The distributions of howling monkeys (<Emphasis Type="Italic">Alouatta pigra</Emphasis> and <Emphasis Type="Italic">A. palliata</Emphasis>) in southeastern Mexico and Central America

We compared the distributions of Alouatta palliata and A. pigra in southeastern Mexico and Central America with geographic and ecological features to infer current barriers and ecological preferences. Distribution data were obtained from museum specimen localities, study sites, historic records and field surveys and integrated into digital elevation and ecosystem maps using GIS. A. pigra evidently occurs at a number of sites above 2,000 m, where temperatures can even drop below zero on some days of the year, thus indicating a broader ecological tolerance than previously reported. Both species occupy a number of vegetation types and can be found in seasonal and nonseasonal forests. We identified the highland massif of northern Central America and its associated coniferous and subalpine vegetation as a geographic barrier that separates the species. In the past, distribution maps for these species have indicated adjacent contiguous ranges, but we propose that they are largely separated by these mountains. There are two contact zones: a broad area of sympatry north of the highland massif in Mexico and a narrow zone in eastern Guatemala where parapatry is maintained by a river barrier and where only A. pigra occurs in the high elevations and cooler habitats inland. We explore an alternative biogeographic scenario for the split of the two species that accounts for the current distribution and differences in elevation and cold tolerances. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Predicted and verified distributions of <Emphasis Type="Italic">Ateles geoffroyi</Emphasis> and <Emphasis Type="Italic">Alouatta palliata</Emphasis> in Oaxaca,Mexico

Primate conservation requires a better knowledge of the distributions and statuses of populations in both large areas of habitat and in areas for which we currently have no information. We focused on spider monkeys (Ateles geoffroyi) and howler monkeys (Alouatta palliata) in the state of Oaxaca, Mexico. This Mexican state has protected large tracts of forest, and has historical records for both primates, although very little is known about them. To update our knowledge of the distributions of these primates and identify potential areas in which they are present, we modeled their geographic distributions by characterizing their ecological niches using the genetic algorithm for rule-set production (GARP), performed interviews and carried out field surveys. The predicted distributions, surveys and interviews indicate that the distributions of these primates are restricted to northeastern Oaxaca. The results suggest that spider monkeys occupy a wider area and elevational range than howler monkeys. Throughout that range there is a wide variety of suitable habitats for these primates. Most of the sites where monkeys were recorded in the field are not officially protected and there was evidence of hunting and habitat destruction. It is important to improve protection, economic alternatives and environmental education as we move towards an integral solution for the conservation of these species. Validation of the GARP model was done for A. geoffroyi, since we had obtained enough field data for this species; this validation indicated that the predicted distribution of the species was statistically better than expected by chance. Hence, ecological niche modeling is a useful approach when performing an initial assessment to identify distribution patterns, detecting suitable areas for future exploration, and for conservation planning. Our findings provide an improved basis for primate conservation and productive fieldwork in Oaxaca.     

Interspecific interaction and predator avoidance behavior in response to tayra (<Emphasis Type="Italic">Eira barbara</Emphasis>) by mantled howler monkeys (<Emphasis Type="Italic">Alouatta palliata</Emphasis>)

This paper reports the response of one howler monkey group (Alouatta palliata) to a group of potential predators, the tayra (Eira barbara). The apparently successful predator avoidance behavior of the monkeys was recorded in detail. We observed a group of four adult tayras moving around theAlouatta group displaying a species-typical aggressive behavioral pattern. The two adult females of the howler group successfully chased the tayras away by repeatedly moving closer to the mustelids and even following them until the predators moved off.     

