[Genetic analysis on diversity of reproductive modes of silver crucian carp inferred by transferrin and isozyme markers].
Silver crucian carp (Carassius auratus gibelio) has been known for its gynogenetic reproduction. In this paper, eggs from clone F of gynogenetic silver crucian carp were inseminated respectively by sperms of clone D, clone A and common carp, and polymorphic patterns of transferrin and isozymes of the produced three offspring FD, FA and FL were studied comparatively to explore the diversity in reproductive modes of silver crucian carp. As control, zymograms of FL progenies exhibited a maternally clonal inheritance, and gynogenesis was reconfirmed. However, differentiation of morphs and electrophoretic patterns was both observed among the FD progenies, and detection of bands specific for the clone F or clone D in some FD individuals urged the occurrence of recombination. Furthermore, extreme linkage disequilibrium for different protein loci suggested that linkage groups composed of different genes might function as the fundamental unit in the recombination. With respect to FA group, phenotypes of parental clones were both detected in the F2 generation (FA x FA progenies) while only maternal phenotypes were detected in the F1 generation. It appeared that both the parental chromosome sets could be transmitted to the offspring but expression of paternal genes were fundamentally upset in the F1 generation because of incompatibility of the parental genes. Generally, genetic analysis of FD and FA offspring primarily exhibited a particular syngamy for silver crucian carp. Besides the clonal reproduction of gynogenesis, syngamy could provide opportunities of recombination for silver crucian carp, which might remove some genetic loads from the genome and introduce new genotypes. Diversity in reproductive modes might play an important role in ecological adaptation of silver crucian carp.
Yang
Lin
L
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072.
Gui
Jian Fang
JF
D000818:Animals; D002347:Carps / Q000235:genetics*; D005260:Female; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics; D012098:Reproduction / Q000235:genetics*; D014168:Transferrin / Q000235:genetics*
D007527:Isoenzymes; D014168:Transferrin