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Molecular systematics of small-eared shrews (Soricomorpha, Mammalia) within Cryptotis mexicanus species group from Mesoamerica

100%

Guevara L., Cervantes F. A.

Acta Theriologica

2014

tom 59

nr 2

Cryptotis mexicanus species group is the most diverse group of Cryptotis shrews in the Mesoamerican highlands (ca.13 species). In México, eight endemic species occurs and several taxa are endangered. The species’ limits and phylogenetic relationships of these taxa have been recently examined using morphology; nevertheless, little is known about phylogenetic relationships among Cryptotis species at the molecular level. Therefore, our research included a mitochondrial DNA marker as a source of additional information to corroborate taxonomic identification and produce a phylogenetic hypothesis of the C. mexicanus species group. We were particularly interested in the status of Cryptotis magnus, a species considered as relict on the basis of primitive characters. Based on the analyses of genetic sequences of a high number of Cryptotis species, outgroups, and phylogenetic analyses of parsimony and Bayesian inference, we confirmed that Cryptotis genus consists of different lineages that represent species groups. A detailed analysis suggests that C. magnus is a species that shares an evolutionary history with the C. mexicanus species group because it is imbedded within this group. In particular, our data strongly support that C. magnus and Cryptotis phillipsii are sister groups, a pair of species that inhabit allopatrically Southern México.

Karyotypes of the Mexican tropical voles Microtus quasiater and M.umbrosus [Arvicolinae: Muridae]

80%

Cervantes F. A., Martinez J., Gonzalez R. M.

Acta Theriologica

1994

tom 39

nr 4

The non-differentially stained karyotypes of the tropical voles Microtus quasiater (Coues, 1874) and M. umbrosus (Merriam, 1898) are described by first time, and compared and contrasted with that of the hypothetical primitive karyotype for Arvicolinae. The karyotype of M. quasiater from Veracruz, Mexico, has 2n = 62 and FN = 66, while that for M. umbrosus from Oaxaca, Mexico, has 2n = 56 and FN = 60. Their chromosomal morphology comprises few two-armed chromosomes and a relatively large number of single-armed chromosomes. Both species share both a medium-sized metacentric X chromosome and a small telocentric Y chromosome. This karyotypical pattern deviates from the hypothetical primitive condition. However, the karyotypes of other Microtus, including Mexican species of temperate affinity, seem to be even more divergent from the ancestral karyotypical pattern.

Ograniczanie wyników

2 Acta Theriologica

2 Cervantes F. A.

1 Gonzalez R. M.

1 Guevara L.

1 Martinez J.

1 2014

1 1994

Wyniki wyszukiwania

Molecular systematics of small-eared shrews (Soricomorpha, Mammalia) within Cryptotis mexicanus species group from Mesoamerica

Karyotypes of the Mexican tropical voles Microtus quasiater and M.umbrosus [Arvicolinae: Muridae]