Cristiane Bastos-Silveira

Variation in the mitochondrial control region sequence between the two maternal lines of the Sorraia horse breed

The mitochondrial control region sequence was compared between the two surviving matrilineal lineages of the Sorraia horse. Two haplotypes were found, showing three differences between them. The reduced number of surviving maternal lineages emphasizes the importance of establishing a conservation plan for this endangered breed.

Deep mitochondrial introgression and hybridization among ecologically divergent vole species

The completion of speciation is typically difficult to ascertain in rapidly diverging taxa but the amount of hybridization and gene flow in sympatry or parapatry contains important information about the level of reproductive isolation achieved. Here, we examined the progress in speciation between the Mediterranean (Microtus duodecimcostatus) and the Lusitanian pine vole (M. lusitanicus), which are part of the most rapid radiation of species known in mammals. These two Iberian pine voles are classified as separate species because of differences in morphology and ecology, but relatively many ambiguous individuals can be found in sympatric conditions. Our phylogenetic analyses of rangewide data from the mitochondrial cytochrome b gene (mtDNA) demonstrated high levels of diversity and a basal separation in two parapatric lineages. However, mtDNA affiliation was at odds with morphological classification or geographical distribution of the taxa. In contrast, statistical analyses of microsatellites (nucDNA) showed two clear genetic clusters in allopatry and sympatry generally matching morphological classification. This cytonuclear discordance over a large geographic area suggests historical introgression of mtDNA from M. duodecimcostatus to M. lusitanicus. There was statistical evidence for at least two recent hybrids in the sympatry zone but gene flow is apparently low given clear‐cut differences in nucDNA. Our results indicate a relatively advanced speciation process in these Iberian pine voles without fully established reproductive isolation. This situation enables use of combined population genomic and experimental approaches for the separation of patterns and mechanisms in the ongoing explosive diversification of these and other Arvicoline rodents in the future.

Description of a new endemic species of shrew (Mammalia, Soricomorpha) from PrÍncipe Island (Gulf of Guinea)

Abstract São Tomé and Príncipe are unique islands off the Gulf of Guinea on account of the high degree of endemism in these areas due to isolation. These islands are known to harbor, among others, two species of shrews of the genus Crocidura: C. thomensis, endemic to São Tomé; and C. poensis, found on Príncipe and common in central Africa. Owing to the uncertainty surrounding the taxonomic status of the population of C. poensis from Príncipe Island, we conducted morphometric and molecular analyses of newly collected specimens and compared them against São Tomé and mainland African specimens. Our results show that the shrew population from Príncipe Island is a separate species: Crocidura fingui sp. nov.

Genetic variation in BoLA microsatellite loci in Portuguese cattle breeds

Major histocompatibility complex (MHC) typing based on microsatellites can be a valuable approach to understanding the selective processes occurring at linked or physically close MHC genes and can provide important information on variability and relationships of populations. Using microsatellites within or in close proximity with bovine lymphocyte antigen (BoLA) genes, we investigated the polymorphisms in the bovine MHC, known as the BoLA, in eight Portuguese cattle breeds. Additional data from non-BoLA microsatellite loci were also used to compare the variability between these regions. Diversity was higher in BoLA than in non-BoLA microsatellites, as could be observed by the number of alleles, allelic richness and observed heterozygosity. Brava de Lide, a breed selected for aggressiveness and nobility, presented the lowest values of observed heterozygosity and allelic richness in both markers. Results from neutrality tests showed few statistically significant differences between the observed Hardy-Weinberg homozygosity (F) and the expected homozygosity (F(E)), indicating the apparent neutrality of the BoLA microsatellites within the analysed breeds. Nevertheless, we detected a trend of lower values of observed homozygosity compared with the expected one. We also detected some differences in the levels of allelic variability among the four BoLA microsatellites. Our data showed a higher number of alleles at the BoLA-DRB3 locus than at the BoLA-DRBP1 locus. These differences could be related to their physical position in the chromosome and may reflect functional requirements for diversity.

The collection of birds from São Tomé and Príncipe at the Instituto de Investigação Científica Tropical of the University of Lisbon (Portugal).

