Molecular phylogeny of microhylid frogs (Anura: Microhylidae) with emphasis on relationships among New World genera

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytogenetic studies of three species of Glandulocaudinae (Pisces, Characiformes, Characidae)

Cytogenetic studies of three species of the subfamily Glandulocaudinae showed that Mimagoniates microlepis presents 2n = 52 chromosomes (6M + 20SM + 18ST + 8A), Mimagoniates lateralis presents 2n = 52 chromosomes (6M + 20SM + 16ST + 10A) and Glandalocauda melanogenys presents 2n = 52 chromosomes (4M + 12SM + 22ST + 14A). The number of NOR-bearing chromosome pairs ranged from two to four. Differences in number and position of NORs at the species and population levels were detected, suggesting that several chromosome rearrangements occurred in the evolutionary process of this group. Some aspects related to the chromosome evolution of the Glandulocaudinae are discussed.

A SequenceSpace analysis of Lys49 phospholipases A2: Clues towards identification of residues involved in a novel mechanism of membrane damage and in myotoxicity

'SequenceSpace' analysis is a novel approach which has been used to identify unique amino acids within a subfamily of phospholipases A2 (PLA2) in which the highly conserved active site residue Asp49 is substituted by Lys (Lys49-PLA2s). Although Lys49-PLA2s do not bind the catalytic co-factor Ca2+ and possess extremely low catalytic activity, they demonstrate a Ca2+-independent membrane damaging activity through a poorly understood mechanism, which does not involve lipid hydrolysis. Additionally, Lys49-PLA2s possess combined myotoxic, oedema forming and cardiotoxic pharmacological activities, however the structural basis of these varied functions is largely unknown. Using the 'SequenceSpace' analysis we have identified nine residues highly unique to the Lys49-PLA2 sub-family, which are grouped in three amino acid clusters in the active site, hydrophobic substrate binding channel and homodimer interface regions. These three highly specific residue clusters may have relevance for the Ca2+-independent membrane damaging activity. Of a further 15 less stringently conserved residues, nine are located in two additional clusters which are well isolated from the active site region. The less strictly conserved clusters have been used in predictive sequence searches to correlate amino acid patterns in other venom PLA2s with their pharmacological activities, and motifs for presynaptic and combined toxicities are proposed.

Kariological study of five Arecoideae palmae species

Kariological data for 5 species of palm subfamily Arecoideae are presented based on somatic methapase chromosomes obtained from seeds germinated on Sphagnum, and using standard methodology for the slides preparation. From the kariogram of Aiphanes. acanthophylla (2n=30),A. caryotaefolia (2n=30), Syagrus coronata (2n=32), S. quinquifaria (2n=32) and Scheelea lauromuelleriana (2n=32) the relative centromere position (short arm x 100/total chromosome length) and the relative length of each chromosome (average chromosome length/total chromosome length) were calculated.

Pejibaye palm (Bactris gasipaes) propagative structures and seedlings morphological study

Palm of Arecoideae subfamily, the pejibaye palm occurs mostly at Tropical America areas, and has achieved outstanding economic importance for heart-of-palm production with traditional farming. This work aimed to describe and record propagation structures and seedlings, throughout the different stages of their germination process, since this species is mainly propagated by seeds. The seeds were set for germination on trays with cotton and sterilized water. Representative samples were taken out from each of the different germination stages. They were photographed and drafted using a clear chamber. The propagation structures and seeds external surface were outlined and photographed. The seeds were longitudinally cut for observation and documentation of the inner morphology. The first germinative event was the growth of an undifferentiated, approximately globular cells mass, which emerged from the micropilar depression. Then, the cells mass acquired a cylinder aspect, with the early shoot and root differentiation taking place. Later, there was evidence of primary root and aerial portion. This shoot was coated by a closed and chlorophylled sheath. A lateral root outgrown at the primary root's base and an adventitious root became visible at the embryonic axis. Three other sheaths evolved at the shoot, unrolling one at a time, allowing, finally, the emergence of the primary leaf which is bifid and has parallel veins, typical of its family. Internally, an haustorial structure was developed and seemed to be related with the digestion of the endosperm, occupying, gradually, all the seed's internal space.

