Robertsonian Polymorphism in the Cotton Rat, Sigmodon fulviventer

Lee, M. Raymond; Zimmerman, Earl G.

doi:10.2307/1378351

Cited by 24 publications

(12 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meylan 6 described (but did not illustrate) the Y-chromosome of his material as being a very small metacentric chromosome, whereas we found it to be a small acrocentric. Lee and Zimmerman 20 do not describe the Y-chromosome in their specimens. Blarina carolinensis (Figure 3).…”

mentioning

confidence: 95%

Karyotypes of shrews of the generaCryptotis andBlarina (mammalia: Soricidae)

1977

View full text Add to dashboard Cite

mentioning

confidence: 95%

Karyotypes of shrews of the generaCryptotis andBlarina (mammalia: Soricidae)

1977

View full text Add to dashboard Cite

“…They also recognized S. zanjonensis which they concluded may or may not be specifically distinct [Carleton et al, 1999;Musser and Carleton, 2005]. Of these 13 species, karyotypes for 9 (S. alleni , S. arizonae , S. fulviventer , S. hirsutus , S. hispidus , S. leucotis , S. mascotensis , S. ochragnathus , and S. toltecus) [Hsu and Benirschke, 1968;Kiblisky, 1969;Lee and Zimmerman, 1969;Zimmerman, 1970;Carroll et al, 2005] have been described with non differentially stained chromosomes, G-bands, and C-bands [Zimmerman, 1970;Elder, 1980;Elder and Lee, 1985]. Diploid numbers ranged from 22 to 82 and fundamental number (total number of autosomal arms) ranged from 34 to 82; G-band data indicate that S. hispidus , S. leucotis , S. alleni , S. ochragnathus , S. arizonae , and S. mascotensis form a species group to the exclusion of S. fulviventer which Elder and Lee [1985] placed in its own species group.…”

mentioning

confidence: 99%

Patterns of Chromosomal Evolution in <i>Sigmodon</i>, Evidence from Whole Chromosome Paints

Swier

Bradley

Rens

et al. 2009

Cytogenet Genome Res

View full text Add to dashboard Cite

Of the superfamily Muroidea (31 genera, 1578 species), the Sigmodontinae (74 genera, 377 species) is the second largest subfamily in number of species and represents a significant radiation of rodent biodiversity. Only 2 of the 74 genera are found in both North and South America (Sigmodon and Oryzomys) and the remainder are exclusively from South America. In recent molecular studies, the genus Sigmodon (Cricetidae, Sigmodontinae) has been considered sister to many other South American Sigmodontines [Steppan et al., 2004]. We examine the chromosomal evolution of 9 species of Sigmodon utilizing chromosomal paints isolated from S. hispidus, proposed to be similar to the ancestral karyotype [Elder, 1980]. Utilizing a phylogenetic hypothesis of a molecular phylogeny of Sigmodon [Henson and Bradley, 2009], we mapped shared chromosomal rearrangements of taxa on a molecular tree to estimate the evolutionary position of each rearrangement. For several species (S. hirsutus, S. leucotis, S. ochrognathus, S. peruanus, and S. toltecus), the karyotype accumulated few or no changes, but in three species (S. arizonae, S. fulviventer, and S. mascotensis) numerous karyotype rearrangements were observed. These rearrangements involved heterochromatic additions, centric fusions, tandem fusions, pericentric inversions, as well as the addition of interstitial DNA not identified by chromosome paints or C-banding. The hypothesis that the ancestral karyotype for this complex had a diploid number of 52, a fundamental number of 52, and a G-band pattern of which most, if not all are similar to that present in modern day S. hispidus fails to be rejected. This hypothesis remains viable as an explanation of chromosomal evolution in Sigmodontine rodents.

show abstract

“…This lack of introgression might be due to differences in the number of Robertsonian polymorphisms that occurs within B. brevicauda and B. hylophaga (Meylan 1967;Lee and Zimmerman 1969;Genoways et al 1977;George et al 1982;Oshida et al 2003), which likely reduces fitness (Searle 1993). Several hybrid zone studies have documented limited introgression between species with chromosomal rearrangements (Bradley et al 1991;Basset et al 2007;Genoways et al 2008).…”