Abstract The former Instituto de Investigação Científica Tropical-IICT (Lisbon, Portugal), recently integrated into the University of Lisbon, gathers important natural history collections from Portuguese-speaking African countries. In this study, we describe the bird collection from the Democratic Republic of São Tomé and Príncipe, which was fully taxonomically checked and georeferenced. The IICT bird collection contains 5598 specimens, of which 559 are from São Tomé and Príncipe, representing 85 taxa, including 19 endemic species and 13 endemic subspecies of birds. The specimens were collected between 1946 and 1973, although 43% of the records are from 1954 and 45% are from 1970. The geographic distribution of samples covers the whole territory, with a higher number of records from São Tomé than from Príncipe. The districts with highest number of records are Pagué (equivalent to Príncipe Island), and Água Grande and Mé-Zochi on São Tomé. Despite the relatively low number of specimens per taxon, the importance of the collection is considerable due to the high number of endemic and threatened species represented. Furthermore, it adds valuable information to the GBIF network, especially for a country whose two islands are each an Endemic Bird Area and for which substantial gaps in ornithological knowledge remain.

The collection and database of Birds of Angola hosted at IICT (Instituto de Investigação Científica Tropical), Lisboa, Portugal.

Abstract The bird collection of the Instituto de Investigação Cientítica Tropical (Lisbon, Portugal) holds 5598 preserved specimens (skins), mainly from Angola, Mozambique, Guinea-Bissau, São Tomé and Principe, and Cape Verde. The subset collection from Angola includes 1560 specimens, which were taxonomically revised and georeferenced for the publication of this data paper. The collection contains a total of 522 taxa, including 161 species and 361 subspecies. Two species are classified by the IUCN Red List as Endangered - the wattled crane (Grus carunculata) and the Gabela bush-shrike (Laniarius amboimensis) - and two are classified as vulnerable - African penguin (Spheniscus demersus) and the white-headed vulture (Trigonoceps occipitalis). The temporal span of the database ranges between 1943 and 1979, but 32% are from years 1958–1959, and 25% from years 1968–1969. The spatial coverage of the collection is uneven, with 2/3 of the records representing only four of the eighteen provinces of the country, namely Huíla, Moxico, Namibe and Cuanza Sul. It adds, however, valuable information for the Huíla area of the Angolan Scarp, which is probably a biodiversity hotspot of global conservation priority. Furthermore, this georeferenced database adds invaluable bird information to the GBIF network, for one of the countries with highest but less known biodiversity in Africa.

Phylogenetic origin of the endemic pigeons from Madeira (Columba trocaz) and Azores Islands (Columba palumbus azorica)

AbstractThis study addresses for the first time the issue of pigeon (genus Columba) phylogeny within the archipelagos of Madeira (Columba trocaz) and Azores (C. palumbus azorica), located in the singular biogeographic area of Macaronesia. The phylogeny of these endemic pigeons was inferred based on mitochondrial (cytochrome b and cytochrome c oxidase I) and nuclear (β-fibrinogen intron 7) genetic markers through multiple approaches. Despite the non-monophyletic pattern for the insular endemic species recovered in the phylogenies, topology tests presented somewhat different results. C. trocaz, the Madeiran endemic species, clustered strongly with the Canarian endemic C. bollii, and these two are thus more closely related to each other than C. bollii to C. junoniae, the other endemic species of Canary Islands, which seems to have diverged independently. Moreover, C. trocaz was found to be phylogenetically closer to C. bollii than to C. palumbus from mainland Europe and Azores Islands. No genetic differentiation was found between the continental C. p. palumbus and the endemic C. p. azorica, which suggests a relatively recent colonisation event of the Azores Islands.ZusammenfassungPhylogenetische Ursprünge endemischer Taubenarten auf Madeira (Columba trocaz) und den Azoren (Columba palumbus azorica) Diese Studie untersucht erstmalig phylogenetische Fragen bei Tauben (Gattung Columba) auf den Inselgruppen Madeira (Columba trocaz) und Azoren (C. palumbus azorica) in der biogeografischen Region Makaronesien. Die Phylogenie dieser endemischen Taubenarten wurde mittels multipler Ansätze auf der Grundlage mitochondrialer (Cytochrom b und Cytochrom-c-Oxidase I) und nukleärer (β-Fibrinogen Intron 7) genetischer Marker rekonstruiert. Obwohl sich in den Phylogenien ein nicht-monophyletisches Muster für die endemischen Inselarten zeigte, führten die Topologie-Tests zu etwas abweichenden Ergebnissen. C. trocaz, die für Madeira endemische Art, war eng mit dem kanarischen Endemiten C. bollii gruppiert; somit sind diese beiden näher miteinander verwandt als C. bollii und C. junoniae, der anderen endemischen Art der Kanaren, welche sich unabhängig davon entwickelt zu haben scheint. Außerdem zeigte sich, dass C. trocaz phylogenetisch C. bollii näher steht als C. palumbus des Europäischen Festlandes und der Azoren. Es gab keine genetische Differenzierung zwischen der Festlandform C. p. palumbus und dem endemischen Taxon C. p. azorica, was für eine erst relativ kürzlich erfolgte Besiedlung der Azoren spricht.

