scholarly journals Population Genetics of New Zealand Nemadactylus macropterus (tarakihi) and Characterisation of their Mitochondrial Genome

2021 ◽  
Author(s):  
◽  
Alexander Halliwell

<p>Nemadactylus macropterus, commonly known as tarakihi in New Zealand is highly regarded by commercial and recreational fishers and considered a taonga by iwi and customary fisheries. For many years N. macropterus was New Zealand’s second most important commercial catch and is currently the third most valuable inshore commercial finfish fishery in which 90% is consumed by the domestic market. However, despite the apparent importance, relatively little is known about the population structure of the N. macropterus. In 2017 the first fully quantitative stock assessment was conducted on the east coast N. macropterus fisheries as one stock. Alarmingly, the east coast fishery was estimated to be 15.9% of the unexploited spawning biomass and predicted to have been declining for the past thirty years. In an effort to rebuild the fishery, several rebuild plans have been purposed and commercial catch limits have been reduced. In order to rebuild and successfully manage a viable future N. macropterus fishery, an understanding of demographic connectivity and genetic connectivity among N. macropterus populations is essential.  The overall goal of this thesis research was to investigate the population genetic structure, genetic diversity and demographic history of N. macropterus using fish sampled from around New Zealand. This was achieved by analysing hyper variable region one of mitochondrial DNA for 370 N. macropterus collected from 14 locations. No genetic differentiation was observed among the 14 locations, an indication that N. macropterus have a panmictic genetic structure. Furthermore, N. macropterus display a relatively high level of genetic diversity and appear to have a large stable population with a long evolutionary history. The Bayesian skyline analysis indicates the N. macropterus historic population has gone through two expansions. The mostly likely cause of this is an expansion before and after the last glacial maximum.  The genetic diversity and demographic history of N. sp was also studied using samples collected from around the Three Kings Islands of New Zealand. The complete mitochondrial genome of N. macropterus was reconstructed from bulk DNA sequencing data and a set of specific mtDNA primers were developed to amplify hyper variable region one. The DNA sequencing data provided by these primers with the addition of published control region sequences was used to reconstruct the Nemadactylus phylogeny.</p>

2021 ◽  
Author(s):  
◽  
Alexander Halliwell

<p>Nemadactylus macropterus, commonly known as tarakihi in New Zealand is highly regarded by commercial and recreational fishers and considered a taonga by iwi and customary fisheries. For many years N. macropterus was New Zealand’s second most important commercial catch and is currently the third most valuable inshore commercial finfish fishery in which 90% is consumed by the domestic market. However, despite the apparent importance, relatively little is known about the population structure of the N. macropterus. In 2017 the first fully quantitative stock assessment was conducted on the east coast N. macropterus fisheries as one stock. Alarmingly, the east coast fishery was estimated to be 15.9% of the unexploited spawning biomass and predicted to have been declining for the past thirty years. In an effort to rebuild the fishery, several rebuild plans have been purposed and commercial catch limits have been reduced. In order to rebuild and successfully manage a viable future N. macropterus fishery, an understanding of demographic connectivity and genetic connectivity among N. macropterus populations is essential.  The overall goal of this thesis research was to investigate the population genetic structure, genetic diversity and demographic history of N. macropterus using fish sampled from around New Zealand. This was achieved by analysing hyper variable region one of mitochondrial DNA for 370 N. macropterus collected from 14 locations. No genetic differentiation was observed among the 14 locations, an indication that N. macropterus have a panmictic genetic structure. Furthermore, N. macropterus display a relatively high level of genetic diversity and appear to have a large stable population with a long evolutionary history. The Bayesian skyline analysis indicates the N. macropterus historic population has gone through two expansions. The mostly likely cause of this is an expansion before and after the last glacial maximum.  The genetic diversity and demographic history of N. sp was also studied using samples collected from around the Three Kings Islands of New Zealand. The complete mitochondrial genome of N. macropterus was reconstructed from bulk DNA sequencing data and a set of specific mtDNA primers were developed to amplify hyper variable region one. The DNA sequencing data provided by these primers with the addition of published control region sequences was used to reconstruct the Nemadactylus phylogeny.</p>


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Surapon Yodsiri ◽  
Komgrit Wongpakam ◽  
Adisak Ardharn ◽  
Chadaporn Senakun ◽  
Sutthira Khumkratok

The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.


