High-Level Gene Flow Restricts Genetic Differentiation in Dairy Cattle Populations in Thailand: Insights from Large-Scale Mt D-Loop Sequencing

Domestication and artificial selection lead to the development of genetically divergent cattle breeds or hybrids that exhibit specific patterns of genetic diversity and population structure. Recently developed mitochondrial markers have allowed investigation of cattle diversity worldwide; however, an extensive study on the population-level genetic diversity and demography of dairy cattle in Thailand is still needed. Mitochondrial D-loop sequences were obtained from 179 individuals (hybrids of Bos taurus and B. indicus) sampled from nine different provinces. Fifty-one haplotypes, of which most were classified in haplogroup “I”, were found across all nine populations. All sampled populations showed severely reduced degrees of genetic differentiation, and low nucleotide diversity was observed in populations from central Thailand. Populations that originated from adjacent geographical areas tended to show high gene flow, as revealed by patterns of weak network structuring. Mismatch distribution analysis was suggestive of a stable population, with the recent occurrence of a slight expansion event. The results provide insights into the origins and the genetic relationships among local Thai cattle breeds and will be useful for guiding management of cattle breeding in Thailand.

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Genetic structure and proposed conservation strategy for natural populations of Calycanthus chinensis Cheng et S.Y. Chang (Calycanthaceae)

Canadian Journal of Plant Science ◽

10.4141/cjps07015 ◽

2008 ◽

Vol 88 (1) ◽

pp. 179-186 ◽

Cited By ~ 2

Author(s):

Chu-Chuan Fan ◽

Nicola Pecchioni ◽

Long-Qing Chen

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Genetic Differentiation ◽

Genetic Distance ◽

Gene Diversity ◽

Genetic Relationships ◽

Natural Populations ◽

Population Level ◽

Conservation Strategy ◽

Information Index

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD

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Spatial genetic structure and asymmetrical gene flow within the Pacific walrus

Journal of Mammalogy ◽

10.1644/11-mamm-a-344.1 ◽

2012 ◽

Vol 93 (6) ◽

pp. 1512-1524 ◽

Cited By ~ 9

Author(s):

Sarah A. Sonsthagen ◽

Chadwick V. Jay ◽

Anthony S. Fischbach ◽

George K. Sage ◽

Sandra L. Talbot

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Genetic Structure ◽

Genetic Differentiation ◽

Spatial Genetic Structure ◽

Genetic Relationships ◽

Breeding Population ◽

Pacific Walrus ◽

Breeding Populations ◽

The Pacific

Abstract Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data suggest that males are distinct among breeding populations (ΦST = 0.051), and between the eastern Chukchi and other nonbreeding aggregations (ΦST = 0.336–0.449). Nonbreeding female aggregations were genetically distinct across marker types (microsatellite FST = 0.019; mtDNA ΦST = 0.313), as was eastern Chukchi and all other nonbreeding aggregations (microsatellite FST = 0.019–0.035; mtDNA ΦST = 0.386–0.389). Gene flow estimates are asymmetrical from St. Lawrence Island into the southeastern Bering breeding population for both sexes. Partitioning of haplotype frequencies among breeding populations suggests that individuals exhibit some degree of philopatry, although weak. High levels of genetic differentiation among eastern Chukchi and all other nonbreeding aggregations, but considerably lower genetic differentiation between breeding populations, suggest that at least 1 genetically distinct breeding population remained unsampled. Limited genetic structure at microsatellite loci between assayed breeding areas can emerge from several processes, including male-mediated gene flow, or population admixture following a decrease in census size (i.e., due to commercial harvest during 1880–1950s) and subsequent recovery. Nevertheless, high levels of genetic diversity in the Pacific walrus, which withstood prolonged decreases in census numbers with little impact on neutral genetic diversity, may reflect resiliency in the face of past environmental challenges.

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Genetic Diversities and Historical Dynamics of Native Ethiopian Horse Populations (Equus caballus) Inferred from Mitochondrial DNA Polymorphisms

Genes ◽

10.3390/genes12020155 ◽

2021 ◽

Vol 12 (2) ◽

pp. 155

Author(s):

Kefena Effa ◽

Sonia Rosenbom ◽

Jianlin Han ◽

Tadelle Dessie ◽

Albano Beja-Pereira

Keyword(s):

