scholarly journals Distribution and population structure in the naked goby Gobiosoma bosc (Perciformes: Gobiidae) along a salinity gradient in two western Atlantic estuaries

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5380 ◽  
Author(s):  
Christopher S. Moore ◽  
Matthew J. Ruocchio ◽  
April M.H. Blakeslee

Many species of fish produce larvae that undergo a prolonged dispersal phase. However, evidence from a number of recent studies on demersal fishes suggests that the dispersal of propagules may not be strongly correlated with gene flow. Instead, other factors like larval behavior and the availability of preferred settlement habitat may be more important to maintaining population structure. We used an ecologically important benthic fish species, Gobiosoma bosc (naked goby), to investigate local and regional scale population structure and gene flow along a salinity gradient (∼3 ppt to ∼18 ppt) in two North Carolina estuaries. G. bosc is an abundant and geographically widespread species that requires complex but patchy microhabitat (e.g. oyster reefs, rubble, woody debris) for reproduction and refuge. We sequenced 155 fish from 10 sites, using a common barcoding gene (COI). We also included recent sequence data from GenBank to determine how North Carolina populations fit into the larger biogeographic understanding of this species. In North Carolina, we found a significant amount of gene flow within and between estuaries. Our analysis also showed high predicted genetic diversity based upon a large number of rare haplotypes found within many of our sampled populations. Moreover, we detected a number of new haplotypes in North Carolina that had not yet been observed in prior work. Sampling along a salinity gradient did not reveal any significant positive or negative correlations between salinity and genetic diversity, nor the proportion of singleton haplotypes, with the exception of a positive correlation between salinity standard deviation and genetic diversity. We also found evidence that an introduced European population of naked gobies may have originated from an Atlantic source population. Altogether, this system offers a compelling way to evaluate whether factors other than dispersal per se mediate recruitment in an estuarine-dependent species of fish with a larval dispersal phase. It also demonstrates the importance of exploring both smaller and larger scale population structure in marine organisms to better understand local and regional patterns of population connectivity and gene flow.

Plant Gene ◽  
2020 ◽  
Vol 21 ◽  
pp. 100206 ◽  
Author(s):  
Bhuwnesh Goswami ◽  
Rekha Rankawat ◽  
Wahlang Daniel Regie ◽  
Bhana Ram Gadi ◽  
Satyawada Rama Rao

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.


Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 135 ◽  
Author(s):  
Jingxue Zhang ◽  
Miaoli Wang ◽  
Zhipeng Guo ◽  
Yongzhuo Guan ◽  
Jianyu Liu ◽  
...  

Understanding the population genetic pattern and process of gene flow requires a detailed knowledge of how landscape characteristics structure populations. Although Cynodon dactylon (L.) Pers. (common bermudagrass) is widely distributed in the world, information on its genetic pattern and population structure along latitudinal gradients is limited. We tried to estimate the genetic diversity and genetic structure of C. dactylon along a latitudinal gradient across China. Genetic diversity among different ploidy levels was also compared in the study. The material used consisted of 296 C. dactylon individuals sampled from 16 geographic sites from 22°35′ N to 36°18′ N. Genetic diversity was estimated using 153 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. Higher within-population genetic diversity appeared at low-latitude, as well as having positive correlation with temperature and precipitation. The genetic diversity increased with the ploidy level of C. dactylon, suggesting polyploidy creates higher genetic diversity. No isolation by distance and notable admixture structure existed among populations along latitudes. Both seed dispersal (or vegetative organs) and extrinsic pollen played important roles for gene flow in shaping the spatial admixture population structure of C. dactylon along latitudes. In addition, populations were separated into three clusters according to ploidy levels. C. dactylon has many such biological characters of perennial growth, wind-pollination, polyploidy, low genetic differentiation among populations, sexual and asexual reproduction leading to higher genetic diversity, which gives it strong adaptability with its genetic patterns being very complex across all the sampled latitudes. The findings of this study are related to landscape population evolution, polyploidy speciation, preservation, and use of bermudagrass breeding.


