scholarly journals Demographic history of the fragmented yellowthroated bulbul (Pycnonotus xantholaemus) population in the Deccan Peninsula, India

2020 ◽  
Vol 43 ◽  
pp. 199-207
Author(s):  
A Jha ◽  
K Vasudevan
Keyword(s):  
Demographic History ◽  
Population Decline ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Mitochondrial Control Region ◽  
Haplotype Network ◽  
Genetic Connectivity ◽  
Founder Population ◽  
Effective Population ◽  
Genetic Structuring

The yellow-throated bulbul (YTB) is an endemic passerine restricted to scrub forests along hill slopes with exposed rocky outcrops in the Deccan Peninsula, India. It is found in small, discontinuous populations and is vulnerable to extinction due to ongoing habitat loss and subsequent population decline. To assess the genetic connectivity and past demography, we sequenced 1050 nucleotide base pairs of the mitochondrial control region of 60 individuals that represent distinct populations in the geographic range of the species. We recovered 39 haplotypes defined by 81 variable sites. Haplotype diversity was high with low nucleotide diversity, suggesting rapid population growth from a founder population with a small effective population size. The negative values of Tajima’s D and Fu’s Fs and small positive value of Ramos-Onsins and Rozas’ R2 suggest deviation from neutrality and population expansion. The haplotype network and demographic expansion parameters further suggest historical population expansion. Mismatch analysis statistics and Bayesian skyline plots estimate population expansion during the late Pleistocene. Although the species presently occurs in small, disconnected we found no structuring of the population. Dispersal events are the most likely explanation for the absence of genetic structuring in the YTB population. These results represent important data for the design of a conservation plan for this endemic and globally threatened species.

scholarly journals Phylogeography of the banded butterflyfish, Chaetodon striatus, indicates high connectivity between biogeographic provinces and ecosystems in the western Atlantic

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Ana M.R. Liedke ◽  
Hudson T. Pinheiro ◽  
Sergio R. Floeter ◽  
Giacomo Bernardi
Keyword(s):  
Population Expansion ◽  
Mitochondrial Control Region ◽  
Haplotype Network ◽  
Genetic Connectivity ◽  
Rocky Reef ◽  
Recent Population Expansion ◽  
Western Atlantic ◽  
Network Analyses ◽  
Biogeographic Provinces ◽  
The Caribbean

ABSTRACT Among the four butterflyfishes of the genus Chaetodon present in the western Atlantic, the banded butterflyfish Chaetodon striatus has the largest distribution range, spanning 44 degrees of latitude (from Massachusetts, USA to Santa Catarina, Brazil). Although the ecology of the banded butterflyfish has been well studied over its entire range, nothing is known about its phylogeography and how biogeographic barriers structure its populations. To assess the level of genetic connectivity among populations from distinct biogeographic provinces and environmental conditions, we collected samples from seven localities: Puerto Rico, in the Caribbean, and Tamandaré, Salvador, Abrolhos, Trindade Island, Arraial do Cabo and Florianópolis, in Brazil. One nuclear (rag 2) and two mitochondrial (control region and cyt b) molecular markers were sequenced. Our findings are consistent with a recent population expansion, around 30-120 thousand years ago, which was found for all populations. Haplotype network analyses point to the Caribbean as a refugium before the population expansion. Results show no geographic pattern of genetic diversity. Indeed, a lack of population structure was found and no isolation was observed across oceanographic barriers, as well as between coral and rocky reef ecosystems. Furthermore, no directionality in the migration pattern was found among populations. Since ecological and environmental characteristics are very diverse across such a vast geographic range, the lack of genetic differentiation suggests that C. striatus evolved ecological plasticity rather than local adaptation in the western Atlantic.

scholarly journals High genetic diversity and mixing of coastal horseshoe crabs (Tachypleus gigas) across major habitats in Sundaland, Indonesia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11739
Author(s):  
Naila Khuril Aini ◽  
Yusli Wardiatno ◽  
Hefni Effendi ◽  
Ali Mashar ◽  
Hawis Madduppa
Keyword(s):  
Dna Sequences ◽  
Horseshoe Crab ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Haplotype Network ◽  
Structured Populations ◽  
Conservation Strategy ◽  
Genetic Connectivity ◽  
High Genetic Diversity ◽  
Geographic Ranges

