共查询到20条相似文献,搜索用时 31 毫秒
1.
J. G. Oakeshott J. B. Gibson D. A. Willcocks G. K. Chambers 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1983,65(3):191-196
Summary The octanol dehydrogenase (Odh) and acid phosphatase (Acph) loci of Drosophila melanogaster are each polymorphic for two electrophoretically detectable alleles. The frequencies of the Odh and Acph alleles have been analysed in populations sampled from up to a 40 ° latitudinal range in each of Australasia, North America and Europe/Asia. Odh
S frequency is found to be significantly negatively associated with distance from the equator in all three zones. The relationship of Acph
S frequency to distance from the equator is significant and negative in Australasia but neither significant nor consistent in sign in North America and Europe/Asia. 相似文献
2.
Nine pairs of polymerase chain reaction (PCR) primers that amplify polymorphic microsatellite loci in the desert locust, Schistocerca gregaria (Forskal), were developed using a magnetic bead‐based enrichment protocol. A sample of 48 locusts collected during the 1993 and 1995 upsurge periods in Eritrea, East Africa, were genotyped. The number of alleles per locus ranged from six to 20; the average was 12.67. Allelic distributions were significantly different between samples from different localities. 相似文献
3.
The distribution ofPapio hamadryas in Saudi Arabia: Ecological correlates and human influence 总被引:1,自引:0,他引:1
Sylvain Biquand Véronique Biquand-Guyot Ahmed Boug Jean-Pierre Gautier 《International journal of primatology》1992,13(3):223-243
We describe the distribution ofPapio hamadryas in Saudi Arabia in relation to ecological constraints and recent changes in human activities and land use. Baboons are present
only in the Sarawat and southern Hijaz mountains, which border the Red Sea in the southwestern region of the country. Our
distribution data confirms that their range, described as of 1981, should be extended 200 km northward, from 21°40N (Taif)
to 23°20N (Al Akhal). This new limit of range is not due to recent deployment of the baboons, but instead corrects inaccurate
surveys by previous reporters. Ecological factors that affect baboon distribution include low annual rainfall (less than 100
mm per yr), which limits baboon range in the north and east, and the absence of suitable sleeping cliffs in the coastal plain,
which limits their range in the west. Relative abundance is discussed in relation to vegetation and predator distribution.
Human influence is also significant: commensal troops persist near urban centers, while agricultural development reduces baboon
numbers in some regions. Habitat characteristics are discussed in comparison with similar data on the range of hamadryas in
Ethiopia. 相似文献
4.
RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii reshov. in Inner Mongolia steppe 总被引:1,自引:0,他引:1
J. L. Wang N. X. Zhao Y. B. Gai F. Lin A. Z. Ren W. B. Ruan L. Chen 《Russian Journal of Genetics》2006,42(5):468-475
Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure
of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10-bp oligonucleotide primers, which generated 237 RAPD bands,
were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from
the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei’s diversity index (h), Shannon’s diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson’s correlation analysis between genetic diversity parameters and ecological
parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by
precipitation and cumulative temperature). Dendrogram based on Jaccard’s genetic distance showed that the individuals from
the same population formed a single subgroup. Although most variation (56.85%) was within populations, there was high genetic
differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei’s unbiased genetic distance (G
ST) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel’s test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection
may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation
in northem grassland in China may be the main factor responsible for high genetic differentiation among populations, within
and among regions.
The text was submitted by the authors in English. 相似文献
5.
Takeo Tadano 《Biochemical genetics》1983,21(5-6):477-485
An esterase locus (Est-2), coding for carboxylesterase, and an acid phosphatase locus (Acph) were genetically studied by agar gel electrophoresis in the mosquito Aedes (Finlaya) togoi. The Est-2 and Acph variants occur as a monomer and a dimer, respectively. Both enzyme loci are linked to the sex locus (M) and s (straw-colored larva); the gene arrangement and recombination distances were Est-2—12.6%—s—31.7%—M—2.9%—Acph—3.2%—Est-3. The Est-3 locus was previously shown to code for carboxylesterase.This work was supported by Grant AI 16983-02 from the National Institutes of Health, Bethesda, Md. 相似文献
6.
