Groundwater oligochaetes show complex genetic patterns of distribution in the Pilbara region of Western Australia

2015 ◽  
Vol 29 (5) ◽  
pp. 405 ◽  
Author(s):  
Louise Brown ◽  
Terrie Finston ◽  
Garth Humphreys ◽  
Stefan Eberhard ◽  
Adrian Pinder

Patterns of genetic diversity in the groundwater fauna of Australia have largely focused on obligate stygobites of relatively large size, namely, crustaceans. Oligochaete worms, with their smaller size and broader ecological niches, provide a contrasting model in which to examine such patterns. Genetic diversity in subterranean oligochaetes in the Pilbara region of Western Australia were examined using one nuclear (18S) and two mitochondrial (COI, 12S) regions. The observed variation was assessed at three levels of hydrology – river basin, creek catchment, and individual bore or site – to document geographic patterns. Most species appeared to be restricted to an individual catchment; however, five species, representing three families, were widespread, with some haplotypes being shared between bores, catchments and even basins. General patterns suggest that while hydrology plays a role in the distribution of oligochaete species, it does not always confine them to catchments, in contrast to patterns observed in groundwater isopods and amphipods in the region. We suggest that intrinsic characteristics of oligochaetes, such as body size, shape, reproductive strategy and ecological requirements, may have allowed them greater dispersal within the subterranean biome of the Pilbara. In particular, oligochaetes may occupy subterranean and surface waters, increasing their opportunities for dispersal.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhigang Wu ◽  
Xinwei Xu ◽  
Juan Zhang ◽  
Gerhard Wiegleb ◽  
Hongwei Hou

Abstract Background Due to the environmental heterogeneity along elevation gradients, alpine ecosystems are ideal study objects for investigating how ecological variables shape the genetic patterns of natural species. The highest region in the world, the Qinghai-Tibetan Plateau, is a hotspot for the studies of evolutionary processes in plants. Many large rivers spring from the plateau, providing abundant habitats for aquatic and amphibious organisms. In the present study, we examined the genetic diversity of 13 Ranunculus subrigidus populations distributed throughout the plateau in order to elucidate the relative contribution of geographic distance and environmental dissimilarity to the spatial genetic pattern. Results A relatively low level of genetic diversity within populations was found. No spatial genetic structure was suggested by the analyses of molecular variance, Bayesian clustering analysis and Mantel tests. Partial Mantel tests and multiple matrix regression analysis showed a significant influence of the environment on the genetic divergence of the species. Both climatic and water quality variables contribute to the habitat heterogeneity of R. subrigidus populations. Conclusions Our results suggest that historical processes involving long-distance dispersal and local adaptation may account for the genetic patterns of R. subrigidus and current environmental factors play an important role in the genetic differentiation and local adaptation of aquatic plants in alpine landscapes.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 40
Author(s):  
Evgeny Genelt-Yanovskiy ◽  
Yixuan Li ◽  
Ekaterina Stratanenko ◽  
Natalia Zhuravleva ◽  
Natalia Strelkova ◽  
...  

Ophiura sarsii is a common brittle star species across the Arctic and Sub-Arctic regions of the Atlantic and the Pacific oceans. Ophiurasarsii is among the dominant echinoderms in the Barents Sea. We studied the genetic diversity of O.sarsii by sequencing the 548 bp fragment of the mitochondrial COI gene. Ophiurasarsii demonstrated high genetic diversity in the Barents Sea. Both major Atlantic mtDNA lineages were present in the Barents Sea and were evenly distributed between the northern waters around Svalbard archipelago and the southern part near Murmansk coast of Kola Peninsula. Both regions, and other parts of the O.sarsii range, were characterized by high haplotype diversity with a significant number of private haplotypes being mostly satellites to the two dominant haplotypes, each belonging to a different mtDNA clade. Demographic analyses indicated that the demographic and spatial expansion of O.sarsii in the Barents Sea most plausibly has started in the Bølling–Allerød interstadial during the deglaciation of the western margin of the Barents Sea.


Author(s):  
Andrew V. Gougherty

In the northern hemisphere, many species have been reported to have greater genetic diversity in southern populations than northern populations - ostensibly due to migration northward following the last glacial maximum (LGM). The generality of this pattern, while well-established for some taxa, remains unclear for North American trees. To address this issue, I collected published population genetics data for 73 North American tree species, and tested whether genetic diversity was associated with latitude or longitude and whether geographic trends were associated with dispersal traits, range or study characteristics. I found there were no general geographic patterns in genetic diversity, and the strength of the geographic gradients were not associated with any species or study characteristics. Species in the northern and western regions of North America tended to have more species with genetic diversity that declined with latitude, but most species had no significant trend. This work shows that North American trees have complex, individualistic, patterns of genetic diversity that may negate explanation by any particular dispersal trait or range characteristic.


