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1.
Integr Zool ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030926

RESUMO

Males of the mountain gazelle deposit dung middens (different colors and shapes represent middens of different haplotypes) in preferable forest plots and countermark the same middens (two color circles) at the boundaries of their territories.

2.
Sci Rep ; 13(1): 16737, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37794058

RESUMO

Multiple paternity is common in many species. While its benefits for males are obvious, for females they are less clear. Female indirect benefits may include acquiring 'good genes' for offspring or increasing litter genetic diversity. The nutria (Myocastor coypus) is a successful invasive species. In its native habitat, it is polygynous, with larger and more aggressive males monopolizing paternity. Here, using culled nutria we genetically examined multiple paternity in-utero and found a high incidence of multiple paternity and maintenance of the number of fathers throughout gestation. Moreover, male fetuses sired by the prominent male have higher testosterone levels. Despite being retained, male fetuses of 'rare' fathers, siring commonly only one of the fetuses in the litter, have lower testosterone levels. Considering the reproductive skew of nutria males, if females are selected for sons with higher future reproductive success, low testosterone male fetuses are expected to be selected against. A possible ultimate explanation for maintaining multiple paternity could be that nutria females select for litter genetic diversity e.g., a bet-hedging strategy, even at the possible cost of reducing the reproductive success of some of their sons. Reproductive strategies that maintain genetic diversity may be especially beneficial for invasive species, as they often invade through a genetic bottleneck.


Assuntos
Núcleo Familiar , Testosterona , Feminino , Masculino , Animais , Reprodução/genética , Feto , Comportamento Sexual Animal
3.
Sci Rep ; 13(1): 9788, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328698

RESUMO

When it comes to aging, some colonial invertebrates present disparate patterns from the customary aging phenomenon in unitary organisms, where a single senescence phenomenon along ontogeny culminates in their inevitable deaths. Here we studied aging processes in 81 colonies of the marine urochordate Botryllus schlosseri each followed from birth to death (over 720 days). The colonies were divided between three life history strategies, each distinct from the others based on the presence/absence of colonial fission: NF (no fission), FA (fission develops after the colony reaches maximal size), and FB (fission develops before the colony reaches maximal size). The study revealed recurring patterns in sexual reproductive statuses (hermaphroditism and male-only settings), colonial vigor, and size. These recurring patterns, collectively referred to as an Orshina, with one or more 'astogenic segments' on the genotype level. The combination of these segments forms the Orshina rhythm. Each Orshina segment lasts about three months (equivalent to 13 blastogenic cycles), and concludes with either the colonial death or rejuvenation, and is manipulated by absence/existing of fission events in NF/FA/FB strategies. These findings indicate that reproduction, life span, death, rejuvenation and fission events are important scheduled biological components in the constructed Orshina rhythm, a novel aging phenomenon.


Assuntos
Urocordados , Animais , Masculino , Urocordados/genética , Rejuvenescimento , Envelhecimento , Reprodução
4.
Evolution ; 77(2): 593-607, 2023 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-36632840

RESUMO

Inbreeding is generally avoided in animals due to the risk of inbreeding depression following an increase in homozygous deleterious alleles and loss of heterozygosity. Species that regularly inbreed challenge our understanding of the fitness effects of these risks. We investigated the fitness consequences of extended inbreeding in the haplodiploid date stone beetle, Coccotrypes dactyliperda. We hypothesized that continuous inbreeding could result in reduced fitness, while outbreeding would either increase fitness due to heterosis or lower fitness if co-adapted gene complexes are disrupted. We established three breeding treatments with beetles from two geographically separated populations: Sib-mating (inbreeding), and outbreeding within and between populations. Between-population outbreeding groups of both populations had lower fecundity and collapsed before the experiment ended, while sib-mated and within-population breeding groups persisted for 10 generations. Sib-mated females had higher fecundity than within- and between-population outbreeding females. Inbreeding coefficients of sib-mated groups were higher than the other treatment groups, yet sib-mated beetles remained genetically polymorphic at the population level. Thus, there was no inbreeding depression, while crossing between distant populations led to outbreeding depression. Our findings are consistent with the life history of C. dactyliperda, in which sib-mating predominates within the date seed, but occasional within-population outbreeding may occur following local dispersal.