Species with limited dispersal abilities are often composed of highly genetically structured populations across small geographic ranges. This study aimed to investigate the haplotype diversity and genetic connectivity of the coastal horseshoe crab (Tachypleus gigas) in Indonesia. To achieve this, we collected a total of 91 samples from six main T. gigas habitats: Bintan, Balikpapan, Demak, Madura, Subang, and Ujung Kulon. The samples were amplified using primers for mitochondrial (mt) AT-rich region DNA sequences. The results showed 34 haplotypes, including seven shared and 22 unique haplotypes, across all localities. The pairwise genetic differentiation (FST) values were low (0 to 0.13) and not significantly different (p > 0.05), except among samples from Ujung Kulon-Madura and Kulon-Subang (p < 0.05). Additionally, the 34 analysis of molecular variance (AMOVA) showed the most variation within populations (95.23%) compared to less among populations (4.77%). The haplotype network showed evidence of shared haplotypes between populations. Tajima’s D and Fu’s FS test values indicated a population expansion. Our results showed a low level of differentiation, suggesting a single stock and high connectivity. Therefore, a regionally-based conservation strategy is recommended for the coastal horseshoe crab in Indonesia.

Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences

2011 ◽  
Vol 102 (3) ◽  
pp. 333-343 ◽  
Author(s):  
K.C. Albernaz ◽  
K.L. Silva-Brandão ◽  
P. Fresia ◽  
F.L. Cônsoli ◽  
C. Omoto
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Heliothis Virescens ◽  
Demographic History ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Haplotype Network ◽  
Demographic Expansion ◽  
Significant Genetic Structure ◽  
History Of

AbstractIntra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's FS parameters. In addition, high values of haplotype diversity (Ĥ) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θπ<θW, suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

scholarly journals Genetic Diversity in the mtDNA control region and population structure of Chrysichthys nigrodigitatus from selected Nigerian rivers: Implications for conservation and aquaculture

2016 ◽  
Vol 24 (2) ◽  
pp. 85-97 ◽  
Author(s):  
Sylvanus A. Nwafili ◽  
Tian-Xiang Gao
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Control Region ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Mitochondrial Control Region ◽  
Recent Population Expansion ◽  
Base Pair Fragment ◽  
Population Structures ◽  
High Level

Abstract The genetic diversity and population structure of Chrysichthys nigrodigitatus were evaluated using a 443 base pair fragment of the mitochondrial control region. Among the eight populations collected comprising 129 individuals, a total of 89 polymorphic sites defined 57 distinct haplotypes. The mean haplotype diversity and nucleotide diversity of the eight populations were 0.966±0.006 and 0.0359±0.004, respectively. Analysis of molecular variance showed significant genetic differentiation among the eight populations (FST =0.34; P < 0.01). The present results revealed that C. nigrodigitatus populations had a high level of genetic diversity and distinct population structures. We report the existence of two monophyletic matrilineal lineages with mean genetic distance of 10.5% between them. Non-significant negative Tajima’s D and Fu’s Fs for more than half the populations suggests that the wild populations of C. nigrodigitatus underwent a recent population expansion, although a weak one since the late Pleistocene.

scholarly journals A globally threatened shark, Carcharias taurus, shows no population decline in South Africa

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juliana D. Klein ◽  
Aletta E. Bester-van der Merwe ◽  
Matthew L. Dicken ◽  
Arsalan Emami-Khoyi ◽  
Kolobe L. Mmonwa ◽  
...  
Keyword(s):  
South Africa ◽  
Census Data ◽  
Demographic History ◽  
Conservation Status ◽  
Population Decline ◽  
Multilocus Genotype ◽  
Population Declines ◽  
Effective Population ◽  
Anthropogenic Pressures ◽  
Carcharias Taurus

Abstract Knowledge about the demographic histories of natural populations helps to evaluate their conservation status, and potential impacts of natural and anthropogenic pressures. In particular, estimates of effective population size obtained through molecular data can provide useful information to guide management decisions for vulnerable populations. The spotted ragged-tooth shark, Carcharias taurus (also known as the sandtiger or grey nurse shark), is widely distributed in warm-temperate and subtropical waters, but has suffered severe population declines across much of its range as a result of overexploitation. Here, we used multilocus genotype data to investigate the demographic history of the South African C. taurus population. Using approximate Bayesian computation and likelihood-based importance sampling, we found that the population underwent a historical range expansion that may have been linked to climatic changes during the late Pleistocene. There was no evidence for a recent anthropogenic decline. Together with census data suggesting a stable population, these results support the idea that fishing pressure and other threats have so far not been detrimental to the local C. taurus population. The results reported here indicate that South Africa could possibly harbour the last remaining, relatively pristine population of this widespread but vulnerable top predator.