Genetic Diversity ◽

Mitochondrial Dna ◽

Genetic Differentiation ◽

Sequence Divergence ◽

Dna Polymorphisms ◽

Base Pairs ◽

Feral Horses ◽

Domestic Horses ◽

D Loop ◽

Diversity Estimates

Matrilineal genetic diversity and relationship were investigated among eight morphologically identified native Ethiopian horse populations using polymorphisms in 46 mtDNA D-loop sequences (454 base pairs). The horse populations identified were Abyssinian, Bale, Borana, Horro, Kafa, Kundido feral horses, Ogaden and Selale. Mitochondrial DNA D-loop sequences were characterized by 15 variable sites that defined five different haplotypes. All genetic diversity estimates, including Reynolds’ linearized genetic distance, genetic differentiation (FST) and nucleotide sequence divergence (DA), revealed a low genetic differentiation in native Ethiopian horse populations. However, Kundido feral and Borana domestic horses were slightly diverged from the rest of the Ethiopian horse populations. We also tried to shed some light on the matrilineal genetic root of native Ethiopian horses from a network constructed by combining newly generated haplotypes and reference haplotypes deposited in the GenBank for Eurasian type Turkish Anatolian horses that were used as a genetic conduit between Eurasian and African horse populations. Ninety-two haplotypes were generated from the combined Ethio-Eurasian mtDNA D-loop sequences. A network reconstructed from the combined haplotypes using Median-Joining algorithm showed that haplotypes generated from native Ethiopian horses formed separate clusters. The present result encourages further investigation of the genetic origin of native African horses by retrieving additional mtDNA sequences deposited in the GenBank for African and Eurasian type horses.

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Evolutionary history and genetic connectivity across highly fragmented populations of an endangered daisy

Heredity ◽

10.1038/s41437-021-00413-0 ◽

2021 ◽

Author(s):

Yael S. Rodger ◽

Alexandra Pavlova ◽

Steve Sinclair ◽

Melinda Pickup ◽

Paul Sunnucks

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Genetic Differentiation ◽

Evolutionary History ◽

Livestock Grazing ◽

Genetic Connectivity ◽

Evolutionary Divergence ◽

Common Component ◽

A Genome ◽

Eastern Australia

AbstractConservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.

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Genetic diversity of Myanmar cattle breeds using complete mitochondrial D-loop sequence

The Journal of Animal Genetics ◽

10.5924/abgri.46.57 ◽

2018 ◽

Vol 46 (2) ◽

pp. 57-67 ◽

Cited By ~ 2

Author(s):

Moe LWIN ◽

Su Lai Yee MON ◽

Yukio NAGANO ◽

Kotaro KAWABE ◽

Hideyuki MANNEN ◽

...

Keyword(s):

Genetic Diversity ◽

Cattle Breeds ◽

Loop Sequence ◽

D Loop

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A clue to invasion success: genetic diversity quickly rebounds after introduction bottlenecks

Biological Invasions ◽

10.1007/s10530-020-02426-y ◽

2020 ◽

Author(s):

Peter Kaňuch ◽

Åsa Berggren ◽

Anna Cassel-Lundhagen

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Large Scale ◽

Invasion Biology ◽

Invasion Success ◽

Founder Population ◽

Establishment Success ◽

Propagule Size ◽

Introduced Populations ◽

Species Invasiveness

AbstractOne of the fundamental questions in invasion biology is to understand the genetic mechanisms behind success or failure during the establishment of a species. However, major limitations to understanding are usually a lack of spatiotemporal population data and information on the populations’ colonisation history. In a large-scale, detailed study on the bush-cricket Metrioptera roeselii 70 groups of founders were introduced in areas outside the species’ distribution range. We examined how (1) the number of founders (2–32 individuals), (2) the time since establishment (7 or 15 years after introduction) and (3) possible gene flow affected establishment success and temporal genetic changes of the introduced populations. We found higher establishment success in introductions with larger propagule sizes but genetic diversity indices were only partly correlated to propagule size. As expected, introduced populations were more similar to their founder population the larger the propagule size was. However, even if apparent at first, most of the differentiation in the small propagule introductions disappeared over time. Surprisingly, genetic variability was regained to a level comparable to the large and outbreeding founder population only 15 generations after severe demographic bottlenecks. We suggest that the establishment of these populations could be a result of several mechanisms acting in synergy. Here, rapid increase in genetic diversity of few introductions could potentially be attributed to limited gene flow from adjacent populations, behavioural adaptations and/or even increased mutation rate. We present unique insights into genetic processes that point towards traits that are important for understanding species’ invasiveness.

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Genetic diversity and differentiation in populations of Japanese stone pine (Pinuspumila) in Japan

Canadian Journal of Forest Research ◽

10.1139/x26-162 ◽

1996 ◽

Vol 26 (8) ◽

pp. 1454-1462 ◽

Cited By ~ 31

Author(s):

Naoki Tani ◽

Nobuhiro Tomaru ◽

Masayuki Araki ◽

Kihachiro Ohba

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Genetic Differentiation ◽

Phylogenetic Trees ◽

Genetic Relationships ◽

Natural Populations ◽

Group Method ◽

Stone Pine ◽

Arithmetic Means ◽

Pair Group

Japanese stone pine (Pinuspumila Regel) is a dominant species characteristic of alpine zones of high mountains. Eighteen natural populations of P. pumila were studied in an effort to determine the extent and distribution of genetic diversity. The extent of genetic diversity within this species was high (HT = 0.271), and the genetic differentiation among populations was also high (GST = 0.170) compared with those of other conifers. In previous studies of P. pumila in Russia, the genetic variation within the species was also high, but the genetic differentiation among populations was low. We infer that this difference originates from differences in geographic distribution and ecological differences between the two countries. The genetic variation within each population tended, as a whole, to be smaller within marginal southern populations than within northern populations. Genetic relationships among populations reflect the geographic locations, as shown by unweighted pair-group method with arithmetic means and neighbor-joining phylogenetic trees.

