable.Phylogenetic relationships among higher categories (orders and families) and among genera,species,and subspecies or populations were involved in these studies.
House mice are important model organisms widely used in biological and medical research.Great progress has been made in the studies of genetics and evolution of the house mice in the past two decades.Genetic relationship and differentiation among different species and populations are more clearly revealed through biochemical and molecular studies.Taxomomy of the house mice has also been amended.It is now commonly accepted that the house mice (Mus musculus species complex) consisting of three or four commensal species (I.e.,M.domesticus,M.musculus,M.castaneus and M.bactrianus) and three aboriginal species (I.e.,M.spicilegus,M.macedonicus and M.spretus).There have been two model hypothesis proposed to account for the origin and radiation of the house mice,one is the centrifugal model and the other is the sequential model.However,with regards to the genetics differentiation and subspecies classification of chinese house mice,no comprehensive studies have been done.
Among the vertebrates,felid species are some special animals,including 37 species,which are all rare or endangered species except domestic cat.Therefore,it is very important to study domestic cats reproductive habits and regularities,especially its reproductive engineering,such as in vitro maturation (IVM),in vitro fertilization (IVF) and inrtocytoplasmic sperm injection (ICSI) of cats ovarian oocytes,etc.These mordern reproductive technique will provide a powerful promotion in the reproduction and protection of the nondomestic felid species.
Protein and lactose concentrations,protein composition were assayed in milk samples from two giant panda individuals.The results were compared with that of Chengdu Ma goat and Chinese Holstein.The average protein concentration in giant panda milk was 41.52 g/L,similar to Chinese Holstein milk.The average lactose content was 15.41 g/L,significantly lower than goat colostrum and bovine milk.The SDS-PAGE profile of skim milk proteins of the giant pandas was different from that of bovine and goat.Casein content in the giant panda milk was lower than that of goat colostrum and bovine milk.Three protein bands with high content were observed in the giant pandas but not in the Chengdu Ma goat or Chinese Holstein.No polymophism of the giant panda milk MUC1 was found in the two milk samples,and only one band with molecular weight of approximately 196 kDa was observed on the SDS-gel.
The standard metabolism of the juvenile Eriocheir sinensis collected from Shanghai were studied under their non-feeding and resting conditions from Oct.to Dec.of 1998 and 1999,respectively.The results showed that oxygen consumption,CO[2] production and ammonia-N excretion of the juvenile crab weight (2.70±1.40)g were (0.414±0.091)mg·g[-1]·h[-1],(0.476±0.125)mg·g[-1]·h[-1] and (4.179±1.171)μg·g[-1]·h[-1] at (20±0.5)℃,respectively.Respiratory quotients,oxygen-nitrogen ratio and metabolic substrate ratio were used to describe the substrate metabolism of crabs.It indicated that oxidation of lipid dominated energy metabolism while carbohydrate and protein were the second and the third sources of energy metabolism,and energy ratio of protein,carbohydrate and lipid in metabolic substrate of the crabs was 7.3∶38.8∶53.9.The rate of oxygen consumption of juvenile crabs (R[0]) was remarkably affected by the level of oxygen dissolved in water,and negatively correlated with the body weight (W) of the crabs (R[0]=0.8403W[-0.7265],n=33,r=-0.9097,P<0.01).
The effects of zinc deficiency on the serum cortisol and adrenocorticotrophic hormone (ACTH) concentration,and the cerebrum nitric oxide synthase (NOS) activity in rats were studied.Growing rats were allotted to three groups,which were zinc deficiency (ZD),paired-fed (PF) and zinc supplementation after feeding zinc deficient food for 21 days (ZS).The duration of feed test was 35 days.Compared with PF rats,serum cortisol concentration in ZD ones was significantly increased,whereas serum ACTH concentration and cerebrum NOS activity were significantly decreased.The results suggested that zinc might influence the metabolism of hypothalamichypophysial-adrenocortical axis and NOS.