突尼斯非洲跳鼠(Jaculus jaculus)和埃及跳鼠(J.orientalis)群体的等位酶多态及遗传分化(英文)

运用16种酶蛋白编码的23个遗传座位对突尼斯非洲跳鼠(Jaculus jaculus)和埃及跳鼠(J. orientalis)自然群体的遗传变异和分化进行了电泳分析。结果表明,与其他啮齿动物等哺乳动物的相关数据比较,发现这两个种群体的遗传变异水平较低。非洲跳鼠群体的观测杂合度 (H_obs) 为0.08—0.19,多态座位百分比(P)为26.2%—45.2%,每个座位的平均等位基因数(A)为1.1—1.4;埃及跳鼠的H_obs为0.10—0.15,P为29.3%—44.1%,A为1.1—1.7。两个种群体各自的遗传分化程度较低(非洲跳鼠和埃及跳鼠的F_st分别为0.0017和0.0019)。而两个种群体间的F_st为0.607（P<0.05）,表明两个种之间高度的遗传分化。本研究支持这两个种分类地位的合法性,并强调了地理因素（环境类型和生物气候阶段）对两个种遗传结构的影响。     

Characterization and PCR multiplexing of polymorphic microsatellite loci for the locust Locusta migratoria

Because of the scarcity of polymorphic genetic markers available in locust species, only a few population genetics studies have been carried out on this taxon. We isolated and characterized 11 polymorphic microsatellite loci in the pest locust Locusta migratoria capito, and described experimental conditions for polymerase chain reaction (PCR) multiplexing and simultaneously genotyping these loci. The number of alleles per locus ranged from six to 25, and the expected heterozygosity ranged from 0.431 to 0.957. Results of cross‐taxon amplification tests are reported in six other Locusta migratoria subspecies, six species of the Oedipodinae subfamily and two other pest locust species.     

Isolation and characterization of microsatellite loci in Tripterygion delaisi

We isolated 49 microsatellite loci from a genomic library of Tripterygion delaisi×anthosoma enriched for CA and GA repeats. Ten loci were screened in 30 individuals with high numbers of alleles per locus (averaging 15.5 ± 2.86) and observed heterozygosity (averaging 0.765 ± 0.052). No deviations from Hardy–Weinberg expectations were detected. These highly polymorphic markers will be useful in determining the spatial patterns of genetic diversity between and within subspecies of Tripterygion delaisi.     

Isolation and characterization of microsatellite markers in the tetraploid birch,Betula pubescens ssp. tortuosa

The mountain birch, Betula pubescens ssp. tortuosa is a tetraploid tree species which forms the tree limit in northern Fennoscandia. We identified nine polymorphic microsatellite loci in order to characterize the genetic structure of populations at different elevations close to the treeline. The microsatellite loci were highly polymorphic, with 14–42 alleles per locus and an average expected heterozygosity of 0.73 ± 0.25 under random chromosome segregation and 0.68 ± 0.23 under random chromatid segregation.     

Genetic diversity following demographic recovery in the insular endemic plant <Emphasis Type="Italic">Galium catalinense</Emphasis> subspecies <Emphasis Type="Italic">acrispum</Emphasis>

Galium catalinense (Rubiaceae) is a perennial shrub consisting of two subspecies endemic to California’s Channel Islands: Galium catalinense subsp. catalinense on Santa Catalina Island, and G. catalinense subsp. acrispum, a state-endangered taxon on San Clemente Island. A long history of overgrazing by introduced herbivores has contributed to population declines in G. catalinense subsp. acrispum. We surveyed 12 populations throughout the taxon’s range for genetic variation using eight polymorphic microsatellite loci to determine the genetic impact of this demographic bottleneck. At the taxon level, 65 alleles were identified with an average of 8.1 alleles per locus, although many alleles were rare; the effective number of alleles per locus averaged 2.6. Expected heterozygosity was 0.550. Individual populations had between six and eight polymorphic loci, with expected heterozygosities ranging from 0.36 to 0.60, and effective numbers of alleles ranging from 1.8 to 3.5 per locus. Populations fell into three or four genetic clusters, depending on type of analysis, which may represent refugia where the populations persisted during intense herbivory. There is little evidence of genetic bottlenecks or substantial inbreeding within populations. These findings, coupled with indications of recent migration between populations, suggest that G. catalinense subsp. acrispum is currently unlikely to be endangered by genetic factors, but small population sizes make the taxon vulnerable to future loss of genetic diversity. Management strategies based on these genetic data, population sizes, and the spatial distribution of populations are discussed.     

