Karyotypic evolution and phylogenetic relationships in the order Chiroptera as revealed by G-banding comparison and chromosome painting

Bats are a unique but enigmatic group of mammals and have a world-wide distribution. The phylogenetic relationships of extant bats are far from being resolved. Here, we investigated the karyotypic relationships of representative species from four families

Phylogeny and biogeography of the Petaurista philippensis complex (Rodentia : Sciuridae), inter- and intraspecific relationships inferred from molecular and morphometric analysis

With modified DNA extraction and Purification protocols, the complete cytochrome b gene sequences (1140 bp) were determined from degraded museum specimens. Molecular analysis and morphological examination of cranial characteristics of the giant flying squirrels of Petaurista philippensis complex (P. grandis, P. hainana, and P. yunanensis) and other Petaurista species yielded new insights into long-standing controversies in the Petaurista systematics. Patterns of genetic variations and morphological differences observed in this study indicate that P. hainana, P. albiventer, and P. yunanensis can be recognized as distinct species, and P. grandis and P. petaurista are conspecific populations. Phylogenetic relationships reconstructed by using parsimony, likelihood, and Bayesian methods reveal that, with P. leucogenys as the basal branch, all Petaurista groups formed two distinct clades. Petaurista philippensis, P. hainana, P. yunanensis, and P. albiventer are clustered in the same clade, while P. grandis shows a close relationship to P. petaurista. Deduced divergence times based on Bayesian analysis and the transversional substitution at the third codon suggest that the retreating of glaciers and upheavals or movements of tectonic plates in the Pliocene-Pleistocene were the major factors responsible for the present geographical distributions of Petaurista groups. (c) 2005 Elsevier Inc. All rights reserved.

Ribosomal DNA gene and phylogenetic relationships of Diplura and lower Hexapods

The monophyly of Diplura and its phylogenetic relationship with other hexapods are important for understanding the phylogeny of Hexapoda. The complete 18SrRNA gene and partial 28SrRNA gene (D3-D5 region) from 2 dipluran species (Campodeidae and Japygidae), 2 proturan species, 3 collembolan species, and 1 locust species were sequenced. Combining related sequences in GenBank, phylogenetic trees of Hexapoda were constructed by MP method using a crustacean Artemia salina as an outgroup. The results indicated that: (i) the integrated data of 18SrDNA and 28SrDNA could provide better phylogenetic information, which well supported the monophyly of Diplura; (ii) Diplura had a close phylogenetic relationship to Protura with high bootstrap support.

Chemical forms of copper, zinc, lead and cadmium in sediments of the northern part of the Red Sea, Egypt

Total concentrations and chemical forms of heavy metals in sediment samples from the Gulf of Suez and the northern part of the Red Sea, collected during January 2003, were determined by atomic absorption spectrometry. Maximum concentrations of 49.56, 65.42, 33.52 and 3.52 µg/g were recorded for total Cu, Zn, Pb and Cd respectively at Adabiya location. These may reflect the high contribution of land-based activities in the northern part of the Gulf. Also, high percentages of heavy metals were found in the residual fraction (Cu=78.61, Zn=77.10 and Pb=66.80%) while a high percentage of Cd was found in the carbonate fraction (45.82%). However, few or negligible percentages were recorded in the exchangeable fractions (Cu=0.51, Zn=1.57 and Pb=1.74%). Concentration of Cd in the exchangeable fraction was too low to be detected.