Assuntos
Besouros , Animais , Feminino , Besouros/genética , Melhoramento Vegetal , Endogamia , Fertilidade , Reprodução/genética
5.
Zootaxa ; 5183(1): 343-354, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36095442

RESUMO

Geoica inbari sp. nov., living on Pistacia palaestina Boiss. (Anacardiaceae), is described based on apterous fundatrigeniae, fall migrants, embryos of apterous exules within fall migrants (fundatrispuriae) and the first instar larva of an apterous exule borne by a fall migrant, collected in the Mount Hermon area of Northern Israel. The new species differs from all other known Geoica species in its mitochondrial DNA, and from those known from Pistacia by the shape of the galls. It makes coral-shaped galls, while all congeners produce spherical galls. The new species is a member of the Geoica utricularia group and morphologically resembles Geoica wertheimae Brown Blackman, 1994.


Assuntos
Afídeos , Pistacia , Animais , Israel
6.
Sci Rep ; 12(1): 15117, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36068259

RESUMO

Each of the few known life-history strategies (e.g., r/K and parity [semelparity and iteroparity]), is a composite stratagem, signified by co-evolved sets of trade-offs with stochastically distributed variations that do not form novel structured strategies. Tracking the demographic traits of 81 Botryllus schlosseri (a marine urochordate) colonies, from birth to death, we revealed three co-existing novel life-history strategies in this long-standing laboratory-bred population, all are bracketed through colonial fission (termed NF, FA and FB for no fission, fission after and fission before reaching maximal colony size, respectively) and derived from organisms maintained in a benign, highly invariable environment. This environment allows us to capture the strategists' blueprints and their net performance through 13 traits, each branded by high within-strategy variation. Yet, six traits differed significantly among the strategies and, in two, the FB was notably different. These results frame fissions in colonial organisms not as demographic traits, but as pivotal agents for life-history strategies.


Assuntos
Características de História de Vida , Urocordados , Animais , Demografia
7.
Mol Phylogenet Evol ; 174: 107549, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35691571

RESUMO

Trees of the genus Pistacia serve as obligate hosts for gall-forming aphids (Hemiptera, Aphididae, Fordini). Each aphid species induces a characteristic gall on a single Pistacia host species. The genus Geoica (Fordini) induce similar spherical closed galls on the lower side of the leaflet's midvein, on different Pistacia species. Two species of Pistacia trees that harbor Geoica galls grow naturally in Israel: P. palaestina and P. atlantica. We analyzed the phylogeny and the genetic structure of the Geoica species complex in Israel, and assessed the genetic differentiation and the level of host plant specificity of the aphids between P. atlantica and P. palaestina. We found that the splitting of the genus between P. atlantica and P. palaestina is estimated to have occurred 24-25 Ma (the Oligocene/Miocene boundary). Five different haplotypes suggesting five different species have been further speciating among Geoica spp., galling on P. atlantica, and an additional three species, on P. palaestina.


Assuntos
Afídeos , Especiação Genética , Pistacia , Animais , Afídeos/classificação , Afídeos/genética , Filogenia , Tumores de Planta , Árvores
8.
Mol Phylogenet Evol ; 164: 107212, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34029718

RESUMO

Sand scorpions of the genus Buthacus Birula, 1908 (Buthidae C.L. Koch, 1837) are widespread in the sandy deserts of the Palearctic region, occurring from the Atlantic coast of West Africa across the Sahara, and throughout the Middle East to Central Asia. The limits of Buthacus, its two species groups, and many of its species remain unclear, and in need of revision using modern systematic methods. The study presented here set out to investigate the phylogeny and biogeography of the Buthacus species occurring in the Levant, last studied in 1980. A phylogenetic analysis was performed on 104 terminals, including six species collected from more than thirty localities in Israel and other countries in the region. Three mitochondrial and two nuclear gene loci were sequenced for a total of 2218 aligned base-pairs. Morphological datasets comprising 22 qualitative and 48 quantitative morphological characters were compiled. Molecular and morphological datasets were analyzed separately and simultaneously with Bayesian Inference, Maximum Likelihood, and parsimony. Divergence time and ancestral range estimation analyses were performed, to understand dispersal and diversification. The results support a revised classification of Levantine Buthacus, and invalidate the traditional species groups of Buthacus, instead recovering two geographically-delimited clades, an African clade and an Asian clade, approximately separated by the Jordan Valley (the Jordan Rift Valley or Syro-African Depression), the northernmost part of the Great Rift Valley. The divergence between these clades occurred in the Early Miocene (ca. 19 Ma) in the Levant, coinciding temporally with the existence of two land bridges, which allowed faunal exchange between Africa and Asia.