The collection of birds from Mozambique at the Instituto de Investigação Científica Tropical of the University of Lisbon (Portugal)

Abstract The Instituto de Investigação Científica Tropical of the University of Lisbon, which resulted from the recent merger (in 2015) of the former state laboratory Instituto de Investigação Científica Tropical in the University of Lisbon, holds an important collection of bird skins from the Portuguese-speaking African Countries (Angola, Mozambique, São Tomé and Príncipe, Guinea Bissau and Cape Verde), gathered as a result of several scientific expeditions made during the colonial period. In this paper, the subset from Mozambique is described, which was taxonomically revised and georeferenced. It contains 1585 specimens belonging to 412 taxa, collected between 1932 and 1971, but mainly in 1948 (43% of specimens) and 1955 (30% of specimens). The collection covers all eleven provinces of the country, although areas south of the Zambezi River are better represented than those north of the river. The provinces with the highest number of specimens were Maputo, Sofala, and Gaza. Although it is a relatively small collection with a patchy coverage, it adds significantly to Global Biodiversity Information Facility, with 15% of all records available before and during the collecting period (1830–1971) being the second largest dataset for that period for Mozambique.

p53 gene discriminates two ecologically divergent sister species of pine voles.

Genes with relevant roles in the differentiation of closely-related species are likely to have diverged simultaneously with the species and more accurately reproduce the species tree. The Lusitanian (Microtus lusitanicus) and Mediterranean (M. duodecimcostatus) pine voles are two recently separated sister species with fossorial lifestyles whose different ecological, physiological and morphological phenotypes reflect the better adaptation of M. duodecimcostatus to the underground habitat. Here we asked whether the differentiation of M. lusitanicus and M. duodecimcostatus involved genetic variations within the tumour suppressor p53 gene, given its role in stress-associated responses. We performed a population-genetic analysis through sequencing of exons and introns of p53 in individuals from sympatric and allopatric populations of both the species in the Iberian Peninsula in which a unidirectional introgression of mitochondrial DNA was previously observed. We were able to discriminate the two species to a large extent. We show that M. duodecimcostatus is composed of one genetically unstructured group of populations sharing a P53 protein that carries a mutation in the DNA-binding region not observed in M. lusitanicus, raising the possibility that this mutation may have been central in the evolutionary history of M. duodecimcostatus. Our results provide suggestive evidence for the involvement of a master transcription factor in the separation of M. lusitanicus and M. duodecimcostatus during Microtus radiation in the Quaternary presumably via a differential adaptive role of the novel p53 in M. duodecimcostatus.

Reproductive isolation between sister species of Iberian pine voles, Microtus duodecimcostatus and M. lusitanicus

Contact zones of recently diverged species provide the ideal opportunity to study the nature of reproductive barriers. The Mediterranean (Microtus duodecimcostatus) and Lusitanian pine voles (M. lusitanicus) are a pair of recently diverged sister species endemic to Western Europe. Recent microsatellite data raised the possibility that hybridisation events, although rare, may still occur in the area of sympatry of both species. Here we evaluated the nature and extent of reproductive isolation between M. duodecimcostatus and M. lusitanicus through a laboratory crossbreeding experiment and two-way mate preference tests on the basis of chemical cues. Crossbreeding of sympatric individuals from the two species was successful and followed Haldane’s rule, revealing hybrid male sterility and reduced fertility of hybrid females. Results from mate preference tests showed males of both pine vole species could discriminate and preferred female conspecifics to heterospecifics or hybrid females on the basis of chemical cues alone. On the contrary, females of both pine vole species did not show a clear preference for conspecific over heterospecific male chemical cues, suggesting females may need additional cues to discriminate between males of the two species. As a whole our results indicate both prezygotic (i.e. species-specific mate recognition systems) and postzygotic barriers (i.e. male hybrid sterility, female reduced fertility and behavioural sterility ― decreased ability to find or attract mates) have evolved, and should make hybridisation of the Iberian pine voles under natural conditions an unlikely event. The role of both species mating preferences and interspecific behavioural interactions in the asymmetric mitochondrial introgression pattern of the Iberian pine voles is discussed.