Phylogenetic Studies of the Rodent Family Gerbillidae: I. Chromosomal Evolution in the Southern African Complex

Systematics and phylogeny of West African gerbils of the genus <i>Gerbilliscus</i> (Muridae: Gerbillinae) inferred from comparative G- and C-banding chromosomal analyses

“…While the East and South African Gerbilliscus were repeatedly the subject of chromosome banding (Qumsiyeh, 1986;Qumsiyeh et al, 1987;Qumsiyeh and Schlitter, 1991;Colangelo et al, 2005), biochemical (Qumsiyeh et al, 1987;Qumsiyeh and Chesser, 1988) and molecular (Colangelo et al, 2005) studies, the West and central African taxa have remained poorly documented: two taxa, G. guineae and G. cf . nigrita were chromosomally studied by R-banding (Benazzou et al, 1984) and only one, G. kempi , by using both G-and C-banding .…”

“…Another pertinent question highlighted in earlier studies is the relationship between the genera Gerbilliscus and Gerbillurus . Qumsiyeh (1986) and Qumsiyeh et al (1987) demonstrated that on chromosomal grounds two Gerbillurus species (G. paeba and G. vallinus) were evolutionarily very close to East African Gerbilliscus . This issue has recently been addressed by molecular data that have quite clearly shown that Gerbillurus should be included in Gerbilliscus (Chevret and Dobigny, 2005;Colangelo et al, 2007).…”

Unusually extensive karyotype reorganization in four congeneric <i>Gerbillus</i> species (Muridae: Gerbillinae)

“…Further, in contrast to numerous mammalian taxa showing little or no changes affecting X chromosome, species of the subfamily Gerbillinae, and in particular of the genus Gerbillus, display a wide range of X chromosome size and morphology that resulted from acquisition of large heterochromatic segments, and/or inversions, and/or autosome-gonosome translocations (Wahrman et al, 1983;Viegas-Péquignot et al, 1982, 1984, 1986Benazzou, 1984;Qumsiyeh, 1986;present study). Interestingly, all ten species of Gerbillus bearing derived sex chromosome systems are those also characterized by extensive karyotype repatterning and, except for G. gerbillus, by high C heterochromatin content (Table 3).…”

“…Indeed, in the four species studied here, and in the species investigated by Viegas-Péquignot et al (1984, 1986, constitutive heterochromatin represents 30 % of the total karyotype length. It also represents about 40 % in G. latestei (Volobouev et al, 1995b;as G. aureus) and reaches 50 % in G. nigeriae (ViegasPéquignot et al, 1984;Volobouev et al, 1995b).…”

“…This was in sharp contrast with the successful interspecific comparisons within and between other gerbilline genera Meriones, Tatera and Taterillus, Gerbillurus, Pachyuromys and Psammomys (Benazzou, 1984;Viegas-Péquignot et al, 1986). In addition to an extensive reorganization of autosomes, the sex chromosomes also appeared rearranged: they displayed a wide range of X chromosome size and morphology via acquisition of large amounts of heterochromatin in various chromosomal locations, pericentric inversions and autosome-gonosome translocations in six of the eight species (Viegas-Péquignot et al, 1982, 1984, 1986). These changes gave rise to three main types of complex sex chromosomes.…”