Assuntos
Escorpiões , África , Animais , Ásia , Teorema de Bayes , Filogenia , Filogeografia , Escorpiões/genética
9.
Plants (Basel) ; 9(3)2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32210122

RESUMO

The flower colour of Anemone coronaria (Ranunculaceae) is a genetically inherited trait. Such intra-specific flower colour polymorphism might be driven by pollinators, other non-pollinating agents, or by abiotic factors. We investigated the genetic relations among red, white and purple-blue flower colour morphs growing in 10 populations of A. coronaria in Israel, in relation to their breeding system, pollination modes, differential perception by bees and visitors' behaviour. Flowers of these three morphs differed in their reflectance that could be perceived by bees. Honeybees, solitary bees and flies demonstrated only partial preferences for the different colour morphs. No spontaneous self-pollination was found; however, fruit set under nets, excluding insects but allowing wind pollination, was not significantly lower than that of natural free pollinated flowers, indicating a potential role of wind pollination. Anemone coronaria flowers were visited by various insects, honeybees and Andrena sp. preferred the white and purple-blue morphs, while the syrphid flies preferred the white flowers. Thus, visitor behaviour can only partially explain the evolution or maintenance of the colour polymorphism. No significant genetic differences were found among the populations or colour morphs. Wind pollination, causing random gene flow, may explain why no significant genetic divergence was found among all studied populations and their colour morphs. The existence of monomorphic red populations, along other polymorphic populations, might be explained by linked resistance to aridity and/or grazing.

10.
Mol Ecol ; 26(23): 6502-6509, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28950415

RESUMO

Adaptation for invasiveness should comprise the capability to exploit and prosper in a wide range of ecological conditions and is therefore expected to be associated with a certain level of genetic diversity. Paradoxically, however, invasive populations are established by only a few founders, resulting in low genetic diversity. As a conceivable way of attaining high genetic diversity and high variance of gene expression even when a small number of founders is involved in invasiveness, I suggest here chimerism, a fusion between different individuals-a common phenomenon found in numerous phyla. The composite entity offers the chimeric organism genetic flexibility and higher inclusive fitness that depends on the joint genomic fitness of the original partners. The ability to form a chimeric entity is also applied to subsequent generations, and consequently, the level of genetic diversity does not decline over generations of population establishment following invasion.


Assuntos
Adaptação Biológica/genética , Quimerismo , Variação Genética , Espécies Introduzidas , Animais , Evolução Biológica , Efeito Fundador , Aptidão Genética , Modelos Genéticos , Urocordados/genética
11.
Ecol Evol ; 6(22): 7943-7953, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27878068

RESUMO

Environmental influences shape phenotypes within and across generations, often through DNA methylations that modify gene expression. Methylations were proposed to mediate caste and task allocation in some eusocial insects, but how an insect's environment affects DNA methylation in its offspring is yet unknown. We characterized parental effects on methylation profiles in the polyembryonic parasitoid wasp Copidosoma koehleri, as well as methylation patterns associated with its simple caste system. We used methylation-sensitive amplified fragment length polymorphism (MS-AFLP) to compare methylation patterns, among (1) reproductive and soldier larvae; and (2) offspring (larvae, pupae, and adults) of wasps that were reared at either high or low larval density and mated in the four possible combinations. Methylation frequencies were similar across castes, but the profiles of methylated fragments differed significantly. Parental rearing density did not affect methylation frequencies in the offspring at any developmental stage. Principal coordinate analysis indicated no significant differences in methylation profiles among the four crossbreeding groups and the three developmental stages. Nevertheless, a clustering analysis, performed on a subset of the fragments, revealed similar methylation patterns in larvae, pupae, and adults in two of the four parental crosses. Nine fragments were methylated at two cytosine sites in all larvae, and five others were methylated at two sites in all adults. Thus, DNA methylations correlate with within-generation phenotypic plasticity due to caste. However, their association with developmental stage and with transgenerational epigenetic effects is not clearly supported.

