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North American rice rats (Oryzomys) inhabit the coastal marshes and inland wetlands of the southeastern United States and parts of Mexico. The phylogeographic origins of rice rat populations in southern Illinois, the northern-most extent of their range in North America, has not previously been examined. Here, we present evidence, based on mitochondrial DNA sequencing, that rice rats in Southern Illinois belong to the western species, Oryzomys texensis and not Oryzomys palustris palustris as current range maps and previous morphological studies indicate. The pattern also points to a potential hybrid zone between the two species located further east than current distribution maps would suggest. Finally, we present a new estimate of the divergence time between O. palustris and O. texensis. [ABSTRACT FROM AUTHOR]

Simple Summary: Nanger soemmerringii, Gazella dorcas and Eudorcas tilonura are the three species of gazelle indigenous to Eritrea. Their status, distribution and habitat selection are poorly studied or unknown. This study fills this knowledge gap by providing the first data on environmental preferences and threats arising from human activities (agriculture and livestock) for the Eritrean populations of the three species. The distribution of the three species is mainly driven by climate and human-related disturbance rather than habitat features. Species tend to avoid agricultural areas and, particularly, areas with high density of livestock. To ensure the persistence of the three gazelle species in the country, it is urgent and decisive to establish targeted protected areas, as well as taking actions to reduce the impact of competition with livestock. The status and habitat selection of the three species of gazelle indigenous to Eritrea, i.e., Nanger soemmerringii, Gazella dorcas and Eudorcas tilonura, are not well known. In this study, we analyzed the present distribution of the three species in the country in order to identify preferred habitats and assess the effect of human disturbance (land use for agricultural purposes and livestock) on species occurrence. These data represent baseline information for evidence-based strategies for conservation of the three species in Eritrea. Presence/absence data of the three species in each of the 67 administrative subregions (Sub Zoba) composing the country were collected using direct (field surveys) and indirect methods (questionnaires). For each sampling unit, we collected fifteen environmental variables, of which three are associated with climatic features, eight with vegetation structure and four with human disturbance (human-related land use and livestock). The occurrence probability of each species was modeled through Generalized Linear Models (GLM). The analyses showed that Dorcas gazelle occurred more frequently in warmer conditions and in a wide range of natural vegetation types. Heuglin's gazelle occurred in warmer regions with higher seasonality in both temperature and precipitation with a preference for closed woody and open grassland areas. In the case of Soemmerring's gazelle, the GLM with climatic variables predicted a preference for warmer conditions but with lower seasonality of temperature and precipitation. The species also seemed to prefer arid and semi-arid open vegetation. Human disturbance is the variable with the strongest, negative, effect on the species occurrence. Indeed, the occurrence probability of each species decreased with increasing livestock density and agricultural land use. Most of these gazelle occurred in unprotected areas, thus the human-related activities are undoubtedly the most important threat for the three species of gazelle in Eritrea. Therefore, the establishment of protected areas that preserve the potential optimal habitats for gazelle and reduce the impact of livestock ranching are essential to ensure a future for these gazelle in Eritrea. [ABSTRACT FROM AUTHOR]

This study focuses on the taxonomic, evolutionary and conservation implications of a striking reduction in body size previously observed in an island population of gazelles by comparing the genetic structure of island and mainland populations. Mitochondrial sequence diversity of the mainland population was found to be comparable to that of other true gazelles of East Africa. We discuss this in the context of the prolonged armed conflict in our study region. In contrast, the gazelles on Dahlak Kebir, one of the over 200 islands and islets of the Dahlak archipelago on the Red Sea, were found to be genetically depauperate. Nucleotide and haplotype diversity estimates were a sixth and a third of that of the mainland population respectively. Using estimates of Tajima's D statistic, we inferred that the Dahlak population has undergone expansion after a recent bottleneck. A minimum spanning genealogical network of mitochondrial control region sequences produced testable hypotheses on the route and timing of the colonization of Dahlak Kebir by gazelles from the mainland. Our mitochondrial DNA dataset has resolved the taxonomic ambiguity of the island gazelles. Their genetic distinctiveness and, their striking conformity to the Island Rule that was highlighted in a previous study, are discussed from evolutionary and conservation perspectives. [ABSTRACT FROM AUTHOR]

