Banded chromosome studies and B chromosomes in wild-caught raccoon dogs, <i>Nyctereutes procyonoides viverrinu</i><i>s</i>

Abstract

Cytogenetic studies were made on Japanese raccoon dogs (Nyctereutes procyonoides viverrinus) that were caught in the wild in southern Kyushu and northern Honshu. G-banding, C-banding, acridine orange (AO) staining following BudR incorporation, and silver staining for nucleolar organizer regions (NORs) were performed on chromosomes from fibroblast cultures. Modal numbers varied from 40 to 42. The karyotype comprised 26 mediocentric and 10 acrocentric autosomes, a submetacentric X, and a minute submetacentric Y. Unpaired B chromosomes which differed in number between animals accounted for the variable modal numbers. B chromosomes stained indistinctly with G-banding but showed a variety of positive patterns with C-banding and differentiated staining with AO. NORs were observed on the telomeric ends of the long arms of chromosomes 11, 12, and 18. No cytogenetic differences were seen between the northern and southern animals.

Canine 5S rRNA: nucleotide sequence and chromosomal assignment of its gene cluster in four canid species

“…The localization of the 5S rRNA gene cluster in the Chinese raccoon dog to chromosome 8q1.3 is confirmed by work of Graphodatsky et al (2001), who found canine chromosome 4 to correspond to the long arm of Japanese raccoon dog chromosome 4, which is homologous to Chinese raccoon dog chromosome 8 (Wurster-Hill et al, 1986).…”

“…), published by Mäkinen et al (1985b) was used. For the Chinese raccoon dog (Nyctereutes procyonoides procyonoides) chromosome nomenclature was according to Wurster-Hill et al (1986) and Ward et al (1987).…”

Cytogenetics of collared lemmings <i>(Dicrostonyx groenlandicus)</i>. II. Meiotic behavior of B chromosomes suggests a Y-chromosome origin of supernumerary chromosomes

“…A mechanistically attractive model suggests that B chromosomes represent the small reciprocal products of Robertsonian translocations. Consistent with this hypothesis is the presence of small, monocentric, supernumerary chromosomes in association with Robertsonian chromosomes in humans (Sordo et al, 1983;Abeliovich et al, 1985;Howard and Fielding, 1987) and cattle (Miyake et al, 1994) and the occurrence of B chromosomes in the Robertsonian-derived karyotypes of various rodents and other mammals (Patton, 1977;Volobujev, 1981;Wurster-Hill et al, 1986;Civitelli et al, 1989;Borowik and Engstrom, 1993;Peppers et al, 1997). A second model hypothesizes the origin of B chromosomes as a result of duplication, most likely as polysomy of small autosomes or as isochromosomes of the X chromosome (Patton, 1977).…”

“…A second model hypothesizes the origin of B chromosomes as a result of duplication, most likely as polysomy of small autosomes or as isochromosomes of the X chromosome (Patton, 1977). The size similarities between B chromosomes and the smaller A chromosomes within animal karyotypes (e.g., Wurster-Hill et al, 1986;Ś witoń ski et al, 1987;Kolomiets et al, 1988) are consistent with a polysomic origin. Cytogenetic (Blackman, 1988;Fletcher and Hewitt, 1988) and molecular data (Ló pez-Leó n et al, 1994) from various insects support X-chromosome and isochromosome models for the origin of B chromosomes.…”

Review

“…The Bs are rather C-band positive; however, the Cbanding patterns are not as distinct as in centromeres of the autosomes. The R-banding showed that these structures are late replicating (WURSTER-HILL et al 1986).…”