scholarly journals Gene flow and selection evidence of sandalwood (Santalum album) under various population structures in Gunung Sewu (Java, Indonesia), and its effects on genetic differentiation

2017 ◽  
Vol 18 (4) ◽  
pp. 1493-1505
Author(s):  
YENI W.N. RATNANINGRUM ◽  
SAPTO INDRIOKO ◽  
ENY FARIDAH ◽  
ATUS SYAHBUDIN

Ratnaningrum YWN, Indrioko S, Faridah E, Syahbudin A. 2017. Gene flow and selection evidence of sandalwood (Santalum album) under various population structures in Gunung Sewu (Java, Indonesia), and its effects on genetic differentiation. Biodiversitas 18: 1493-1505. Field observations on population structures and isoenzyme analysis were conducted to determine gene flow and selection evidence of sandalwood under various population structures in Gunung Sewu, and its effects on genetic differentiation. Sandalwood (Santalum album Linn., Santalaceae) is origin to the south-eastern islands but recently emerged as new landraces in Java Island, Indonesia. Results suggested that (i) natural barriers contributed to habitat fragmentation and disrupted gene flow among populations; (ii) gene flow affected selection processes regarding bottleneck effects and genetic drifts, which determined allelic richness and population diversity; and (iii) variation on gene flow and selection processes affected genetic differentiation among populations. Gene flow restriction and genetic drift occurred when population had lower genetic base, highly clonalized, fragmented, and/or more inbreeding in mating. Genetic differentiation was highest between populations within Timor island, and between Gunung Sewu (Java Island) and Sumba-Timor islands. Populations were not clustered based on geographical sites, but more by the similarity of genetic structures. Genetic differentiations were the combined effect of the differences on genetical processes regarding gene flow and selection events. Both differences existed due to differences on (i) population structures including landscape, clonality and parental genetic composition, and (ii) the disturbance histories of population, which affected the equilibrium between gene flow and drift. These findings emphasized the importance of larger gene flow and genetic base to naturally maintain genetical processes of sandalwood population under various landscapes structures.

Parasitology ◽  
2013 ◽  
Vol 140 (9) ◽  
pp. 1061-1069 ◽  
Author(s):  
IRIS I. LEVIN ◽  
PATRICIA G. PARKER

SUMMARYParasites often have shorter generation times and, in some cases, faster mutation rates than their hosts, which can lead to greater population differentiation in the parasite relative to the host. Here we present a population genetic study of two ectoparasitic flies, Olfersia spinifera and Olfersia aenescens compared with their respective bird hosts, great frigatebirds (Fregata minor) and Nazca boobies (Sula granti). Olfersia spinifera is the vector of a haemosporidian parasite, Haemoproteus iwa, which infects frigatebirds throughout their range. Interestingly, there is no genetic differentiation in the haemosporidian parasite across this range despite strong genetic differentiation between Galapagos frigatebirds and their non-Galapagos conspecifics. It is possible that the broad distribution of this one H. iwa lineage could be facilitated by movement of infected O. spinifera. Therefore, we predicted more gene flow in both fly species compared with the bird hosts. Mitochondrial DNA sequence data from three genes per species indicated that despite marked differences in the genetic structure of the bird hosts, gene flow was very high in both fly species. A likely explanation involves non-breeding movements of hosts, including movement of juveniles, and movement by adult birds whose breeding attempt has failed, although we cannot rule out the possibility that closely related host species may be involved.


2017 ◽  
Vol 20 (2) ◽  
pp. 182
Author(s):  
Yeni Widyana Nurchahyani ◽  
Sapto Indrioko ◽  
Eny Faridah ◽  
Atus Syahbudin

We combined feld observations with isoenzyme analysis to compare population demographic and its effects on genetic diversity and mating systems, among six populations of sandalwood in Gunung Sewu, Indonesia, during March to August 2015. This endangered economic-important species was originated from the southeastern parts of Indonesia, but is recently occured as new landraces in Gunung Sewu, Java island. The observed heterozygosity varied from Ho 0.184 to 0.385 in parents, and from Ho 0.083 to 0.348 in offspring levels, based on the degree of clonality and genetic base. Most of genetic variation is distributed within populations, and only 2.7% were presented among populations, that was indicated by the low DST and FST value (HT 0.30; HS 0.276; DST 2.4%; FST 7.98%). A dendrogram indicated a grouping of populations into three clusters. However, there were seemed to be no association between geographical and genetic distance. Genetic depletion occured due to (i) clonality events as result of heavy-exploitation and/or natural disturbance which induced root suckering, (ii) genetic drifts and bottleneck effects, (iii) the founder effects due to parental low diversity, and (iv) the alteration on mating systems to be more inbreeders. Some of the results confrmed a “reproductive assurance prediction” while some others were contradicting this. It seemed that genetic diversity and mating systems are not much affected by population size, but more by the parental heterozygosity and the degree of clonality. Our results emphasized the importance of populations’ genetic base or parental genetic diversity to naturally maintain the genetic and evolutionary processes under equilibrium conditions.