采用SCoT标记分析了18个皂荚种质的遗传多样性,并采用UPGMA法对18个皂荚种质进行了聚类分析。在此基础上,通过筛选出的多态性条带构建了18个皂荚种质的SCoT指纹图谱。扩增结果表明:从51个SCoT引物中筛选了15个引物进行PCR扩增,共扩增出226条带,其中多态性条带216条,多态性比率为96.61%。各引物多态性信息含量(PIC)、观测等位基因数(Na)、有效等位基因数(Ne)、Nei’s基因多样性指数(H)和Shannon’s信息指数(I)的平均值分别为0.875 9、1.964 9、1.440 1、0.272 6、0.426 1。18个皂荚种质的遗传相似系数在0.491 4~0.938 1之间,表明供试材料之间具有较丰富的遗传多样性。聚类分析结果表明:在遗传相似系数为0.60处可将18个皂荚种质分为3组,其中野皂荚单独为一组,山皂荚和皂荚-T聚为一组,其它皂荚材料聚为一组。利用3个引物扩增的8个多态性位点构建了18份皂荚种质资源的DNA指纹图谱,可以将其区分并精准鉴定。该研究结果为皂荚种质的鉴定和新品种选育提供了一定的理论依据。 相似文献
7.
V. Volobouev M. Lombard M. Tranier B. Dutrillaux 《Journal of Zoological Systematics and Evolutionary Research》1995,33(2):54-61
An analysis was made of the R- and C-banding of chromosomes of the following Gerbillus species (Rodentia, Gerbillidae): G. poecilops (Taif, Saudi Arabia), G. henleyi (Oursi, Burkina Faso; Kairouan, Tunisia), and G. nanus (Taif and Hofuf, Saudi Arabia; Sind desert, Pakistan). Their karyotypes show the same chromosome number (2n = 52), but a different N.F.a. (number of autosomal arms), ranging from 58 to 62 in the species overall, and from 58 to 60 among G. nanus forms, due to pericentric inversions involving chromosomes 1 and 4. Moreover, large inter-individual variations of heterochromatin segments of chromosomes 25, X, and Y were found. Considering morphology and karyotype, G. poecilops and G. henleyi appear to be rather monomorphous species, whereas G. nanus produces a series of forms as a consequence of speciation, in which both chromosomal and morphological differentiations occur that do not correlate. 相似文献
8.
HERMANS G. CONTRERAS‐DÍAZ JOS PESTANO NICOLS M. SUREZ PEDRO OROMÍ CARLOS JUAN 《Molecular ecology resources》2006,6(1):54-56
Six polymorphic microsatellite markers have been developed for the Canary endemic ground beetle Trechus flavocinctus, and the performance of primer pairs amplifying these loci in closely related taxa (including two cave‐obliged species) has been tested. The number of alleles in T. flavocinctus samples taken from three distant localities in two islands ranged from four to 14 per locus. Observed heterozygosities were from 0.333 to 0.933. These markers could be useful tools to study the population structure and the genetic consequences of island and cave colonization by ground beetles. 相似文献
9.