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Genetic Relationships of Cattle Breeds Assessed by PCR-RFLP of the Bovine Mitochondrial DNA D-loop Region

Asian-Australasian Journal of Animal Sciences ◽

10.5713/ajas.2005.1368 ◽

2005 ◽

Vol 18 (10) ◽

pp. 1368-1374 ◽

Cited By ~ 3

Author(s):

Du Hak Yoon ◽

Hak Kyo Lee ◽

Sung Jung Oh ◽

Ki Chang Hong ◽

Gwang Joo Jeon ◽

...

Keyword(s):

Mitochondrial Dna ◽

Genetic Relationships ◽

Cattle Breeds ◽

Loop Region ◽

Pcr Rflp ◽

D Loop

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Large-scale geographic survey provides insights into the colonization history of a major aphid pest on its cultivated apple host in Europe, North America and North Africa

10.1101/2020.12.11.421644 ◽

2020 ◽

Author(s):

S.G. Olvera-Vazquez ◽

C. Remoue ◽

A. Venon ◽

A. Rousselet ◽

O. Grandcolas ◽

...

Keyword(s):

Gene Flow ◽

North America ◽

Genetic Differentiation ◽

North Africa ◽

Large Scale ◽

Demographic History ◽

High Genetic Diversity ◽

The North ◽

The Us ◽

History Of

With frequent host shifts involving the colonization of new hosts across large geographical ranges, crop pests are good models for examining the mechanisms of rapid colonization. The microbial partners of pest insects may be involved or affected by colonization, which has been little studied so far. We investigated the demographic history of the rosy apple aphid, Dysaphis plantaginea, a major pest of the cultivated apple (Malus domestica) in Europe, North Africa and North America, as well as the diversity of its endosymbiotic bacterial community. We genotyped a comprehensive sample of 714 colonies from Europe, Morocco and the US using mitochondrial (CytB and CO1), bacterial (16s rRNA and TrnpB), and 30 microsatellite markers. We detected five populations spread across the US, Morocco, Western and Eastern Europe, and Spain. Populations showed weak genetic differentiation and high genetic diversity, except the Moroccan and the North American that are likely the result of recent colonization events. Coalescent-based inferences releaved high levels of gene flow among populations during the colonization, but did not allow determining the sequence of colonization of Europe, America and Morroco by D. plantaginea, likely because of the weak genetic differentiation and the occurrence of gene flow among populations. Finally, we found that D. plantaginea rarely hosts any other endosymbiotic bacteria than its obligate nutritional symbiont Buchnera aphidicola. This suggests that secondary endosymbionts did not play any role in the rapid spread of the rosy apple aphid. These findings have fundamental importance for understanding pest colonization processes and implications for sustainable pest control programs.

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Evolution during seed production for ecological restoration? A molecular analysis of 19 species finds only minor genomic changes

10.1101/2021.11.03.467064 ◽

2021 ◽

Author(s):

Malte Conrady ◽

Christian Lampei ◽

Oliver Bossdorf ◽

Walter Durka ◽

Anna Bucharova

Keyword(s):

Genetic Diversity ◽

Genetic Differentiation ◽

Ecological Restoration ◽

Seed Production ◽

Large Scale ◽

Gene Diversity ◽

Natural Populations ◽

Genetic Change ◽

Breeding Systems ◽

Wild Plants

A growing number of restoration projects require large amounts of seeds. As harvesting natural populations cannot cover the demand, wild plants are often propagated in large-scale monocultures. There are concerns that this cultivation process may cause genetic drift and unintended selection, which would alter the genetic properties of the cultivated populations and reduce their genetic diversity. Such changes could reduce the pre-existing adaptation of restored populations, and limit their adaptability to environmental change. We used single nucleotide polymorphism (SNP) markers and a pool-sequencing approach to test for genetic differentiation and changes in gene diversity during cultivation in 19 wild grassland species, comparing the source populations and up to four consecutive cultivation generations grown from these sources. We then linked the magnitudes of genetic changes to the species breeding systems and seed dormancy, to understand the roles of these traits in genetic change. The propagation of native seeds for ecosystem restoration changed the genetic composition of the cultivated generations only moderately. The genetic differentiation we observed as a consequence of cultivation was much lower than the natural genetic differentiation between different source regions, and the propagated generations harbored even higher gene diversity than wild-collected seeds. Genetic change was stronger in self-compatible species, probably as a result of increased outcrossing in the monocultures. Synthesis and applications: Our study indicates that large-scale seed production maintains the genetic integrity of natural populations. Increased genetic diversity may even increase the adaptive potential of propagated seeds, which makes them especially suitable for ecological restoration. However, we have been working with seeds from Germany and Austria, where the seed production is regulated and certified. Whether other seed production systems perform equally well remains to be tested.

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