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1.
The heavily traded Grey Parrot Psittacus erithacus is believed to have undergone rapid population decline, yet there are almost no quantitative data on abundance changes over time from anywhere within its huge range. We reviewed the species’ historical abundance across Ghana, undertook targeted searches during 3‐ to 5‐day visits to 42 100‐km2 cells across the country's forest zone, repeated counts at 22 parrot roosts first performed two decades ago and gauged around 900 people's perceptions of the decline and its causes. In over 150 days of fieldwork, just 32 groups (maximum group size = 12) were recorded in 10 cells. Encounter rates averaged 0.15 individuals per hour of targeted search, around 15 times lower than those recorded in the early 1990s. No active roosts were found, and only 18 individuals were recorded in three roost areas that each harboured 700–1200 birds two decades ago. Interviewees stressed the importance of very tall trees of commercially important species such as Terminalia superba and Ceiba pentandra for nesting and roosting, and believed that the felling of large trees on farmland (42% of responses) and trapping for trade (37%) were the two main causes of decline. Ghana has lost 90–99% of its Grey Parrots since 1992, a time when the population had presumably already been seriously reduced by two decades of extremely heavy trade. There is no evidence that, away from one or two localities, declines are less severe anywhere else within the West African range of P. erithacus, or across the entire range of the recently split Timneh Parrot Psittacus timneh.  相似文献   

2.
This study describes 12 microsatellite loci identified in the African grey parrot Psittacus erithacus. Eleven were polymorphic, with observed heterozygosities 42–94% (average 68) and exclusion powers of PE1 = 0.996 and PE2 = 0.999. Microsatellites have previously been developed for a number of other parrots but showed limited cross‐species polymorphism. Here high levels of cross‐species amplification were observed: 71% of 32 Psittacines (22 genera). At least seven loci, 58%, were polymorphic in other African parrots as well as Neotropical and Australasian parrots, which diverged from the African parrots c30.6 and over 41.4 million years ago, respectively.  相似文献   

3.

Background  

Analysis of the first reported complete genome sequence ofBifidobacterium longumNCC2705, an actinobacterium colonizing the gastrointestinal tract, uncovered its proteomic relatedness toStreptomyces coelicolorandMycobacterium tuberculosis. However, a rapid scrutiny by genometric methods revealed a genome organization totally different from all so far sequenced high-GC Gram-positive chromosomes.  相似文献   

4.

Background  

The Class II DNA transposons are mobile genetic elements that move DNA sequence from one position in the genome to another. We have previously demonstrated that the naturally occurring Tol2 element from Oryzias latipes efficiently integrates its corresponding non-autonomous transposable element into the genome of the diploid frog, Xenopus tropicalis. Tol2 transposons are stable in the frog genome and are transmitted to the offspring at the expected Mendelian frequency.  相似文献   

5.

Background  

Molecular genetic maps provide a means to link heritable traits with underlying genome sequence variation. Several genetic maps have been constructed for Brassica species, yet to date, there has been no simple means to compare this information or to associate mapped traits with the genome sequence of the related model plant, Arabidopsis.  相似文献   

6.

Background  

Mitochondrial DNA has been detected in the nuclear genome of eukaryotes as pseudogenes, or Numts. Human and plant genomes harbor a large number of Numts, some of which have high similarity to mitochondrial fragments and thus may have been inadvertently included in population genetic and phylogenetic studies using mitochondrial DNA. Birds have smaller genomes relative to mammals, and the genome-wide frequency and distribution of Numts is still unknown. The release of a preliminary version of the chicken (Gallus gallus) genome by the Genome Sequencing Center at Washington University, St. Louis provided an opportunity to search this first avian genome for the frequency and characteristics of Numts relative to those in human and plants.  相似文献   

7.
Summary Keratinized structures from the African Grey Parrot (feather, down, claw, scale, rhamphotheca, soft lingual epithelium, and lingual nail) were compard by combining biochemical and functional-morphological approaches. At the molecular level, the keratinized structures of Psittacus erithacus are organized essentially like those of other avian species. Correlations were established (or verified) between the mechanical properties of the tissues and the molecular size of the keratin monomers, between the mechanical properties and the x-ray diffraction patterns of the tissues, and between the Polyacrylamide gel electrophoresis (PAGE) patterns of the keratins and certain aspects of growth patterns of the structures. The keratin proteins of the lingual nail, described here for the first time, resemble those of the claw and rhamphotheca. Morphological, biochemical and functional differences between the lingual nail and the rest of the lingual epithelium were established.  相似文献   

8.

