scholarly journals A phylogenetic community approach for studying termite communities in a West African savannah

2015 ◽  
Vol 11 (10) ◽  
pp. 20150625 ◽  
Author(s):  
Barbara Hausberger ◽  
Judith Korb
Keyword(s):  
Environmental Filtering ◽  
Single Species ◽  
Insect Species ◽  
Conservation Strategies ◽  
Closely Related Species ◽  
Community Processes ◽  
Community Approach ◽  
Macrotermes Bellicosus ◽  
Single Insect ◽  
West African Savannah

Termites play fundamental roles in tropical ecosystems, and mound-building species in particular are crucial in enhancing species diversity, from plants to mammals. However, it is still unclear which factors govern the occurrence and assembly of termite communities. A phylogenetic community approach and null models of species assembly were used to examine structuring processes associated with termite community assembly in a pristine savannah. Overall, we did not find evidence for a strong influence of interspecific competition or environmental filtering in structuring these communities. However, the presence of a single species, the mound-building termite Macrotermes bellicosus , left a strong signal on structuring and led to clustered communities of more closely related species. Hence, this species changes the assembly rules for a whole community. Our results show the fundamental importance of a single insect species for community processes, suggesting that more attention to insect species is warranted when developing conservation strategies.

scholarly journals THE SPECIFICITY OF OXIDIZED AND REDUCED PROTEINS OF THE OCULAR LENS

1940 ◽  
Vol 71 (5) ◽  
pp. 585-590 ◽  
Author(s):  
E. E. Ecker ◽  
L. Pillemer
Keyword(s):  
Related Species ◽  
Redox State ◽  
Single Species ◽  
Species Specificity ◽  
Ocular Lens ◽  
Closely Related Species ◽  
Pure Compounds

Oxidized and reduced proteins were prepared from the ocular lenses of sheep, swine, chicken and fish (pike). The proteins were prepared under conditions designed to avoid denaturation and to produce relatively pure compounds. Serologic studies revealed that species specificity is demonstrable in the proteins from chicken and fish lenses, but in the more closely related species (swine and sheep) this characteristic is not so evident. Serologic differences may be detected in the lens preparations from a single species, depending on the redox state of the protein.

scholarly journals Co-occurring cryptic species pose challenges for conservation: a case study of the African dwarf crocodile (Osteolaemusspp.) in Cameroon

Oryx ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 584-590 ◽  
Author(s):  
Nicole L. Smolensky
Keyword(s):  
Cryptic Species ◽  
Conservation Status ◽  
Taxonomic Revision ◽  
Single Species ◽  
Conservation Strategies ◽  
Encounter Rates ◽  
Distribution Maps ◽  
Species Complexes ◽  
Threatened Taxa ◽  
Population Structures

AbstractThe conservation status of threatened taxa may be obfuscated by the detection of cryptic species complexes, in both vertebrate and invertebrate species. African dwarf crocodiles (Osteolaemusspp.) are hunted throughout their range but their conservation status is unknown. Few population assessments have been carried out and there has been a taxonomic revision of the number of species in the genus. The similar morphologies ofOsteolaemus tetraspisandOsteolaemus osbornipose a challenge for conservation in Cameroon, where they are still managed as a single species. Nocturnal spotlight surveys were conducted in three regions during August–November 2010 and December 2011–February 2012 to provide population assessments ofO. tetraspisandO. osborniand raise awareness of the two species in Cameroon. The mean encounter rates ofO. tetraspisandO. osborniwere 1.02 ± SD 1.34 (65 individuals in 39 surveys) and 0.61 ± SD 0.38 (three in four surveys) crocodiles per km, respectively. TheO. tetraspispopulation comprised juveniles predominantly and had a male-biased sex ratio. The fewO. osbornidetected comprised both adults and juveniles. Both species are threatened in Cameroon, based on low encounter rates, young population structures and the threats of habitat loss and hunting pressure. This study provides distribution maps and serves as a baseline to quantify population trends and inform conservation strategies.

scholarly journals It Cuts Both Ways: An Annelid Model System for the Study of Regeneration in the Laboratory and in the Classroom

2021 ◽  
Vol 9 ◽  
Author(s):  
Veronica G. Martinez Acosta ◽  
Fausto Arellano-Carbajal ◽  
Kathy Gillen ◽  
Kay A. Tweeten ◽  
Eduardo E. Zattara
Keyword(s):  
Wound Healing ◽  
Developmental Process ◽  
Recovery Of Function ◽  
Single Species ◽  
Model System ◽  
Regenerative Capacity ◽  
Closely Related Species ◽  
Complete Replacement ◽  
Successful Recovery ◽  
The Individual

