C-banding And High Resolution G-banding Of Northeastern Sika Deer (Cervus Nippon Hortulorum)

Objectives:Sika deer is subordinated to artiodactyla,cervidae,muntiacus.Northeasten sika deer (cervus nippon hortulorum),one of the three survival subspecies in China,has important value of medical use and economy value.It has generally forcused on physiochemiacal identity,feeding management,diseases prevention and cure in cervus nippon hortulorum researches,but the researches about the nuclear genes and chromosomes are much less.The analysis of C-banding and high resolution G-banding will provide the basic information for cytogenetic researches of c. n. hortulorum,and also provide references to improve the number of high resolution G-bands for the gene localization.Methods:(1)The peripheral blood was obtained while sawing the velvet antler.Collect lymphocytes after 72-hours culture.The chromosomes were dealed with C-banding technique,and the result of C-bands of c. n. hortulorum chromosomes was analysed.(2) The peripheral blood was obtained while sawing the velvet antler.Group A:The methotrexate(MTX)was taken off after the lymphocytes were synchronized by it.Add thymidine (TdR) to startup the cell cycle. Group B: MTX was taken off after the lymphocytes were synchronized by it.Add 5-bromodexyuridine (BrdU) to startup the cell cycle. Group C: TdR was added to synchronized lymphocytes by MTX without getting rid of MTX in order to startup the cell cycle. Group D: BrdU was added to synchronized lymphocytes by MTX without getting rid of MTX in order to startup the cell cycle.At last,mensurate the mitotic index of each group.(3) The peripheral blood was obtained while sawing the velver antler.The blood cells were cultivated by the the means of group A.Collected the lymphocytes and dealed the chromosomes with GTG technique,then analysed the high resolution G-bands.Results and conclusions: (1)It is banded in centromeres of autosomes, and there are much lighter colouration in the centromeres of the first pair and second pair autosomes.There is a piece of bigger and darker area in the centromeres of X chromosome.All parts of Y chromosome is coloured lightly and the centromere is not identified clearly.Therefore,comparing with other c. n. hortulorum C-bands,it is maybe infered that the C-bands of c. n. hortulorum is polymorphic in subspecies.(2)The statistics show that the mitotic index is significantly different between group A and C,group B and D, and the mitotic index will increase notably with MTX taken off.Therefore,MTX not only restrains the synthesis of TdR even purine but also restrains the DNA reproduction which TdR and BrdU (structure analog) participate in. Significant different mitotic index between group A and group B shows that TdR will lead a much higher mitotic index than BrdU to start the cell cycle if the MTX is taken off before.Therefore, the ability to start DNA replication is obviously different between TdR and BrdU in certain concentration. The mitotic index is not significant different between group C and D.It is shows that if the cells take MTX for more than 17 hours,the mitotic index will not be effected significantly no matter TdR or BrdU is added.(3)The number of the bands for haploid chromosomes is 456.According to Reading Conference,International System for Cytogenetic Nomenclature of Domestic Animals(ISCNDA),and chromosome bands of c. n. hortulorum,the high resolution G-bands idiogram is achieved.