Genetic structures of allopatric and sympatric populations in Pseudorasbora pumila pumila and Pseudorasbora parva

Abstract:Fragmentation of tropical forests influences abiotic and biotic processes that affect the genetic structure of plant populations. In forest fragments, edge effects, i.e. changes of abiotic and biotic factors at forest edges, may be prevalent. In two forest fragments (c. 200 ha atc. 2450 m asl) of tropical montane forest in Bolivia, sympatric populations of the dioecious tree speciesClusia sphaerocarpaandC. lechleriwere used as case study species to compare genetic diversity and small-scale genetic structure (SGS) between edge and interior habitats. Eight microsatellite markers were employed to genotype 343 individuals including adults, juveniles and seedlings ofC. sphaerocarpaand 196 ofC. lechleri. Genetic differentiation was found between habitats in both species (ΦRT= 0.071 forC. sphaerocarpaand ΦRT= 0.028 forC. lechleri) and among ages inC. sphaerocarpa(ΦRT= 0.016). Overall, SGS was weak but significant with more pronounced SGS inC. lechleri(Sp= 0.0128) than inC. sphaerocarpa(Sp= 0.0073). However, positive spatial genetic autocorrelation extended only up to 10 m. ForC. sphaerocarpa, SGS was stronger in seedling and juvenile stages than in adults and in the forest interior than at forest edges. Our results show that edge effects can extend to the genetic level by breaking-up local genetic structures, probably due to increased gene flow and enhanced pollination and seed-dispersal interactions at forest edges.

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THE PARTHENOGENETIC CAPACITIES AND GENETIC STRUCTURES OF SYMPATRIC POPULATIONS OF DROSOPHILA MERCATORUM AND DROSOPHILA HYDEI

Genetics ◽

10.1093/genetics/92.4.1283 ◽

1979 ◽

Vol 92 (4) ◽

pp. 1283-1293

Author(s):

Alan R Templeton

Keyword(s):

Natural Populations ◽

Population Increase ◽

Sympatric Populations ◽

Sexual Population ◽

Garbage Dump ◽

Drosophila Hydei ◽

Drosophila Mercatorum ◽

Hardy Weinberg Equilibrium ◽

Genetic Structures ◽

Low Rate

ABSTRACT Drosophila mercatorum is a sexual species that can reproduce parthenogenetically in the laboratory. A previous study showed that a natural population of D. mercatorum inhabiting the Kamuela garbage dump on the Island of Hawaii could produce both viable parthenogenetic adults and self-sustaining parthenogenetic lines. The present study deals with a second screen for parthenogenesis and an isozyme survey performed on natural populations of D. mercatorum and D. hydei caught in patches of Opuntia tuna about 10 kilometers from Kamuela. Both cactus-patch species produced viable partheno-genetic adults, but only D. mercatorum produced parthenogenetic females themselves capable of parthenogenesis. Moreover, D. mercatorum produced several "hot" lines characterized by high parthenogenetic rates, while all lines of D. hydei had a homogenous low rate. The parthenogenetic capacity of the cactus-patch D. mercaiorum was lower than that of the garbage-dump D. mercatorum. Moreover, both the cactus-patch D. mercatorum and D. hydei had lower levels of polymorphism (26% and 22%, respectively) then the garbage-dump D. mercatorum (44%), and both cactus-patch populations had heterozygote deficiencies with respect to Hardy-Weinberg equilibrium, unlike the garbage-dump population. Consequently, these data do not support the idea that decreased levels of heterozygosity in a sexual population increase the chance that sexual females will produce totally homozygous, parthenogenetic progeny.

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GENOTOXIC ACTIVITY OF THE PESTICIDE MIXTURES

Токсикологический вестник ◽

10.36946/0869-7922-2020-3-9-13 ◽

2020 ◽

pp. 9-13 ◽

Cited By ~ 1

Author(s):

N. A. Ilyushina ◽

Yu. A. Revazova

Keyword(s):

Public Health ◽

Combined Effect ◽

Literature Information ◽

Genotoxic Effects ◽

Antagonistic Effects ◽

Pesticide Mixtures ◽

The World ◽

Living Organisms ◽

Genetic Structures ◽

Active Substances

In order to overcome resistance to individual pesticides and improve their effectiveness, formulations containing two or more active substances are constantly being developed and put on the market over recent years. Mixtures of residual amounts of pesticides can be present in water and food and enter the human and animal bodies. However, the combined effect of pesticides on living organisms, including genetic structures in cells, has not been studied enough and it is not yet possible to predict the genotoxic effects of their mixtures based on available data. The purpose of this review was to collect and summarize literature information on the genotoxicity of pesticide combinations obtained at different objects. The results of studies conducted in different countries of the world are discussed, examples of detected synergistic, additive and antagonistic effects are given, indicating the need for testing the genotoxicity of preparative forms of pesticides containing several active substances, as well as mixtures of jointly used pesticides in order to ensure the safe use of pesticides for public health.