Section: Extent Of Hybridization and Introgressionmentioning

confidence: 99%

“…Problems during the pairing and segregation phases of meiosis caused by increased chromosomal heterozygosity can reduce hybrid fitness (Baker and Bickham 1986). This explanation seems highly plausible given the number of Robertsonian polymorphisms that occurs within B. brevicauda and B. hylophaga (Meylan 1967;Lee and Zimmerman 1969;Genoways et al 1977;George et al 1982;Oshida et al 2003;Thompson and Hoffman 2009). Thus, the chromosomal rearrangements between B. brevicauda and B. hylophaga might be a strong isolating mechanism (Shaw et al 1993;Benedict et al 2006).…”

Section: Extent Of Hybridization and Introgressionmentioning

confidence: 99%

Identification and characterization of the contact zone between short-tailed shrews (Blarina) in Iowa and Missouri

et al. 2011

View full text Add to dashboard Cite

Short-tailed shrews (genus Blarina Gray, 1838) are characterized by divergent karyotypes and are genetically distinct. Blarina species are similar morphologically but, in most cases, can be distinguished morphometrically. Blarina distributions tend to be parapatric along well-defined contact zones; however, it has been suggested that the northern short-tailed shrew (Blarina brevicauda (Say, 1823)) and Elliot's short-tailed shrew (Blarina hylophaga Elliot, 1899) occur sympatrically in Iowa and Missouri. To evaluate this possibility, 179 specimens were collected in southwestern Iowa and northwestern Missouri. Karyotypes and total length were used for field identification, and amplified fragment length polymorphism (AFLP) analysis was used to verify field identifications and to investigate the extent of hybridization. One hundred seventyeight of 179 specimens were identified to species. The one exception had a karyotype of B. brevicauda (2n = 50, FN = 48); however, AFLP analysis indicated that this individual was likely an F1 hybrid. No backcrosses were detected, so it appears that introgression is minimal. The putative hybrid was trapped at a locality with B. brevicauda just north of a locality having only B. hylophaga. No locality contained both species. Therefore, these species are not broadly sympatric as has been suggested, but rather exhibit a distribution similar to the pattern of parapatry seen in most of the contact zones of Blarina.Résumé : Les musaraignes à queue courte (du genre Blarina Gray, 1838) se caractérisent par des caryotypes divergents et sont génétiquement distinctes. Les espèces de Blarina sont semblables morphologiquement, mais dans la plupart des cas, la morphométrie permet de les distinguer. Les répartitions des Blarina ont tendance à être parapatriques le long de zones de contact bien définies; on croit néanmoins que la grande musaraigne à queue courte (Blarina brevicauda (Say, 1823)) et la musaraigne à queue courte d'Elliot (Blarina hylophaga Elliot, 1899) se retrouvent en sympatrie en Iowa et au Missouri. Afin de vérifier cette possibilité, nous avons récolté 179 spécimens dans le sud-ouest de l'Iowa et le nord-ouest du Missouri. Les caryotypes et la longueur totale nous ont servi pour les identifications de terrain et une analyse du polymorphisme des longueurs des segments amplifiés (AFLP) a permis de confirmer les identifications de terrain et de déterminer l'importance de l'hybridation. Des 179 spécimens, 178 ont été identifiés à l'espèce. La seule exception avait un caryotype de B. brevicauda (2n = 50, FN = 48); cependant l'analyse de ALFP indique que cet individu est vraisemblablement un hybride de F1. Comme il n'y a aucune indication de rétrocroisement, l'introgression semble minimale. L'hybride putatif a été piégé dans une localité contenant B. brevicauda située juste au nord d'une localité où vit seulement B. hylophaga. Aucune localité ne contient les deux espèces. Les deux espèces ne possèdent donc pas une importante zone de sympatrie, comme on le croyait; ils ont plu...

show abstract

Robertsonian Polymorphism in the Cotton Rat, Sigmodon fulviventer

Cited by 24 publications

References 17 publications

Karyotypes of shrews of the generaCryptotis andBlarina (mammalia: Soricidae)

Karyotypes of shrews of the generaCryptotis andBlarina (mammalia: Soricidae)

Patterns of Chromosomal Evolution in <i>Sigmodon</i>, Evidence from Whole Chromosome Paints

Identification and characterization of the contact zone between short-tailed shrews (Blarina) in Iowa and Missouri

Contact Info

Product

Resources

About