Genetic variability and demographic history of Anguilla mossambica (Peters, 1852) from continental Africa and Madagascar

In this study, population genetic and demographic parameters were inferred using sequence data from 151 individuals of Anguilla mossambica originating from continental south and south-east Africa and Madagascar. The analyses were based on a 532 bp segment of the mitochondrial cytochrome b gene. The absence of genetic structuring was observed thereby supporting the hypothesis of panmixia for the endemic A. mossambica. The overall nucleotide diversity π = 0.002 and the haplotype diversity reached h = 0.691. Significant negative values from several tests of neutrality and mismatch analysis pointed to fluctuating historical population sizes. Bayesian averaging resulted in higher support for population growth models vs. a constant population-size model. Population decline and subsequent growth most likely predated the last glacial and were probably related to extended periods of extreme drought followed by wetter and more stable hydroclimate between 150 and 75,000 years before present (kBP). According to this scenario the female effective population size has increased since 110 kBP by c. two orders of magnitude to a recent level of about 650,000 (219,317–2,292,000).     

Seed image analysis and taxonomy of Diplotaxis DC. (Brassicaceae,Brassiceae)

West European Rock lizards, Lacerta (Iberolacerta) have small widely separated ranges in highland areas. Mitochondrial and nuclear DNA sequences corroborate the monophyly of the group and show it is not closely related to any of the other Rock lizards with which it was formerly placed in Archaeolacerta, an assemblage for which there is no evidence of clade status. L. (Iberolacerta) consists of four main units: L. (I.) horvathi of NW Croatia and neighbouring regions; the Pyrenees species, L. (I.) bonnali, L. (I.) aranica and L. (I.) aurelioi; L. (I.) cyreni of the Iberian Sistema Central, with distinctive populations in the Sierras de Bejar, Gredos and Guadarrama; and L. (I.) monticola of the Serra da Estrela of Central Portugal and NW Spain, this unit also contains L. (I.) cyrenimartinezricai of La Peña de Francia, W. Spain and a distinctive population in the Montañas de Sanabria. L. (Iberolacerta) has persisted in some mountain ranges for at least 4.2 ± 1.4 Ma and may have been restricted to mountains by competition from Wall lizards (Podarcis). Its clade status shows it has lost range extensively and has produced few external branches since its initial fragmentation. In contrast, Podarcis diversified about the time L. (Iberolacerta) fragmented, producing a series of widespread lineages that have persisted until the present time. The mainly European subfamily Lacertinae, to which both L. (Iberolacerta) and Podarcis belong, diversified rapidly 13–9 Ma ago, probably largely replacing other lacertid lizards of earlier origin. As another round of replacement started at approximately 9 Ma ago with the spread of Podarcis, this may be a recurrent phenomenon in the evolution of some lizard communities.     

鬣羚干皮标本中的DNA提取和PCR扩增

为了澄清鬣羚（Ｃａｐｒｉｃｏｒｎｉｓ ｓｕｍａｔｒａｅｎｓｉｓ）这种动物在系统进化和分类上的混乱局面,有效地保护其种群的遗传多样性,本文以鬣羚不同种群的干皮标本为样品,分别提取了总ＤＮＡ（ｔｏｔａｌＤＡＮ）,并以此为模板,特异性扩增了ｍｔＤＮＡ（ｍｉｔｏｃｈｏｎｄｒｉａｌＤＡＮ）细胞色素ｂ（ｃｙｔ ｂ）基因的约５００ｂｐ的片段,从而证明了通过干皮标本研究这种珍贵动物遗传分化的可行性。     

Development of New Oomycete Taxon‐specific Mitochondrial Cytochrome b Region Primers for Use in Phylogenetic and Phylogeographic Studies

Here, we describe the development of an oomycete‐specific primer pair for amplification of the cytochrome b region in plant pathogenic species that span the order Peronosporales (Phytophthora spp., downy mildews). Because of the high number of variable sites at both inter‐ and intra‐specific levels this marker provides a powerful tool for population genetics and phylogenetic studies in this taxa. We also demonstrate its potential compared with other oomycete‐specific mitochondrial markers currently available.     

