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1.
Endobiotic ciliates of native Yakut horse are investigated. 57 ciliate species have been found. From 17 up to 43 species of ciliates have been revealed in each host specimen. The specimens of Alloiozona trizona Hsiung, 1930 and Triadinium caudatum Fiorentini, 1890 were present in 100 % of the horses. The endemic genus and species of allantosomides, Strelkowella urunbasiensis Kornilova, 2004, has been found in 11 horses. Allantoxena japonensis (Imai, 1979) and Cycloposthium ishikawai Gassovsky, 1919 being recorded previously in Japan only were found for the first time in Russia. The species Cycloposthium ponomarevi Kornilova, 2001 peculiar to the Turkmenistan koulan has been found in the Yakut horses.  相似文献   

2.
Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga (Equus quagga) museum skin, an extinct South African equid (Higuchi et al. 1984 Nature312, 282-284). This was the first extinct species from which genetic information was retrieved. The DNA sequences of the quagga showed that it was more closely related to zebras than to horses. However, quagga evolutionary history is far from clear. We have isolated DNA from eight quaggas and a plains zebra (subspecies or phenotype Equus burchelli burchelli). We show that the quagga displayed little genetic diversity and very recently diverged from the plains zebra, probably during the penultimate glacial maximum. This emphasizes the importance of Pleistocene climate changes for phylogeographic patterns in African as well as Holarctic fauna.  相似文献   

3.
The evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. Distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives of this microbial community. Analyses of a total of 484 different 18S rRNA genes show that extremely complex, but related ciliate communities can occur in the rumen of cattle, sheep, goats and red deer (301 sequences). The communities in the hindgut of equids (Equus caballus, Equus quagga), and elephants (Elephas maximus, Loxodonta africanus; 162 sequences), which are clearly distinct from the ruminant ciliate biota, exhibit a much higher diversity than anticipated on the basis of their morphology. All these ciliates from the gastro-intestinal tract constitute a monophyletic group, which consists of two major taxa, i.e. Vestibuliferida and Entodiniomorphida. The ciliates from the evolutionarily older hindgut fermenters exhibit a clustering that is specific for higher taxa of their hosts, as extant species of horse and zebra on the one hand, and Africa and Indian elephant on the other hand, share related ciliates. The evolutionary younger ruminants altogether share the various entodiniomorphs and the vestibuliferids from ruminants.  相似文献   

4.
The relictual Mastotermes darwiniensis is one of the world's most destructive termites. Like all phylogenetically basal termites, it possesses protozoa in its hindgut, which are believed to help it digest wood. L. Li, J. Frohlich, P. Pfeiffer, and H. Konig (Eukaryot. Cell 2:1091-1098, 2003) recently cloned the genes encoding cellulases from the protozoa of M. darwiniensis; however, they claimed that these genes are essentially inactive, not contributing significantly to cellulose digestion. Instead, they suggested that the protozoa sequester enzymes produced by the termite in its salivary glands and use these to degrade cellulose in the hindgut. We tested this idea by performing gel filtration of enzymes in extracts of the hindgut, as well as in a combination of the salivary glands, foregut, and midgut. Three major cellulases were found in the hindgut, each of which had a larger molecular size than termite-derived salivary gland enzymes. N-terminal amino acid sequencing of one of the hindgut-derived enzymes showed that it was identical to the putative amino acid sequence of one mRNA sequence isolated by Li et al. (Eukaryot. Cell 2:1091-1098, 2003). The overall activity of the hindgut cellulases was found to be of approximately equal magnitude to the termite-derived cellulases detected in the mixture of salivary gland, foregut, and midguts. Based on these results, we conclude that, contrary to Li et al. (Eukaryot. Cell 2:1091-1098, 2003), the hindgut protozoan fauna of M. darwiniensis actively produce cellulases, which play an important role in cellulose digestion of the host termite.  相似文献   

