scholarly journals Habitat Adaptation Drives Speciation of a Streptomyces Species with Distinct Habitats and Disparate Geographic Origins

mBio ◽  
2022 ◽  
Author(s):  
Jiao Wang ◽  
Yisong Li ◽  
Adrián A. Pinto-Tomás ◽  
Kun Cheng ◽  
Ying Huang

Both isolation by distance and isolation by environment occur in bacteria, and different diversification patterns may apply to different species. Streptomyces species, typified by producing useful natural products, are widespread in nature and possess high genetic diversity. However, the ecological processes and evolutionary mechanisms that shape their distribution are not well understood.

2021 ◽  
Vol 288 (1945) ◽  
pp. 20202398
Author(s):  
Eleni L. Petrou ◽  
Angela P. Fuentes-Pardo ◽  
Luke A. Rogers ◽  
Melissa Orobko ◽  
Carolyn Tarpey ◽  
...  

The timing of reproduction influences key evolutionary and ecological processes in wild populations. Variation in reproductive timing may be an especially important evolutionary driver in the marine environment, where the high mobility of many species and few physical barriers to migration provide limited opportunities for spatial divergence to arise. Using genomic data collected from spawning aggregations of Pacific herring ( Clupea pallasii ) across 1600 km of coastline, we show that reproductive timing drives population structure in these pelagic fish. Within a specific spawning season, we observed isolation by distance, indicating that gene flow is also geographically limited over our study area. These results emphasize the importance of considering both seasonal and spatial variation in spawning when delineating management units for herring. On several chromosomes, we detected linkage disequilibrium extending over multiple Mb, suggesting the presence of chromosomal rearrangements. Spawning phenology was highly correlated with polymorphisms in several genes, in particular SYNE2 , which influences the development of retinal photoreceptors in vertebrates. SYNE2 is probably within a chromosomal rearrangement in Pacific herring and is also associated with spawn timing in Atlantic herring ( Clupea harengus ). The observed genetic diversity probably underlies resource waves provided by spawning herring. Given the ecological, economic and cultural significance of herring, our results support that conserving intraspecific genetic diversity is important for maintaining current and future ecosystem processes.


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.


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.


2019 ◽  
Vol 11 (20) ◽  
pp. 5863 ◽  
Author(s):  
Qingqing Yu ◽  
Qian Liu ◽  
Yi Xiong ◽  
Yanli Xiong ◽  
Zhixiao Dong ◽  
...  

Elymus breviaristatus is a grass species only distributed in the southeast of Qinghai-Tibetan Plateau (QTP), which has suffered from serious habitat fragmentation. Therefore, understanding patterns of genetic diversity within and among natural E. breviaristatus populations could provide insight for future conservation strategies. In this study, sequence-related amplified polymorphism markers were employed to investigate the genetic diversity and hierarchical structure of seven E. breviaristatus populations from QTP, China. Multiple measures of genetic diversity indicated that there is low to moderate genetic variation within E. breviaristatus populations, consistent with its presumed mating system. In spite of its rarity, E. breviaristatus presented high genetic diversity that was equivalent to or even higher than that of widespread species. Bayesian clustering approaches, along with clustering analysis and principal coordinate analysis partitioned the studied populations of E. breviaristatus into five genetic clusters. Differentiation coefficients (Fst, GST, etc.) and AMOVA analysis revealed considerable genetic divergence among different populations. BARRIER analyses indicated that there were two potential barriers to gene flow among the E. breviaristatus populations. Despite these patterns of differentiation, genetic distances between populations were independent of geographic distances (r = 0.2197, p = 0.2534), indicating little isolation by distance. Moreover, despite detecting a common outlier by two methods, bioclimatic factors (altitude, annual mean temperature, and annual mean precipitation) were not related to diversity parameters, indicating little evidence for isolation caused by the environment. These patterns of diversity within and between populations are used to propose a conservation strategy for E. breviaristatus.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Anne C. Latreille ◽  
Pascal Milesi ◽  
Hélène Magalon ◽  
Patrick Mavingui ◽  
Célestine M. Atyame

Abstract Background In recent years, the Asian tiger mosquito Aedes albopictus has emerged as a species of major medical concern following its global expansion and involvement in many arbovirus outbreaks. On Réunion Island, Ae. albopictus was responsible for a large chikungunya outbreak in 2005–2006 and more recently an epidemic of dengue which began at the end of 2017 and is still ongoing at the time of writing. This dengue epidemic has seen a high number of human cases in south and west coastal regions, while few cases have been reported in the north and east of the island. To better understand the role of mosquito populations in such spatial patterns of dengue virus transmission in Réunion Island, we examined the genetic diversity and population structure of Ae. albopictus sampled across the island. Results Between November 2016 and March 2017, a total of 564 mosquitoes were collected from 19 locations in three main climatic regions (West, East and Center) of Réunion Island and were genotyped using 16 microsatellite loci. A high genetic diversity was observed with 2–15 alleles per locus and the average number of alleles per population varying between 4.70–5.90. Almost all FIS values were significantly positive and correlated to individual relatedness within populations using a hierarchical clustering approach based on principal components analyses (HCPC). However, the largest part of genetic variance was among individuals within populations (97%) while only 3% of genetic variance was observed among populations within regions. Therefore, no distinguishable population structure or isolation by distance was evidenced, suggesting high rates of gene flow at the island scale. Conclusions Our results show high genetic diversity but no genetic structure of Ae. albopictus populations in Réunion Island thus reflecting frequent movements of mosquitoes between populations probably due to human activity. These data should help in the understanding of Ae. albopictus vector capacity and the design of effective mosquito control strategies.


2020 ◽  
Author(s):  
Xu-Ming Wang ◽  
Zhongzhi Zhao ◽  
Miao Wang ◽  
Buyun Cui ◽  
Zhiguo Liu ◽  
...  

