The chromosomes of spinyhead croaker Collichthys lucidus（Richardson,1844） were characterized for the first time by fluorescence staining,self genomic in situ hybridization（self-GISH）,and multicolor fluorescence in...The chromosomes of spinyhead croaker Collichthys lucidus（Richardson,1844） were characterized for the first time by fluorescence staining,self genomic in situ hybridization（self-GISH）,and multicolor fluorescence in situ hybridization（FISH） with 18 SrDNA,5 SrDNA and telomeric sequence probes.The female karyotype has exclusively 24 pairs of acrocentric chromosomes（2 n=48 a,NF=48）,while the male one consists of 22 pairs of acrocentric chromosomes,2 monosomic acrocentric chromosomes and a metacentric chromosome（2 n=1 m＋46 a,NF=48）.The difference between female and male karyotypes indicates the presence of a sex chromosome of X1 X1 X2 X2/X1 X2 Y type,where Y is the unique metacentric chromosome in the male karyotype.As revealed by FISH,5 S r DNA and 18 S r DNA sites were mapped at syntenic position of the largest acrocentric chromosome（X_1）,and the short arms of the Y chromosome as well.An X_1-chromosome specific interstitial telomeric signal（ITS） was detected overlapping the 5 S r DNA sites.In addition,self-GISH revealed that the repetitive DNAs accumulated on all the putative sex chromosome.Chromosome fusion accompanied by a partial deletion in the ancestral karyotype（2 n=48 a） is hypothesized for the origin of such multiple sex chromosome system.The present study,as the first description of differentiated sex chromosome in family Sciaenidae,will give clues to the studies on the sex chromosome of other Sciaenids.展开更多
基金The National Natural Science Foundation of China under contract Nos 31272653 and 41706157the Natural Science Foundation of Fujian Province under contract No.2017J01449
文摘The chromosomes of spinyhead croaker Collichthys lucidus（Richardson,1844） were characterized for the first time by fluorescence staining,self genomic in situ hybridization（self-GISH）,and multicolor fluorescence in situ hybridization（FISH） with 18 SrDNA,5 SrDNA and telomeric sequence probes.The female karyotype has exclusively 24 pairs of acrocentric chromosomes（2 n=48 a,NF=48）,while the male one consists of 22 pairs of acrocentric chromosomes,2 monosomic acrocentric chromosomes and a metacentric chromosome（2 n=1 m＋46 a,NF=48）.The difference between female and male karyotypes indicates the presence of a sex chromosome of X1 X1 X2 X2/X1 X2 Y type,where Y is the unique metacentric chromosome in the male karyotype.As revealed by FISH,5 S r DNA and 18 S r DNA sites were mapped at syntenic position of the largest acrocentric chromosome（X_1）,and the short arms of the Y chromosome as well.An X_1-chromosome specific interstitial telomeric signal（ITS） was detected overlapping the 5 S r DNA sites.In addition,self-GISH revealed that the repetitive DNAs accumulated on all the putative sex chromosome.Chromosome fusion accompanied by a partial deletion in the ancestral karyotype（2 n=48 a） is hypothesized for the origin of such multiple sex chromosome system.The present study,as the first description of differentiated sex chromosome in family Sciaenidae,will give clues to the studies on the sex chromosome of other Sciaenids.