Overexpression, purification, and pharmacological activity of a biosynthetically derived conopeptide

A high yielding fusion protein system based on the protein cytochrome b(5) has been used for the production of novel 13-residue acyclic conopeptide. This peptide, Mo1659, can be liberated from the carrier protein using CNBr cleavage and subsequent purification using RP-HPLC methods. The yield of isotopically enriched peptides is high, ranging from 3 to 4mg of purified peptide from a 500ml culture, indicating that this system can be widely used for peptide production. Biosynthetic Mo1659 is active on non-inactivating K(+) channel much like the natural Mo1659, despite the absence of C-terminal amidation. Heteronuclear NMR studies show that the peptide exists in a conformational equilibrium involving proline-10. To our knowledge this is the first report of the production of an isotopically (15)N/(13)C-enriched conopeptide.     

Genetic variability in mitochondrial and nuclear genes of Larus dominicanus (Charadriiformes,Laridae) from the Brazilian coast

Several phylogeographic studies of seabirds have documented low genetic diversity that has been attributed to bottleneck events or individual capacity for dispersal. Few studies have been done in seabirds on the Brazilian coast and all have shown low genetic differentiation on a wide geographic scale. The Kelp Gull is a common species with a wide distribution in the Southern Hemisphere. In this study, we used mitochondrial and nuclear markers to examine the genetic variability of Kelp Gull populations on the Brazilian coast and compared this variability with that of sub-Antarctic island populations of this species. Kelp Gulls showed extremely low genetic variability for mitochondrial markers (cytb and ATPase) and high diversity for a nuclear locus (intron 7 of the β-fibrinogen). The intraspecific evolutionary history of Kelp Gulls showed that the variability found in intron 7 of the β-fibrinogen gene was compatible with the variability expected under neutral evolution but suggested an increase in population size during the last 10,000 years. However, none of the markers revealed evidence of a bottleneck population. These findings indicate that the recent origin of Kelp Gulls is the main explanation for their nuclear diversity, although selective pressure on the mtDNA of this species cannot be discarded.     

Hidden species diversity in Marcusenius moorii (Teleostei: Mormyridae) from the Congo Basin

New collections from the Yangambi Biosphere Reserve (YBR) and Okapi Wildlife Reserve (OWR) revealed the presence of two groups of specimens similar to, but different from Marcusenius moorii. To study both these groups, an integrated morphological and genetic (mtDNA, cytb) approach was used. This study revealed that one of the two groups is conspecific with Marcusenius lambouri, a junior synonym of M. moorii, which is herein revalidated, with M. moorii longulus as its junior synonym. Marcusenius lambouri differs from M. moorii by a higher number of lateral line scales (44–46 vs. 40–43), a shorter pectoral-fin length (14.6–19.9 vs. 20.3–25.2% standard length; L_S) and a more elongated body due to a usually shallower middle body depth (19.8–26.5 vs. 26.3–35.9% L_S). The other group revealed to be a new species for science, Marcusenius verheyenorum, which can be distinguished from its congeners with eight circumpeduncular scales by the following unique combination of characters: a rounded head with a terminal mouth; a short and deep caudal peduncle (middle caudal-peduncle depth, 44.9–54.6% caudal-peduncle length; L_CP), a deep body (middle body depth, 27.7–34.2% L_S), 38–43 scales on the lateral line, 40–41 vertebrae, 20–21 dorsal-fin rays and 26 anal-fin rays. Some specimens previously attributed to M. moorii were examined and reassigned to M. lambouri or M. verheyenorum. As a result, M. moorii and M. lambouri occur in sympatry in the middle Congo Basin, with the distribution area of M. moorii still further extending into the lower Congo Basin. Instead, the distribution of M. verheyenorum is limited to some right bank tributaries of the upstream part of the middle Congo Basin. Two museum records from the Lilanda River (YBR), collected in the 1950s and previously identified as M. moorii, were re-identified as belonging to the new species, M. verheyenorum. However, the species now seems locally extinct in that region, which reflects the significant anthropogenic effects even within this reserve.     

