scholarly journals Genetic diversity of redclaw crayfish Cherax quadricarinatus von Martens 1868 using 16S mitochondrial DNA marker

2021 ◽  
Vol 919 (1) ◽  
pp. 012023
Author(s):  
M Z Mohd Dali ◽  
Q Aidi ◽  
M S A Mohd Nasir ◽  
N Ismail ◽  
A S Kamarudin

Abstract There have been reported around 11 aquatic invasive alien species (IAS) found in Malaysian waters. Cherax quadricarinatus, or commonly known as Australian redclaw crayfish, is one of the invasive species. C. quadricarinatus has the potential of causing negative impacts ecologically and economically in the local environment as it has reported in several countries if they get established and not monitored properly. Habitat alteration, native species depletion and spreading of diseases are among the reported negative impacts of C. quadricarinatus. This study was conducted with the aim to assess the genetic diversity of C. quadricarinatus from 4 different populations. Uncovering the diversity and population structure of the redclaw crayfish will help in enhancing the understanding of adaptation and survival of C. quadricarinatus. Thus, the information can be used in monitoring and management of this invasive crayfish in future. DNA of C. quadricarinatus was successfully extracted from its tissue and amplified via polymerase chain reaction (PCR) using mitochondrial DNA (mtDNA) 16S gene then proceeded for sequencing and analysed using several genetic analysis software to understand the diversity, phylogeny and population structure of this invasive crayfish species. A total of 493 bp fragments of 32 samples from four sampling sites were obtained. Four haplotypes were observed which Hap-1 was the most common haplotype. The highest genetic variation is Selangor (Pi = 0.00248, Hd = 0.694). However, low levels of both haplotype and nucleotide diversity indicates the loss of genetic diversity. Analysis of molecular variance (AMOVA) results revealed that the percentage of genetic variation within the population was 69.58% while among populations was 30.42%, indicating significant genetic differentiation among population (P < 0.05). The maximum likelihood tree showed that all haplotypes were clustered and grouped together with United States, Czech Republic, China and Australia.

ZooKeys ◽  
2021 ◽  
Vol 1055 ◽  
pp. 135-148
Author(s):  
Dongqi Liu ◽  
Feng Lan ◽  
Sicai Xie ◽  
Yi Diao ◽  
Yi Zheng ◽  
...  

To investigate the genetic effects on the population of Coreius guichenoti of dam constructions in the upper reaches of the Yangtze River, we analyzed the genetic diversity and population structure of 12 populations collected in 2009 and 2019 using mitochondrial DNA (mtDNA) control regions. There was no significant difference in genetic diversity between 2009 and 2019 (P &gt; 0.05), but the population structure tended to become stronger. Genetic differentiation (FST) among five populations (LX, BB, YB, SF and JA) collected in 2009 was not significant (P &gt; 0.05). However, some populations collected in 2019 were significantly differentiated (P &lt; 0.05), indicating that the population structure has undergone change. A correlation analysis showed that the genetic diversity of the seven populations collected in 2019 was significantly negatively correlated with geographical height (r = −0.808, P = 0.028), indicating that the populations at high elevations were more vulnerable than those at low elevations. In order to prevent the further decrease of genetic diversity and population resources, some conservation and restoration suggestions, such as fish passage and artificial breeding, are put forward.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10274 ◽  
Author(s):  
Mirella Pupo Santos ◽  
João V.S. Rabelo Araujo ◽  
Arthur V. Sant’anna Lopes ◽  
Julio Cesar Fiorio Vettorazzi ◽  
Marcela Santana Bastos Boechat ◽  
...  

Background Two endemic lycophyte species Isoetes cangae and Isoetes serracarajensis have been recently described in the State of Pará in the Amazon forest located in northern Brazil. Isoetes L. has survived through three mass extinctions. Plants are considered small-sized, heterosporous, and can display a great diversity of physiological adaptations to different environments. Thus, the current study aimed to estimate the genetic variation of the populations of I. cangae and I. serracarajensis to generate information about their different mechanisms for survival at the same geographical location that could point to different reproductive, adaptative and dispersal strategies and should be considered for effective conservation strategies. Methods The genetic diversity and population structure of I. cangae and I. serracarajensis were investigated using Inter Simple Sequence Repeat (ISSR) molecular markers. Total genomic DNA was isolated, and the genetic diversity parameters were calculated. Results The sixteen primers produced 115 reproducible bands, 87% of which were polymorphic. A high level of polymorphic loci (81.74% and 68.48%) and a high Shannon index (Sh = 0.376 and 0.289) were observed for I. cangae and I. serracarajensis, respectively. The coefficient of genetic differentiation between population areas (GST) showed a higher value in I. serracarajensis (0.5440). Gene flow was higher in I. cangae (1.715) and lower in I. serracarajensis populations (0.419). Overall, the results further show that I. serracarajensis and I. cangae are two species with considerable genetic variation and that these differences may reflect their habitats and modes of reproduction. These results should be considered in the development of effective conservation strategies for both species.