Ben-Jie Li Kun-Kun Wang Dong-Ping Chen Ying Yan Xu-Ling Cai Hui-Min Chen Ke Dong Fei Lin Han-Hong Xu 《Insect Science》2021,28(6):1721-1733
The phenylpyrazole insecticide fipronil blocks resistance to dieldrin (RDL) γ-aminobutyric acid (GABA) receptors in insects, thereby impairing inhibitory neurotransmission. Some insect species, such as the diamondback moth (Plutella xylostella), possess more than one Rdl gene. The involvement of multiple Rdls in fipronil toxicity and resistance remains largely unknown. In this study, we investigated the roles of two Rdl genes, PxRdl1 and PxRdl2, in P. xylostella fipronil action. In Xenopus oocytes, PxRDL2 receptors were 40 times less sensitive to fipronil than PxRDL1. PxRDL2 receptors were also less sensitive to GABA compared with PxRDL1. Knockout of the fipronil-sensitive PxRdl1 reduced the fipronil potency 10-fold, whereas knockout of the fipronil-resistant PxRdl2 enhanced the fipronil potency 4.4-fold. Furthermore, in two fipronil-resistant diamondback moth field populations, PxRdl2 expression was elevated 3.7- and 4.1-fold compared with a susceptible strain, whereas PxRdl1 expression was comparable among the resistant and susceptible strains. Collectively, our results indicate antagonistic effects of PxRDL1 and PxRDL2 on fipronil action in vivo and suggest that enhanced expression of fipronil-resistant PxRdl2 is potentially a new mechanism of fipronil resistance in insects. 相似文献
10.
Mohammed R. Al Zahrani Khalid M. Al Ghamdi Mohammad M. Aljameeli Mohamed N. Bakr Tariq S. Alghamdi Touseef Amna Haider Fatehia N. Gharsan Samia Q. Alghamdi Ehab M. Abdella Jazem A. Mahyoub 《Entomological Research》2023,53(12):572-583
As Aedes mosquitoes are the predominant carriers of arboviruses responsible for global dengue fever and chikungunya outbreaks, understanding their genetic diversity and population structure can enhance dengue prevention and vector control efforts. Although sympatric cryptic species have been acknowledged in Aedes species subgroups in Southeast Asia, little information is available regarding the occurrence and dispersal of cryptic Aedes species in Saudi Arabia. In the present investigation, we intend to analyze genetic variations and perform a phylogenetic study of sympatric Aedes samples collected from various locations in Taif Province, Saudi Arabia. The locus of mitochondrial DNA cytochrome c oxidase subunit 1 (COX1, analyzed with DNA barcoding) was utilized to determine genetic variance and to build phylogenetic trees. For species identification, the COX1 sequences of Aedes samples from Taif Province were compared with those of Aedes samples from GenBank (National Center for Biotechnology Information, NCBI). To identify phylogenetic relationships and genetic variability, phylogenetic trees were created using Taif Province samples, GenBank A. albopictus samples, and GenBank A. aegypti samples. The phylogenetic analysis revealed that some Taif samples (A3, A7, F2, F4, F1, A4, A1, F9 and F6) were closer to A. aegypti and A. albopictus samples from Africa and East Asia, especially Kenya and Malaysia. Whereas other samples (F9, F6, A4, F1 and A1) were closer to the GenBank A. aegypti samples KP843383 (Thailand), HM399357(Australia), MK533632 (Kenya), KX420460 (Kenya), KU495081 (Australia) and MF179160 (China) than the remaining Taif samples. Overall, our findings demonstrate that examining the genetic diversity and phylogenetic linkages of Aedes samples can aid in understanding the evolution of Aedes cryptic species in the western regions of Saudi Arabia. 相似文献
11.
Microsatellite Variation Among Red Snapper (Lutjanus campechanus) from the Gulf of Mexico 总被引:4,自引:0,他引:4
Allelic variation at a total of 20 nuclear-encoded microsatellites was examined among adult red snapper (Lutjanus campechanus) sampled from 4 offshore localities in the Gulf of Mexico. The number of alleles at the 20 microsatellites ranged from 5
to 20; average (± SE) direct count heterozygosity values ranged from 0.148 ± 0.025 to 0.902 ± 0.008. No significant departures
from expectations of Hardy-Weinberg equilibrium were found for any locus within samples, and genotypes at pairs of microsatellites
appeared to be randomly associated, i.e., in genotypic equilibrium. Tests of homogeneity in allele distributions among the
4 localities were nonsignificant for 19 of the microsatellites. Allele distribution at microsatellite Lca 43 was heterogeneous among localities before (but not after) Bonferroni corrections for multiple tests executed simultaneously.