Isolation,characterization and cross‐salmonid amplification of 31 microsatellite loci in the lake whitefish (Coregonus clupeaformis,Mitchill)

Coregonine fish represent the most successful evolutionary lineage of salmonids with Coregonus as the most speciose salmonid genus inhabiting numerous postglacial lakes across the northern hemisphere. We isolated and characterized 31 polymorphic microsatellite loci in Coregonus clupeaformis with an average number of 5.3 alleles per locus (range three to eight) and an overall expected heterozygosity of 0.74 ± 0.11. Two loci revealed significant linkage associations through analyses of mapping families. Six additional salmonid taxa assessed for cross‐species amplification revealed between 18 and 26 positive amplifications and between two and 12 polymorphic loci per species.     

Are there two cryptic species of the lesser jerboa Jaculus jaculus (Rodentia: Dipodidae) in Tunisia? Evidence from molecular,morphometric, and cytogenetic data

Jerboas belonging to the genus Jaculus are widely distributed rodents inhabiting Palearctic desert and semi‐desert areas. Previous studies on the lesser Egyptian jerboa Jaculus jaculus showed the existence of various morphological forms of controversial taxonomic status. They were sometimes related to two different species, J. jaculus and Jaculus deserti, although this has not been recognized in recent taxonomic updates. To clarify the systematic status of J. jaculus in Tunisia, we performed molecular (phylogenetic analyses of cytochrome b sequences), morphological (multivariate analyses of 13 skull measurements) and karyotypic (standard preparations from bone marrow cells) analyses on a number of specimens collected from ten localities. Our analyses revealed two monophyletic, well differentiated clades, with a mean genetic divergence value (K2P = 10.9 ± 0.01%), which is within the range of distances generally observed between rodent species. Morphometric analyses clearly separated populations of the two genetic clades from each other. However, karyotypes of individuals from both clades appeared similar. Individuals from both molecular clades/morphometric groups were found in sympatry in most of the localities sampled. These results, as obtained from a restricted area of the total distribution, suggest that there are two separate species within the currently accepted J. jaculus in Tunisia. Alternative hypotheses such as the occurrence of a strong, ancient phylogeographic structure, or the presence of pseudogenes, are also considered to account for the results obtained. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 673–686.     

Growth and maturation of metatarsals and their taxonomic significance in the jerboas Allactaga and Jaculus (Rodentia: Dipodidae)

The development of metatarsals in Allactaga tetradactyla, Jaculus jaculus jaculus and J. orientalis was studied and their taxonomic significance was elucidated. The five metatarsals, as a rule, are developed and ossified in the three species, but variation in the fate of the first and fifth metatarsals was found. Ossification begins in the median part of the metatarsals; however, it appears in the distal part of the digits’ phalanges, beginning with the third phalanx. The first metatarsal appears just distal to the entocuneiform and develops as a small, separate bone located either in close contact with the distal end of the entocuneiform in A. tetradactyla or completely fused with it, forming a compound bone, in both of J. j. jaculus and J. orientalis. The second, third and fourth metatarsals differentiate distal to the mesocuneiform, ectocuneiform and cuboid, respectively, and fuse with one another into a single long cannon bone in all species. Nevertheless, the fifth metatarsal differentiates ventro‐lateral to the head of the fourth metatarsal and ossifies ventral to the head process of the developing cannon bone. The fifth metatarsal either extends to articulate with the phalanges of the fourth digit in A. tetradactyla or persists as a separate, small bone in both of J. j. jaculus and J. orientalis. On this basis, it is concluded that J. jaculus and J. orientalis are both distinct congeneric species and are somewhat more distant from A. tetradactyla.     

Intraspecific diversity and relationship between subspecies of Origanum vulgare revealed by comparative AFLP and SAMPL marker analysis

The genus Origanum is often referred to as an under-utilized taxon because of its complex taxonomy. Origanum vulgare L., the most variable species of the genus, is a spice and medicinal herb that is characterized by high morphological diversity (six subspecies). In this study, the relative efficiencies of two PCR-based marker approaches, amplified fragment length polymorphism (AFLP) and selectively amplified microsatellite polymorphic loci (SAMPL), were used for comparable genetic diversity surveys and subspecies discrimination among 42 oregano accessions. Seven assays each of AFLP and SAMPL markers were utilized. Effective multiplex ratio (EMR), average heterozygosity (H_av-p), marker index (MI), and resolving power (RP) of the primer combinations were calculated for the two marker systems. UPGMA and Structure analysis along with PCoA plots derived from the binary data matrices of the two markers depicted the genetic distinction of accessions. Our results indicate that both marker systems are suitable but SAMPL markers are slightly more efficient in differentiating accessions and subspecies than AFLPs.     