5.
1. Peripheral blood serum alpha-L-fucosidases have been studied from various mammalian species: Sus scropha var domestica L. (pig), Capra hircus L. (goat), Bos taurus L. (bull, races Morucha and Charolais), Equus caballus L. (horse) and Equus asinus L. (donkey). 2. Fluorimetric and spectrophotometric procedures were used for determination of alpha-L-fucosidases. 3. alpha-L-Fucosidases were more active towards fluorescent substrates than towards chromogenic substrates. 4. pH optima values of the enzymes are: (A) 5.5 for sera from all above-mentioned species when fluorescent substrates were employed; (B) 4.0 for goat, 4.5 for bull, 5.0 for pig and 4.5-5.0 for horse and donkey sera when chromogenic substrates were used. 5. pH activity profiles are very similar for two races (Morucha and Charolais) of the same species (Bos taurus L.) and also for two species of the same genus (Equus caballus and Equus asinus L.). 6. These serum alpha-L-fucosidases are very labile under heat treatment, even at 37 degrees C.  相似文献   

6.
河北蔚县大南沟哺乳动物化石及其地层时代   总被引:4,自引:1,他引:3  
近年来,在河北蔚县一带晚新生界陆相沉积中,陆续发现有四个不同的化石层位,使这一地区晚新生代地层关系更加明确。本文所记述的大南沟化石点中的哺乳动物化石属于泥河湾期哺乳动物群,其地层时代为早更新世。  相似文献   

7.
Unusual equids named hippidions inhabited South America for more than 2 MY (million years). Like many other animals they succumbed to the worldwide climatic change that occurred 10 KY (thousand years) ago and completely disappeared during the great late Pleistocene megafaunal extinction. According to fossil records and numerous dental, cranial, and postcranial characters, Hippidion and Equus lineages are known to have diverged prior to 10 MY. Some equid bones from Rio Verde and Ultima Esperanza (Patagonia, Chile) dating back to the late Pleistocene period (8-13 KY) have been identified as Hippidion saldiasi, while a few teeth have been assigned to Equus. Six samples of those remains have been obtained from the Zoological Museum of Amsterdam for ancient DNA analysis to try to place Hippidion in the evolutive tree of Perissodactyla. Two samples of Hippidion and one sample of Equus yielded 241-394 bp of the mtDNA control region and 172-296 bp of the cytochrome b gene. Unexpectedly, all the sequences clustered deep inside the Equus genus, casting doubt on the initial identification of the bones. For paleontologists, one of the striking and classical diagnostic characters of Hippidion is their extremely short and massive metapodials, a probable locomotory adaptation to the Andine steep slopes. However, our DNA analysis reveals that a very Hippidion-like metapod might also have been possessed by another South American equid, i.e., Equus (Amerhippus), an interpretation supported by complementary anatomical observations. This adaptive convergence between members of the two South American equid genera may lead paleontologists to limb bone misidentification.  相似文献   

8.
Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing considerably, we investigated the role of CR in the karyotype evolution of the genus Equus. Using appropriate panels of BAC clones in FISH experiments, we compared the centromere position and marker order arrangement among orthologous chromosomes of Burchelli's zebra (Equus burchelli), donkey (Equus asinus), and horse (Equus caballus). Surprisingly, at least eight CRs took place during the evolution of this genus. Even more surprisingly, five cases of CR have occurred in the donkey after its divergence from zebra, that is, in a very short evolutionary time (approximately 1 million years).These findings suggest that in some species the CR phenomenon could have played an important role in karyotype shaping, with potential consequences on population dynamics and speciation.  相似文献   