2017 ◽  
Author(s):  
Yeşerin Yıldırım ◽  
Marti J. Anderson ◽  
Selina Patel ◽  
Craig D. Millar ◽  
Paul B. Rainey

AbstractPleurobranchaea maculatais a rarely studied species of the Heterobranchia found throughout the south and western Pacific – and recently recorded in Argentina – whose population genetic structure is unknown. Interest in the species was sparked in New Zealand following a series of dog deaths caused by ingestions of slugs containing high levels of the neurotoxin tetrodotoxin. Here we describe the genetic structure and demographic history ofP. maculatapopulations from five principle locations in New Zealand based on extensive analyses of 12 microsatellite loci and theCOIandCytBregions of mitochondrial DNA (mtDNA). Microsatellite data showed significant differentiation between northern and southern populations with population structure being associated with previously described regional variations in tetrodotoxin concentrations. However, mtDNA sequence data did not support such structure, revealing a star-shaped haplotype network with estimates of expansion time suggesting a population expansion in the Pleistocene era. Inclusion of publicly available mtDNA sequence from Argentinian sea slugs did not alter the star-shaped network. We interpret our data as indicative of a single founding population that fragmented following geographical changes that brought about the present day north-south divide in New Zealand waters. Lack of evidence of cryptic species supports data indicating that differences in toxicity of individuals among regions are a consequence of differences in diet.


2011 ◽  
Vol 102 (3) ◽  
pp. 333-343 ◽  
Author(s):  
K.C. Albernaz ◽  
K.L. Silva-Brandão ◽  
P. Fresia ◽  
F.L. Cônsoli ◽  
C. Omoto

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.


2019 ◽  
Author(s):  
Aude Saint Pierre ◽  
Joanna Giemza ◽  
Matilde Karakachoff ◽  
Isabel Alves ◽  
Philippe Amouyel ◽  
...  

ABSTRACTThe study of the genetic structure of different countries within Europe has provided significant insights into their demographic history and their actual stratification. Although France occupies a particular location at the end of the European peninsula and at the crossroads of migration routes, few population genetic studies have been conducted so far with genome-wide data. In this study, we analyzed SNP-chip genetic data from 2 184 individuals born in France who were enrolled in two independent population cohorts. Using FineStructure, six different genetic clusters of individuals were found that were very consistent between the two cohorts. These clusters match extremely well the geography and overlap with historical and linguistic divisions of France. By modeling the relationship between genetics and geography using EEMS software, we were able to detect gene flow barriers that are similar in the two cohorts and corresponds to major French rivers or mountains. Estimations of effective population sizes using IBDNe program also revealed very similar patterns in both cohorts with a rapid increase of effective population sizes over the last 150 generations similar to what was observed in other European countries. A marked bottleneck is also consistently seen in the two datasets starting in the fourteenth century when the Black Death raged in Europe. In conclusion, by performing the first exhaustive study of the genetic structure of France, we fill a gap in the genetic studies in Europe that would be useful to medical geneticists but also historians and archeologists.


2013 ◽  
Vol 59 (4) ◽  
pp. 458-474 ◽  
Author(s):  
Sen Song ◽  
Shijie Bao ◽  
Ying Wang ◽  
Xinkang Bao ◽  
Bei An ◽  
...  

Abstract Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species. Although the effects of recent glacial cycles on genetic diversity have been well studied on species in Europe and North America, genetic legacy of species in the Pleistocene in north and northwest of China where glaciations was not synchronous with the ice sheet development in the Northern Hemisphere or or had little or no ice cover during the glaciations’ period, remains poorly understood. Here we used phylogeographic methods to investigate the genetic structure and population history of the chukar partridge Alec-toris chukar in north and northwest China. A 1,152 – 1,154 bp portion of the mtDNA CR were sequenced for all 279 specimens and a total number of 91 haplotypes were defined by 113 variable sites. High levels of gene flow were found and gene flow estimates were greater than 1 for most population pairs in our study. The AMOVA analysis showed that 81% and 16% of the total genetic variability was found within populations and among populations within groups, respectively. The demographic history of chukar was examined using neutrality tests and mismatch distribution analyses and results indicated Late Pleistocene population expansion. Results revealed that most populations of chukar experienced population expansion during 0.027 ? 0.06 Ma. These results are at odds with the results found in Europe and North America, where population expansions occurred after Last Glacial Maximum (LGM, 0.023 to 0.018 Ma). Our results are not consistent with the results from avian species of Tibetan Plateau, either, where species experienced population expansion following the retreat of the extensive glaciation period (0.5 to 0.175 Ma).


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