Tests of homogeneity in the distribution of individual alleles at Lca 43 gave similar results: one low frequency allele was distributed heterogeneously among samples before, but not after, Bonferroni
correction. Molecular analysis of variance indicated that more than 99% of variation at each microsatellite was distributed
within sample localities. These results generally are consistent with the hypothesis of a single population (stock) of red
snapper in the northern Gulf of Mexico.
Received September 25, 2000; accepted January 16, 2001 相似文献
12.
Xingyi Gao Weikang Yang Jianfang Qiao Jun Yao Kefen Xu 《Frontiers of Biology in China》2008,3(4):385-391
This article presents the distribution and status of bustards, which are listed as first-category protected animals according
to the survey results during 1990–2002 in China. The Chinese populations of Otis tarda dybowskii are breeding in south-west of Heilongjiang Province, western Jilin Province, east and middle Inner Mongolia, north Ningxia
Hui Autonomous Region, and Gansu Province. A few can winter in the south breeding-range. Its winter-range lies from the south
to the Yellow River, as far as to Guizhou Province and Jiangxi Province. Its population number is about 200–300 or 500–800.
The Chinese populations of O. t. tarda are breeding in the north and west of Xinjiang. It is unclear about its winter-range, which is presumed to be in south Asia.
Recently we found individuals wintering in Chabuchaer and west Xinjiang. The population number is about 2000–3000. The habitat
in breeding range includes steppe, grassland, desert grassland, and farmland. The habitat in winter range is the beach of
rivers and lakes, meadows, meadow-grassland, and wheatland. The Chinese populations of Chlamydotis undulata macqueeni are breeding in the fringe of the Jungar Basin, the banks of the Ulungur River, Balikun and south Turpan Basin in Xinjiang,
west Inner Mongolia, and west Gansu. NortheastMulei in eastern Jungar Basin of Xinjiang is the main breeding-range in the
world. The bird uses desert and desert grassland as its habitat. Its winter-range is west Asia and south Asia. Its population
number is about 2000. The Chinese populations of Tetrax tetrax are breeding in north Xinjiang, and China is located on the east border of its breeding-range. Its habitat is grassland and
semi-desert, and its winter-range lies in south Asia. Its population in China is very scarce. In addition, we analyzed the
causes of their endangerment and put forward protection tactics of Chinese Bustards.
__________
Translated from Arid Zone Research, 2007, 24(2): 179–186 [译自: 干旱区研究] 相似文献
13.
Arctostaphylos glauca has evolved two growth forms in the San Bernardino Mountains of Southern California. A chaparral ecotype of upright shrubs with relatively long leaves occurs in chaparral on the south and west sides of the mountain range. A desert woodland ecotype of low, compact, spreading shrubs with shorter leaves occurs in pinyon woodland on the north and northeast sides of the same range. The chaparral ecotype flowers early and fruits heavily. Upon periodic destruction by fire its populations are replaced by numerous seedlings. The woodland ecotype flowers late and fruits sparingly. Its lower seed reproductive potential is further indicated by the lower total number of floral units, by a lower proportion of fruit set, and by an apparent truncation of the flowering season before all the flower buds open. An alternative strategy, involving long life, compact growth form, and the exploitation of new soil resources by layering and vegetative reproduction in the absence of regular fire recycling has evidently adapted an old chaparral plant to recent desert woodland conditions. 相似文献
14.