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Balancing Selection on Electrophoretic Variation of Phosphoglucose Isomerase in Two Species of Field Cricket: Gryllus veletis and G. pennsylvanicus

Genetics ◽

10.1093/genetics/147.2.609 ◽

1997 ◽

Vol 147 (2) ◽

pp. 609-621

Author(s):

Laura A Katz ◽

Richard G Harrison

Keyword(s):

Balancing Selection ◽

Emergent Property ◽

Phosphoglucose Isomerase ◽

Field Cricket ◽

Nucleotide Variation ◽

Eastern United States ◽

Electrophoretic Variation ◽

Sympatric Populations ◽

Field Crickets ◽

Gryllus Veletis

Two species of crickets, Gryllus veletis and G. pennsylvanicus, share six electrophoretic mobility classes for the enzyme phosphoglucose isomerase (PGI), despite evidence from other genetic markers that the two species are not closely related within eastern North American field crickets. Moreover, the frequencies of the two most common PGI electrophoretic classes (PGI-100 and PGI-65) covary in sympatric populations of these species in the eastern United States, suggesting that PGI may be subject to trans-specific balancing selection. To determine the molecular basis of the electrophoretic variation, we characterized the DNA sequence of the Pgi gene from 29 crickets (15 G. veletis and 14 G. pennsylvanicus). Amino acid substitutions that distinguish the electrophoretic classes are not the same in the two species, and there is no evidence that specific replacement substitutions represent trans-specific polymorphism. In particular, the amino acids that diagnose the PGI-65 allele relative to the PGI-100 allele differ both between G. veletis and G. pennsylvanicus and within G. pennsylvanicus. The heterogeneity among electrophoretic classes that covary in sympatric populations coupled with analysis of patterns of nucleotide variation suggest that Pgi is not evolving neutrally. Instead, the data are consistent with balancing selection operating on an emergent property of the PGI protein.

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Premating barriers in young sympatric snail species

Scientific Reports ◽

10.1038/s41598-021-84407-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Arina L. Maltseva ◽

Marina A. Varfolomeeva ◽

Arseniy A. Lobov ◽

Polina O. Tikanova ◽

Egor A. Repkin ◽

...

Keyword(s):

Gene Flow ◽

Snail Species ◽

Sympatric Populations ◽

Gastropod Species ◽

Shell Size ◽

Closely Related Species ◽

Partial Canonical Correspondence Analysis ◽

In The Wild ◽

Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

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Origin and Potential Expansion of the Invasive Longan Lanternfly, Pyrops candelaria (Hemiptera: Fulgoridae) in Taiwan

Biology ◽

10.3390/biology10070678 ◽

2021 ◽

Vol 10 (7) ◽

pp. 678

Author(s):

You-Sheng Lin ◽

Jhih-Rong Liao ◽

Shiuh-Feng Shiao ◽

Chiun-Cheng Ko

Keyword(s):

Machine Learning ◽

Invasive Species ◽

Habitat Suitability ◽

Invasion History ◽

Crop Cultivation ◽

Main Island ◽

Genetic Structures

The longan lanternfly Pyrops candelaria is a new invasive species on the main island of Taiwan. The introduction of an invasive species may negatively influence the native fauna, flora and environment. Thus, this study aimed to infer the invasion history, predict habitat suitability and potential expansion and assess the risk to crop cultivation areas in Taiwan. Genetic structures of P. candelaria from the main island of Taiwan and related regions were analyzed based on partial COI and ND2 sequences. Additionally, machine learning MaxEnt was utilized to study habitat suitability. The results suggested that the Taiwanese populations may originate from the Kinmen Islands and the plain areas of Taiwan are considered to have high habitat suitability. Furthermore, most of the cultivation areas of longan and pomelo crops showed high habitat suitability.

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