Mammalia ◽  
2014 ◽  
Vol 78 (2) ◽  
Author(s):  
Claudine Montgelard ◽  
Saliha Zenboudji ◽  
Anne-Laure Ferchaud ◽  
Véronique Arnal ◽  
Bettine Jansen van Vuuren

AbstractThe focus of this review is on landscape genetics (LG), a relatively new discipline that arose approximately 10 years ago. LG spans the interface between population genetics and landscape ecology and thus incorporates the concepts, methods, and tools from both disciplines. On the basis of an understanding of the spatial distribution of genetic diversity, LG aims to explain how landscape and environmental characteristics influence microevolutionary processes and metapopulation dynamics, including gene flow (i.e., connectivity) and selection (i.e., local adaptations). LG is concerned with events that occurred during the recent time scale, and the individual is the operational unit. As a discipline that combines spatial genetic diversity with ecological features, LG is able to address questions relating to different evolutionary processes. We illustrate some of these here using examples taken from mammals: population structure; gene flow and the identification of barriers; fragmentation, connectivity, and corridors; local adaptation and selection; there are two different questions: applications in conservation genetics; and future developments in LG. We will then present the methods and tools commonly used in the different steps of LG analyses: the genetic and landscape sampling, the quantification of genetic variation, the characterization of spatial landscape structures, and finally, the correlation between genetic patterns and landscape features.


2020 ◽  
Author(s):  
Aaliyah D. Wright ◽  
Nicole L. Garrison ◽  
Ashantye’ S. Williams ◽  
Paul D. Johnson ◽  
Nathan V. Whelan

AbstractMany freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Leptoxis compacta does not display an isolation by distance pattern, contrasting patterns seen in many riverine taxa. Our findings also indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Fang ◽  
Jie Chen ◽  
Honghua Ruan ◽  
Nan Xu ◽  
Ziting Que ◽  
...  

The earthworm species Metaphire vulgaris (a member of the Clitellata class) is widely distributed across China, and has important ecological functions and medicinal value. However, investigations into its genetic diversity and differentiation are scarce. Consequently, we evaluated the genetic diversity of five populations of M. vulgaris (GM, HD, NYYZ, QDDY, and QDY) in Yancheng, China via the mitochondrial COI gene and the novel microsatellites developed there. A total of nine haplotypes were obtained by sequencing the mitochondrial COI gene, among which NYYZ and QDDY populations had the greatest number of haplotypes (nh = 5). Further, the nucleotide diversity ranged from 0.00437 to 0.1243. The neighbor-joining trees and the TCS network of haplotypes indicated that earthworm populations within close geographical range were not genetically isolated at these small scale distances. Results of the identification of microsatellite molecular markers revealed that the allele number in 12 microsatellite loci ranged from 4 to 13. The observed heterozygosity ranged from 0.151 to 0.644, whereas the expected heterozygosity ranged from 0.213 to 0.847. The polymorphism data content of most sites was >0.5, which indicated that the designed sites had high polymorphism. Structural analysis results indicated that GM, HD, and NYYZ had similar genetic structures across the five populations. The Nei’s genetic distance between HD and NYYZ populations was the smallest (Ds = 0.0624), whereas that between HD and QDY populations was the largest (Ds = 0.2364). The UPGMA tree showed that HD were initially grouped with NYYZ, followed by GM, and then with QDDY. Furthermore, cross-species amplification tests were conducted for Metaphire guillelmi, which indicated that the presented markers were usable for this species. This study comprised a preliminary study on the genetic diversity of M. vulgaris, which provides basic data for future investigations into this species.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9789
Author(s):  
Aaliyah D. Wright ◽  
Nicole L. Garrison ◽  
Ashantye’ S. Williams ◽  
Paul D. Johnson ◽  
Nathan V. Whelan

Many freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Our findings indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.


BMC Genetics ◽  
2016 ◽  
Vol 17 (S3) ◽  
Author(s):  
Alexander Kononov ◽  
Kirill Ustyantsev ◽  
Baode Wang ◽  
Victor C. Mastro ◽  
Victor Fet ◽  
...  

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