Gene mapping of Microcebus murinus (Lemuridae): a comparison with man and Cebus capucinus (Cebidae)

The karyotype of microcebus murinus (MIM) (lemuridae) is considered by Dutrillaux (1979) as the closest to the karyotype ancestral to all primates. A large number of homoeologies exists between the banding patterns of MIM chromosomes and those of man (HSA). We report a comparison of the gene maps of these two species which confirms most of these homoeologies. Fifteen cell hybrids were obtained by fusing MIM fibroblasts and an HPRT- Chinese hamster cell line. Twenty-seven enzyme markers were investigated. The following assignments were demonstrated: NP to chromosome MIM 2, homoeologous to HSA 14; the syntenic group PGD-ENO1-PGM1 to MIM 3, homoeologous to HSA 1p; LDHA to MIM 5, homoeologous to HSA 11; Me1 to MIM 6, homoeologous to HSA 6; the syntenic group LDHB-CS-PEPB-ENO2-TPI to MIM 7, homoeologous to HSA 12; the syntenic group AK1-AK3 to MIM 10, which we considered to be homoeologous to HSA 9 (we do not consider MIM 9 to be homoeologous to HSA 9, as does Dutrillaux, 1979); GOT1 to MIM 15, homoeologous to HSA 10; the syntenic group HPRT-G6PD-PGK-GLA to MIM X. Synteny dissociation in three hybrids suggests closer linkage between G6PD and HPRT than between PGK-GLA and HPRT. Three syntenic groups, known in man, were confirmed in MIM but could not be assigned with full confidence: ACP1-MDH1, MP1-PKM2, and PEPD-GPI. GUK1 and PEPC, known to be syntenic in man, were found to be asyntenic in MIM and could not be assigned. PGM2 and SOD1 could not be assigned. A comparison of these gene assignments with those known in Cebus capucinus showed a remarkable homoeology for six chromosomes of the two species.