Genetic diversity of mitochondrial cytochrome b gene in swamp buffalo

The swamp buffalo (Bubalus carabanensis) is mainly bred for meat, transport and rice cultivation in China and Southeast Asian countries. In the current study, we investigated the genetic diversity, maternal origin and phylogenetic relationship of swamp buffalo by analyzing 1,786 mitochondrial cytochrome b (cytb) sequences from China, Vietnam, Laos, Thailand, India and Bangladesh. Our results indicated that the swamp buffalo can be divided into two major lineages (SA and SB with the sublineages) and three rare lineages (SC, SD and SE), which showed strong geographic differentiation. The SA1 lineage represented a major domestication event, which involved population expansion. Regions III and V showed higher haplotype diversity than the other regions, indicating that the regions of Southwest China and IndoChina are potential domestication centers for the swamp buffalo. In addition, the swamp buffalo showed a closer phylogenetic relationship to tamaraw. In conclusion, our findings revealed a high level of genetic diversity and the phylogenetic pattern of the swamp buffalo.     

Social but lonely: Species delimitation of social voles and the evolutionary history of the only Microtus species living in Africa

The social vole of Cyrenaica, Libya, is the only extant representative of the Cricetidae family found in Africa. Its taxonomic status has been under debate, partly due to the problematic systematics of the entire group of social voles and partly due to the lack of morphological and molecular data from Cyrenaican specimens. In this study, we applied ancient DNA protocols to produce three cytochrome b (cytb) sequences of Cyrenaican voles and built a phylogenetic reconstruction (195 sequences in total) incorporating all available cytb sequences of the remaining social voles, other representatives of the genus Microtus and closely related cricetids. We used this phylogeny to test the performance of the model-based, single-locus, species delimitation approach implemented in mPTP and delimited nine species of social voles. Among them are the Cyrenaican vole, Microtus mustersi and its sister species M. guentheri, distributed along the Mediterranean coasts of southwestern Asia. Biogeographical reconstruction of ancestral area and molecular clock estimations of the time since the divergence of the two sister lineages suggest that their common ancestor dispersed into Africa through a coastal route and was isolated in Cyrenaica as a result of population fragmentation associated with Middle Pleistocenic pluvial/interpluvial cycles. Geographic isolation triggered the speciation process, but species distribution modeling gave evidence of subsequent niche divergence; M. guentheri has adapted to the xeric conditions of its distributional area, while M. mustersi benefited from the milder Cyrenaican climate. The Cyrenaican vole is a relict species more than 200,000 years old, has a small and isolated distribution and probably merits conservation.     

The complete mitochondrial genomes of three grasshoppers, Asiotmethis zacharjini, Filchnerella helanshanensis and Pseudotmethis rubimarginis (Orthoptera: Pamphagidae)

The complete mitogenomes of Asiotmethis zacharjini, Filchnerella helanshanensis and Pseudotmethis rubimarginis are 15,660 bp, 15,657 bp and 15,661 bp in size, respectively. All three mitogenomes contain a standard set of 13 protein - coding genes, 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and an A + T-rich region in the same order as those of the other analysed caeliferan species, including the rearrangement of trnAsp and trnLys. The putative initiation codon for the cox1 gene in the three species is CCG. The long polythymine stretch (T-stretch) in the A + T-rich region of the three species is not adjacent to the trnIle but inside the stem–loop sequence in the majority strand. The mitogenomes of F. helanshanensis and P. rubimarginis have higher overall similarities. The characterization of the three mitogenomes will enrich our knowledge on the Pamphagidae mitogenome. The phylogenetic analyses indicated that within the Caelifera, Pyrgomorphoidea is a sister group to Acridoidea. The species from the Pamphagidae form a monophyletic group, as is the case for Acrididae. Furthermore, the two families cluster as sister groups, supporting the monophyly of Acridoidea. The relationships among eight acridid subfamilies were (Cyrtacanthacridinae + (Calliptaminae + (Catantopinae + (Oxyinae + (Melanopline + (Acridinae + (Oedipodinae + Gomphocerinae))))))).