9.
1. Leucocytes from the blood of adult and young donkeys (Equus asinus L.), adult horses (Equus caballus L.), adult mules (Equus asinus x Equus caballus) and adult pigs (Sus scrofa L.) were obtained in a high degree of purity (99.9%) using Na2-EDTA-dextrans mixtures. 2. Sialic acids were released, purified, identified and determined from both non-delipided and delipided leucocytes. 3. N-glycolylneuraminic was the predominant sialic acid. N-acetylneuraminic acid and N,O-diacetyl-neuraminic acid were also found in all materials. Except in pig, other unidentified sialic acid(s) were also detected. 4. The concentration of total sialic acids (microgram/mg protein) is different according to the species, and in donkey species according to the age. 5. Galactose, glucose, mannose, fucose and (in a less amount) ribose were determined. Their total content is about 2-3-fold that of hexosamines. 6. There is a higher cholesterol content in adult donkey leucocytes than in those of young ones. 7. Total lipids, cholesterol or phospholipid contents are similar among the leucocytes of the above-mentioned species. 8. The similarities are marked in the electrophoresis patterns of proteins and glycoproteins for the donkey, mule and horse samples. 9. The molecular weights for leucocytes proteins were estimated as ranging between 230,000 and 20,000; and for the main protein bands, between 120,000 and 22,000.  相似文献   

10.
Hippidions are past members of the equid lineage which appeared in the South American fossil record around 2.5 Ma but then became extinct during the great late Pleistocene megafaunal extinction. According to fossil records and numerous dental, cranial, and postcranial characters, Hippidion and Equus lineages were expected to cluster in two distinct phylogenetic groups that diverged at least 10 MY, long before the emergence of the first Equus. However, the first DNA sequence information retrieved from Hippidion fossils supported a striking different phylogeny, with hippidions nesting inside a paraphyletic group of Equus. This result indicated either that the currently accepted phylogenetic tree of equids was incorrect regarding the timing of the evolutionary split between Hippidion and Equus or that the taxonomic identification of the hippidion fossils used for DNA analysis needed to be reexamined (and attributed to another extinct South American member of the equid lineage). The most likely candidate for the latter explanation is Equus (Amerhippus) neogeus. Here, we show by retrieving new ancient mtDNA sequences that hippidions and Equus (Amerhippus) neogeus were members of two distinct lineages. Furthermore, using a rigorous phylogenetic approach, we demonstrate that while formerly the largest equid from Southern America, Equus (Amerhippus) was just a member of the species Equus caballus. This new data increases the known phenotypic plasticity of horses and consequently casts doubt on the taxonomic validity of the subgenus Equus (Amerhippus).  相似文献   

11.
Autochthonous and allochthonous bacteria were isolated from hindgut chamber and large intestine of fed and starved Atlantic cod (Gadus morhua L.). All bacterial strains isolated from hindgut chamber belong to carnobacteria. However, only 10.2% of the bacteria strains from the large intestine belong to carnobacteria. Random amplification of polymorphic DNA (RAPD) analysis using three selective primers, was performed to further identify the carnobacteria strains. Nine of these were isolated from hindgut chamber contents, ten associated with epithelial cells of the hindgut chamber, and six isolated from the large intestines of fed and starved fish. The 25 isolates segregated into eight clusters. The major cluster comprised nine strains isolated from the hindgut chamber of both fed and starved fish showing low similarity with the reference strains. The other strains isolated from the hindgut were located in clusters showing high similarity with Carnobacterium gallinarum or Carnobacterium piscicola. Strains isolated from large intestine appeared more divergent and were located in five different clusters. Autochthonous (indigenous) bacteria were clearly demonstrated in the hindgut chamber as transmission electron microscopy revealed rod-shaped bacteria between adjacent microvilli. Endocytosis of bacteria by epithelial cells was observed in the hindgut chamber.  相似文献   

12.
Foraging and territoriality in the ant Lasius neonigerinvolves a series of trails which channel foragers away from adjacent colonies. Experimental studies suggest that the trails are composed of colony-specific, persistent orientation components of hindgut material that accumulate on trails during foraging. A less durable component of the hindgut trail pheromone regulates recruitment. Foraging directionality and the use of a trail could be modified by experimentally arranging confrontations with conspecifics. The orientation of foragers is mediated by visual as well as chemical cues. Components of the foraging and territorial system of L. neonigerappear to include (1) a network of subnests which change in position seasonally within each polydomous nest; (2) a series of trails emanating from each subnest that adjusts search toward resource patches and away from aggressive, neighboring conspecifics; and (3) trail communication involving an ephemeral component of the hindgut trail pheromone that regulates the organization of cooperative prey retrieval and a more persistent component that serves as an orientation guide.  相似文献   