The mechanisms supporting regeneration and successful recovery of function have fascinated scientists and the general public for quite some time, with the earliest description of regeneration occurring in the 8th century BC through the Greek mythological story of Prometheus. While most animals demonstrate the capacity for wound-healing, the ability to initiate a developmental process that leads to a partial or complete replacement of a lost structure varies widely among animal taxa. Variation also occurs within single species based on the nature and location of the wound and the developmental stage or age of the individual. Comparative studies of cellular and molecular changes that occur both during, and following, wound healing may point to conserved genomic pathways among animals of different regenerative capacity. Such insights could revolutionize studies within the field of regenerative medicine. In this review, we focus on several closely related species of Lumbriculus (Clitellata: Lumbriculidae), as we present a case for revisiting the use of an annelid model system for the study of regeneration. We hope that this review will provide a primer to Lumbriculus biology not only for regeneration researchers but also for STEM teachers and their students.

scholarly journals Trace amines inhibit insect odorant receptor function through antagonism of the co-receptor subunit

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 84 ◽  
Author(s):  
Sisi Chen ◽  
Charles W. Luetje
Keyword(s):  
Odorant Receptor ◽  
Olfactory Receptors ◽  
Single Species ◽  
Insect Species ◽  
Receptor Subunit ◽  
Trace Amines ◽  
Vector Mosquito ◽  
Exogenous Compounds ◽  
Potent Antagonist ◽  
High Degree

Many insect behaviors are driven by olfaction, making insect olfactory receptors (ORs) appealing targets for insect control.  Insect ORs are odorant-gated ion channels, with each receptor thought to be composed of a representative from a large, variable family of odorant binding subunits and a highly conserved co-receptor subunit (Orco), assembled in an unknown stoichiometry.  Synthetic Orco directed agonists and antagonists have recently been identified.  Several Orco antagonists have been shown to act via an allosteric mechanism to inhibit OR activation by odorants.  The high degree of conservation of Orco across insect species results in Orco antagonists having broad activity at ORs from a variety of insect species and suggests that the binding site for Orco ligands may serve as a modulatory site for compounds endogenous to insects or may be a target of exogenous compounds, such as those produced by plants.  To test this idea, we screened a series of biogenic and trace amines, identifying several as Orco antagonists.  Of particular interest were tryptamine, a plant-produced amine, and tyramine, an amine endogenous to the insect nervous system.  Tryptamine was found to be a potent antagonist of Orco, able to block Orco activation by an Orco agonist and to allosterically inhibit activation of ORs by odorants.  Tyramine had effects similar to those of tryptamine, but was less potent.  Importantly, both tryptamine and tyramine displayed broad activity, inhibiting odorant activation of ORs of species from three different insect orders (Diptera, Lepidoptera and Coleoptera), as well as odorant activation of six diverse ORs from a single species (the human malaria vector mosquito, Anopheles gambiae).  Our results suggest that endogenous and exogenous natural compounds serve as Orco ligands modulating insect olfaction and that Orco can be an important target for the development of novel insect repellants.

scholarly journals Estimation of the relative abundance of species in artificial mixtures of insects using low-coverage shotgun metagenomics

2020 ◽  
Vol 4 ◽  
Author(s):  
Lidia Garrido-Sanz ◽  
Miquel Àngel Senar ◽  
Josep Piñol
Keyword(s):  
Relative Abundance ◽  
Species Abundance ◽  
Single Species ◽  
Insect Species ◽  
Individual Species ◽  
Advanced Degree ◽  
Mixed Species ◽  
Species List ◽  
Shotgun Metagenomics ◽  
Low Coverage

Amplicon metabarcoding is an established technique to analyse the taxonomic composition of communities of organisms using high-throughput DNA sequencing, but there are doubts about its ability to quantify the relative proportions of the species, as opposed to the species list. Here, we bypass the enrichment step and avoid the PCR-bias, by directly sequencing the extracted DNA using shotgun metagenomics. This approach is common practice in prokaryotes, but not in eukaryotes, because of the low number of sequenced genomes of eukaryotic species. We tested the metagenomics approach using insect species whose genome is already sequenced and assembled to an advanced degree. We shotgun-sequenced, at low-coverage, 18 species of insects in 22 single-species and 6 mixed-species libraries and mapped the reads against 110 reference genomes of insects. We used the single-species libraries to calibrate the process of assignation of reads to species and the libraries created from species mixtures to evaluate the ability of the method to quantify the relative species abundance. Our results showed that the shotgun metagenomic method is easily able to set apart closely-related insect species, like four species of Drosophila included in the artificial libraries. However, to avoid the counting of rare misclassified reads in samples, it was necessary to use a rather stringent detection limit of 0.001, so species with a lower relative abundance are ignored. We also identified that approximately half the raw reads were informative for taxonomic purposes. Finally, using the mixed-species libraries, we showed that it was feasible to quantify with confidence the relative abundance of individual species in the mixtures.

