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1.
Morphological and metabolic characterization of a new species of strictly anaerobic rumen fungus: Neocallimastix joyonii 总被引:2,自引:0,他引:2
André Breton Annick Bernalier Frédérique Bonnemoy Gérard Fonty Brigitte Gaillard Philippe Gouet 《FEMS microbiology letters》1989,58(2-3):309-314
A new strain of strictly anaerobic fungi was isolated from the rumen of sheep. This strain is characterized by a polycentric thallus, an extensive and polynuclear rhizomycelium, polyflagellated zoospores with gamma particle-like bodies. We propose to assign this strain in a new species: Neocallimastix joyonii. 相似文献
2.
《Molecular & general genetics : MGG》1996,253(3):315-323
A clone containing a Neocallimastix frontalis cDNA assumed to encode the β subunit of succinyl-CoA synthetase (SCSB) was identified by sequence homology with prokaryotic
and eukaryotic counterparts. An open reading frame of 1311 bp was found. The deduced 437 amino acid sequence showed a high
degree of identity to the β-succinyl-CoA synthetase of Escherichia coli (46%), the mitochondrial β-succinyl-CoA synthetase from pig (48%) and the hydrogenosomal β-succinyl-CoA synthetase from Trichomonas vaginalis (49%). The G+C content of the succinyl-CoA synthetase coding sequence (43.8%) was considerably higher than that of the 5′
(14.8%) and 3′ (13.3%) non-translated flanking sequences, as has been observed for other genes from N. frontalis. The codon usage pattern was biased, with only 34 codons used and a strong preference for a pyrimidine (T) in the third positions
of the codons. The coding sequence of the β-succinyl-CoA synthetase cDNA was cloned in an E. coli expression vector encoding a 6(His) tag. The recombinant protein was purified by affinity binding and used to produce polyclonal
antibodies. The anti-succinyl-CoA synthetase serum recognized a 45 kDa protein from a N. frontalis fraction enriched for hydrogenosomes and similar polypeptides in two related anaerobic fungi, Piromyces rhizinflata (45 kDa) and Caecomyces communis (47 kDa). Immunocytochemical experiments suggest that succinyl-CoA synthetase is located in the hydrogenosomal matrix. Staining
for SCS activity in native electrophoretic gels revealed a band with an apparent molecular weight of approximately 330 kDa.
The C-terminus of the succinyl-CoA synthetase sequence was devoid of the typical targeting signals identified so far in microbody
proteins, indicating that N. frontalis uses a different signal for sorting SCSB into hydrogenosomes. Based on comparisons with other proteins we propose a putative
N-terminal targeting signal for succinyl-CoA synthetase of N. frontalis that shows some of the features of mitochondrial targeting sequences.
Received: 16 October 1995 / Accepted: 29 July 1996 相似文献
3.
MICHELLE L. GREEN DENISE L. HERZING JOHN D. BALDWIN 《Molecular ecology resources》2007,7(6):1287-1292
Genetic sampling and molecular investigations are important parts of studying wild populations. However, collecting tissues from free‐ranging animals can be difficult or impractical. This study develops a sampling and extraction protocol for template DNA from faecal material collected in a marine environment from small cetaceans. DNA was extracted from faecal material of free‐ranging Atlantic spotted dolphins (Stenella frontalis) and subsequently tested for its suitability in molecular investigations by amplifying both mitochondrial and nuclear DNA. The resulting mitochondrial sequences were found to closely match known S. frontalis haplotypes. Three microsatellite loci were amplified and fall within the expected size range for cetaceans. Mother and calf families previously assigned by observation were genetically confirmed using both mitochondrial haplotype and allele sharing between the mother and offspring. The protocol effectively collects and extracts dolphin DNA from faecal samples and enables species identification as well as confirmation of genetic relatedness and should be considered as a noninvasive alternative to current protocols. 相似文献
4.
5.
采用直接观察法对大额牛(Bos frontalis)的产前离群与产后带犊归群、分娩等产犊行为进行了观察。结果表明,(1)野外观察17头临产母牛中,76.47%(13头)的个体在产前(11.23±7.14)d离开社群独行觅食,寻找分娩场所;分娩地点多选择在靠近溪河、地势较高、食物丰富、光照好、地面相对平坦的草地、林边或林中。母牛野外产犊后带犊归群的时间为产后(5.57±2.64)d。(2)在设围栏的人工草地上放牧条件下对6头母牛分娩行为观察表明,产前24~12 h母牛的警觉巡视行为明显增多;产前12~5h表现为烦燥不安和频繁爬跨;产前3~1 h领地行为明显,对分娩地点4~6 m2内长势较高的牧草等进行清理,为新生犊牛行动清除障碍;分娩时间为6:00~18:00时,其中在6:00~7:00时分娩的占66.67%(4/6);母牛从卧地进入分娩至犊牛产出期间起卧(7.00±6.00)次,从卧地到犊牛完全产出需(25.00±5.00)min,胎衣排出的时间为产后(5.64±1.80)h;犊牛(n=6,♂1+♀5)初生体重为(16.46±2.56)kg,母牛无难产现象;母牛对犊牛能及时舔饰,定时授乳和用心守护。犊牛从产出至第一次站稳需(52.70±29.69)min,第一次站稳到吮吸初乳需(38.7±29.14)min,第一次吃初乳到向周边活动需(61.33±1.53)min。 相似文献
6.
7.
