title: Abnormal chromosome behavior during meiosis in the allotetraploid of Carassius auratus red var. (♀)×Megalobrama amblycephala (♂).
abstract: BACKGROUND
  Allopolyploids generally undergo bivalent pairing at meiosis because only homologous chromosomes pair up. On the other hand, several studies have documented abnormal chromosome behavior during mitosis and meiosis in allopolyploids plants leading to the production of gametes with complete paternal or maternal chromosomes. Polyploidy is relatively rare in animals compared with plants; thus, chromosome behavior at meiosis in the allopolyploid animals is poorly understood.
  
  
  RESULTS
  Tetraploid hybrids (abbreviated as 4nRB) (4n=148, RRBB) of Carassius auratus red var. (abbreviated as RCC) (2n=100, RR) (♀)×Megalobrama amblycephala (abbreviated as BSB) (2n=48, BB) (♂) generated gametes of different size. To test the genetic composition of these gametes, the gynogenetic offspring and backcross progenies of 4nRB were produced, and their genetic composition were examined by chromosome analysis and FISH. Our results suggest that 4nRB can produce several types of gametes with different genetic compositions, including allotetraploid (RRBB), autotriploid (RRR), autodiploid (RR), and haploid (R) gametes.
  
  
  CONCLUSIONS
  This study provides direct evidence of abnormal chromosome behavior during meiosis in an allotetraploid fish.
authors.forename: Qinbo
authors.initials: Q
authors.lastname: Qin
authors.forename: Yude
authors.initials: Y
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Dai
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of the State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410018, People's Republic of China. lsj@hunnu.edu.cn.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D002678:Chimera / Q000235:genetics*; D002875:Chromosomes; D003433:Crosses, Genetic; D003530:Cyprinidae / Q000235:genetics*; D005260:Female; D006054:Goldfish / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008540:Meiosis; D010063:Ovum / Q000166:cytology; D013094:Spermatozoa / Q000166:cytology; D057891:Tetraploidy