A study of molecular sequences, sexuality, and morphological variation in Plagiomnium carolinianum, P. maximoviczii, and P. rhynchophorum (Bryophyta, Mniaceae)

Phytotaxa ◽  
2018 ◽  
Vol 375 (1) ◽  
pp. 81
Author(s):  
YAN-JUN YI ◽  
ZHEN-WEI SUN ◽  
SI HE ◽  
MAMTIMIN SULAYMAN
Keyword(s):  
Phylogenetic Analyses ◽  
Single Species ◽  
Molecular Study ◽  
Geographic Range ◽  
Similar Species ◽  
Monophyletic Clade ◽  
Closely Related Species ◽  
Molecular Phylogenetic ◽  
Different Populations ◽  
Rps4 Gene

Morphologically, recognition of the genus Plagiomnium may be relatively easy. Yet identifications of closely related species have met great difficulties. The contemporary species delimitations of P. carolinianum, P. maximoviczii, and P. rhynchophorum largely based on sexuality as the sole distinction have not been satisfactory. As shown from literature, character variations among these three taxa were continuous and intergraded within or among different populations throughout a wide geographic range. No gametophytic characters could be reliably used to distinguish them from each other. Molecular phylogenetic analyses using ITS2 and rps4 gene were undertaken to resolve delineations for these three morphologically similar species. The results suggest that they form a well support monophyletic clade, which can be defined as representing one single species with two subspecies, i.e. P. rhynchophorum subsp. maximoviczii and P. rhynchophorum subsp. rhynchophorum. The present molecular study supports the treatment of P. carolinianum as synonym of P. rhynchophorum as purposed previously by Koponen based on morphology.

scholarly journals Does advertisement call variation coincide with genetic variation in the genetically diverse frog taxon currently known as Leptodactylus fuscus (Amphibia: Leptodactylidae)?

2003 ◽  
Vol 75 (1) ◽  
pp. 39-54 ◽  
Author(s):  
W. RONALD HEYER ◽  
YANA R. REID
Keyword(s):  
Genetic Variation ◽  
South America ◽  
Genetic Differentiation ◽  
Related Species ◽  
Geographic Distance ◽  
Single Species ◽  
Advertisement Call ◽  
Closely Related Species ◽  
Multiple Species ◽  
Disturbed Habitats

The frog Leptodactylus fuscus is found throughout much of South America in open and disturbed habitats. Previous study of genetic differentiation in L. fuscus demonstrated that there was lack of genetic exchange among population units consistent with multiple species, rather than a single species. We examine advertisement vocalizations of L. fuscus to determine whether call variation coincides with genetic differentiation. Calls were analyzed for 32 individual frogs from 25 localities throughout the distributional range of L. fuscus. Although there is variation in calls among geographic samples, call variation is not concordant with genetic variation or geographic distance and the call variation observed is less than that typically found among other closely related species of Leptodactylus. This study is an example of the rare pattern of strong genetic differentiation unaccompanied by salient differences in advertisement calls. The relative infrequency of this pattern as currently understood may only reflect the lack of detailed analyses of genetic and acoustic differentiation within population systems currently understood as single species with substantial geographic distributions.

Female gametophyte and seed development in Musella lasiocarpa (Musaceae), a monotypic genus endemic to Southwestern China

2007 ◽  
Vol 85 (10) ◽  
pp. 964-975 ◽  
Author(s):  
Chun-Ying Xue ◽  
Hong Wang ◽  
De-Zhu Li
Keyword(s):  
Seed Development ◽  
Female Gametophyte ◽  
Wild Population ◽  
Embryo Sac ◽  
Single Species ◽  
Ex Situ ◽  
Southwestern China ◽  
Conservation Strategies ◽  
Female Sterility ◽  
Monotypic Genus