Rühli FJ Kuhn G Evison R Müller R Schultz M 《American journal of physical anthropology》2007,133(4):1099-1111
Cases of pathologically changed bone might constitute a diagnostic pitfall and frequently need histological methods to be etiologically properly evaluated. With micro‐computed tomography (μCT), a new epoch of 2D and 3D imaging has been launched. We evaluated the diagnostic investigation of this analytical method versus well established histological investigations of historical human bone. Pathological changes due to various etiologies (infectious, traumatic, endocrinological, neoplasia) observed in autopsy‐based macerated human skulls (Galler Collection, Natural History Museum Basel, Switzerland) were investigated by μCT and compared with histological thin ground sections using polarized light. Micro‐CT images visualize the architecture of the bone with high spatial resolution without preparation or destruction of the sample in the area to be sectioned. Changes in the bone surfaces as well as alterations of the diploë can be assessed. However, morphological patterns caused by reactive response, such as typical arrangements of collagen fibers, can only be visualized by the microscopic investigation of thin ground sections using polarized light. A great advantage of μCT is the high number of slices obtained so that spatial differences within the areas of the specimen become visible. Micro‐CT is a valuable tool for the diagnosis of vestiges of skull bone diseases. Its advantages over histology are the fast, automated image acquisition and the fact that the specimen is not completely destroyed. Only excision of the area to be scanned is necessary, if the specimen is too large to be scanned as a whole. Further, the 3D visualization of the micro‐architecture allows an easy orientation within the sample, for example, for the choice of the location of the histological slices. However, the need to differentiate woven from lamellar bone still makes histology an indispensable method. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc. 相似文献
8.
J.D. Waldron C.W. Lafon R.N. Coulson D.M. Cairns M.D. Tchakerian A. Birt K.D. Klepzig 《应用植被学》2007,10(1):53-64
Question: Can fire be used to maintain Yellow pine (Pinus subgenus Diploxylon) stands disturbed by periodic outbreaks of southern pine beetle? Location: Southern Appalachian Mountains, USA. Methods: We used LANDIS to model vegetation disturbance and succession on four grids representative of xeric landscapes in the southern Appalachians. Forest dynamics of each landscape were simulated under three disturbance scenarios: southern pine beetle, fire, and southern pine beetle and fire, as well as a no disturbance scenario. We compared trends in the abundance of pine and hardwood functional types as well as individual species. Results: Yellow pine abundance and open woodland conditions were best maintained by a combination of fire and southern pine beetle disturbance on both low elevation sites as well as mid‐elevation ridges & peaks. On mid‐elevation SE‐W facing slopes, pine woodlands were best maintained by fire alone. Conclusions: Our simulations suggest that fire can help maintain open pine woodlands in stands affected by southern pine beetle outbreaks. 相似文献
9.
ANWARUDDIN CHOUDHURY 《Mammal Review》2002,32(3):199-226
The Gaur Bos gaurus ranges from India to peninsular Malaysia. Its distribution, status and conservation in the Indian subcontinent are reviewed here on the basis of available information, both published papers and unpublished census reports of forest departments, and field survey data from north‐eastern India and parts of Bhutan and Nepal. The Gaur is found in three disjunct regions, south‐western India, central India and north‐eastern India (including Nepal, Bhutan and Bangladesh). Within these regions the distribution is highly fragmented and includes a number of small non‐viable isolated populations. The habitat in north‐eastern India is still contiguous with that in Bhutan, Myanmar and Bangladesh and to some extent with Nepal. Although the estimated population of the Gaur is 23 000–34 000, it is declining alarmingly. Populations outside the protected areas may not last long. An action plan has been proposed for its conservation. 相似文献
10.
R. W. Hofstetter Z. Chen M. L. Gaylord J. D. McMillin & M. R. Wagner 《Journal of Applied Entomology》2008,132(5):387-397
The southern pine beetle (Dendroctonus frontalis) and western pine beetle (Dendroctonus brevicomis) cause significant mortality to pines in the southern and western United States. The effectiveness of commercial lures at capturing these bark beetles in Arizona has not been tested and may vary from other regions of their distribution. We conducted experiments using baited Lindgren funnel traps to investigate (i) if D. frontalis is more attracted to the standard commercial lure for D. brevicomis (frontalin + exo‐brevicomin + myrcene) than the D. frontalis lure (frontalin + terpene blend), (ii) whether replacement of myrcene with α‐pinene changes trap catches of Dendroctonus and associated insects, and (iii) whether the attraction to these lures varies across the geographical range of ponderosa pine forests throughout Arizona. In 2005, we tested various combinations of frontalin, exo‐brevicomin, myrcene and α‐pinene to D. frontalis, D. brevicomis and associated species. Dendroctonus frontalis, D. brevicomis and the predator Temnochila chlorodia were most attracted to lures with exo‐brevicomin. The replacement of the myrcene component with α‐pinene in the D. brevicomis lure resulted in the capture of twice as many bark beetles and Elacatis beetles. However, T. chlorodia did not differentiate between monoterpenes. In 2006, traps were set up in 11 locations around Arizona to test the relative attraction of lure combinations. In 9 out 11 locations, the D. brevicomis lure with α‐pinene was more attractive than the lure with myrcene or a terpene blend. These results suggest that the D. brevicomis lure with α‐pinene rather than myrcene is more effective lure to capture D. brevicomis and D. frontalis in Arizona. However, geographical variation in attractiveness to lures is evident even within this region of the beetles’ distributions. Differential attraction of Dendroctonus and their predators to these lures suggests potential use in field trapping and control programmes. 相似文献