12.
Front Plant Sci ; 7: 549, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27200024

RESUMO

To study the effects of wildfire on population genetics of a wind pollinated and wind dispersed tree, we have analyzed the genetic structure of a post-fire, naturally regenerating seedling population of Pinus halepensis Miller, on Mt. Carmel, Israel. We tested the existence of spatial genetic structure, which is expected due to the special spatial demographic structure of the post-fire seedling and sapling populations of this species. Explicitly, we asked whether or not seedlings that germinated under large, burned, dead pine trees are also their offspring. The results revealed that the post-fire seedling population is polymorphic, diverse, and reflects the pre-fire random mating system. In contrast to our prediction, we found no division of the post-fire seedling population to distinct sub-populations. Furthermore, as a result of post-fire seed dispersal to longer range than the average pre-fire inter-tree distance, seedlings found under individual burned trees were not necessarily their sole offspring. Although the population as a whole showed a Hardy-Weinberg equilibrium, significant excess of heterozygotes was found within each tallest seedlings group growing under single, large, burned pine trees. Our finding indicates the possible existence of intense natural selection for the most vigorous heterozygous genotypes that are best adapted to the special post-fire regeneration niche, which is the thick ash bed under large, dead, pine trees.

13.
Sci Rep ; 6: 19493, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26758405

RESUMO

The globally distributed coral species Pocillopora damicornis is known to release either sexual or asexual derived planula-larvae in various reef locations. Using microsatellite loci as markers, we documented the release of asexually derived chimeric larvae (CL), originating from mosaicked maternal colonies that were also chimeras, at Thai and Philippines reefs. The CL, each presenting different combinations of maternal genotypic constituents, create genetically-complex sets of asexual propagules. This novel mode of inheritance in corals challenges classical postulations of sexual/asexual reproduction traits, as asexual derived CL represent an alliance between genotypes that significantly sways the recruits' absolute fitness. This type of inherited chimerism, while enhancing intra-entity genetic heterogeneity, is an evolutionary tactic used to increase genetic-heterogeneity, primarily in new areas colonized by a limited number of larvae. Chimerism may also facilitate combat global change impacts by exhibiting adjustable genomic combinations of within-chimera traits that could withstand alterable environmental pressures, helping Pocillopora become a successful cosmopolitan species.


Assuntos
Antozoários/genética , Quimerismo , Variação Genética , Genótipo , Alelos , Animais , Marcadores Genéticos , Larva , Repetições de Microssatélites , Análise de Sequência de DNA
14.
Mol Phylogenet Evol ; 91: 226-37, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25987530

RESUMO

Scorpio Linnaeus, 1758 (family Scorpionidae Latreille, 1802) was considered monotypic for over a century, and comprised a single species, Scorpio maurus Linnaeus, 1758, with 19 subspecies, distributed from West Africa, throughout the Maghreb and the Middle East, to Iran. Two parapatric subspecies, Scorpio maurus fuscus (Ehrenberg, 1829) and Scorpio maurus palmatus (Ehrenberg, 1828), have long been recognized in the eastern Mediterranean region. We examined morphological variation, burrow architecture and genetic divergence among 39 populations across the distribution of the two subspecies to assess whether they are conspecific and, if not, how many species might be involved. Cuticle coloration, pedipalp chela digital carina condition, and selected measurements were recorded. Sixty burrows were excavated and examined for burrow structure and depth. A multilocus dataset comprising concatenated fragments of one nuclear (28S rDNA) and three mitochondrial (12S rDNA, 16S rDNA, Cytochrome c Oxidase Subunit I) loci, totaling ca. 2400 base-pairs, was produced for 41 individuals, and a single-locus dataset comprising 658 base-pairs of the COI locus for 156 individuals. Despite overlapping ranges in morphometric characters of pedipalp chela shape, the putative subspecies were easily distinguished by cuticle coloration and condition of the pedipalp chela digital carina, and were also found to differ significantly in burrow architecture and depth. Phylogeographical analyses of the COI and multilocus datasets recovered seven distinct clades. Separate analyses of mitochondrial sequences, and combined analyses of mitochondrial and nuclear sequences support most clades. The two major clades corresponded with the geographical distributions of S. m. fuscus and S. m. palmatus in the region. Specimens from these clades were genetically distinct, and exhibited different burrow structure in geographically-proximate localities, suggesting reproductive isolation. The palmatus clade included two distinct subclades of specimens from localities adjacent to the Dead Sea. Three other clades, comprising specimens from the most northeastern localities, were tentatively assigned to subspecies previously recorded in neighboring Jordan and Syria. The morphological, behavioral and genetic evidence supports previous suggestions that Scorpio maurus is a species complex and justifies the following taxonomic emendations: Scorpio fuscus (Ehrenberg, 1829), stat. nov.; Scorpio kruglovi Birula, 1910, stat. nov.; Scorpio palmatus (Ehrenberg, 1828), stat. nov.; Scorpio propinquus (Simon, 1872), stat. nov.


