The First Chromosome Analysis and Localization of the Nucleolar Organizer Region of Phayre's Flying Squirrel, <i>Hylopetes phayrei</i> (Rodentia, Sciuridae) in Thailand

Abstract

SummaryWe report the first chromosome analysis and localization of the nucleolar organizer region of the Phayre s flying squirrel, Hylopetes phayrei (Blyth, 1985) from Thailand. After standard peripheral blood lymphocytes had been cultured at 37 C for 96 h in the presence of colchicine, the metaphase spreads were performed on microscopic slides and air-dried. Conventional staining, GTG-banding, high-resolution and Ag-NOR staining techniques were applied to stain the chromosomes. The results showed that the diploid chromosome number of H. phayrei was 2n = 38 and the fundamental number (NF) were 76 in both males and females. The karyotype has the presence of 2 large metacentric, 8 large submetacentric, 8 large acrocentric, 6 medium acrocentric, 6 small metacentric and 6 small acrocentric chromosomes. The X chromosome is a small submetacentric chromosome and the Y chromosome is a small acrocentric chromosome. From the GTG-banding and high-resolution techniques, the numbers of bands and locations in the H. phayrei are 182 and 234, respectively; each chromosome pair could be clearly differentiated. The Ag-NOR staining demonstrated that the three pairs of nucleolar organizer regions (NORs) were observed on the long arm regions of chromosome pairs 1, 5, and 14. The karyotype formula of H. phayrei could be deduced as:2n (diploid) Flying squirrels (Petauristinae, Sciuridae, Rodentia) are members of rodents that can make gliding leaps by means of the patagium (parachute-like membrane) connected on each side to their forelegs and hind legs. They are found in North America, Europe and Asia, including at least 37 species grouped into 15 genera. Flying squirrels are special in their life history characteristics. They are nocturnal gliders and hide in holes or leaf drays during the daytime (Nowak 1991). The flying squirrel consists of six genera and 12 species in Thailand, namely, the lesser giant flying squirrel (Petaurista elegans), red giant flying squirrel (Peta. petaurista), Indian giant flying squirrel (Peta.

Which Is a Reliable Approach in the Generation of Artificial Minichromosomes, Bottom-Up or Top-Down?

“…Cytogenetical and karyotypic studies have revealed variations of chromosomes in size, morphology, and number in various clades of plant and animal species (Al-Dakan and Al-Saleh 2015, Al-Qahtani et al 2014, Arslan and Zima 2014, Bagane et al 2014, Çakmak and Koca 2014, Deshpande et al 2014, El-Esawi and Sammour 2014, Gholave et al 2014, Haroun and Alotaibi 2015, Jantarat et al 2014a, Kaewmad et al 2014, 2014c, Kantek et al 2015, Kasiroek et al 2014, Kaur and Singhal 2015, Khakhong et al 2014, Kumar et al 2015, Kumar et al 2014, Li et al 2015, Martin et al 2015, Miura and Iwatsubo 2014, Parai and Mukherjee 2014, Park 2015, Patawang et al 2014a, Phimphan et al 2015, Pierozzi and Baroni 2014, Pinthong et al 2014, Qumsiyeh et al 2014, Rezaei et al 2014, Samanta et al 2015, Sato et al 2015, Tahami et al 2014, Venkatesh and Munirajappa 2015, Venkatesh et al 2014, Walia et al 2015. Cytogenetical techniques including banding methods and FISH have revealed the evolutionary process in structural and number changes of chromosomes (Lombello and Pinto-maglio 2014…”