Bats of Portugal : zoogeography and systematics / by Jorge M. Palmeirim.

no.82 (1990)

New insights into the phylogenetics and biogeography of Arum (Araceae): unravelling its evolutionary history

The heat- and odour-producing genus Arum (Araceae) has interested scientists for centuries. This long-term interest has allowed a deep knowledge of some complex processes, such as the physiology and dynamics of its characteristic lure-and-trap pollination system, to be built up. However, mainly because of its large distributional range and high degree of morphological variation, species' limits and relationships are still under discussion. Today, the genus comprises 28 species subdivided into two subgenera, two sections and six subsections. In this study, the phylogeny of the genus is inferred on the basis of four plastid regions, and the evolution of several morphological characters is investigated. Our phylogenetic hypothesis is not in agreement with the current infrageneric classification of the genus and challenges the monophyly of several species. This demonstrates the need for a new infrageneric classification based on characters reflecting the evolution of this enigmatic genus. To investigate the biogeography of Arum deeply, further spatiotemporal analyses were performed, addressing the importance of the Mediterranean basin in the diversification of Arum. Our results suggest that its centre of origin was the European-Aegean region, and that major diversification happened during the last 10 Myr.

The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution.

Based on histology, the placentae of eutherians are currently grouped in epitheliochorial, endotheliochorial and haemochorial placentae. In a haeckelian sense, the epitheliochorial contact with marked histiotrophic feeding by uterine milk is generally considered as primitive, especially since similar contacts exist in Marsupials. In contrast, the more intimate endotheliochorial and haemochorial contact, facilitating haemotrophic nutrition, is interpreted as a derived state. A cladistic analysis based on the phylogenetic relationships established by molecular analyses reveals that the basic clades are all characterized by an endotheliochorial or haemochorial placenta, and that the epitheliochorial placenta evolved at least three times in a convergent manner. This evolution may be explained by the fact that the epitheliochorial placenta in eutherians is more efficient in nutritional transfer (flow rate by exchange surface). Moreover, this arrangement may confer an advantage to the mother who can probably reduce the degree of manipulation by a genetically imprinted embryo.

Systematics of Triatoma sordida, T. guasayana and T. patagonica (Hemiptera, Reduviidae)

Because of the relative epidemiological significance of Triatoma sordida, T. guasayana and T. patagonica, and the need to resolve doubts about their taxonomic validity, we report here a detailed taxonomic comparison of the three species using multivariate analysis of morphometric measures combined with comparisons of their genitalia and antennal structures. From the 17 metric variables studied, the length of the second segment of the rostrum and the anteocular length provided a discrimination function able to separate without error T. sordida from T. guasayana and T. patagonica. The multivariate discriminant functions classified T. guasayana and T. patagonica with an error of 2.44%. Comparison of the male genitalia of T. guasayana and T. sordida showed that there are minor differences in the articulatory apparatus, the median process of the pygophore, the phallosome support and the vesica, with bigger differences in the endosomal process and the phallosome. However, the already described male genitalia of T. patagonica is very similar to that of T. sordida. Analysis of antennal structure by scanning electron microscope showed that sensilla distribution around the pedicel is slightly different in the three species and sensilla density is highest in T. sordida and lowest in T. patagonica. The study showed that the three species form a closely related group. The results confirm the earlier classification of sordida and guasayana as separate species, but they raise some doubts about the taxonomic status of T. patagonica.

Neotropical Monogenoidea. 24. Rhinoxenus bulbovaginatus n. sp. (Dactylogyridae, Ancyrocephalinae) from the nasal cavity of Salminus maxillosus (Osteichthyes, Characidae) from the Rio Paraná, Paraná, Brazil

Rhinoxenus bulbovaginatus n. sp. is described from the nose of Salminus maxillosus (Characidae) collected in the basin of the rio Paraná, near the city of Porto Rico, state of Paraná, Brazil. The new species can be differentiated from the other three species in the genus by the morphology of the copulatory complex, vagina, and ventral anchor. The sister group relationship of the known species of Rhinoxenus was determined using techniques of Phylogenetic Systematics (Cladism). The resulting cladogram (C.I.=100%) indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species of the genus, R. arietinus Kritsky, Boeger and Thatcher, 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988, both parasites of Anostomidae fishes, have a paraphyletic position in the cladogram, suggesting that the origin of at least one of them can not be associated to cospeciation.

A Mitochondrial DNA Phylogeny Indicates Close Relationships between Populations of Lutzomyia whitmani (Diptera: Psychodidae, Phlebotominae) from the Rain-forest Regions of Amazônia and Northeast Brazil

Phylogenetic analysis of all 31 described mitochondrial (cytochrome b) haplotypes of Lutzomyia whitmani demonstrated that new material from the State of Rondônia, in southwest Amazônia, forms a clade within a lineage found only in the rain-forest regions of Brazil. This rain-forest lineage also contains two other clades of haplotypes, one from eastern Amazônia and one from the Atlantic forest zone of northeast Brazil (including the type locality of the species in Ilhéus, State of Bahia). These findings do not favour recognizing two allopatric cryptic species of L. whitmani, one associated with the silvatic transmission of Leishmania shawi in southeast Amazônia and the other with the peridomestic transmission of Le. braziliensis in northeast Brazil. Instead, they suggest that there is (or has been in the recent past) a continuum of inter-breeding populations of L. whitmani in the rain-forest regions of Brazil.