Assuntos
Escorpiões/classificação , Animais , DNA Mitocondrial/química , Fenômenos Ecológicos e Ambientais , Oriente Médio , Filogenia , Filogeografia , Escorpiões/anatomia & histologia , Escorpiões/genética , Escorpiões/fisiologia
15.
Indian J Exp Biol ; 52(5): 399-403, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24851401

RESUMO

Chronodisruption, a disturbance in "natural" daily light/dark regulation, is possibly linked to disturbances in cell cycle homeostasis. The association and the synchronization between circadian rhythms and mitosis are not yet clear. The circadian oscillator is involved in the major cellular pathways of cell division. A molecular link between the circadian clock and the mammalian DNA damage checkpoints has been outlined. Analyses suggest an association between light disruption and obstruction of the cell cycle homeostasis. Disruption in the homeostatic control of the cell cycle has been associated with cancer and acceleration of malignant growth, possibly as a result of the interruption of DNA damage check-points. Studies further indicate that light signal during the dark phase affects the transcription level of a substantial number of genes that are associated with cell cycle progression, cell proliferation and tumorigenesis. Indeed, the International Agency for Research in Cancer categorized "shift work that involves circadian disruption" as possibly carcinogenic. In this review the current finding on light pollution and its potential influence on cell cycle check-points and DNA repair is presented.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Transtornos Cronobiológicos/genética , Ritmo Circadiano/genética , Reparo do DNA , Animais , Humanos
16.
Proc Biol Sci ; 280(1765): 20130016, 2013 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-23825201

RESUMO

Seasonal recurrence of biological processes (phenology) and its relationship to environmental change is recognized as being of key scientific and public concern, but its current study largely overlooks the extent to which phenology is based on biological time-keeping mechanisms. We highlight the relevance of physiological and neurobiological regulation for organisms' responsiveness to environmental conditions. Focusing on avian and mammalian examples, we describe circannual rhythmicity of reproduction, migration and hibernation, and address responses of animals to photic and thermal conditions. Climate change and urbanization are used as urgent examples of anthropogenic influences that put biological timing systems under pressure. We furthermore propose that consideration of Homo sapiens as principally a 'seasonal animal' can inspire new perspectives for understanding medical and psychological problems.


Assuntos
Relógios Biológicos/fisiologia , Mudança Climática , Periodicidade , Estações do Ano , Adaptação Fisiológica , Migração Animal/fisiologia , Animais , Aves/fisiologia , Hibernação/fisiologia , Humanos , Fotoperíodo , Reprodução/fisiologia , Urbanização
17.
Elife ; 2: e00569, 2013 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-23840927

RESUMO

Botryllus schlosseri is a colonial urochordate that follows the chordate plan of development following sexual reproduction, but invokes a stem cell-mediated budding program during subsequent rounds of asexual reproduction. As urochordates are considered to be the closest living invertebrate relatives of vertebrates, they are ideal subjects for whole genome sequence analyses. Using a novel method for high-throughput sequencing of eukaryotic genomes, we sequenced and assembled 580 Mbp of the B. schlosseri genome. The genome assembly is comprised of nearly 14,000 intron-containing predicted genes, and 13,500 intron-less predicted genes, 40% of which could be confidently parceled into 13 (of 16 haploid) chromosomes. A comparison of homologous genes between B. schlosseri and other diverse taxonomic groups revealed genomic events underlying the evolution of vertebrates and lymphoid-mediated immunity. The B. schlosseri genome is a community resource for studying alternative modes of reproduction, natural transplantation reactions, and stem cell-mediated regeneration. DOI:http://dx.doi.org/10.7554/eLife.00569.001.