Expanded food choice as a possible factor in the evolution of sociality of Vespidae (Hymenoptera)

A recent theory suggests that economic considerations are more important than genetic ones in the emergence and maintenance of social behavior. Evolution of social behavior in wasps, thus, could be based on the development of worker castes, which increase the efficiency of brood care and energy use of the colony. If so, social wasps should collect a larger range of prey, favoring polyethism, as social behavior should increase the adaptive value of social species among wasps by increasing the range of prey accessible. We explored the literature and showed that the Eumeninae, which are mostly solitary, draw prey from significantly fewer orders of arthropods than wasps in the subfamily Vespinae and Polistinae, which are mainly social, supporting the hypothesis that social behavior may have emerged as a more efficient way to feed and care for the young by opening a wider range of food sources, increasing the amount of food and quality of care provided to the young. Two alternative explanations of this data are also discussed.

ZmPUMP encodes a maize mitochondrial uncoupling protein that is induced by oxidative stress

A cDNA clone (designated ZmPUMP) encoding an uncoupling protein (UCP) from maize (Zea mays) was identified by searching for homologous sequences among the expressed sequence tags of the GenBank database. The ZmPUMP cDNA contains a single open reading frame of 933 nucleotides encoding 310 amino acids. Several features identified the predicted ZmPUMP protein as a member of the mitochondrial UCP subfamily of mitochondrial carriers. Expression studies demonstrated that ZmPUMP is ubiquitously expressed in maize tissues and its transcript level is not altered in early stages of embryo germination. In contrast to known UCP genes, ZmPUMP is not responsive to cold stress. Instead its expression is increased in response to H 2O 2- or menadione-induced oxidative stress. © 2003 Elsevier Science Ireland Ltd. All rights reserved.

Non-Specific Interaction between Ants (Hymenoptera; Formicidae) and Fruits of Syagrus romanzoffiana (Arecaceae) in an Area of the Brazilian Atlantic Forest

On the forest floor of a fragment of the Atlantic Forest which is considered to be in a stage of recuperation, located in southeastern Brazil, we recorded 54 species of ants interacting with the fruits of Syagrus romanzoffiana (Arecaceae). Myrmicinae was the subfamily which was the richest in species, followed by Ponerinae, Formicinae, Ecitoninae, Dolichoderinae, Pseudomyrmecinae and Cerapachyinae. The fruits of S. romanzoffiana can be classified according to whether or not they are preyed by the squirrel Sciurus ingrami, and the ant fauna that visits the fruits has an average similarity. Regarding diversity, the data suggest that there is no significant difference between ant assemblages at preyed and non-preyed-upon fruit falls. The results also indicate that there is no specific interaction between the ant fauna that visits the fruits of S. romanzoffiana, as it consists largely of species with omnivorous feeding habits.

Differential fruit consumption of two Melastomataceae by birds in Serra da Mantiqueira, southeastern Brazil

In this study we report on the consumption of two syntopic Melastomataceae species by birds in a lower montane forest in Monte Verde, southeastern Brazil. The species of frugivores were identified and characterized by their methods of capture and consumption of fruits. We also provide information on abundance, phenology of plants and fruit characteristics of the two Melastomataceae species. The 13 observed species of birds formed two statistically distinct frugivorous groups with taxonomic and behavioral differences. Five of seven bird species that fed on L. aff. sublanata fruits belong to the subfamily Thraupinae and most fruits were mashed before swallowed. Four of the eight bird species that visited M. cinerascens belong to the subfamily Turdinae and all fruits were swallowed whole. Only two bird species were common visitors of both Melastomataceae species. Our findings show that fruits of the two Melastomataceae species with similar morphological characteristics were exploited differently by frugivorours birds.

Canonical P elements are transcriptionally active in the saltans group of Drosophila

Up to now, investigations of expression and regulation of P transposable element have been almost exclusively carried out with the Drosophila melanogaster canonical P element. Analyzing eight species of the saltans group, we detected transposase mRNA in germline tissues of D. saltans and D. prosaltans and repressor mRNA in somatic tissues of D. saltans and D. sturtevanti. Sequencing analysis suggested that these transcripts might belong to the canonical subfamily and that they can be transpositionally active only in D. saltans. dN and dS values of Adh and the P element suggested that the sequences found in D. saltans and D. prosaltans might have been present in the ancestor of the saltans subgroup and that the sequence found in D. sturtevanti might have been horizontally transferred from D. saltans.