Plant Disease ◽  
2021 ◽  
Author(s):  
Anfei Fang ◽  
Zhuangyuan Fu ◽  
Zexiong Wang ◽  
Yuhang Fu ◽  
Yubao Qin ◽  
...  

Rice false smut caused by Ustilaginoidea virens is currently one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from SNP-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. The groups Ⅰ and Ⅵ were the largest including 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. AMOVA showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup. The UPGMA dendrogram and population structure revealed that the genetic composition of isolates collected from ST (Santai), NC (Nanchong), YC (Yongchuan), and WS (Wansheng) dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.


2020 ◽  
Vol 19 (1) ◽  
pp. 1275-1288
Author(s):  
Nkosinathi Nxumalo ◽  
Simone Ceccobelli ◽  
Irene Cardinali ◽  
Hovirag Lancioni ◽  
Emiliano Lasagna ◽  
...  

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alice Backes ◽  
Geraldo Mäder ◽  
Caroline Turchetto ◽  
Ana Lúcia Segatto ◽  
Jeferson N Fregonezi ◽  
...  

Abstract Different genetic patterns have been demonstrated for narrowly distributed taxa, many of them linking rarity to evolutionary history. Quite a few species in young genera are endemics and have several populations that present low variability, sometimes attributed to geographical isolation or dispersion processes. Assessing the genetic diversity and structure of such species may be important for protecting them and understanding their diversification history. In this study, we used microsatellite markers and plastid sequences to characterize the levels of genetic variation and population structure of two endemic and restricted species that grow in isolated areas on the margin of the distribution of their respective genera. Plastid and nuclear diversities were very low and weakly structured in their populations. Evolutionary scenarios for both species are compatible with open-field expansions during the Pleistocene interglacial periods and genetic variability supports founder effects to explain diversification. At present, both species are suffering from habitat loss and changes in the environment can lead these species towards extinction.


Parasitology ◽  
2002 ◽  
Vol 125 (7) ◽  
pp. S51-S59 ◽  
Author(s):  
J. CURTIS ◽  
R. E. SORENSEN ◽  
D. J. MINCHELLA

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.


2009 ◽  
Vol 75 (10) ◽  
pp. 3187-3195 ◽  
Author(s):  
E. Gentekaki ◽  
D. H. Lynn

ABSTRACT Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation in Carchesium polypinum (Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies of C. polypinum from locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers—ITS1, ITS2, and the hypervariable regions of the large subunit rRNA—and an 819-bp fragment of the mitochondrial cytochrome c oxidase I gene (cox-1) to investigate the intraspecific genetic variation of C. polypinum and the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate that C. polypinum is likely not a single morphospecies as previously thought.


Author(s):  
Johanna Honka ◽  
Serena Baini ◽  
Jeremy Searle ◽  
Laura Kvist ◽  
Jouni Aspi

The population numbers of taiga bean goose (Anser fabalis fabalis) have halved during recent decades. Since this subspecies is hunted throughout most of its range, the decline is of management concern. Knowledge of the genetic population structure and diversity is important for guiding management and conservation efforts. Genetically unique subpopulations might be hunted to extinction if not managed separately, and any inbreeding depression or lack of genetic diversity may affect the ability to adapt to changing environments and increase the extinction risk. We used microsatellite and mitochondrial DNA markers to study the genetic population structure and diversity among taiga bean geese breeding within the Central flyway management unit using non-invasively collected feathers. We found some genetic structuring with the maternally inherited mitochondrial DNA between four geographic regions (ɸ = 0.11-0.20) but none with the nuclear microsatellite markers (all pairwise F-values 0.002- 0.005). These results could be explained by female natal philopatry and male-biased dispersal, which completely homogenizes the nuclear genome. Therefore, the population could be managed as a single unit. Genetic diversity was still at a moderate level (average H = 0.69) and there were no signs of past population size reductions, although significantly positive inbreeding coefficients in all sampling sites (F = 0.05-0.10) and high relatedness values (r = 0.60-0.86) between some individuals could indicate inbreeding. In addition, there was evidence of either incomplete lineage sorting or introgression from the pink-footed goose (A. brachyrhynchus). The current population is not under threat by genetic impoverishment but monitoring in the future is desirable.


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