Seed survival and dispersal of an endemic Atlantic forest palm: the combined effects of defaunation and forest fragmentation

About 45 palm species occur in the Atlantic forest of Brazil, and most of them are affected by loss of seed dispersers resulting from forest fragmentation and hunting. Here we report the effects of habitat loss and defaunation on the seed dispersal system of an endemic palm, Astrocaryum aculeatissimum . We evaluated seed removal, insect and rodent seed predation, and scatter-hoarding in nine sites, ranging from 19 ha to 79 000 ha. We report the seedling, juvenile and adult palm densities in this range of sites. Endocarps remaining beneath the parent palm had a higher probability of being preyed upon by insects in small, mostly fragmented and more defaunated sites. The frequency of successful seed removal, scatter-hoarding and consumption by rodents increased in the larger, less defaunated sites. Successful removal and dispersal collapsed in small (< 1000 ha), highly defaunated sites and frequently resulted in low densities of both seedlings and juveniles. Our results indicate that a large fraction of Atlantic forest palms that rely on scatter-hoarding rodents may become regionally extinct due to forest fragmentation and defaunation. Current management practices including palm extraction and hunting pressure have a lasting effect on Atlantic forest palm regeneration by severely limiting successful recruitment of prereproductive individuals. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 141–149.     

Zea systematics: ribosomal ITS evidence

Ribosomal internal transcribed spacer (ITS) sequences were used to evaluate the phylogenetics of Zea and Tripsacum. Maximum likelihood and polymorphism parsimony were used for phylogenetic reconstructions. Zea ITS nucleotide diversity was high compared to other plant species, but approximately equivalent to other maize loci. Coalescence of ITS alleles was rapid relative to other nuclear loci; however, there was still much diversity within populations. Zea and Tripsacum form a clade clearly differentiated from all other Poaceae. Four Zea ITS pseudogenes were identified by phylogenetic position and nucleotide composition. The phylogenetic position of Z. mays ssp. huehuetenangensis was clearly established as basal to the other Z. mays. The ITS phylogeny disfavored a Z. luxurians and Z. diploperennis clade, which conflicted with some previous studies. The introgression of Z. mays alleles into Z. perennis and Z. diploperennis was also established. The ITS data indicated a near contemporary divergence of domesticated maize and its two closest wild relatives.      

Polymorphism of PCR profiles and expression of alleles at the locus Adh1 in agamospermous progeny of beet root Beta vulgaris L

A modification of the ISSR amplification method based on using a combination of microsatellite and specific unique primer is proposed and tested. This modification simplifies the detected PCR profiles and allows the examination of DNA regions containing definite genes. Combinations of microsatellite primer Mic2 (5'-gacag-acaga-cagac-a-3') and one of the primers specific to the Adh1 locus, which controls alcohol dehydrogenase (ADH1) in sugar beet, were employed in this work. The microsatellite primer was used in combination with the following specific primers: Adh1f (5'-agagt-gttgg-agagg-gtgtg-ac-3') containing the binding site at the fourth exon of gene Adh1, or Adh1r (5'-act(ct)a-cagca-ag(ct)cc-(ct)ac(ct)g-ctcc-3') that binds to the fifth exon of the same gene. In the agamospermous progeny of individual heterozygous diploid plants of sugar beet with the Adh1-F/Adh1-S genotype, polymorphism of PCR profiles obtained in plants of each of three phenotypic classes (FF, FS, and SS) was detected. Among plants of the progeny from an individual plant that represents the heterozygous phenotypic class FS, differences were revealed not only between the PCR profiles but also in the relative activity of allele isozymes of ADH1.     

Vibrational communication and mating behaviour of Dichelops melacanthus (Hemiptera: Pentatomidae) recorded from loudspeaker membranes and plants

Vibrational communication is important for successful mating in various stink bugs species. The vibrational signals from males and females of Dichelops melacanthus Dallas (Hemiptera: Pentatomidae) are recorded from a nonresonant substrate (i.e. a loudspeaker membrane) to characterize the temporal and spectral properties of these vibrational signals, as well as on a resonant substrate (i.e. bean plants) to obtain information about how these signals are altered when they are transmitted through the plants. On the loudspeaker membrane, D. melacanthus males and females emit only one male or one female song, respectively. However, when the insects are placed on bean leaves, a more complex repertoire is recorded, with three different songs for each sex. The first female and male songs appear to have calling functions and the third male and female songs are emitted during courtship. The second female and male songs are emitted after the first song, although their functions in mating behaviour are not clear. The identified repertoire is similar to those of other Neotropical stink bugs, starting with songs 1 and 2 and developing into song 3. Frequency modulation is observed in the female songs recorded from the loudspeaker membrane and the plants. The signals recorded from plants present higher harmonic peaks compared with the signals recorded from the loudspeaker membrane. The presence of species and sex‐specific songs during mating confirms the important role of vibrational communication in mate location and recognition. The temporal and spectral characteristic signals are influenced by the substrate used to record the songs emitted by D. melacanthus.     

Loss of Allograft Inflammatory Factor-1 Ameliorates Experimental Autoimmune Encephalomyelitis by Limiting Encephalitogenic CD4 T-Cell Expansion

Experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS), is mediated by myelin-specific autoreactive T cells that cause inflammation and demyelination in the central nervous system (CNS), with significant contributions from activated microglia and macrophages. The molecular bases for expansion and activation of these cells, plus trafficking to the CNS for peripheral cells, are not fully understood. Allograft inflammatory factor-1 (Aif-1) (also known as ionized Ca²⁺ binding adapter-1 [Iba-1]) is induced in leukocytes in MS and EAE; here we provide the first assessment of Aif-1 function in this setting. After myelin oligodendrocyte glycoprotein peptide (MOG_35–55) immunization, Aif-1–deficient mice were less likely than controls to develop EAE and had less CNS leukocyte infiltration and demyelination; their spinal cords contained fewer CD4 T cells and microglia and more CD8 T cells. These mice also showed significantly less splenic CD4 T-cell expansion and activation, plus decreased proinflammatory cytokine expression. These findings identify Aif-1 as a potent molecule that promotes expansion and activation of CD4 T cells, plus elaboration of a proinflammatory cytokine milieu, in MOG_35–55-induced EAE and as a potential therapeutic target in MS.     

Terrestrial Activity in Pitheciins (Cacajao,Chiropotes, and Pithecia)

Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc.