Cytogenetic Study on Microtus guentheri (Danford and Alston, 1880) (Mammalia: Rodentia) from Turkey: Constitutive Heterochromatin Distribution and Nucleolar Organizer Regions

Abstract

AÞAN BAYDEMÝR N., ALBAYRAK Ý., GÖZÜTOK S. 2011. Cytogenetic study on Microtus guentheri (Danford and Alston, 1880) (Mammalia: Rodentia) from Turkey: Constitutive heterochromatin distribution and nucleolar organizer regions. Folia biologica (Kraków) #': 35-40. Conventionally stained, C-and Ag-NOR banded karyotypes of Guenthers vole, Microtus guentheri were studied from Turkey. The species possesses a karyotype of 2n=54, NFa= 52 and NF=54 in specimens from Kahramanmaraº and Gaziantep provinces, whereas NF= 56 in females and NF=55 in males were found in individuals from Kýrýkkale and Nevþehir provinces. The X chromosome was a large acrocentric (NF=54) or submetacentric (NF=55, 56) while the Y chromosome was a small telocentric in all specimens examined. Blocks of constitutive heterochromatin were located in the pericentromeric areas of autosomes including the X chromosome. Nucleolar organizer regions (NORs) were located at the telomeric regions of the short arms of five acrocentric pairs and centromeric regions of two telocentric pairs in the Nevþehir and Kýrýkkale specimens.

Cytogenetic Characteristics of Microtus guentheri, Microtus arvalis sensu lato and Microtus majori (Mammalia: Rodentia) From Turkey: Constitutive Heterochromatin Distribution

“…Microtus guentheri karyotype (2n=54) was found to be compatible in similar with the studies conducted in the Anatolia and neighbouring regions (Kefelioğlu, 1995;Baydemir et al, 2011;Zima et al, 2013). M. guentheri shows variations in terms of sex chromosome morphology (X=acrocentric, metacentric, submetacentric, subtelocentric).…”

“…M. guentheri shows variations in terms of sex chromosome morphology (X=acrocentric, metacentric, submetacentric, subtelocentric). X chromosome is metacentric in studies conducted in South Anatolia (Çolak et al, 1997a) and in various regions of Anatolia (Kefelioğlu, 1995;Yiğit and Çolak, 2002); acrocentric in studies conducted in Central and Southern Anatolia (Çolak et al, 1998;Baydemir et al, 2011); submetacentric in studies conducted in Central Anatolia (Baydemir et al, 2011); and subtelocentric in Southern Anatolia and Syria population and the present study (central Anatolia). Constitutive heterochromatin distribution is homomorphic and pericentromeric in autosomal chromosomes (O'Brien, 2006;Baydemir et al, 2011;Zima et al, 2013;in this study).…”

“…X chromosome is metacentric in studies conducted in South Anatolia (Çolak et al, 1997a) and in various regions of Anatolia (Kefelioğlu, 1995;Yiğit and Çolak, 2002); acrocentric in studies conducted in Central and Southern Anatolia (Çolak et al, 1998;Baydemir et al, 2011); submetacentric in studies conducted in Central Anatolia (Baydemir et al, 2011); and subtelocentric in Southern Anatolia and Syria population and the present study (central Anatolia). Constitutive heterochromatin distribution is homomorphic and pericentromeric in autosomal chromosomes (O'Brien, 2006;Baydemir et al, 2011;Zima et al, 2013;in this study). In Harput (Southern Anatolia) samples, while the short arm of the X chromosome consists of completely heterochromatin block , constitutive heterochromatin is in the pericentromeric region of subtelocentric or submetacentric X chromosome in Central Anatolia sample (Nevşehir samples, Baydemir et al, 2011;Konya samples, Zima et al, 2013; Tokat samples in the present study).…”

“…Constitutive heterochromatin distribution is homomorphic and pericentromeric in autosomal chromosomes (O'Brien, 2006;Baydemir et al, 2011;Zima et al, 2013;in this study). In Harput (Southern Anatolia) samples, while the short arm of the X chromosome consists of completely heterochromatin block (Zima et al, 2013), constitutive heterochromatin is in the pericentromeric region of subtelocentric or submetacentric X chromosome in Central Anatolia sample (Nevşehir samples, Baydemir et al, 2011;Konya samples, Zima et al, 2013; Tokat samples in the present study). In terms of M. arvalis (obscurus cytotype) diploid chromosome number, this study was similar to previously conducted (Zima and Král, 1984;Kefelioğlu, 1995;Yorulmaz et al, 2013) studies.…”

“…These cytotypes were attributed to the common (arvalis) and Altai (obscurus) voles having, respectively, fundamental number of autosomes (NFa)=80 in Caucasian populations; NFa=68-70 (Meyer et al, 1996). Within the distribution areas of populations of M. majori, M. guentheri and obscurus cytotype, various researchers have conducted karyological studies in the form of conventional chromosome staining (Kefelioğlu, 1995;Çolak et al, 1997a, b;Çolak et al, 1998;Kefelioğlu and Kryštufek, 1999;Yiğit and Çolak, 2002;Arslan and Zima, 2014), G-banding (Macholan et al, 2001;Zima et al, 2013), C and Ag-NOR banding (Yiğit and Çolak, 2002;Baydemir et al, 2011;Tougard et al,2013;Yorulmaz et al, 2013;Zima et al, 2013). According to these studies, variations was found in the autosomal and sex chromosome morphologies of M. guentheri, M. arvalis (obscurus cytotype) and M. majori species.…”