Raquel Sobrino Pelayo Acevedo Marco A. Escudero Javier Marco Christian Gortázar 《European Journal of Wildlife Research》2009,55(2):161-165
We conducted spotlight counts from 1992 to 2006 in 59 localities to describe carnivore presence, distribution and relative
abundance in open agriculture lands in Aragon, northeastern Spain. During the study period, urban waste and carcases of domestic
livestock became less available to wild animals, and rabbit (Oryctolagus cuniculus) abundance was low after rabbit haemorragic disease. We calculated a kilometric abundance index (KAI, individuals seen per
100 km surveyed) and the ratio between the number of positive localities in which a species was detected and the total of
localities surveyed in a year. Indices to abundance and presence included: red fox (Vulpes vulpes), KAI per 100 km 10.70 and 100.0% localities per year; stray dog (Canis familiaris), KAI 0.48 and 22.6% localities; wildcat (Felis silvestris), KAI 0.10 and 19.1% localities; domestic cat (Felis catus), KAI 0.21 and 20.6% localities; polecat (Mustela putorius), KAI 0.02 and 2.0% localities; badger (Meles meles), KAI 0.16 and 23.6% localities; stone marten (Martes foina), KAI 0.11 and 19.6% localities; weasel (Mustela nivalis), KAI 0.002 and 0.6% localities; and genet (Genetta genetta), KAI 0.06 and 10.0% localities. Indices of badger abundance increased significantly, whereas indices of stray dogs decreased
significantly over the study period. Abundance indices of red fox, the most important predator of small game, were stable
throughout the study period. No significant trend was observed to other studied species. This study concludes that Aragon
region maintains a diverse and rather stable carnivore community and shows that large scale data may help to identify trends
of the more abundant wild and feral carnivores. 相似文献
15.
Uwe Fritz Mafalda Barata Stephen D. Busack Guido Fritzsch & Rita Castilho 《Zoologica scripta》2006,35(1):97-108
Mauremys leprosa, distributed in Iberia and North‐west Africa, contains two major clades of mtDNA haplotypes. Clade A occurs in Portugal, Spain and Morocco north of the Atlas Mountains. Clade B occurs south of the Atlas Mountains in Morocco and north of the Atlas Mountains in eastern Algeria and Tunisia. However, we recorded a single individual containing a clade B haplotype in Morocco from north of the Atlas Mountains. This could indicate gene flow between both clades. The phylogenetically most distinct clade A haplotypes are confined to Morocco, suggesting both clades originated in North Africa. Extensive diversity within clade A in south‐western Iberia argues for a glacial refuge located there. Other regions of the Iberian Peninsula, displaying distinctly lower haplotype diversities, were recolonized from within south‐western Iberia. Most populations in Portugal, Spain and northern Morocco contain the most common clade A haplotype, indicating dispersal from the south‐western Iberian refuge, gene flow across the Strait of Gibraltar, and reinvasion of Morocco by terrapins originating in south‐western Iberia. This hypothesis is consistent with demographic analyses, suggesting rapid clade A population increase while clade B is represented by stationary, fragmented populations. We recommend the eight, morphologically weakly diagnosable, subspecies of M. leprosa be reduced to two, reflecting major mtDNA clades: Mauremys l. leprosa (Iberian Peninsula and northern Morocco) and M. l. saharica (southern Morocco, eastern Algeria and Tunisia). Peripheral populations could play an important role in evolution of M. leprosa because we found endemic haplotypes in populations along the northern and southern range borders. Previous investigations in another western Palearctic freshwater turtle (Emys orbicularis) discovered similar differentiation of peripheral populations, and phylogeographies of Emys orbicularis and Mauremys rivulata underline the barrier status of mountain chains, in contrast to sea straits, suggesting common patterns for western Palearctic freshwater turtles. 相似文献
16.
《Journal of bryology》2013,35(3):511-517
AbstractEight new localities for Homalothecium nitens (Hedw.) Robins are recorded from north Co. Mayo, Ireland. The first observations of H. nitens in fruit in Ireland are reported. 相似文献
17.
Taylor Edwards Caren S. Goldberg Matthew E. Kaplan Cecil R. Schwalbe Don E. Swann 《Molecular ecology resources》2003,3(4):589-591
The desert tortoise, Gopherus agassizii, is a threatened species native to the North American desert southwest and is recognized as having distinct Mojave and Sonoran populations. We identified six polymorphic microsatellite loci in the desert tortoise. All six loci were polymorphic in Sonoran samples. Five of the loci were variable in Mojave samples with varying degrees of amplification success. Two of the loci exhibited low allelic variation (2–3 alleles) while four were highly variable (8–27 alleles). 相似文献
18.