Five NiII macrocyclic complexes are studied as water proton shift agents and as paraCEST agents (paraCEST = paramagnetic chemical exchange saturation transfer) for MRI applications. The five macrocycles have amide and/or alcohol pendent groups with either tetraaza‐ or triazamacrocycles including 1,1′,1′′‐(1,4,7‐triazonane‐1,4,7‐triyl)tris(propan‐2‐ol) (L1), 1,1′,1′′,1′′′‐(1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetra)tetrakis(propan‐2‐ol) (L2), 1,1′,1′′,1′′′‐(1,4,8,11‐tetraazacyclotetradecane‐1,4,8,11‐tetrayl)tetrakis(propan‐2‐ol) (L3), 2,2′,2′′‐(1,4,7‐triazonane‐1,4,7‐triyl)triacetamide (L4), or 2,2′‐(7‐benzyl‐1,4,7‐triazonane‐1,4‐diyl) diacetamide (L5). Solution magnetic moments are consistent with paramagnetic NiII complexes. The complexes are characterized by pH‐potentiometric titrations to determine the pKa values of the bound amide or alcohol pendents or water ligand. Variable temperature 17O NMR studies are consistent with a water ligand in [Ni(L5)]2+ with an exchange rate constant of 4 × 104 s–1. All NiII complexes produce a substantial hyperfine shift of bulk water proton resonances. The smallest shifts are observed for [Ni(L4)]2+, which lacks alcohol pendents or bound water and the largest are observed for [Ni(L5)]2+ which contains a bound water molecule. The alcohol‐appended complexes, [Ni(L2)]2+ and [Ni(L3)]2+ produce CEST spectra with far‐shifted peaks of low intensity at 94 and 104 ppm versus bulk water, whereas [Ni(L5)]2+ shows a CEST peak at δ = 72 ppm. [ABSTRACT FROM AUTHOR]

Descriptions of the mosquitoes of the Republic of the Sudan are mostly limited to works published more than 60 years ago. Khartoum State in central Sudan, which encompasses the capital city, has experienced many outbreaks of diseases caused by mosquito-borne pathogens, including Rift Valley fever. In this paper we focus on the composition ofAedesmosquitoes in high-risk areas in and around major agricultural projects. This is based on longitudinal surveillance of adults and larvae during the hot dry and rainy seasons in 2013. A total of 630 adult female mosquitoes were collected.Anophelesmosquitoes were the most abundant (n = 456, 72.4%), followed byCulex(n = 96, 15.2%) andAedes(n = 78, 12.4%). Only threeAedesspecies were identified:Aedes caballus(n = 38, 48.7% of theAedes),Aedes vexans arabiensis(n = 30, 38.5%) andAedes caspius(n = 10, 12.8%). A total of 42,549 larvae were collected.Aedeslarvae were the most abundant (n = 30,936, 72.7%), followed byCulex(n = 9656, 22.7%) andAnopheles(n = 1957, 4.6%). TheAedeslarvae includedAe. caspius(n = 21,957, 71.0% of theAedes),Ae. vexans arabiensis(n = 5577, 18.0%),Aedes quasiunivittatus(n = 107, 0.3%),Aedes dentatus(Theobald) (n = 204, 0.7%) and 3091 unidentifiable larvae (10.0%), denoted as Forms X, Y and Z. We discuss the bionomics of the four identified species ofAedesand provide updated keys for the identification of the mosquito genera and the larvae and adults of theAedesspecies recorded from the Republic of the Sudan. [ABSTRACT FROM PUBLISHER]

Abstract The desert locust (Schistocerca gregaria) undergoes crowding-induced phase transformation from solitary form to gregarious form. The transformations involves changes in behaviour, colour, development, morphometry, fecundity and endocrine physiology. Recession populations of the desert locust exist primarily in the solitary phase as small populations in patchy environments and are prone to extinction because of climatic events. Significant genetic differentiation among recession populations along the Red Sea coast of Eritrea was previously reported. It was hypothesized that despite the mixing effect of recurrent swarms, metapopulation dynamics could have produced genetic divergence among these highly scattered recession populations. A Monte Carlo simulation of the population dynamics of the desert locust in a metapopulation setting, with a realistic range of parameter values clearly demonstrated that this is possible. Population growth was represented by a discrete-time logistic equation. The duration of recessions and swarms was sampled from normal distributions whose means and standard deviations were varied based on reported estimates. An average recession duration of 10 ± 3 generations and swarm periods half as long but almost twice as variable produced a partitioning of the total genetic variance most similar to that in the empirical study. In conventional metapopulation analysis, whether turnover leads to increased or reduced divergence is dependent on the number of colonists relative to the number of recurrent migrants, and on whether the colonists arise from a single patch or many patches. In the case of locusts, the stochastic boom and bust cycle is the overriding factor. Divergence between patches during recession due to founder effect and recurrent drift is balanced by the high rate of mixing during plagues. [ABSTRACT FROM AUTHOR]

