We documented the number, morphology, and distribution of intermuscular bones in five fishes of different ploidy： Carassius auratus （Abbr.WCC, 2n=100）, Carassius auratus variety PengZe （Abbr.PZCC, 3n=150）, improved triploid crucian carp （Abbr.ITCC, 3n=150）, improved red crucian carp （Carassius auratus red var., Abbr.IRCC, , 2n=100）, and improved allotet- raploids （Abbr.GAT, （, 4n=200）. The number of intermuscular bones in WCC, PZCC, and GxAT ranged from 78 to 83 （n =81）, 80 to 86 （n =84）, and 77 to 84 （n=82）, respectively. The numbers in ITCC and IRCC were significantly lower, ranging from 77 to 82 （ n =79） and 58 to 77 （ n =71）, respectively. The average number of intermuscular bones in each sarco- mere, ranked in order from highest to lowest, was 0.721 （WCC）, 0.673 （PZCC）, 0.653 （GAT）, 0.633 （ITCC）, and 0.608 （IRCC）. There was no difference between ITCC and GxAT or between GxAT and PZCC. However, the average number of intermuscular bones in the sarcomeres of ITCC, WCC, and PZCC differed significantly, as did that of IRCC and the four other kinds of fish. The intermuscular bone of these five fishes was divided into seven shape categories, non-forked （I）, one-end-unequal-bi-fork （）, one-end-equal-bi-fork （Y）, one-end-multi-fork, two-end-bi-fork, two-end-multi-fork, and tree- branch types. Generally, the morphological complexity was higher in the anterior intermuscular bones than in the posterior body. The number of intermuscular bones was similar but not equal between the left and right sides of the body. ITCC had sig- nificantly fewer intermuscular bones than either WCC or PZCC, making it of greater commercial value. Additionally, IRCC and ITCC had fewer intermuscular bones than WCC. Our observations are significant in both fish bone developmental biology and genetic breeding.
LI LingZHONG ZeZhouZENG MingLIU ShaoJunZHOU YiXIAO JunWANG JunLIU Yun
In the Dongting water system, the Carassius auratus(Crucian carp) complex is characterized by the coexistence of diploid forms(2n=100, 2n CC) and polyploid forms. Chromosomal and karyotypic analyses have suggested that the polyploid C. auratus has a triploid(3n=150, 3n CC) and a tetraploid origin(4n=200), respectively. However, there is a lack of direct genetic evidence to support this conclusion. In this paper, analysis of the 5S r DNA chromosomal locus revealed that the 3n CC is of triploid origin. Analysis of the species-specific chromosomal centromere locus revealed that 3n CC individuals possess three sets of C. auratus-derived chromosomes. Our results provide direct cytogenetic evidence suggesting that individuals with 150 chromosomes are of autotriploid origin within the C. auratus complex. It marks an important contribution to the study of polyploidization and the evolution of vertebrates.
Distant hybridization refers to crosses between two different species or higher-ranking taxa that enables interspecific genome transfer and leads to changes in phenotypes and genotypes of the resulting progeny.If progeny derived from distant hybridization are bisexual and fertile,they can form a hybrid lineage through self-mating,with major implications for evolutionary biology,genetics,and breeding.Here,we review and summarize the published literature,and present our results on fish distant hybridization.Relevant problems involving distant hybridization between orders,families,subfamilies,genera,and species of animals are introduced and discussed,with an additional focus on fish distant hybrid lineages,genetic variation,patterns,and applications.Our review serves as a useful reference for evolutionary biology research and animal genetic breeding.
运用Western-blot技术和免疫组织化学来检测丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)家族成员细胞外调节蛋白激酶(extracellular regulated protein kinase,ERK)和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)在不同生殖特性鲫鲤杂交鱼性腺组织中的表达。研究表明,JNK、ERK在鱼类性腺组织中均有较高量的表达,但在鱼类卵巢和精巢间、雌核发育二倍体鲫鲤和不同倍性鱼的性腺组织间,JNK或ERK的表达量并不存在明显的差异,而P-JNK在雌核发育二倍体鲫鲤性腺中的表达量远高于三倍体和四倍体鲫鲤的卵巢组织。此外,JNK和ERK在雌核发育二倍体鲫鲤早期性腺性原细胞中均有阳性表达。其中,JNK在10月龄雌核发育二倍体鲫鲤性腺中的阳性反应强度高于6、8月龄;而ERK在8月龄和10月龄的性腺中的阳性反应则弱于6月龄。结果表明JNK通路可能对雌核发育二倍体鲫鲤产生不减数配子具有重要调控作用。
