Chromosome Unipolar Division and Low Expression of May Cause Parthenogenesis of Rice Water Weevil ( Kuschel).

Rice water weevil (RWW) is divided into two types of population, triploid parthenogenesis and diploid bisexual reproduction. In this study, we explored the meiosis of triploid parthenogenesis RWW (Shangzhuang Town, Haidian District, Beijing, China) by marking the chromosomes and microtubules of parthenogenetic RWW oocytes via immunostaining. The immunostaining results show that there is a canonical meiotic spindle formed in the triploid parthenogenetic RWW oocytes, but chromosomes segregate at only one pole, which means that there is a chromosomal unipolar division during the oogenesis of the parthenogenetic RWW. Furthermore, we cloned the conserved sequences of parthenogenetic RWW and , and designed primers based on the parthenogenetic RWW sequence to detect expression patterns by quantitative PCR (Q-PCR). Q-PCR results indicate that the expression of and in ovarian tissue of bisexual is 0.98 and 10,000.00 times parthenogenetic RWW, respectively ( < 0.01). The results show that had low expression in parthenogenetic RWW ovarian tissue, and was expressed normally. Our study suggests that the chromosomal unipolar division and deletion of may cause parthenogenesis in RWW.