Phenotypic and molecular characteristics of a chimera mutant of red swamp crayfish (Procambarus clarkii)

Chimera is a special biological individual formed under natural conditions. In this study, an individual with bilateral differences in body color and patterns in the F 1 generation from the cross between black king crayfish ( Procambarus clarkii ) (♂) and its wild type (♀) were taken as the research objects. Nine tissue parts were selected for bilateral symmetric sampling (a total of 18 samples), and 16 SSR markers were used to detect their genotypes. The results showed that taking the central axis as the boundary, the color and patterns of the carapace from the cephalothorax to the dorsal abdomen presented a symmetric chimeric phenotype; the individual showed a chimeric state with the coexistence of multiple genotypes in the body, and the genotype distribution was irregular, which was not completely corresponding to the bilaterally symmetric phenotype of its carapace. It is speculated that the hybridization between different varieties of red swamp crayfish may be the reason for the formation of this chimera. This study provides an important reference for the research on the regulatory mechanism of the coexistence of tissues or organs with different genetic compositions in chimeras, and for interpreting the mechanism of immune rejection in organ transplantation of higher organisms.