Intersexual Conflict and Group Size in <Emphasis Type="Italic">Alouatta palliata</Emphasis>: A 23-year Evaluation

Models of optimal primate group size suggest that group formation and growth arise to benefit individual fitness, but that size is limited by costs. The ecological constraints hypothesis posits that group formation and growth is driven by protection from predation or the advantages of group foraging, while an upper limit on group size is constrained by travel costs and intragroup competition for food or other critical resources. Socioecological models also predict that individual reproductive success, hypothesized to decrease with increasing group size, also places an upper limit on the number of individuals in a group. Our analysis of 23 yr of group composition data on mantled howlers (Alouatta palliata) from a single Panamanian study site on Barro Colorado Island not only corroborates the socioecological model but also shows that female reproductive success increased, whereas that of males decreased, with the less female-biased sex ratios in larger groups. We suggest that the conflict of interest between the sexes over adult sex ratio, particularly the male proportion in a group, in combination with ecological factors, is an important determinant of group size and composition.     

Social Relationships Among Male <Emphasis Type="Italic">Alouatta pigra</Emphasis>

We investigated male social relationships in 2 groups of black howlers (Alouatta pigra) in Palenque National Park, Mexico, over a 14-mo study characterized by frequent changes in male group membership. Both single males and pairs of males entered our focal groups. Single males tended to join groups, whereas pairs of males entering groups together successfully evicted resident males. The 19 male dyads across the 11 periods defined by changes in group membership were rarely in close proximity or interacting with one another. Nevertheless, 1 male formed significantly closer associations with resident females in 6 periods and achieved higher mating success during 4 of the periods when ≥1 female was sexually active. In the other 5 periods, no particular male maintained significantly closer associations with resident females, which may be a result of the rapid sequence of changes in male membership and corresponding social instability. Resident males participated frequently and consistently in mutual howling, but the resident male with the strongest female associations and highest mating success initiated howling bouts more frequently in all but 1 of the 6 socially stable periods. Though still preliminary, our findings suggest that variation in social relationships among male black howlers may be more related to their ability to establish strong relationships with females than to their relationships with one another.     

Novel<Emphasis Type="Italic"> eceriferum</Emphasis> mutants in<Emphasis Type="Italic"> Arabidopsis thaliana</Emphasis>

We conducted a novel non-visual screen for cuticular wax mutants in Arabidopsis thaliana (L.) Heynh. Using gas chromatography we screened over 1,200 ethyl methane sulfonate (EMS)-mutagenized lines for alterations in the major A. thaliana wild-type stem cuticular chemicals. Five lines showed distinct differences from the wild type and were further analyzed by gas chromatography and scanning electron microscopy. The five mutants were mapped to specific chromosome locations and tested for allelism with other wax mutant loci mapping to the same region. Toward this end, the mapping of the cuticular wax (cer) mutants cer10 to cer20 was conducted to allow more efficient allelism tests with newly identified lines. From these five lines, we have identified three mutants defining novel genes that have been designated CER22, CER23, and CER24. Detailed stem and leaf chemistry has allowed us to place these novel mutants in specific steps of the cuticular wax biosynthetic pathway and to make hypotheses about the function of their gene products.Abbreviations EMS Ethyl methane sulfonate - SEM Scanning electron microscopy - SSLP Simple sequence length polymorphism - WT Wild type     

Interactions between tayras (<Emphasis Type="Italic">Eira barbara</Emphasis>) and red-handed howlers (<Emphasis Type="Italic">Alouatta belzebul</Emphasis>) in eastern Amazonia

Two tayras (Eira barbara) were observed attacking an infant red-handed howler (Alouatta belzebul) on an island in eastern Brazilian Amazonia, as a nearby adult male watched passively. In a separate incident, four tayras were seen attacking a subadult female on the ground. Tayras were also observed in the vicinity of the two howler study groups on a number of occasions over a 9-month period. During this same period, the two groups lost a third of their members, including infants and subadults, and the remains of six animals were found at the study site. While tayras were the only predators seen attacking the howlers, it remains unclear to what extent they were responsible for apparently high mortality rates in this high-density, isolated howler population.     