13.
Summary The transport of calcium from mineralized granules stored in the Malpighian tubules to the puparium of the face fly,Musca autumnalis De Geer, was studied. Calcium was transported directly from the tubules to the cuticle via the hemolymph. Little, if any, calcium entered the hindgut or other tissues during or prior to transport. A total of approximately 0.8 mg of calcium per larva was transported, beginning at the wandering stage; peak hemolymph concentrations occurred at anterior retraction. Hemolymph calcium levels subsequently decreased as puparial calcium increased. Puparial mineralization utilized most of the minerals stored during the larval stage, with lesser amounts of minerals being recovered in the adult or excreted. Deposition of mineral salts in the cuticle was accompanied by an increase in cuticular pH from 7.0 to 8.4. The house fly,Musca domestica L., which contains much lower concentrations of minerals in the puparial cuticle, exhibited no increase in cuticular pH during pupariation. Biomineralization of the face fly puparial cuticle appears to occur, in part, as a result of ionic equilibria involving calcium and magnesium phosphates and carbonates, which have relatively low solubility products at alkaline pH.Contribution No. 87-237-J from the Kansas Agricultural Experiment Station, Kansas State University, Manhattan, Kansas. Cooperative investigation between Agricultural Research Service, U.S. Department of Agriculture and the Kansas Agricultural Experiment Station. K.J.K. is a research chemist and adjunct professor at U.S. Grain Marketing Research Laboratory and Kansas State University, respectively. Mention of a proprietary product in this paper does not imply its approval by the USDA to the exclusion of other products that may also be suitable. Reprint requests to A.B. Broce  相似文献   

14.
15.
The type series of the earliest kulan Equus (Hemionus) nalaikhaensis Kuznetsova et Zhegallo, 1996 from the Pleistocene of Mongolia is described in detail. The lectotype (an almost complete skull without a lower jaw) is designated. The assignment of this species to the subgenus Hemionus is validated.  相似文献   

16.
南京汤山驼子洞的马科化石及其意义   总被引:6,自引:1,他引:5  
200 0年在南京汤山葫芦洞直立人地点附近的驼子洞堆积中发现了又一处哺乳动物化石点。其中的马科化石有两种 :黄河马Equushuanghoensis和中国 (长鼻 )三趾马Hipparion(Proboscidipparion)sinense。这是自 1 95 9年发现黄河马化石以来首次发现黄河马的颅骨和完整的颊齿列标本。这两种马的同时出现说明含驼子洞动物群的堆积形成于早更新世。因此驼子洞堆积的发现是江宁地区下更新统的首次记录。驼子洞的黄河马和长鼻三趾马均为这两类马在秦岭淮河以南的首次记录 ,并反映了在早更新世曾发生过北方动物群跨越长江的南迁事件。  相似文献   

17.
中国竹飞虱属分类研究(半翅目,蜡蝉总科,飞虱科)   总被引:1,自引:0,他引:1  
整理记述中国飞虱科竹飞虱属Bambusiphaga Huang et Ding 14种.研究发现丁锦华、黄其林(1979)对该属模式种黑斑竹飞虱B.nigripunctata雄性外生殖器阳茎结构的图示与王金川、丁锦华(1996)在<甘肃飞虱>中对该种阳茎结构的记述及图示不同,通过解剖西北农林科技大学昆虫?骀 博物馆馆藏的该种标本,发现其阳茎结构与王金川、丁锦华(1996)记述及图示的阳茎结构相同,在检查了该种的模式标本后,确认丁锦华、黄其林(1979)图示的雄性外生殖器阳茎结构并非本种.本文对该种雄性外生殖器结构作了重新描记,并绘制了该种成虫及雄性外生殖器鉴别特征图.文中还建立1个新组合:B.bakeri(Muir)nov.comb.及2个新异名:B.membranacea Yang et Yang,1986为B.furca Huang et Ding,1979的异名;B.latispina Qin et Yuan,1999为B.bakeri(Muir,1919)的异名.文中还提供了该属所有中国种类的检索表.  相似文献   

