Studies on aneuploid pearl oyster (Pinctada martensii Dunker) produced by crossing triploid females and a diploid male following the inhibition of PB1

Viable aneuploid embryos of pearl oyster, Pinctada martensii Dunker, were produced by inhibiting the first polar body (PB1) with cytochalasin B treatment in eggs from triploids fertilized with haploid sperm. During the period of growth measurement, aneuploid showed the slowest growth compared with diploid and triploid groups. The body size and weight measurement data showed that there were no differences between aneuploids (as a group) and diploids in body size and weight (P>0.10), but that they were significantly different from triploids (P <0.01). There were no differences between aneuploids within diploid condition (2n±n) and diploids in SL (P>0.1), but significant differences in BW were found (P <0.05). Aneuploids within triploid condition (3n±n) were significantly smaller than triploids in BW (P<0.05), but not different from triploids in SL (P>0.05), and almost identical to diploids in both (P>0.1). These dada indicated that some aneuploids might be associated with growth retardation. Karyotype analysis revealed that there were metacentric, submetacentric or subtelocentric chromosomes losses or gains; aneuploid pearl oysters with the same chromosome numbers had different chromosome composition. Aneuploids are valuable research materials for genetic analysis.