<Emphasis Type="Italic">ZWILLE</Emphasis> buffers meristem stability in<Emphasis Type="Italic"> Arabidopsis thaliana</Emphasis>

The shoot apical meristem of higher plants consists of a population of stem cells at the tip of the plant body that continuously gives rise to organs such as leaves and flowers. Cells that leave the meristem differentiate and must be replaced to maintain the integrity of the meristem. The balance between differentiation and maintenance is governed both by the environment and the developmental status of the plant. In order to respond to these different stimuli, the meristem has to be plastic thus ensuring the stereotypic shape of the plant body. Meristem plasticity requires the ZWILLE (ZLL) gene. In zll mutant embryos, the apical cells are misspecified causing a variability of the meristems size and function. Using specific antibodies against ZLL, we show that the zll phenotype is due to the complete absence of the ZLL protein. In immunohistochemical experiments we confirm the observation that ZLL is solely localized in vascular tissue. For a better understanding of the role of ZLL in meristem stability, we analysed the genetic interactions of ZLL with WUSCHEL (WUS) and the CLAVATA1, 2 and 3 (CLV) genes that are involved in size regulation of the meristem. In a zll loss-of-function background wus has a negative effect whereas clv mutations have a positive effect on meristem size. We propose that ZLL buffers meristem stability non-cell-autonomously by ensuring the critical number of apical cells required for proper meristem function.Edited by G. JürgensAn erratum to this article can be found at     

Terrestrial Behavior of <Emphasis Type="Italic">Ateles</Emphasis> spp

Spider monkeys (Ateles spp.) are well known for their highly arboreal lifestyle, spending much of their time in the highest levels of the canopy and rarely venturing to the ground. To investigate terrestriality by Ateles and to illuminate the conditions under which spider monkeys venture to the ground, we analyzed ad libitum data from 5 study sites, covering 2 species and 5 subspecies. Three of the sites are in Central/North America: Barro Colorado Island (BCI), Panama (Ateles geoffroyi panamensis), Santa Rosa National Park, Costa Rica (A. g. frontatus), and Punta Laguna, Mexico (A. g. yucatanensis). The 2 remaining sites are in South America: Cocha Cashu Biological Station, Perú (A. belzebuth chamek) and Yasuni National Park, Ecuador (A. b. belzebuth). Terrestrialism by Ateles at all sites is rare; however, it is more restricted at the 2 South American sites. In South America, ground use only occurred in the contexts of eating soil or rotten wood and visiting salt licks. In contrast at the 3 sites with Ateles geoffroyi it rarely occurred in a feeding context, but instead more frequently while drinking from streams during the dry season, by adult females escaping attack by adult males, and as part of a chase game. In addition, on BCI adult males were on the ground before attacking adult females. We discuss potential explanations, e.g., climate, species differences, predation pressure, for the differences between the Central/North and South American observations.     

The <Emphasis Type="Italic">Caenorhabditis</Emphasis><Emphasis Type="Italic">briggsae</Emphasis> genome contains active <Emphasis Type="Italic">CbmaT1</Emphasis> and <Emphasis Type="Italic">Tcb1</Emphasis> transposons

The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.     

Identification of self-incompatibility groups in<Emphasis Type="Italic"> Hatiora</Emphasis> and<Emphasis Type="Italic"> Schlumbergera</Emphasis> (Cactaceae)