Genetic stock structure of blue-eye trevalla (Hyperoglyphe antarctica) and warehous (Seriolella brama and Seriolella punctata) in south-eastern Australian waters

2008 ◽  
Vol 59 (6) ◽  
pp. 502 ◽  
Author(s):  
Nick Robinson ◽  
Alexandra Skinner ◽  
Lakshmi Sethuraman ◽  
Helen McPartlan ◽  
Neil Murray ◽  
...  
Keyword(s):  
Haplotype Diversity ◽  
Population Expansion ◽  
Stock Structure ◽  
Population Bottlenecks ◽  
Sources Of Information ◽  
Multiple Sources ◽  
Genetic Structuring ◽  
Genetic Stock ◽  
Important Species ◽  
History Of

Blue-eye trevalla (Hyperoglyphe antarctica), blue warehou (Seriolella brama) and silver warehou (Seriolella punctata) from the family Centrolophidae are three commercially important species in the Australian fishery. These species are currently managed as single stocks. We tested the hypothesis that patterns of phenotypic structuring in these species reflect underlying genetic stock structure using an analysis of mitochondrial DNA control region sequences. The analysis revealed high levels of haplotype diversity within populations. The most common haplotypes for the species occurred in all geographical locations sampled. For S. brama, although structuring was not significant after Bonferroni correction, differences between two sites were sufficient to warrant caution in the management of fishery zones for this species. There were also some indications of structuring when sites were grouped into common regions. Demographic analysis suggested that S. brama might have had a history of population bottlenecks followed by sudden population expansion, potentially contributing to genetic structuring in the fishery. No structuring was detected for H. antarctica and S. punctata. The present study highlights the need for, and the utility of, multiple sources of information, that is, genetic, phenotypic, behavioural and ecological, when managing marine fisheries and the need to take a cautionary approach to the interpretation of genetic data for fisheries management.

Nuclear and cytoplasmic genetic diversity reveals long-term population decline in Abies semenovii, an endemic fir of central Asia

2012 ◽  
Vol 42 (12) ◽  
pp. 2142-2152 ◽  
Author(s):  
Svetlana A. Semerikova ◽  
Martin Lascoux ◽  
Vladimir L. Semerikov
Keyword(s):  
Genetic Diversity ◽  
Central Asia ◽  
Population Decline ◽  
Population Expansion ◽  
Nuclear Marker ◽  
Effective Population ◽  
Species Status ◽  
Siberian Fir ◽  
Low Genetic Diversity

The genus Abies is one of the largest conifer genera and many of the marginal species remain poorly characterized. Abies semenovii B. Fedtsch. is a rare mountain fir species from central Asia, and its species status is still disputed. We used both nuclear (allozymes and AFLP) and chloroplastic (cpSSR) markers to show that A. semenovii deserves to be considered as a species and that its low genetic diversity justifies more a proactive conservation policy. First, A. semenovii was significantly differentiated from the Siberian fir Abies sibirica Ledeb. and we did not detect gene flow between the two species. Second, A. semenovii has a very low nuclear genetic diversity, suggesting a prolonged restricted effective population size. Abies semenovii had low cpSSR diversity too but the identification of seven closely related haplotypes suggests that these mutations accumulated recently during a phase of population expansion. This agrees well with the palynological record and is in contrast with the situation observed in another rare Eurasian fir endemic to Kamchatka, Abies gracilis Kom., which was devoid of variation in cpSSRs but that also had a more substantial nuclear marker diversity than A. semenovii, thereby suggesting a more recent but less severe population bottleneck.

scholarly journals Redefining Dispersal Boundaries of Siganus fuscescens In The Coral Triangle Area

2019 ◽  
Vol 24 (1) ◽  
pp. 31
Author(s):  
Ni Putu Dian Pertiwi ◽  
Nur Ismu Hidayat ◽  
Chloe Henderson ◽  
I Nyoman Giri Putra ◽  
Andrianus Sembiring
Keyword(s):  
Population Structure ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Restricted Gene Flow ◽  
Coral Triangle ◽  
Genetic Structuring ◽  
Haplotype Data ◽  
Minor Population ◽  
Species Population ◽  
Increasing Demand