Mitochondrial DNA variation of Triatoma infestans populations and its implication on the specific status of T. melanosoma

DNA sequence comparison of 412 base-pairs fragments of the mitochondrial cytochrome B gene was used to infer the genetic structure of nine geographical Triatoma infestans populations and their phylogenetic relationship with T. melanosoma and T. brasiliensis. T. infestans and T. melanosoma were compared by morphometry, allozyme and cytogenetic analyses, as well as subjected to reciprocal crosses, in order to clarify the taxonomic status of the latter. No differences were found to distinguish the two species and the crosses between them yielded progeny. T. infestans populations presented four haplotypes that could be separated in two clusters: one formed by the samples from Bolivia (Andes and Chaco) and the other formed by samples from Argentina and Brazil. Silvatic and domestic T. infestans populations from Bolivia (Andes) were genetically identical.

Further studies on the molecular systematics of Biomphalaria snails from Brazil

The polymerase chain reaction and restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS) region of the rRNA gene, using the enzyme DdeI were used for the molecular identification of ten species and one subspecies of Brazilian Biomphalaria. Emphasis is given to the analysis of B. oligoza, B. schrammi and B. amazonica. The RFLP profiles obtained using this enzyme were highly distinctive for the majority of the species and exhibited low levels of intraspecific polymorphism among specimens from different regions of Brazil. However, B. peregrina and B. oligoza presented very similar profiles that complicated their identification at the molecular level and suggested a very close genetic similarity between the two species. Others enzymes including HaeIII, HpaII, AluI and MnlI were tested for their ability to differentiate these species. For B. amazonica three variant profiles produced with DdeI were observed. The study demonstrated that the ITS contains useful genetic markers for the identification of these snails

Parasite systematics in the 21st century: opportunities and obstacles

Thanks to the phylogenetic systematics revolution, systematic parasitology is poised to make significant contributions in tropical medicine and public health, biodiversity science, and evolutionary biology. At the same time, the taxonomic impediment is acute within parasitology. Both systematists and non-systematists must be interested in working towards common goals and establishing collaborative efforts in order to re-vitalize and re-populate systematic parasitology.

Phylogeny of the kinetoplastida: taxonomic problems and insights into the evolution of parasitism

To further investigate phylogeny of kinetoplastid protozoa, the sequences of small subunit (18S) ribosomal RNA of nine bodonid isolates and ten isolates of insect trypanosomatids have been determined. The root of the kinetoplastid tree was attached to the branch of Bodo designis and/or Cruzella marina. The suborder Trypanosomatina appeared as a monophyletic group, while the suborder Bodonina was paraphyletic. Among bodonid lineages, parasitic organisms were intermingled with free-living ones, implying multiple transitions to parasitism and supporting the `vertebrate-first hypothesis'. The tree indicated that the genera Cryptobia and Bodo are artificial taxa. Separation of fish cryptobias and Trypanoplasma borreli as different genera was not supported. In trypanosomatids, the genera Leptomonas and Blastocrithidia were polyphyletic, similar to the genera Herpetomonas and Crithidia and in contrast to the monophyletic genera Trypanosoma and Phytomonas. This analysis has shown that the morphological classification of kinetoplastids does not in general reflect their genetic affinities and needs a revision.

Brazilian Flavivirus phylogeny based on NS5

In this work, a comprehensive phylogenetic study based on 600 base pair nucleotide and on putative 200 amino acid sequences of NS5 was carried out in order to establish genetic relationships among 15 strains of 10 Brazilian flaviviruses: Bussuquara, Cacipacore, dengue type 1, 2 and 4, Iguape, Ilheus, Rocio, Saint Louis encephalitis (SLE), and yellow fever. Phylogenetic trees were created by neighbor-joining and maximum parsimony methods. These trees showed Brazilian flaviviruses grouped into three main branches: yellow fever branch, dengue branch subdivided in types 1, 2 and 4 branches, and Japanese encephalitis virus (JEV) complex branch including SLE virus strains, Cacipacore, Iguape, Rocio, Ilheus and Bussuquara. Viruses transmitted by Aedes mosquitoes, such as dengue and urban yellow fever, that are also the only Flavivirus causing hemorrhagic fevers in Brazil, were grouped in the same cluster. Encephalitis associated viruses, transmitted by Culex mosquitoes such as JEV complex branch including SLE virus strains, Cacipacore, Iguape, Rocio, Ilheus and Bussuquara were also grouped in the same clade.

Phylogeny of subtribe Gentianinae (Gentianaceae): biogeographic inferences despite limitations in temporal calibration points

The subtribe Gentianinae comprises ca. 425 species, most of them within the well-studied genus Gentiana and mainly distributed over the Eurasian continent. Phylogenetic relationships between Gentiana and its closest relatives, the climbing gentians (Crawfurdia, Tripterospermum) and the new genus Metagentiana, remain unclear. All three genera were recently found to be polyphyletic, possibly because of poor sampling of Tripterospermum and Crawfurdia. Highest diversity of Gentianinae occurs in the western Himalaya, but the absence of uncontroversial fossil evidence limits our understanding of its biogeography. In the present study, we generated ITS and atpB-rbcL sequences for 19 species of Tripterospermum, 9 of Crawfurdia and 11 of Metagentiana, together representing about 60 percent of the species diversity of these genera. Our results show that only Metagentiana is polyphyletic and divided into three monophyletic entities. No unambiguous synapomorphies were associated with the three Metagentiana entities. Different combinations of three approximate calibration points were used to generate three divergence time estimation scenarios. Although dating hypotheses were mostly inconsistent, they concurred in associating radiation of Gentiana to an orogenic phase of the Himalaya between 15 and 10 million years ago. Our study illustrates the conceptual difficulties in addressing the time frame of diversification in a group lacking sufficient fossil number and quality.