PHYLOGENETIC-RELATIONSHIPS AMONG MALAGASY LEMURS AS REVEALED BY MITOCHONDRIAL-DNA SEQUENCE-ANALYSIS

Systematics and evolution of Malagasy lemurs has been analyzed using m orphological characters, fossil evidence, ecological/ethological data, and chromosomal banding patterns. Recent developments in DNA technolo gy have provided evolutionary biologists with additional and powerful tools for making phylogenetic inference. In the last years several stu dies concerning highly repeated DNA sequences (hrDNA) provided new ins ights about the systematic relationships among the differ ent species of Lemuridae and Cheirogaleidae. Here, a reconstruction of molecular p hylogeny of extant Malagasy lemurs based on the comparison of cytochro me-b mitochondrial DNA sequences is presented. With the Polymerase Cha in Reaction (PCR) and direct sequencing of amplified DNA fragments, bo th the phylogenetic range and resolving power of comparative analysis can be extended. These techniques allow to gather sequence data useful to evaluate the pattern of molecular evolution offering opportunities for phylogenetic purposes. A 290-bp fragment of cytochrome-b gene has been amplified and sequenced from the following species: Tupaia glis, Galago alleni, Daubentonia madagascariensis, Indri indri, Variegata v ariegata, Eulemur fulvus, Eulemur coronatus, Eulemur rubriventer, Eule mur mongoz, Eulemur macaco, Lemur catta, and Hapalemur griseus griseus . The phylogenetic trees obtained show the relationships among the Eul emur species and confirm the karyological and hrDNA results of a separ ated clade for L. catta/Hapalemur. The separation of Varecia variegata from the other genus of the family Lemuridae is discussed.