Structure and development of the ovule in Bromeliaceae

Ovule structure and development are described for twelve species of Bromeliaceae, representing ten genera and all three subfamilies, including all three tribes of the polyphyletic subfamily Pitcairnioideae (Brocchinieae, Puyeae and Pitcairnieae). The characteristic micropylar and chalazal seed appendages of Bromeliaceae are compared with developing structures in the ovules. Chalazal seed appendages have also been reported in the putatively related family Rapateaceae, but they differ in detailed structure, and may have evolved independently in the two families.

Occurrence of polygyny in Procornitermes araujoi (Termitidae, Nasutitermitinae)

Procornitermes araujoi is a mandibulate termite of the Nasutitermitinae subfamily that builds mounds in savannas of the Central and Southeastern regions of Brazil. This paper reports the occurrence of three imaginai queens in the same nest of this termite located in Rio Claro, (SP), Brazil. The associated queens were similar in size, degree of physogastry, and pigmentation. The king was not found. The polygyny and nest architecture of P. araujoi are discussed.

Description of the nucleolar activity and karyotype in germinative cell lines of Rhodnius domesticus (Triatominae, Heteroptera)

The purpose of this work was to study the karyotype, spermatogenesis and nucleolar activity at meiosis, in the species Rhodnius domesticus (Heteroptera, Triatominae). The testicular tubules were cytologically prepared by the conventional method of cell crushing and subsequent application of cytogenetic staining techniques with lacto-acetic orcein and silver-ion impregnation. The species under study presented karyotype 2n= 20A+XY, the modal number of the subfamily Triatominae. The chromosomes presented no primary constriction and were therefore characterized as holocentric. It was observed that the sex chromosomes sometimes were located at the periphery, close to the ring formed by autosomes, at first meiotic division. At metaphases II, sex chromosomes were positioned in the center of the autosomal ring, thus evidencing a postreductional behavior. These same chromosomes showed late migration at anaphases and were clearly impregnated with silver-ions, suggesting they bore Nucleolar Organizer Regions. Dispersed nucleolar corpuscles in cytoplasm until telophase II and small dots in spermatids strongly impregnated with silver, could be seen. Thus, it may be inferred that, in triatomines, the nucleolus does not completely disappear but remains in the form of small corpuscles that have a role in cell differentiation.

Comparative cytogenetics of nine species of Hypoptopomatinae (Teleostei: Siluriformes: Loricariidae): The importance of structural rearrangements in chromosome evolution

Fishes of the subfamily Hypoptopomatinae are very common and found in the lowlands of cis-Andean South America from Venezuela to the north of Argentina. With the main objective of contributing for a better understanding of the importance of chromosome rearrangements in the loricariid evolution, cytogenetic analyses were conducted in nine species of Hypoptopomatinae. The results showed a marked gross karyotypic conservation with the presence of 2n=54 chromosomes in all species analyzed. The main differences were found in the karyotypic formulae level. Most species had a single interstitial Ag-NORs, however terminal Ag-NORs were observed in three species. One species exhibited two Ag-NOR-bearing chromosome pairs. The distribution of C-band positive segments was species specific but chromosome markers were observed among the species analyzed. The gross cytogenetic characteristics observed among the Hypoptopomatinae species are similar to those observed in other primitive Loricariidae species suggesting that small changes, mainly paracentric and pericentric inversion were the main events in the karyotypic evolution of this fish group.

Systematic review of the frog family Hylidae, with special reference to Hylinae: Phylogenetic analysis and taxonomic revision