The increasing demand of fish in the Coral Triangle Area has led to overexploitation of some species of fishes. One of the commercial fishes, which is also known to be the source of food and income for local communities, is the Mottled Spinefoot (Siganus fuscescens). Population studies on this species are important in order to manage sustainable stock populations. Genetic variation of the mitochondrial DNA was analyzed to examine the population structure of Siganus fuscescens in Indonesia, as part of the Coral Triangle Area. In total, 789 basepairs of control region mtDNA sequences were determined from 133 specimens collected from six localities, including Seribu Islands (n=27), Karimunjawa (n=19), Komodo (n=39), Selayar (n=20), Lembeh (n=19) and Luwuk (n=9). From the data, 27 variable sites and 24 haplotypes were detected, with most of the haplotypes unique to each location. Haplotype data show that one haplotype was shared among all populations, three haplotypes were shared between two populations (Komodo & Selayar; Lembeh & Seribu; Komodo & Karimunjawa), and 20 were unique to a single population. Haplotype diversity (h=0.444) and nucleotide diversity (π=0.00165) were low. The diversity result, i.e. the ΦST value (0.0658, P < 0.0001) revealed genetic structure in S. fuscescens populations in Indonesia. A non-dispersal strategy led to restricted gene flow and genetic structuring in S. fuscescens. However, both the neutrality test and the mismatch distribution indicated that S. fuscescens might have been in populations at demographic equilibrium, with restriction to the population expansion. Although indicating unexpected minor population structure pattern, the overall result still suggest the management of this species population as a single unit across Indonesia.

scholarly journals Low Genetic Diversity in Turkish Populations of Wels Catfish Silurus glanis L., 1758 (Siluridae, Pisces) Revealed by Mitochondrial Control Region Sequences

2020 ◽  
Vol 20 (10) ◽  
pp. 767-776
Author(s):  
Yusuf Bektas ◽  
Ismail Aksu ◽  
Gokhan Kalayci ◽  
Davut Turan
Keyword(s):  
Genetic Diversity ◽  
Control Region ◽  
Mismatch Distribution ◽  
Phylogenetic Trees ◽  
Goodness Of Fit ◽  
Haplotype Diversity ◽  
Mitochondrial Control Region ◽  
Haplotype Network ◽  
Silurus Glanis ◽  
Low Genetic Diversity

This study aimed to investigate the genetic diversity and population structure of Wels catfish Silurus glanis L. 1758 in Turkey using squences of the mitochondrial DNA control region The 887-bp fragment of D-loop was aligned for 112 S. glanis individuals from ten wild populations in Turkey, defined by 29 polymorphic sites comprising 16 haplotypes. The low haplotype diversity and nucleotide diversity within each population ranged from 0.000 to 0.378 and from 0.0000 to 0.0045, respectively. Analysis of molecular variance showed significant genetic differentiation among ten populations (FST =0.940; P<0.01). AMOVA revealed that the most of genetic variation was found between Thrace and Anatolia clades (74,07 %). The phylogenetic trees and haplotype network topologies were consistent with the results of AMOVA analysis. The non-significant negative Tajima's D (-0.875 P<0.05) and Fu's Fs (-0.381, P<0.02) values and mismatch distribution for S. glanis populations indicated no evidence for changes in population size. Furthermore, goodness-of-fit of the observed versus the theoretical mismatch distribution tested the sum of squared deviation (SSD; 0.00308, P>0.05), Harpending’s raggedness index (Hri; 0,300, P>0.05) and Ramos-Onsins & Rozas (R2; 0,0771, P>0.05), supporting population neutrality.

scholarly journals Holocene Population Decline and Conservation Implication for the Western Hercules Beetle, Dynastes grantii (Coleoptera, Scarabaeidae)

2019 ◽  
Vol 110 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Jen-Pan Huang
Keyword(s):  
United States ◽  
Genetic Structure ◽  
Population Size ◽  
Demographic History ◽  
Population Decline ◽  
Southwestern United States ◽  
Effective Population ◽  
Mogollon Rim ◽  
Major Factors ◽  
Forest Habitats

Abstract The Western Hercules beetle (Dynastes grantii) is endemic to the highland forest habitats of southwestern United States and northern Mexico. The habitats harbor many endemic species, but are being threatened by rapid climate change and urban development. In this study, the genetic structure of D. grantii populations from southwestern United States was investigated. Specifically, genomic data from double-digest restriction-site-associated DNA sequencing libraries were utilized to test whether geographically distant populations from the Mogollon Rim (Arizona [N = 12 individuals] and New Mexico [N = 10 individuals]) are genetically structured. The study also estimated the effective population size of the Mogollon Rim populations based on genetic diversity. The results indicated that the 2 geographic populations from the Mogollon Rim were not genetically structured. A population size reduction was detected since the end of the last glacial period, which coincided with a reduction of forest habitat in the study area. The results implied that the connectivity and the size of highland forest habitats in the Mogollon Rim could have been the major factors shaping the population genetic structure and demographic history of D. grantii. The Western Hercules beetle could be a useful flagship species for local natural history education and to promote the conservation of highland forest habitats.

Sign in / Sign up

Export Citation Format

Share Document