18.
19.
The hindgut of the semi-terrestrial tardigrade, Milnesium tardigradum was examined with light and electron microscopy. The hindgut consists of a cloaca and an anterior hindgut. It is delineated anteriorly by the pylorus into which four Malpighian tubules empty and posteriorly, by a broad cloacal slit. A single oviduct enters the hindgut at the junction between the cloaca and the anterior hindgut. Two pairs of muscles insert on the cloaca and anterior hindgut respectively. Electron microscopic observations demonstrate that the anterior hindgut is a specialized transporting epithelium. The luminal surface is covered by a thin layer of cuticle which penetrates into channel-like invaginations. Numerous mitochondria are concentrated apically. The basal and lateral surfaces are also folded. The cells are joined apically by deep tight junctions and a simple basal lamina lines the entire hindgut. The cloaca which receives the contents of the gut and Malpighian tubules as well as gametes of the reproductive tract is a transitional organ that exhibits several characteristics of the hypodermis and anterior hindgut. The cuticle of the cloaca changes sequentially from the complex structure of the integument to a simple layer of the anterior hindgut. The function of the hindgut is discussed with emphasis on the possible response of the anterior hindgut to a hypoosmotic habitat, evaporative water loss during the induction of anhydrobiosis and low oxygen tension.  相似文献   

20.
记述了发现于陕西镇安黄家湾早更新世晚期的一个大型哺乳动物群。动物群包括哺乳动物4目、11科、24种,它们是:Canis variabilis, Hyaenidae gen. et sp. indet. , Homotherium sp. , Megantereon sp. , Lynx cf. shansius , Panthera pardus , Elephantidae gen. et sp. indet. , Equus qingyangensis , Hesperotherium sinense , Ancylotherium sp. , Megatapirus augustus, Rhinocerotidae gen. et sp. indet. , Dicerorhinus lantianensis, Sus sp. , Moschus moschi ferus , Cervus unicolor , Cervus sp. 1, Cervus sp. 2, Hydropotes sp. , Capreolus sp. , Strepsiceros annectens , Leptobos sp. , Bubalus sp. 和 Budorcas taxicolor等。动物群伴生植物孢粉分析表明,当时在化石产地生长着下列植物:Selaginella sp. , Pinaceae gen. et sp. indet. , Picea sp. , Cotinus coggygria , Juglans regia , Quercus sp. , Myrica rubra , Meliaceae gen. et sp. indet. , Celtis sp. , Oleaceae ( Syringa sp. ?) gen. et sp. indet. , Chenopodiaceae gen. et sp. indet. ,Kobresia sp. , Scrophulariaceae gen. et sp. indet. , Humulus sp. , Gramineae gen. et sp. indet. , Ranunculaceae gen. et sp. indet. , Sparganium sp. ,Celastraceae gen. et sp. indet. ,Elaeagnaceae gen. et sp. indet. ,Compositae gen. et sp. indet. ,Aremisia sp. , Xanthium sibiricum 和Carex sp.等。分析了动物群生活时栖息地的气候、植被和地貌特征,结果表明,动物群栖息在温暖、湿润、有森林、灌丛草地并富有水体的生境中,当时秦岭腹地存在着相当开阔的河谷地带,山势没有现在这么险峻,因此阻断秦岭南北动物交流的天然屏障当时可能还未真正形成,秦岭南北两侧的动物可以沿着开阔的河谷地带随季节和气候的变化互相扩散迁移。  相似文献   

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