The Cactaceae, a family of about 1,800 species of succulent perennials, contains numerous species that exhibit self-incompatibility (SI). The objective of the current study was to determine the number of incompatibility groups present among diploid (2n=2x=22) cultivars of the genera Schlumbergera Lem. (Christmas cacti) and Hatiora Britton & Rose (Easter cacti). Two partial diallel crosses were performed, one with 19 cultivars of Christmas cacti [= S. truncata (Haworth) Moran and S. × buckleyi (Buckley) Tjaden] and the other with 10 cultivars of Easter cacti [= H. gaertneri (Regel) Barthlott, H. rosea (Lagerheim) Barthlott, and H. × graeseri Barthlott ex D. Hunt]. The compatibility/incompatibility status of crosses was determined by percent fruit set and presence of seed in mature fruit. None of the cultivars set fruit when selfed or crossed with a cultivar in the same incompatibility group, but fruit set ranged from 35% to 100% following compatible crosses. For the Christmas cacti, eight intra-incompatible but reciprocally compatible groups were identified, with 13 of the 19 cultivars assigned to three incompatibility groups (68%). The ten cultivars of Easter cacti yielded nine intra-incompatible but reciprocally compatible groups, with two cultivars in one incompatibility group and the other eight cultivars each assigned to a unique group. One cultivar of Christmas cactus ('Abendroth 6') was incompatible when crossed as a male with cultivars in incompatibility group 2 but was compatible in reciprocal crosses, results that suggest that this cultivar is an S-allele homozygote. The crossing relationships are consistent with a one-locus, gametophytic SI system with multiple alleles. Allozyme locus Lap-1, shown previously to be linked with the S locus (recombination frequency 7%) in Schlumbergera, exhibited insufficient allelic diversity for determining the S genotypes of the 19 cultivars of Christmas cacti. Based on the number of incompatibility groups in each diallel, at least five S-alleles occur in the 19 Christmas cacti and the 10 Easter cacti.Publication 3337 of the Massachusetts Agricultural Experiment Station. This material is based on work supported in part by the Cooperative State Research, Extension, Education Service, United States Department of Agriculture, Massachusetts Agricultural Experiment Station, under Project No. 746     

Structural and transcriptional analysis of<Emphasis Type="Italic"> S</Emphasis>-locus F-box genes in<Emphasis Type="Italic"> Antirrhinum</Emphasis>

A class of ribonucleases termed S-RNases, which control the pistil expression of self-incompatibility, represents the only known functional products encoded by the S locus in species from the Solanaceae, Scrophulariaceae and Rosaceae. Previously, we identified a pollen-specific F-box gene, AhSLF (S locus F-box)-S₂, very similar to S₂-RNase in Antirrhinum, a member of the Scrophulariaceae. In addition, AhSLF-S₂ also detected the presence of its homologous DNA fragments. To identify these fragments, we constructed two genomic DNA libraries from Antirrhinum self-incompatible lines carrying alleles S₁S₅ and S₂S₄, respectively, using a transformation-competent artificial chromosome (TAC) vector. With AhSLF-S₂-specific primers, TAC clones containing both AhSLF-S₂ and its homologs were subsequently identified (S₂TAC, S₅TACa, S₄TAC, and S₁TACa). DNA blot hybridization, sequencing and segregation analyses revealed that they are organized as single allelic copies (AhSLF-S₂, -S₁, -S₄ and -S₅) tightly linked to the S-RNases. Furthermore, clusters of F-box genes similar to AhSLF-S₂ were identified. In total, three F-box genes (AhSLF-S₂, -S₂A and -S₂C) in S₂TAC (51 kb), three (AhSLF-S₄, -S₄A and -S₄D) in S₄TAC (75 kb), two (AhSLF-S₅ and -S₅A) in S₅TACa (55 kb), and two (AhSLF-S₁ and -S₁E) in S₁TACa (71 kb), respectively, were identified. Paralogous copies of these genes show 38–54% identity, with allelic copies sharing 90% amino acid identity. Among these genes, three (AhSLF-S₂C, -S₄D and -S₁E) were specifically expressed in pollen, similar to AhSLF-S₂, implying that they likely play important roles in pollen, whereas three AhSLF-SA alleles showed no detectable expression. In addition, several types of retroelements and transposons were identified in the sequenced regions, revealing some detailed information on the structural diversity of the S locus region. Taken together, these results indicate that both single allelic and tandemly duplicated genes are associated with the S locus in Antirrhinum. The implications of these findings in evolution and possible roles of allelic AhSLF-S genes in the self-incompatible reaction are discussed in species like Antirrhinum.Sequence data from this article have been deposited with the EMBL/GenBank databases under accession numbers AJ300474, AJ515534, AJ515536 and AJ515535     

Floral development and systematic position of <Emphasis Type="Italic">Arillastrum</Emphasis>, <Emphasis Type="Italic">Allosyncarpia</Emphasis>, <Emphasis Type="Italic">Stockwellia</Emphasis> and <Emphasis Type="Italic">Eucalyptopsis</Emphasis> (Myrtaceae)

We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan.     

