315 ISSN 0095-4527, Cytology and Genetics, 2017, Vol. 51, No. 4, pp. 315–324. © Allerton Press, Inc., 2017. Karyotypic Study of Five Lutjanid Species Using Conventional and Ag-NORs Banding Techniques 1 Sumalee Phimphan a , Weerayuth Supiwong e , Alongklod Tanomtong a, *, Krit Pinthong b , Wiwat Sangpakdee c , and Sarawut Kaewsri d a Department of Biology, Faculty of Science, Khon Kaen University, Muang, Khon Kaen 40002, Thailand b Department of Fundamental Science, Faculty of Science and Technology, Surindra Rajabhat University, Muang, Surin 32000, Thailand c Biology Program, Faculty of Science, Udon Thani Rajabhat University, Muang, Udon Thani 41000, Thailand d Biology Program, Department of Science, Faculty of Science, Buriram Rajabhat University, Muang, Buriram 31000, Thailand e Faculty of Applied Science and Engineering, Khon Kaen University, Nongkhai Campus, Muang, Nongkhai 43000, Thailand * e-mail: tanomtong@hotmail.com Received January 19, 2016 Abstract⎯The first cytogenetic comparisons of five snapper species from Thailand were presented here. Renal cell samples were taken from blacktail snapper (Lutjanus fulvus), five lined snapper (L. quinquelineatus), dory snapper (L. fulviflamma), brownstripe red snapper (L. vitta), and mangrove red snapper (L. argentimaculatus). The mitotic chromosome preparation was prepared directly from kidney cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results exhibited that all five snapper species have the dip- loid chromosome numbers of 2n = 48 and the fundamental numbers (NF) of 48. The presences of large, medium, and small telocentric chromosomes were 22-24-2, 24-20-4, 36-10-2, 28-16-4 and 36-10-2, respectively. The Ag- NORs banding technique provides the pair of nucleolar organizer regions (NORs) at subcentromeric region of the long arm of the respective telocentric chromosome pairs 9, 1, 3, 4 and 9. Their karyotype formulas is as follows: L. fulvus (2n = 48): + + , L. quinquelineatus (2n = 48): + + , L. fulviflamma (2n = 48): Lt36 + Mt10 + St2, L. vitta (2n = 48): + + , and L. argentimaculatus (2n = 48): + + . Keywords: Lutjanus, chromosome, karyotype, nucleolar organizer regions DOI: 10.3103/S0095452717040077 Nowadays, several methods namely, conventional staining, C-banding, Ag-NOR banding and FISH (fluorescence in situ hybridization) have been used by ichthyologists for gathering of cytogenetic information of fish [1, 2], yet each of these methods provides a dif- ferent aspect of the karyotype characteristics. For example, Ag-NORs staining show the regions con- taining the actively transcribed ribosomal RNA genes (rDNA). As the chromosomal distribution patterns of heterochromatic bands, NORs, and rDNAs revealed by cytogenetic techniques are typically species specific in fish, they prove to be useful chromosome markers in fish studies, particularly as cytotaxonomical markers in systematic evolutionary studies of closely related fish taxa [3–6]. The Lutjanidae or snappers are a family of perci- form fishes, mainly marine but with some members living in estuaries and entering fresh water to feed. Some are important food fish. The Lutjanidae is a group composed of 17 genera and 105 species of mostly reef-associated marine fish, which are distrib- uted in all the tropical and subtropical seas of the world [7]. In genus Lutjanus, cytogenetic studies have been performed in sixteen species including, L. alex- andrei [8], L. analis [8, 9], L. argentimaculatus [10– 12], L. bohar [10], L. cyanopterus [8], L. erythropterus [10], L. griseus [9], L. jocu [9], L. johnii [13, 14], L. kasmira [15, 16], L. quinquelineatus [16], L. russelli [16], L. sanguineus [17], L. sebae [18, 19], L. synagris [8, 9] and L. vitta [13] (table). Most of these species have 2n = 48 (NF = 48) chromosome consisting of only telocentric chromosomes and there was no obser- vation of strange size chromosomes related to sex. 22 t L 24 t M 2 t S 24 t L 20 t M 4 t S 28 t L 16 t M 4 t S 36 t L 10 t M 2 t S 1 The article is published in the original.