2013 ◽  
Vol 45 (6) ◽  
pp. 799-813 ◽  
Author(s):  
Kyle M. FONTAINE ◽  
Elfie STOCKER-WÖRGÖTTER ◽  
Tom BOOTH ◽  
Michele D. PIERCEY-NORMORE

AbstractDermatocarpon luridum is a subaquatic lichen which is distributed within temperate climatic zones around the world. It colonizes rock substrata along the shoreline of lakes and rivers of watersheds that regularly experience water level fluctuations. The mycobiont produces perithecia with small, simple spores that are thought to be wind dispersed. The photobiont, Diplosphaera chodatii, occurs both free-living and lichenized but little is known about its distribution and dispersal. The goal of this study was to compare the population structure of the photobiont from lakes and rivers in central North America with those of Europe. Specimens were collected in Manitoba, Canada and Austria. Population structure of the algal symbiont was assessed using the internal transcribed spacer (ITS) of ribosomal DNA (rDNA) and actin gene sequences. Results showed that genetic diversity and gene flow was high within local populations, but gene flow was low between continental populations. Low levels of gene flow between the most distant populations support the isolation-by-distance theory. The photobiont on both continents is also reported to be the photobiont for other lichen species contributing to photobiont availability for D. luridum.


Author(s):  
Diana Sr Alcazar ◽  
Marc Kochzius

Coral reef associated marine invertebrates, such as the blue sea starLinckia laevigata, have a life history with two phases: sedentary adults and planktonic larvae. On the one hand it is hypothesised that the long pelagic larval duration facilitates large distance dispersal. On the other hand, complex oceanographic and geographic characteristics of the Visayan seascape could cause isolation of populations. The study aims to investigate the genetic diversity, genetic population structure and gene flow inL. laevigatato reveal connectivity among populations in the Visayas. The analysis is based on partial sequences (626 bp in length) of the mitochondrial cytochrome oxidase I gene (COI) from 124 individuals collected from five localities in the Visayas. A comparative analysis of these populations with populations from the Indo-Malay Archipelago (IMA) published previously is also presented. Genetic diversity was high (h = 0.98, π = 1.6%) and comparable with preceding studies. Analyses of molecular variance (AMOVA) revealed a lack of spatial population differentiation among sample sites in the Visayas (ΦST-value = 0.009;P > 0.05). The lack of genetic population structure indicates high gene flow among populations ofL. laevigatain the Visayas. Comparative analysis with data from the previous study indicates high connectivity of the Visayas with the central part of the IMA.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11953
Author(s):  
Jing-Xue Zhang ◽  
Miaoli Wang ◽  
Jibiao Fan ◽  
Zhi-Peng Guo ◽  
Yongzhuo Guan ◽  
...  

Background Environmental variation related to ecological habitat is the main driver of plant adaptive divergence. Longitude plays an important role in the formation of plant population structure, indicating that environmental differentiation can significantly shape population structure. Methods Genetic diversity and population genetic structure were estimated using 105 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. A total of 249 C. dactylon (L.) Pers. (common bermudagrass) individuals were sampled from 13 geographic sites along the longitude (105°57′34″–119°27′06″E). Results There was no obvious linear trend of intra-population genetic diversity along longitude and the intra-population genetic diversity was not related to climate in this study. Low gene flow (Nm = 0.7701) meant a rich genetic differentiation among populations of C. dactylon along longitude gradients. Significantly positive Mantel correlation (r = 0.438, P = 0.001) was found between genetic distance and geographical interval while no significant partial Mantel correlation after controlling the effect of mean annual precipitation, which indicated geographic distance correlated with mean annual precipitation affect genetic distance. The genetic diversity of C. dactylon with higher ploidy level was higher than that with lower ploidy level and groups of individuals with higher ploidy level were separated further away by genetic distance from the lower ploidy levels. Understanding the different genetic bases of local adaptation comparatively between latitude and longitude is one of the core findings in the adaptive evolution of plants.


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