Assuntos
Cordados/genética , Genoma , Animais , Cordados/classificação , Cordados/fisiologia , Mapeamento Cromossômico , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Reprodução
18.
Environ Sci Pollut Res Int ; 18(8): 1264-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21384142

RESUMO

PURPOSE: We tested the genetic diversity in wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of asbestos. Hazardous effects of deposited asbestos persist in the environment because of low rate of fiber disintegration. The upper layers of the soil in the vicinity of a former asbestos factory are nearly "saturated" with asbestos fibers and dust. Natural populations of mice dwell in this area and are constantly exposed to asbestos fibers. METHODS: We measured the microsatellites genetic diversity of wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of this environmental toxin. RESULTS: The six tested microsatellites were highly polymorphic, revealing 111 different alleles for the two sampled populations. Effective number of alleles was slightly higher in the polluted population relative to the control population, while observed heterozygosity was lower. The chromatographic profile of the polluted population exhibited a significantly higher number of bands, probably resulting from somatic mutations, in addition to the ordinary microsatellite band profiles. CONCLUSIONS: Long-term exposure to asbestos fibers significantly elevates the level of somatic mutations. It also leads to a relatively high level of observed homozygosity, a phenomenon that may be associated with loss of heterozygosity. Based on the mice population, our data suggest elevated health risks for humans living in an asbestos-polluted area.


Assuntos
Amianto/toxicidade , Monitoramento Ambiental , Poluentes Ambientais/toxicidade , Animais , Ecotoxicologia , Camundongos , Repetições de Microssatélites , Testes de Mutagenicidade , Polimorfismo Genético
19.
Bioessays ; 30(11-12): 1048-51, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18937348

RESUMO

The process of allorecognition consists of an ability to discriminate self from non-self. This discrimination is used either to identify non-self cells and reject them ("non-self histocompatibility") or to identify self cells and reject them (as in the avoidance of self-fertilization by hermaphrodites ("self incompatibility"). The molecular basis governing these two distinct systems has been studied recently in hermaphroditic ascidian urochordates. Harada et al. postulated two highly polymorphic self-incompatibility loci, Themis (A and B), that are transcribed from both strands, forward to yield sperm (s-) trans-membrane antigen, and reverse to yield the egg vitelline coat (v-) receptor. De Tomaso et al. characterized a candidate histocompatibility locus, encoding a highly variable immunoglobulin. Nyholm et al. isolated its candidate allorecognition receptor, fester. Only a minute similarity was found in the structure of the genes involved. It appears that ascidian harbor two very separate types of labeling and recognition genetic systems: one for self and the other for non-self.


Assuntos
Urocordados/fisiologia , Animais , Feminino , Fertilização/imunologia , Variação Genética , Antígenos de Histocompatibilidade/química , Sistema Imunitário , Imunoglobulinas/química , Complexo Principal de Histocompatibilidade , Masculino , Modelos Biológicos , Óvulo/metabolismo , Interações Espermatozoide-Óvulo/genética , Interações Espermatozoide-Óvulo/imunologia , Espermatozoides/metabolismo , Urocordados/metabolismo , Membrana Vitelina/imunologia
20.
Genetica ; 132(1): 51-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17410473

RESUMO

Colonies of the cosmopolitan urochordate Botryllus schlosseri that share one or both alleles at a single allorecognition locus (Fu/HC) and come into tissue contacts, may fuse and form a mixed entity, a chimera. Botryllus populations worldwide exhibit unprecedented extensive polymorphism at this locus, a result that restricts fusions to kin encounters. This study aims to compare spatiotemporal configurations in source and introduced B. schlosseri populations, residing on natural and man-made substrata, respectively. By using four microsatellite loci, we tested genetic consanguinity of colonies settled naturally along spatial vectors on both, natural (native populations) and man-made (introduced) substrates. Four populations were studied. Results revealed that B. schlosseri colonies, on both substrate types, assemble in groups of relatives that share similar microsatellite profiles. We suggest that this pattern of settlement promotes the formation of chimeras, which evoke conflicting interactions: cooperation between different somatic cell lines that constitute the colonial soma and competition between germ cells that inhabit the chimera gonads. Under natural conditions, the chimera may allow genetic flexibility that depends on joint genomic fitness of its partners. This is probably one of the life history characteristics that led to the worldwide distribution success of this species.


Assuntos
Quimerismo , Urocordados/classificação , Urocordados/genética , Alelos , Animais , Filogenia , Polimorfismo Genético , População
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