Abstract Background Brucella abortus is a facultative intracellular Gram-negative bacterium that causes chronic persistent infections in humans and livestock. In this study, conventional bio-typing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole-genome sequencing-single-nucleotide polymorphism (WGS-SNP) were used to investigate the molecular epidemiology characteristics of Brucella abortus strains in China and their relationships to world lineages. Results A total of 100 strains were collected from 1953 to 2013, suggesting that B. abortus circulated in China in the past five decades. Moreover, most strains were mainly distributed in the Northwest areas, suggest that provinces in the Northwest were a dominant epidemic area of this disease. During this period, seven biovars were found, indicating that B. abortus had a high diversity of biovars and it is also a potential reason for the disease ongoing spread in the Northern provinces. Strains have high genetic diversity, and bruce07 is the most helpful locus for genotyping of this population. Moreover, 17 MLVA-11 genotypes were found; 13 of them are of known genotypes and four are unassigned genotypes, indicating that B. abortus in this study had several geographic origins. Still, strains from unassigned genotypes may originate from China. Many shared MLVA-16 genotypes were observed in strains from the same provinces in Northern China, which confirmed a B. abortus brucellosis outbreak within Northern regions. WGS-SNP analysis showed that eight Chinese strains formed a ladder-like phylogram (C. Ⅶ) with strains from nine countries, including Uganda, Iraq, Russia, Georgia, Spain, Italy, Egypt, Mongolia, and China; suggest that strains were introduced to these countries from a single source. Conclusions Chinese B. abortus strains had high biovars and genetic diversity as well as represent characteristics of multiple geographic origins, and B. abortus strains from several mainly epidemic areas were closely related to strains from Russia and Mongolia; frequent animal (cattle) trade and exchanges may promote this process. We will provide new and valuable information to strengthening surveillance and control of B. abortus brucellosis in China.


2020 ◽  
Author(s):  
Mayara Delagnelo Medeiros ◽  
Daniel Galiano ◽  
Bruno Busnello Kubiak ◽  
Paula Angélica Roratto ◽  
Thales Renato Ochotorena de Freitas

Abstract Endemic, small range species are susceptible to environmental changes and landscape modification. Understanding genetic diversity and distributional patterns is important for implementation of effective conservation measures. In this context, genetic diversity was evaluated to update the conservation status of an endemic tuco-tuco, Ctenomys ibicuiensis. Phylogeographic and population genetic analyses of mitochondrial DNA and microsatellite loci were carried out using 46 individuals sampled across the species’ distribution. Ctenomys ibicuiensis presented moderate to high genetic diversity and highly structured populations with low levels of gene flow and isolation by distance. Anthropogenic landscape changes threaten this restricted-range tuco-tuco. Considering its limited geographic distribution and highly structured populations with low gene flow, we consider C. ibicuiensis to be at significant risk of extinction.


Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 141-150
Author(s):  
Bo Shi ◽  
Majid Khayatnezhad ◽  
Abdul Shakoor

One of the most crucial aspects of biological diversity for conservation strategies is genetic diversity, particularly in rare and narrow endemic species. Our study is the first attempt to utilize SCoT markers to check the genetic diversity in Iran. We used 115 plant samples. Our objectives were 1) to check genetic diversity among Geranium species 2) Genetic structure of the Geranium 3) Do the Geranium species exchange genes? 4) To detect isolation by distance among the Geranium species. We used traditional morphological and molecular methods to assess genetic diversity and genetic structure in the Geranium species. A total of 129 amplified polymorphic bands were generated across 13 Geranium species. The size of the amplified fragments ranged from 150 to 3000 bp. G. stepporum showed the highest values for the effective number of alleles (Ne = 1.30) and Shannon information index (I =0.35). Significant ANOVA results (P <0.01) showed differences in quantitative morphological characters in plant species. G. sylvaticum showed high genetic diversity. Mantel test showed a significant correlation (r = 0.17, p=0.0002) between genetic distance and geographical distance, so isolation by distance (IBD) occurred among the Geranium species. According to the SCoT markers analysis, G. kotschyi and G. dissectum had the lowest similarity, and the species of G. sylvaticum and G. pratense had the highest similarity. The present study revealed that a combination of morphological and SCoT methods could distinguish the species of Geranium.


2021 ◽  
Vol 11 (14) ◽  
pp. 6484
Author(s):  
Martina Grdiša ◽  
Zlatko Šatović ◽  
Zlatko Liber ◽  
Jernej Jakše ◽  
Filip Varga ◽  
...  

Hop (Humulus lupulus L.) is used in the brewing industry as a source of compounds responsible for the bitterness, aroma, and preservative properties of beer. In this study, we used microsatellite markers to investigate genetic diversity and genetic differentiation of wild hop populations sampled in the northwestern part of Croatia. Analysis of 12 microsatellite loci revealed high diversity and weak population differentiation among wild hop populations. A total of 152 alleles were determined with an average of 12.67 alleles per locus. Observed heterozygosity ranged from 0.689 to 0.839 (average 0.767) and expected heterozygosity ranged from 0.725 to 0.789 (average 0.760). A total of 38 private alleles were detected. The data suggest that H. lupulus populations are not affected by recent bottlenecks. The degree of genetic differentiation among populations was low and not significant for most pairwise FST values, except for the pair of geographically most distant populations. The results did not indicate the existence of genetic structure among the sampled populations. The high genetic diversity and low differentiation among populations, combined with the absence of isolation by distance, indicate the existence of substantial gene flow among wild hop populations. Therefore, extensive sampling per population is clearly required to assess the genetic diversity of hop populations. Sampling strategies involving sampling across a large number of localities represented by only a few samples could lead to erroneous conclusions.


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