Background  

Members of the disintegrin metalloproteinase (ADAM) family play important roles in cellular and developmental processes through their functions as proteases and/or binding partners for other proteins. The amphibian Xenopus has long been used as a model for early vertebrate development, but genome-wide analyses for large gene families were not possible until the recent completion of the X. tropicalis genome sequence and the availability of large scale expression sequence tag (EST) databases. In this study we carried out a systematic analysis of the X. tropicalis genome and uncovered several interesting features of ADAM genes in this species.  相似文献   

9.

Background  

Bioinformatic analysis of the genome sequence of Neisseria gonorrhoeae revealed the presence of nine probable prophage islands. The distribution, conservation and function of many of these sequences, and their ability to produce bacteriophage particles are unknown.  相似文献   

10.

Background  

Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW).  相似文献   

11.
Genome of an avian papillomavirus.   总被引:3,自引:2,他引:1       下载免费PDF全文
A papillomavirus which we designate FPV was isolated from chaffinches (Fringilla coelebs). A physical map of the FPV genome was constructed, and selected regions of this genome were studied by nucleotide sequence analysis. The results make it possible to align the FPV genome with the genome of bovine papillomavirus type 1 and to show, moreover, that avian and mammalian papillomaviruses have a similar genome organization.  相似文献   

12.
Haemoproteus psittaci n. sp., a microsomal halteridial haemoproteid, is described from the African grey parrot Psittacus erithacus. This species differs from Haemoproteus handai, the only other haemoproteid described from the Psittaciformes, in that it is halteridial, not circumnuclear, is much smaller in all dimensions and has only 10–12 pigment granules compared to 20–24 noted in the latter species.  相似文献   

13.

Background  

Musa species contain the fourth most important crop in developing countries. Here, we report the analysis of 6,252 BAC end-sequences, in order to view the sequence composition of the Musa acuminata genome in a cost effective and efficient manner.  相似文献   

14.
15.

Background  

The genome of the avian adenovirus Chicken Embryo Lethal Orphan (CELO) has two terminal regions without detectable homology in mammalian adenoviruses that are left without annotation in the initial analysis. Since adenoviruses have been a rich source of new insights into molecular cell biology and practical applications of CELO as gene a delivery vector are being considered, this genome appeared worth revisiting. We conducted a systematic reannotation and in-depth sequence analysis of the CELO genome.  相似文献   

16.

Background  

S. aureus is a coloniser and pathogen of humans and mammals. Whole genome sequences of 58 strains of S. aureus in the public domain and data from multi-strain microarrays were compared to assess variation in the sequence of proteins known or putatively interacting with host.  相似文献   

17.

Background  

Wolbachia are endosymbiotic bacteria that commonly infect numerous arthropods. Despite their broad taxonomic distribution, the transmission patterns of these bacteria within and among host species are not well understood. We sequenced a portion of the wsp gene from the Wolbachia genome infecting 138 individuals from eleven geographically distributed native populations of the fire ant Solenopsis invicta. We then compared these wsp sequence data to patterns of mitochondrial DNA (mtDNA) variation of both infected and uninfected host individuals to infer the transmission patterns of Wolbachia in S. invicta.  相似文献   

18.

Background  

Extraintestinal pathogenic E. coli (ExPEC) represent a phylogenetically diverse group of bacteria which are implicated in a large range of infections in humans and animals. Although subgroups of different ExPEC pathotypes, including uropathogenic, newborn meningitis causing, and avian pathogenic E. coli (APEC) share a number of virulence features, there still might be factors specifically contributing to the pathogenesis of a certain subset of strains or a distinct pathotype. Thus, we made use of suppression subtractive hybridization and compared APEC strain IMT5155 (O2:K1:H5; sequence type complex 95) with human uropathogenic E. coli strain CFT073 (O6:K2:H5; sequence type complex 73) to identify factors which may complete the currently existing model of APEC pathogenicity and further elucidate the position of this avian pathoype within the whole ExPEC group.  相似文献   

19.

Background  

Efforts to sequence the genomes of different organisms continue to increase. The DNA sequence is usually decoded for one individual and its application is for the whole species. The recent sequencing of the highly heterozygous Vitis vinifera L. cultivar Pinot Noir (clone ENTAV 115) genome gave rise to several thousand polymorphisms and offers a good model to study the transferability of its degree of polymorphism to other individuals of the same species and within the genus.  相似文献   

20.

Background  

Plastid genome content and protein sequence are highly conserved across land plants and their closest algal relatives. Parasitic plants, which obtain some or all of their nutrition through an attachment to a host plant, are often a striking exception. Heterotrophy can lead to relaxed constraint on some plastid genes or even total gene loss. We sequenced plastid genomes of two species in the parasitic genus Cuscuta along with a non-parasitic relative, Ipomoea purpurea, to investigate changes in the plastid genome that may result from transition to the parasitic lifestyle.  相似文献   

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