Genetic and phylogenetic analyses of hantaviral sequences amplified from archival tissues of deer mice (Peromyscus maniculatus nubiterrae) captured in the eastern United States.

The S and M segments of a hantavirus, enzymatically amplified from tissues of Cloudland deer mice (Peromyscus maniculatus nubiterrae) captured during 1985 in West Virginia, diverged from strains of Four Corners virus from the southwestern United States by more than 16% and 6% at the nucleotide and amino acid levels, respectively. Phylogenetic analysis suggested that this virus strain (designated Monongahela) forms a possible evolutionary link between the Four Corners and New York hantaviruses.

Chromosomal and protein evolution in morphologically similar species of Praomys sensu lato (Rodentia, Muridae).

Evidence of extensive chromosomal evolution in a biologically and economically important group of African murids of the Praomys/Mastomys complex was provided by examination of G- and C-band chromosomal data on P. coucha (2n = 32), P. fumatus (2n = 38), P. hildebrandti (2n = 32), P. jacksoni (2n = 28), P. misonnei (2n = 36), and P. cf. tullbergi (2n = 35). A coding system was developed for the chromosomal characters, and analyses were performed by a computer program to find the shortest tree with a minimum of 35 autosomal rearrangements (pericentric inversions, complex translocations, centric fusions, centric fissions, tandem fusions, euchromatic additions, and heterochromatic additions). The resulting phylogenetic hypothesis differs from traditionally accepted hypotheses regarding this complex group of rodents. The cytogenetic data show that 1) there is no support for the dichotomy of Mastomys/Praomys previously based on morphology, 2) the 2n = 32 species from eastern Africa (P. hildebrandti) is distinct from the 2n = 32 species from southern Africa (P. natalensis), and 3) there is a close association between P. jacksoni and P. cf. tullbergi. Polyacrylamide gel electrophoresis of liver membrane proteins demonstrated few differences in protein mobilities between species and even fewer between individuals of the same species taken from different habitats and localities in Kenya. Monoclonal antibodies produced against liver proteins of one species and tested for reactivity to other species confirmed the evolutionary similarity of species of this complex. This immunologic approach may provide a robust data set for future phylogenetic studies of muroid rodents.(ABSTRACT TRUNCATED AT 250 WORDS)

Problems in using Robertsonian rearrangements in determining monophyly: examples from the genera Tatera and Gerbillurus.

Chromosomal banding data on three species of Tatera from Kenya significantly alter the previous hypothesis of relationships between and within the genera Tatera and Gerbillurus based on cladistic analyses and the rule of parsimony (Qumsiyeh, 1986b). Of the many possible hypothetical relationships, the most parsimonious tree showed three homoplasies and allowed the genus Gerbillurus to be paraphyletic. The alternative trees, depicting larger number of homoplasies but with homoplasies restricted to fusion or fission events, were compatible with the morphological data in supporting the monophyly of Gerbillurus. To choose between the hypothesis based on the most parsimonious chromosomal tree and those supported by both morphology and slightly less parsimonious chromosomal trees, we performed an electrophoretic study on this group of gerbils. The conclusions are that the genus Gerbillurus is monophyletic and represents a branch that is closely related to the T. robusta group of Taterillini. The study documents that fissions and fusions must have occurred frequently and that in some cases the same fusions were acquired in two independent lineages in numbers exceeding those that are predicted by strict parsimony. The results raise questions about the validity of systematic conclusions based solely on fusion/fission data and utilizing the parsimony criterion.

Capillaria hepatica in small mammals collected from Shoa Province, Ethiopia.

A total of 1,110 small mammals has been examined for Capillaria hepatica in Shoa Province, Ethiopa. Nineteen of 308 (6.2%) Rattus rattus and 1 of 212 (0.5%) Praomys albipes were infected. The data indicate that C. hepatica was essentially limited to commensal rats (R. rattus).