Musella is a monotypic genus composed of a single species, Musella lasiocarpa (Franch.) C.Y. Wu ex H.W. Li, endemic to Southwestern China. The genus status of Musella remains controversial. Musella had been placed first in Musa , then in Ensete , and back to Musa before its monotypic status was recognized. Musella was reported to be extinct in the wild and maintained through cultivation only via vegetative propagation through sprouting of rhizomes. In this study, female gametophyte and seed development of Musella are described to assess its systematic position and possible reasons why the wild population is now extinct. The ovules are anatropous, bitegmic, and crassinucellar. The micropyle is formed by both integuments. The megaspore mother cell undergoes meiotic division and forms a linear megaspore triad or more rarely, a T-shaped megaspore tetrad. The chalazal megaspore develops into a Polygonum type embryo sac. A nucellar pad forms, and a hypostase differentiates. Fertilization is porogamous. Endosperm formation is of the nuclear type. The zygote degenerates and so the process by which the embryo develops, if it does, remains unclear. An operculum, micropylar collar, and chalazal chamber form in mature seeds. The storage tissue is mainly endosperm containing large, compound starch grains and some perisperm. The seed coat has lignified exotestal cells, 25–30 cell layers of sclerotic mesotestal cells, and unspecialized endotesta cells; the tegment consists of two layers of longitudinally elongated cells. The seed is inviable. After comparison with the other Musaceae s. str. taxa using embryological and botanical features, we conclude that Musella should be a distinct genus. Female sterility in Musella may be the main reason why the wild population is extinct. Based on these findings, we propose conservation strategies for this endemic species, including habitat protection as well as ex-situ conservation.

scholarly journals Diet breadth and its relationship with genetic diversity and differentiation: the case of southern beech aphids (Hemiptera: Aphididae)

2004 ◽  
Vol 94 (3) ◽  
pp. 219-227 ◽  
Author(s):  
C. Gaete-Eastman ◽  
C.C. Figueroa ◽  
R. Olivares-Donoso ◽  
H.M. Niemeyer ◽  
C.C. Ramírez
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Diet Breadth ◽  
Aphid Species ◽  
Insect Species ◽  
Herbivorous Insect ◽  
Genetic Structuring ◽  
Closely Related Species ◽  
Single Host ◽  
Southern Beech

AbstractHerbivorous insect species with narrow diet breadth are expected to be more prone to genetic differentiation than insect species with a wider diet breadth. However, a generalist can behave as a local specialist if a single host-plant species is locally available, while a specialist can eventually behave as a generalist if its preferred host is not available. These problems can be addressed by comparing closely related species differing in diet breadth with overlapping distributions of insect and host populations. In this work, diet breadth, genetic diversity and population differentiation of congeneric aphid species from southern beech forests in Chile were compared. While at the species level no major differences in genetic diversity were found, a general trend towards higher genetic diversity as diet breadth increased was apparent. The aphid species with wider diet breadth, Neuquenaphis edwardsi (Laing), showed the highest genetic diversity, while the specialist Neuquenaphis staryi Quednau & Remaudière showed the lowest. These differences were less distinct when the comparisons were made in the same locality and over the same host. Comparison of allopatric populations indicates that genetic differentiation was higher for the specialists, Neuquenaphis similis Hille Ris Lambers and N. staryi, than for the generalist N. edwardsi. Over the same host at different locations, genetic differentiation among populations of N. edwardsi was higher than among populations of N. similis. The results support the assumption that specialists should show more pronounced genetic structuring than generalists, although the geographical distribution of host plants may be playing an important role.

scholarly journals Population genomic analysis of the speckled dace species complex (Rhinichthys osculus) identifies three species-level lineages in California

2021 ◽  
Author(s):  
Yingxin Su ◽  
Peter B. Moyle ◽  
Matthew A. Campbell ◽  
Amanda J. Finger ◽  
Sean M. O’Rourke ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Principal Component ◽  
Single Species ◽  
Death Valley ◽  
Conservation Strategies ◽  
Geologic History ◽  
Santa Ana ◽  
Long Valley ◽  
Rhinichthys Osculus ◽  
Speckled Dace

The speckled dace ( Rhinichthys osculus ) is small cyprinid fish that is widespread in the Western USA. Currently treated as a single species, speckled dace consists of multiple evolutionary lineages that can be recognized as species and subspecies throughout its range. Recognition of taxonomic distinctiveness of speckled dace populations is important for developing conservation strategies. In this study, we collected samples of speckled dace from 38 locations in the American West, with a focus on California. We used RAD sequencing to extract thousands of SNPs across the genome from samples to identify genetic differences among seven California populations informally recognized as speckled dace subspecies: Amargosa, Owens, Long Valley, Lahontan, Klamath, Sacramento, and Santa Ana speckled dace. We performed principal component analysis, admixture analysis, estimated pairwise Fst, and constructed a phylogeny to explore taxonomic relationships among these groups and test if these subspecies warrant formal recognition. Our analyses show that the seven subspecies fit into three major lineages equivalent to species: western (Sacramento-Klamath), Santa Ana, and Lahontan speckled dace. Death Valley speckled dace were determined to be two lineages (Amargosa and Long Valley) within Lahontan speckled dace. Western and Lahontan speckled dace lineages had branches that can be designated as subspecies. These designations fit well with the geologic history of the region which has promoted long isolation of populations. This study highlights the importance of genetic analysis for conservation and management of freshwater fishes.

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