STUDIES ON THE KARYOTYPE AND NORs OF THREE TURTLES IN THE SACALIA AND MAUREMYS FRO CHINA

The karyotypes and NORs of three species of turtles, i.e.Sacalia bealei,S.quadriocellata and Mauremys mutica were studied from mitotic metaphase ofcultured blood cells prepared by the colchicine-hypotonic-air drying method.Thediploid chromo-some numberis = 52 consisting of 9 meta-or submetacentric pairs,5 ter-orsubterminal pairs and 12 pairs of microchromosomes.The karyotypic formulais 9 + 5 + 12, being the primitive type in karyotypes of Emydidae.The nombrefondamental (NF) of S.bealei is 76 and those of S.quadriocellata and M.muticaare 78 respechvely.The feature of karyotypic structure of S.bealei is similar to thatof M.quadriocellata.The secondary constriction and satellite were reported for thefirst time in M.mutica.The secondary constriction locates on the short arm of 3rdand the long arm of 6th chromosome of group A, and the satellite is on the 6thchromosome of group A.NO dimorphic sex chromosomes were observed in either sexof the three species examined.The NORs occurred on the long arm of the 7th pair of chromosomes in S.bealia,and located on long arm of the sib pair of chromosomes in S. quadriocellata and M.mutica.The evidence of NORs indicated in mis paper for the three species rereals theextreme conservativeness with regard tO karyotype and it is reported hitherto.