Genome evolution arises from two main ways of duplication and reduction. Fish specific genome duplication (FSGD) may have occurred before the radiation of the teleosts. Common carp (Cyprinus carpio L.) has been considered to be a tetraploid species, because of its chromosome numbers (2n=100) and its high DNA content. Using 69 microsatellite primer pairs, the variations were studied to better understand the genome evolution (genome duplication and diploidization) of common carp from a gynogenetic family. About 48% of primer pairs were estimated to amplify duplicates based on the number of PCR amplification per individual. Segregation patterns in the family suggested a partially duplicated genome structure and disomic inheritance. This indicates that the common carp is tetraploid and polyploidy occurred by allotetraploidy. Two primer pairs (HLJ021 and HLJ332) were estimated to amplify reduction based on the number of PCR amplification per individual. One allele in HLJ002 locus and HLJ332 locus was clearly lost in the gynogenetic family and the same as in six wild populations. Segregation patterns in the family suggested a partially diplodization genome structure. A hypothesis transition (dynamic) and equilibrium (static) were proposed to explain the common carp genome evolution between genome duplication and diploidization.
Yah ZhangLiqun LiangPeng JiangDayu LiCuiyun LuXiaowen Sun
A total of 85 interspecific hybrid F2 （Cyprinus carpio var.wuyuanensis ×Cyprinus pellegrini pellegrini） were cooled to specific temperatures and held at those temperatures over a maximum of 4 days in a water-recycled and temperature-controlled aquarium inside.As a result,the blood homeostasis of experimental fish changed violently as acute temperature changed from 16 ℃ to 10 ℃ and 4 ℃ at a rate of 1 ℃·h-1 according to the data we collected.Whole blood pH,also called extracellular pH（pHe） were very sensitive to temperature changes,where there was a significant difference between 10 ℃（7.41） and 16 ℃（7.17）（P<0.01）,compared to other values of hematology and serum chemistry.When the water temperature was continually decreased to an extreme temperature of 4 ℃,the content of Na+ of serum decreased remarkably in comparison with that of 10 ℃ and 16 ℃,which was 85.2 mmol·L-1,113.3 mmol·L-1 and 118.7 mmol·L-1,respectively.The values of hematology and serum chemistry also altered in gentle temperature changes of（10±2） ℃ and（4±2） ℃.Most values of serum chemistry and pH changed significantly,whereas the values of blood plasma changed slightly.pH was up slowly in 4 days at（10±2） ℃ and down slowly in 3 days at（4±2） ℃.A variety of values of serum chemistry changed remarkably both at（10±2） ℃ and（10±2） ℃,but the values of TP,TG and ALB only changed significantly at（4±2） ℃.These results distinguished at least two mechanisms involved in cold-induced stress in hybrid F2.Cold-induced pH changes resulted in other values altered.What’s more,pH correlated negatively with water temperature above 10 ℃,and the content of Na+.We also found that gentle temperature changes will be physiologically compensated for on day one at（10±2） ℃ and on day 2 at（4±2） ℃ in hybrid F2.
We describe a new method for sequencing-based cross-species transcriptome comparisons and define a new metric for evaluating gene expression across species using protein-coding families as units of comparison.Using this measure transcriptomes from different species were evaluated by mapping them to gene families and integrating the mapping results with expression data.Statistical tests were applied to the transcriptome evaluation results to identify differentially expressed families.A Perl program named Pro-Diff was compiled to im-plement this method.To evaluate the method and provide an example of its use,two liver EST transcriptomes from two closely related fish that live in different temperature zones were compared.One EST library was from a recent sequencing project of Dissosticus maw-soni,a fish that lives in cold Antarctic sea waters,while the other was newly sequenced data(available at:http://www.fishgenome.org/polarbank/) from Notothenia angustata,a species that lives in temperate near-shore water of southern New Zealand.Results from the comparison were consistent with results inferred from phenotype differences and also with our previously published Gene Ontology-based method.The Pro-Diff program and operation manual can be downloaded from:http://www.fishgenome.org/download/Prodiff.rar.
Zuozhou ChenHua YeLonghai ZhouChi-Hing C. ChengLiangbiao Chen