Hylidae is a large family of American, Australopapuan, and temperate Eurasian treefrogs of approximately 870 known species, divided among four subfamilies. Although some groups of Hylidae have been addressed phylogenetically, a comprehensive phylogenetic analysis has never been presented. The first goal of this paper is to review the current state of hylid systematics. We focus on the very large subfamily Hylinae (590 species), evaluate the monophyly of named taxa, and examine the evidential basis of the existing taxonomy. The second objective is to perform a phylogenetic analysis using mostly DNA sequence data in order to (1) test the monophyly of the Hylidae; (2) determine its constituent taxa, with special attention to the genera and species groups which form the subfamily Hylinae, and c) propose a new, monophyletic taxonomy consistent with the hypothesized relationships. We present a phylogenetic analysis of hylid frogs based on 276 terminals, including 228 hylids and 48 outgroup taxa. Included are exemplars of all but 1 of the 41 genera of Hylidae (of all four nominal subfamilies) and 39 of the 41 currently recognized species groups of the species-rich genus Hyla. The included taxa allowed us to test the monophyly of 24 of the 35 nonmonotypic genera and 25 species groups of Hyla. The phylogenetic analysis includes approximately 5100 base pairs from four mitochondrial (12S, tRNA valine, 16S, and cytochrome b) and five nuclear genes (rhodopsin, tyrosinase, RAG-1, seventh in absentia, and 28S), and a small data set from foot musculature. Concurring with previous studies, the present analysis indicates that Hemiphractinae are not related to the other three hylid subfamilies. It is therefore removed from the family and tentatively considered a subfamily of the paraphyletic Leptodactylidae. Hylidae is now restricted to Hylinae, Pelodryadinae, and Phyllomedusinae. Our results support a sister-group relationship between Pelodryadinae and Phyllomedusinae, which together form the sister taxon of Hylinae. Agalychnis, Phyllomedusa, Litoria, Hyla, Osteocephalus, Phrynohyas, Ptychohyla, Scinax, Smilisca, and Trachycephalus are not monophyletic. Within Hyla, the H. albomarginata, H. albopunctata, H. arborea, H. boons, H. cinerea, H. eximia, H. geographica, H. granosa, H. microcephala, H. miotympanum, H. tuberculosa, and H. versicolor groups are also demonstrably nonmonophyletic. Hylinae is composed of four major clades. The first of these includes the Andean stream-breeding Hyla, Aplastodiscus, all Gladiator Frogs, and a Tepuian clade. The second clade is composed of the 30-chromosome Hyla, Lysapsus, Pseudis, Scarthyla, Scinax (including the H. uruguaya group), Sphaenorhynchus, and Xenohyla. The third major clade is composed of Nyctimantis, Phrynohyas, Phyllodytes, and all South American/West Indian casque-headed frogs: Aparasphenodon, Argenteohyla, Corythomantis, Osteocephalus, Osteopilus, Tepuihyla, and Trachycephalus. The fourth major clade is composed of most of the Middle American/Holarctic species groups of Hyla and the genera Acris, Anotheca, Duellmanohyla, Plectrohyla, Pseudacris, Ptychohyla, Pternohyla, Smilisca, and Triprion. A new monophyletic taxonomy mirroring these results is presented where Hylinae is divided into four tribes. Of the species currently in Hyla, 297 of the 353 species are placed in 15 genera; of these, 4 are currently recognized, 4 are resurrected names, and 7 are new. Hyla is restricted to H. femoralis and the H. arborea, H. cinerea, H. eximia, and H. versicolor groups, whose contents are redefined. Phrynohyas is placed in the synonymy of Trachycephalus, and Pternohyla is placed in the synonymy of Smilisca. The genus Dendropsophus is resurrected to include all former species of Hyla known or suspected to have 30 chromosomes. Exerodonta is resurrected to include the former Hyla sumichrasti group and some members of the former H. miotympanum group. Hyloscirtus is resurrected for the former Hyla armata, H. bogotensis, and H. larinopygion groups. Hypsiboas is resurrected to include several species groups - many of them redefined here - of Gladiator Frogs. The former Hyla albofrenata and H. albosignata complexes of the H. albomarginata group are included in Aplastodiscus. New generic names are erected for (1) Agalychnis calcarifer and A. craspedopus; (2) Osteocephalus langsdorffii; the (3) Hyla aromatica, (4) H. bromeliacia, (5) H. godmani, (6) H. mixomaculata, (7) H. taeniopus, (8) and H. tuberculosa groups; (9) the clade composed of the H. pictipes and H. pseudopuma groups; and (10) a clade composed of the H. circumdata, H. claresignata, H. martinsi, and H. pseudopseudis groups. Copyright © American Museum of Natural History 2005.