AbstractThe desert locust (Schistocerca gregaria) undergoes crowding-induced phase transformation from solitary to gregarious, which involves changes in behaviour, colour, development, morphometry, fecundity and endocrine physiology. During recession, solitary locusts persist in the central, drier part of the species’ range in small pocket populations that are prone to extinction. During the intermittent upsurges and the subsequent plagues, gregarious swarms attain huge population size and invade a vast area causing major damage to agriculture. A highly variable nuclear DNA marker, a noncoding 3′ end fragment of an antennapedia-class homeobox gene, was screened in locust samples from Eritrea. Despite the homogenizing potential of plague swarms, the last of which was in 1986–89 and originated in this region, the population genetic structure of solitary phase locusts along the Red Sea coast of Eritrea revealed significant divergence. The pattern of divergence indicated that the invasion of the western and northern plains in the summer of 1995 may not, as reported then, have originated in eastern Chad or western Sudan. A number of interrelated hypotheses have been presented to explain the observed genetic heterogeneity between the sampled populations. We conclude, with caution due to the limited sample sizes, that: (i) geographical isolation between breeding sites during plagues and recession; (ii) the marked differences in the flight behaviour of plague swarms and recession populations; (iii) possible failure of gregarious locusts to solitarize and re-establish in recession areas; and (iv) the effect of repeated extinction and recolonization in the meta-population contribute to the maintenance of the genetic structure of recession populations. Potentially productive future research has been identified. [ABSTRACT FROM AUTHOR]

The European wild rabbit (Oryctolagus cuniculus) is an introduced species in Britain, and populations have been profoundly influenced by both man and disease. In stable environmental conditions, distinct social behaviour is observed, and this social structure leads to significant genetic structuring at the intrapopulation level. In this study, European wild rabbits were sampled from 17 sites across the East Anglian region of Britain and genotyped with nine microsatellite loci. Genotypical proportions deviated significantly from Hardy–Weinberg equilibrium, reflecting a degree of population subdivision and non-random mating. Several estimates of measures of population genetic structure revealed that populations are genetically distinct and have small effective population sizes. These distinctive properties are seen to be the combined effects of the social structure and random drift acting on bottlenecked populations after myxomatosis. It is concluded that the genetic structure seen in rabbit populations today is unlikely to reflect historical structuring present before myxomatosis, but that it results from recent events. [ABSTRACT FROM AUTHOR]

Four morphological taxa of the beetle genus Pimelia (Coleoptera, Tenebrionidae) are known to exist on the Atlantic island of Tenerife. We have obtained DNA sequences for 61 individuals from these taxa across the island for a 200 bp long fragment of the mitochondrial COI gene. In addition, a restriction site polymorphism in the nuclear rRNA ITS-1 sequence was identified and screened in a sample of these individuals using the enzyme Kpn2I. The results were analysed using approaches which allow inferences to be made about the population genetic structure and the mitochondrial genealogy of these closely related beetles. The mtDNA haplotype distribution and the estimates of sequence divergence revealed the presence of two ancient mtDNA lineages which coincide with the disjunct volcanic evolution of the island. The ITS-1 polymorphism was found to be diagnostic of these two lineages. However, the morphological and mitochondrial phylogenies were found to be discordant. We argue that this is possibly the result of rapid morphological change, produced by selection in different habitats, which has been recently superimposed on an older mitochondrial DNA divergence. [ABSTRACT FROM AUTHOR]

We examined the impact of three forms of dispersal, stepping-stone, normal and leptokurtic, on spatial genetic structure of expanding populations using computer simulations. When dispersal beyond neighbouring demes is allowed, rare long-distance migration leads to the establishment of pocket populations in advance of the main invasion front and results in spatial clustering of genotypes which persists for hundreds of generations. Patchiness is more pronounced when dispersal is leptokurtic as is the case in many animal and plant species. These results are of particular interest because population genetic parameters such as gene flow and effective population size are commonly estimated using gene frequency divergence information assuming equilibrium conditions and island models. We show how the three forms of dispersal during colonization bring about contrasting population genetic structures and how this affects estimates of gene flow. The implications for experimental studies of the spatial dimension of population genetic structure are discussed. [ABSTRACT FROM AUTHOR]

Nine pairs of polymerase chain reaction (PCR) primers that amplify polymorphic microsatellite loci in the desert locust, Schistocerca gregaria (Forskal), were developed using a magnetic bead-based enrichment protocol. A sample of 48 locusts collected during the 1993 and 1995 upsurge periods in Eritrea, East Africa, were genotyped. The number of alleles per locus ranged from six to 20; the average was 12.67. Allelic distributions were significantly different between samples from different localities. [ABSTRACT FROM AUTHOR]

Eight pairs of polymerase chain reaction (PCR) primers that amplify polymorphic microsatellite loci were developed for the African armyworm, Spodoptera exempta (Walker) to be used in the study of its population dynamics in sub-Sahara Africa where the species is a major pest of cereals and rangeland. A magnetic beads based enrichment protocol was used; it appears that previously reported scarcity of microsatellites in Lepidoptera species does not apply to the African armyworm. All the loci showed significant heterozygote deficit; possibly because the samples were laboratory reared from limited stock. Four primer pairs successfully amplified single fragments of beet and fall armyworm DNA of comparable size to the African armyworm alleles. [ABSTRACT FROM AUTHOR]