Search

Mitochondrial DNA (mtDNA) is a popular marker for studying genetic diversity, population and phylogeny. However, it has characteristics that may be a source of error in some studies. A new investigation reports on the occurrence of nuclear mtDNA-like sequences in the nuclear genome of the neotropical opossum species Didelphis (Didelphidae, Marsupialia) The study establishes the occurrence of mtDNA-like sequences in the four Didelphis species and the presence of paralogous nuclear sequences suggests that mtDNA migration to the nuclear genome occurred several times during their evolution.

The assignment in Ateles paniscus chamek, the spider monkey, of three human X-linked genes and two HSA 14q genes is reported. The process of karytypic evolution in Ateles was better understood following a comparison with chromosome painting data in A. geoffroyi, a karyotypically similar congeneric species.

A cytochrome b region is analysed using heteroduplex mobility assays (HMAs) with results comparable to those based on DNA sequences, including similar topologies with identical intrageneric, intraspecific and intergeneric relationships, in selected Callitrichids. HMA is sensitive enough to detect a 1-2% mismatch and can distinguish closely related species. HMAs can be used for detecting mismatches in the DNAs of different organisms, determining the genetic distances among them and constructing phylogenetic trees.

Presents a study that isolated and characterized several monomorphic and highly polymorphic microsatellites of Nectomys squamipes in a sample of specimens from different Brazilian localities. Function of microsatellites; Examination of the efficacy of cross-specific, heterologous microsatellite DNA amplification across a range of sigmodontine rodent taxa; Genetic variation of microsatellite loci in Nectomys squamipes.

Comparative gene assignments of 18 markers, based on analyses of somatic cell hybrids and previous data in the literature, indicated that human (HSA) syntenic groups 3, 12, 14, and 15 are dissociated in the spider monkey species Ateles paniscus chamek (APC). Markers present in HSA 3p were allocated to APC 3 and APC 9. The HSA 12 cluster was split into two syntenic groups, one mainly including HSA 12p markers in APC 16 and the other, including HSA 12q markers, in APC 2p. The HSA 14q cluster split into three syntenic groups, corresponding to APC 2q, APC 6, and APC 12. Finally, the HSA 15 cluster split into two syntenic groups, APC 2q and APC 3. Comparisons with previous gene assignments and human SROs led to the tentative postulation of rearrangements having occurred during the evolutionary divergence of man and A. paniscus chamek. Chromosome painting data in the congeneric species A. geoffroyi, other New World and Old World primates, and several representative non-primate animals were compared in an attempt to delineate the ancestral and derived conditions underlying the evolutionary rearrangement of syntenic groups in mammals. Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]