Variation in the genetic structure of Peromyscus populations. I. Genetic heterozygosity—its relationship to adaptive divergence

The genetic structure of nine Peromyscus maniculatus nebrascensis demes from southeastern Wyoming was determined by analyzing allozymes encoded by 23 genetic loci with polyacrylamide gel electrophoresis. Genetic variability is extremely high for two genetic parameters; the proportion of loci heterozygous per individual averaged 0.16, and the proportion of loci polymorphic per deme averaged 0.41. Previous estimates of genetic heterozygosity for species within the genus Peromyscus have a mean of 0.06. The results of the present study suggest that genetic heterozygosity is considerably higher within P. maniculatus demes than within demes of other species in the genus. Geographic range is correlated with heterozygosity among Peromyscus species, as is adaptive divergence into broad-niched species. These correlates suggest that high heterozygosity may reflect an adaptation to a variable environment.     

GENETIC DIFFERENTIATION IN THE FLORIDA SUBSPECIES OF HELIANTHUS DEBILIS (ASTERACEAE)

Techniques of horizontal starch gel electrophoresis were employed to estimate levels of genetic variation within and genetic differentiation among populations of the three Florida subspecies of Helianthus debilis. The subspecies are H. d. debilis, H. d. vestitus, and H. d. tardiflorus. These taxa are very similar with respect to levels of genetic variability. The average values across all populations for proportion of polymorphic loci (25.5%) and number of alleles per polymorphic locus (2.35) are comparable to those found in other outcrossing plants. The average frequency of heterozygotes per locus (0.05) is lower than that found in other outcrossers. Local populations within each subspecies are genetically very similar. The average genetic distance between local populations is D = 0.010 ± 0.001. Subspecies vestitus and subspecies tardiflorus are also genetically very similar (D = 0.015 ± 0.001). However, subspecies debilis is differentiated from both subspecies vestitus (D = 0.121 ± 0.006) and subspecies tardiflorus (D = 0.103 ± 0.005). This genetic differentiation parallels morphological differentiation. The average genetic distance among all three subspecies is D = 0.080 ± 0.003. A moderate amount of genetic differentiation accompanies the process of subspeciation in Helianthus debilis.     

Are cryptic species of the Lesser Egyptian Jerboa,Jaculus jaculus (Rodentia,Dipodidae), really cryptic? Re‐evaluation of their taxonomic status with new data from Israel and Sinai

Two clades of the lesser Egyptian jerboa Jaculus jaculus sensu lato were recently described in North Africa and considered as cryptic species. Members of both clades are also found in Israel, where they can be easily identified according to fur and tail colouration and morphology of the male external genitalia, but cannot be separated confidently using skull characters. Examination of type specimens demonstrated that the correct names for the two species are Jaculus jaculus (Linnaeus 1758) and Jaculus hirtipes (Lichtenstein, 1823). Comparisons of geographic and habitat differences of the two species revealed a high niche divergence between them, slightly higher in the sympatric North African populations than in the parapatric populations of Israel and Sinai. A low niche divergence was detected between North African and Middle Eastern populations of J. jaculus, and a low niche convergence between North African and Middle Eastern populations of J. hirtipes. The levels of niche differentiation coincide with those of genetic differences.     

Cloning and characterization of novel microsatellite DNA markers for the grass rockfish,Sebastes rastrelliger,and cross‐species amplification in 10 related Sebastes spp

Here we report development and characterization of seven polymorphic loci derived from grass rockfish (Sebastes rastrelliger) genomic DNA phagemid libraries enriched for microsatellite motifs. Within grass rockfish, average allelic diversity was 11.3 alleles per locus and average heterozygosity was 0.73. The seven loci also were surveyed in 10 related species of Sebastes, where allelic diversity ranged from highly polymorphic to monomorphic. Deviations from Hardy–Weinberg were nonsignificant in all but one species/locus combination suggesting low occurrence of null alleles. Significant linkage disequilibrium was detected among three loci, but these events were limited to a single species in each case.     

Biochemical genetics in the yellow wagtail complex: Conservative avian protein evolution reconfirmed by isoelectric focusing

Seventeen protein loci were examined by ultrathin layer isoelectric focusing in three subspecies of the problematic Motacilla flava complex. The percentage of polymorphic loci is 41. Mean heterozygosity per locus and individual ranges from 0.063 to 0.150. Nei's genetic distance ranges from 0.0034 to 0.0054, which is within the range previously reported for other avian subspecies-relations. The genetic differentiation pattern coincides well with morphological and ethological differentiation within this complex and even with the amount of interbreeding of its members in contact zones. Peculiarities of avian evolution are discussed.     