IS<Emphasis Type="Italic">Rm31</Emphasis>, a new insertion sequence of the IS<Emphasis Type="Italic">66</Emphasis> family in<Emphasis Type="Italic"> Sinorhizobium meliloti</Emphasis>

Sinorhizobium meliloti natural populations show a high level of genetic polymorphism possibly due to the presence of mobile genetic elements such as insertion sequences (IS), transposons, and bacterial mobile introns. The analysis of the DNA sequence polymorphism of the nod region of S. meliloti pSymA megaplasmid in an Italian isolate led to the discovery of a new insertion sequence, ISRm31. ISRm31 is 2,803 bp long and has 22-bp-long terminal inverted repeat sequences, 8-bp direct repeat sequences generated by transposition, and three ORFs (A, B, C) coding for proteins of 124, 115, and 541 amino acids, respectively. ORF A and ORF C are significantly similar to members of the transposase family. Amino acid and nucleotide sequences indicate that ISRm31 is a member of the IS66 family. ISRm31 sequences were found in 30.5% of the Italian strains analyzed, and were also present in several collection strains of the Rhizobiaceae family, including S. meliloti strain 1021. Alignment of targets sites in the genome of strains carrying ISRm31 suggested that ISRm31 inserts randomly into S. meliloti genomes. Moreover, analysis of ISRm31 insertion sites revealed DNA sequences not present in the recently sequenced S. meliloti strain 1021 genome. In fact, ISRm31 was in some cases linked to DNA fragments homologous to sequences found in other rhizobia species.     

Sex determination in<Emphasis Type="Italic"> Drosophila melanogaster</Emphasis> and<Emphasis Type="Italic"> Musca domestica</Emphasis> converges at the level of the terminal regulator<Emphasis Type="Italic"> doublesex</Emphasis>

Sex-determining cascades are supposed to have evolved in a retrograde manner from bottom to top. Wilkins 1995 hypothesis finds support from our comparative studies in Drosophila melanogaster and Musca domestica, two dipteran species that separated some 120 million years ago. The sex-determining cascades in these flies differ at the level of the primary sex-determining signal and their targets, Sxl in Drosophila and F in Musca. Here we present evidence that they converge at the level of the terminal regulator, doublesex (dsx), which conveys the selected sexual fate to the differentiation genes. The dsx homologue in Musca, Md-dsx, encodes male-specific (MdDSX^M) and female-specific (MdDSX^F) protein variants which correspond in structure to those in Drosophila. Sex-specific regulation of Md-dsx is controlled by the switch gene F via a splicing mechanism that is similar but in some relevant aspects different from that in Drosophila. MdDSX^F expression can activate the vitellogenin genes in Drosophila and Musca males, and MdDSX^M expression in Drosophila females can cause male-like pigmentation of posterior tergites, suggesting that these Musca dsx variants are conserved not only in structure but also in function. Furthermore, downregulation of Md-dsx activity in Musca by injecting dsRNA into embryos leads to intersexual differentiation of the gonads. These results strongly support a role of Md-dsx as the final regulatory gene in the sex-determining hierarchy of the housefly.Edited by D. Tautz     

Phylogenetic analyses of <Emphasis Type="Italic">Uromyces viciae-fabae</Emphasis> and its varieties on <Emphasis Type="Italic">Vicia</Emphasis>, <Emphasis Type="Italic">Lathyrus</Emphasis>, and <Emphasis Type="Italic">Pisum</Emphasis> in Japan

A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

<Emphasis Type="Italic">Drosophila</Emphasis><Emphasis Type="Italic">P</Emphasis> transposons of the urochordata <Emphasis Type="Italic">Ciona intestinalis</Emphasis>

P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.