2021 ◽  
Author(s):  
Jeremy B Yoder ◽  
Albert Dang ◽  
Caitlin MacGregor ◽  
Mikhail Plaza

Interactions between species are widely understood to have promoted the diversification of life on earth, but how interactions spur the the formation of new species remains unclear. Interacting species often become locally adapted to each other, but they may also be subject to shared dispersal limitations and environmental conditions. Moreover, theory predicts that different kinds of interactions have different effects on diversification. To better understand how species interactions promote diversification, we compiled published genetic data for host plants and intimately associated herbivores, parasites, and mutualists. We first tested whether host and associate population structures were correlated --- an indication of associates locally adapting to hosts --- and tested for confounding correlations with geographic distance or climate variation. We used Bayesian multiple regression to estimate the effect of host plant genetic differentiation on associate genetic differentiation over and above the confounding effects of geography and climate. We found that plant and associate genetic structures are indeed often congruent, but isolation by distance and by climate are also common. Multiple regressions established that the effect of host plants on associates is robust to accounting for geographic distance and climate. Finally, associate genetic structure was significantly explained by plant genetic structure more often in antagonistic interactions than in mutualistic ones. This supports a key prediction of coevolutionary theory, that antagonistic interactions promote diversity through local adaptation of antagonists to hosts, while mutualistic interactions promote diversity via the effect of hosts' geographic distribution on mutualists' dispersal.


1999 ◽  
Vol 22 (3) ◽  
pp. 387-394 ◽  
Author(s):  
J. Jordana ◽  
J. Piedrafita ◽  
X. Carre ◽  
A. Martell

We biochemically analyzed and characterized the genetic structure of a population in danger of extinction ,"Alberes", a local cattle breed of the Catalonian Pyrenees (Spain and France). Ninety-two individuals were analyzed for five polymorphic genetic loci (Hb, Alb, Tf, Gc and Ptf2). The animals were grouped according to coat color: Fagina Alberes variety (N = 39) and Black Alberes variety (N = 53). The genetic structures and relationships between these subpopulations and one "outgroup" breed ("Bruna dels Pirineus") were analyzed and compared by using F-statistics. We determined that inbreeding in the Alberes breed is not significant, since negative and nonsignificant FIT and FIS values were obtained. The average genetic differentiation between subpopulations within the Alberes breed was 1.5% (FST = 0.015; P < 0.05), with an effective number of 4.1 individuals exchanged between subpopulations per generation (gene flow). The results obtained in this study corroborate the potential danger of extinction of the breed. The Black Alberes variety is proposed as the principal nucleus of genetic conservation for this breed, as it seems to show a higher degree of genetic isolation from other foreign populations.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yong Wei ◽  
Jiatian Wang ◽  
Zhangyao Song ◽  
Yulan He ◽  
Zihao Zheng ◽  
...  

Abstract Background The Asian tiger mosquito, Aedes albopictus, is one of the 100 worst invasive species in the world and the vector for several arboviruses including dengue, Zika and chikungunya viruses. Understanding the population spatial genetic structure, migration, and gene flow of vector species is critical to effectively preventing and controlling vector-borne diseases. Little is known about the population structure and genetic differentiation of native Ae. albopictus in China. The aim of this study was to examine the patterns of the spatial genetic structures of native Ae. albopictus populations, and their relationship to dengue incidence, on a large geographical scale. Methods During 2016–2018, adult female Ae. albopictus mosquitoes were collected by human landing catch (HLC) or human-bait sweep-net collections in 34 localities across China. Thirteen microsatellite markers were used to examine the patterns of genetic diversity, population structure, and gene flow among native Ae. albopictus populations. The correlation between population genetic indices and dengue incidence was also examined. Results A total of 153 distinct alleles were identified at the 13 microsatellite loci in the tested populations. All loci were polymorphic, with the number of distinct alleles ranging from eight to sixteen. Genetic parameters such as PIC, heterozygosity, allelic richness and fixation index (FST) revealed highly polymorphic markers, high genetic diversity, and low population genetic differentiation. In addition, Bayesian analysis of population structure showed two distinct genetic groups in southern-western and eastern-central-northern China. The Mantel test indicated a positive correlation between genetic distance and geographical distance (R2 = 0.245, P = 0.01). STRUCTURE analysis, PCoA and GLS interpolation analysis indicated that Ae. albopictus populations in China were regionally clustered. Gene flow and relatedness estimates were generally high between populations. We observed no correlation between population genetic indices of microsatellite loci in Ae. albopictus populations and dengue incidence. Conclusion Strong gene flow probably assisted by human activities inhibited population differentiation and promoted genetic diversity among populations of Ae. albopictus. This may represent a potential risk of rapid spread of mosquito-borne diseases. The spatial genetic structure, coupled with the association between genetic indices and dengue incidence, may have important implications for understanding the epidemiology, prevention, and control of vector-borne diseases.