Molecular genetic diversity of Satureja bachtiarica

Fifty-seven genotypes from eight population of Satureja bachtiarica was evaluated using fifteen ISSR and eleven RAPD markers. DNA profiling using RAPD primers amplified 84 loci, among which 81 were polymorphic with an average of 7.36 polymorphic fragments per locus. Also, using RAPD markers maximum and minimum polymorphic bands observed for Semyrom (77.38 %) and Farsan (40.48 %) populations, respectively. Semyrom population recorded the highest unbiased expected heterozygosity (0.259) and Shannon’s Indices (0.38). While, the lowest values of unbiased expected heterozygosity (0.172) and Shannon’s Index (0.245) were recorded for Eghlid and Farsan populations, respectively. On the other hand, ISSR primers produced 136 bands, from which 134 were polymorphic with an average of 9.06 polymorphic fragments per primer (98.52 %). The ISSR markers evaluation revealed that maximum and minimum polymorphic bands observed for Semyrom (66.18 %) and Farsan (31.62 %), respectively. Shahrekorud population recorded the highest unbiased expected heterozygosity (0.211) and Shannon’s Indices (0.301). While, the lowest value of unbiased expected heterozygosity (0.175) observed for Farsan and Yazd populations and the lowest Shannon’s Index (0.191) recorded by Farsan population. The overall results of the study revealed that both ISSR and RAPD markers were effective for evaluation of genetic variation of S. bachtiarica.     

New polymorphic microsatellite loci for the Macedonian crested newt, Triturus macedonicus, and cross-priming testing in four other crested newt species

Eleven microsatellites have been characterized for Triturus macedonicus. Nine loci showed different variation patterns in a sample of 40 individuals from a single breeding pond in Zagori province (Greece), with an average number of 4.2 alleles per locus and an expected heterozygosity ranging from 0.1199 to 0.8079. Distinct cross-priming amplification rates were recovered on four additional crested newt species. Two monomorphic T. macedonicus loci were polymorphic in other Triturus species. The microsatellites developed herein could be a useful intraspecific genetic tool to undertake fine-scale population genetic analyses as well as in the study of contact zones between crested newt species.     

Nine microsatellite DNA primers for <Emphasis Type="Italic">Hippophae rhamnoides</Emphasis> ssp. <Emphasis Type="Italic">sinensis</Emphasis> (Elaeagnaceae)

Hippophae rhamnoides ssp. sinensis occurs mainly in the arid regions of northwest China. The wood stands of this subspecies play an important role in maintaining the local ecosystems in these regions. In addition, the genetic characteristics are essential to understand the historical range changes of this subspecies and its morphological differentiation with other subspecies. In this study, we developed nine microsatellite loci for this subspecies for the first time. We used the combining biotin capture method to enrich AG/CT/AC/GT/CG/GTG/CCA microsatellites. Twenty-six microsatellites were isolated from the enriching library and nine of them were found to be polymorphic through screening 12 distantly distributed individuals. The number of alleles per locus ranged from three to twelve and expected heterozygosity from 0.2659 to 0.4767, respectively. We further performed cross-priming tests in another subspecies and two congeneric species. These firstly isolated loci will provide a useful tool to investigate the genetic structure of this subspecies and its morphological differentiation from the other subspecies.     

The origin of two cryptic species of African desert jerboas (Dipodidae: Jaculus)

The desert biota is exposed to extreme and variable conditions that shape its evolution and diversification processes. In this respect, the Jaculus jerboas have gained the attention of researchers as a result of their broad Saharan–Arabian distribution and their high and unexplained, morphological, anatomical, and molecular variation. In the present study, mitochondrial and nuclear genealogies where used to confirm monophyly of two cryptic species: Jaculus jaculus and Jaculus deserti. The reconstructed demography showed that the evolutionary histories of the species are markedly different and that the expansion into North‐West Africa by J. deserti was more recent than that of J. jaculus. The weak ecological separation between species and the signs of recent population growth and expansion of J. deserti suggest that its sympatric occurrence with J. jaculus is recent and that these species evolved in isolated populations, after diverging around the Pliocene–Pleistocene boundary. The importance of climate changes on the Sahara Desert biota is discussed in the context of genetic diversification. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 435–445.     

Isolation and characterization of microsatellite markers for the heavily exploited rockfish Sebastes schlegeli, and cross-species amplification in four related Sebastes spp.

Here we report development and characterization of 14 polymorphic microsatellite loci from Sebastes schlegel. Polymorphism at these loci revealed from 3 to 23 alleles. The observed heterozygosity ranged from 0.34 to 1.00, and the expected heterozygosity ranged from 0.31 to 0.95. No linkage disequibrium was found. Two loci were significantly deviated from HWE (P < 0.01). The 14 loci were also surveyed in four other Sebastes species and 12 loci successfully amplified, where allelic diversity ranged from highly polymorphic to monomorphic. These results demonstrate these microsatellite markers can be used for the study of intra- and inter-specific genetic diversity.