John C. Hafner Nathan S. Upham Emily Reddington Candice W. Torres 《Journal of Biogeography》2008,35(11):2102-2118
Aim Kangaroo mice, genus Microdipodops Merriam, are endemic to the Great Basin and include two species: M. pallidus Merriam and M. megacephalus Merriam. The pallid kangaroo mouse, M. pallidus, is a sand‐obligate desert rodent. Our principal intent is to identify its current geographical distribution and to formulate a phylogeographical hypothesis for this taxon. In addition, we test for orientation patterns in haplotype sharing for evidence of past episodes of movement and gene flow. Location The Great Basin Desert region of western North America, especially the sandy habitats of the Lahontan Trough and those in south‐central Nevada. Methods Mitochondrial DNA sequence data from portions of three genes (16S ribosomal RNA, cytochrome b, and transfer RNA for glutamic acid) were obtained from 98 individuals of M. pallidus representing 27 general localities sampled throughout its geographical range. Molecular sequence data were analysed using neighbour‐joining, maximum‐parsimony, maximum‐likelihood and Bayesian methods of phylogenetic inference. Directional analysis of phylogeographical patterns, a novel method, was used to examine angular measurements of haplotype sharing between pairs of localities to detect and quantify historical events pertaining to movement patterns and gene flow. Results Collecting activities showed that M. pallidus is a rather rare rodent (mean trapping success was 2.88%), and its distribution has changed little from that determined three‐quarters of a century ago. Two principal phylogroups, distributed as eastern and western moieties, are evident from the phylogenetic analyses (mean sequence divergence for cytochrome b is c. 8%). The western clade shows little phylogenetic structure and seems to represent a large polytomy. In the eastern clade, however, three subgroups are recognized. Nine of the 42 unique composite haplotypes are present at two or more localities and are used for the orientation analyses. Axial data from haplotype sharing between pairwise localities show significant, non‐random angular patterns: a north‐west to south‐east orientation in the western clade, and a north‐east to south‐west directional pattern in the eastern clade. Main conclusions The geographical range of M. pallidus seems to be remarkably stable in historical times and does not show a northward (or elevationally upward) movement trend, as has been reported for some other kinds of organism in response to global climate change. The eastern and western clades are likely to represent morphologically cryptic species. Estimated times of divergence of the principal clades of M. pallidus (4.38 Ma) and between M. pallidus and M. megacephalus (8.1 Ma; data from a related study) indicate that kangaroo mice diverged much earlier than thought previously. The phylogeographical patterns described here may serve as a model for other sand‐obligate members of the Great Basin Desert biota. 相似文献
19.
Hermans G. Contreras-Díaz Heriberto López Pedro Oromí Carlos Juan 《Conservation Genetics》2006,7(5):767-771
The five recognized endemic pamphagid species (Orthoptera) of the Canary Islands have restricted and fragmented ranges due to habitat decline. Seven polymorphic microsatellite markers have been developed for Acrostira tamarani, and the performance of primer pairs amplifying these loci in related taxa has been tested. The number of alleles in A. tamarani samples taken from two distant localities in the island of Gran Canaria ranged from two to eight per locus. Observed heterozygosities were from 0.151 to 0.559. Up to four primer pairs amplified in related species with moderate heterozigosities (maximum of 0.687 and 10 alleles for Ata67 locus in Purpuraria erna). These markers could be useful tools to study the population structure and management of endemic threatened pamphagids of the Canary archipelago. 相似文献
20.
The geographical distribution of different karyotypes in Tropical African genera of Hyacinthaceae is studied. In Albuca, Dipcadi, Drimia (including Urginea), and Drimiopsis there seem to be a general trend of increasing level of ploidy and/or basic number. There is also a tendency of increasing karyotype asymmetry from the south towards north and west. Southern Africa is therefore probably a centre of dispersal (and origin?) for these genera. In the subgenus Urophyllon of Ornithogalum the cytological conditions are in accordance with a hypothesis of northern origin and migration via East Africa towards south and west. Several new chromosome numbers are presented. 相似文献