The Auk ◽  
2019 ◽  
Vol 136 (4) ◽  
Author(s):  
Catalina Palacios ◽  
Silvana García-R ◽  
Juan Luis Parra ◽  
Andrés M Cuervo ◽  
F Gary Stiles ◽  
...  

Abstract Ecological speciation can proceed despite genetic interchange when selection counteracts the homogenizing effects of migration. We tested predictions of this divergence-with-gene-flow model in Coeligena helianthea and C. bonapartei, 2 parapatric Andean hummingbirds with marked plumage divergence. We sequenced putatively neutral markers (mitochondrial DNA [mtDNA] and nuclear ultraconserved elements [UCEs]) to examine genetic structure and gene flow, and a candidate gene (MC1R) to assess its role underlying divergence in coloration. We also tested the prediction of Gloger’s rule that darker forms occur in more humid environments, and examined morphological variation to assess adaptive mechanisms potentially promoting divergence. Genetic differentiation between species was low in both ND2 and UCEs. Coalescent estimates of migration were consistent with divergence with gene flow, but we cannot reject incomplete lineage sorting reflecting recent speciation as an explanation for patterns of genetic variation. MC1R variation was unrelated to phenotypic differences. Species did not differ in macroclimatic niches but were distinct in morphology. Although we reject adaptation to variation in macroclimatic conditions as a cause of divergence, speciation may have occurred in the face of gene flow driven by other ecological pressures or by sexual selection. Marked phenotypic divergence with no neutral genetic differentiation is remarkable for Neotropical birds, and makes C. helianthea and C. bonapartei an appropriate system in which to search for the genetic basis of species differences employing genomics.


Crustaceana ◽  
1993 ◽  
Vol 65 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Barbara A. Stewart

AbstractThe use of protein electrophoretic data for determining species boundaries in amphipods is addressed. Analysis of published literature on genetic differentiation in amphipods showed that pairs of allopatric populations which have genetic identities (I) above a value of 0.85 probably represent intraspecific populations, whereas pairs of populations which have genetic identities below about 0.45 probably represent different species. It was recommended that if I values fall between 0.45 and 0.85, additional factors such as evidence of a lack of gene flow between the populations, and concordant morphological variation should be considered.


2008 ◽  
Vol 2 (3) ◽  
pp. 338-342 ◽  
Author(s):  
Yan Geng ◽  
Zhangping Yang ◽  
Hong Chang ◽  
Yongjiang Mao ◽  
Wei Sun ◽  
...  

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Akiko Kyuno ◽  
Mifue Shintaku ◽  
Yuko Fujita ◽  
Hiroto Matsumoto ◽  
Motoo Utsumi ◽  
...  

We sequenced the mitochondrial ND4 gene to elucidate the evolutionary processes ofBathymodiolusmussels and mytilid relatives. Mussels of the subfamily Bathymodiolinae from vents and seeps belonged to 3 groups and mytilid relatives from sunken wood and whale carcasses assumed the outgroup positions to bathymodioline mussels. Shallow water mytilid mussels were positioned more distantly relative to the vent/seep mussels, indicating an evolutionary transition from shallow to deep sea via sunken wood and whale carcasses.Bathymodiolus platifronsis distributed in the seeps and vents, which are approximately 1500 km away. There was no significant genetic differentiation between the populations. There existed high gene flow betweenB. septemdierumandB. breviorand low but not negligible gene flow betweenB. marisindicusandB. septemdierumorB. brevior, although their habitats are 5000–10 000 km away. These indicate a high adaptability to the abyssal environments and a high dispersal ability ofBathymodiolusmussels.


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