Comparison of the genome sequences between sexes in the Amami spiny rat, Tokudaia osimensis. Tokudaia osimensis

The Amami spiny rat, Tokudaia osimensis, has very unique sex chromosomes and sex-determining mechanism. The sex chromosome constitution of this species is XO/XO, which is caused by the absence of the Y chromosome. This species also lacks the SRY gene which is sex-determining gene in eutherian mammals. Therefore, it is hypothesized that T. osimensis acquires a new sex-determining gene superseded SRY. Furthermore, T. osimensis is an endangered species and has been protected by the Japanese government as such since 1972. Therefore, we compared male and female genome sequences for two aims: use the information for study of sex-determining mechanism and evolution of the Y chromosome, reserve the information as important resources.

奄美刺鼠（Amami spiny rat，学名Tokudaia osimensis）拥有极为独特的性染色体与性别决定机制。该物种的性染色体组型为XO/XO型，这一特征源于Y染色体的缺失。同时，该物种还缺失了真兽类哺乳动物中作为性别决定关键基因的SRY基因（SRY gene）。据此，学界推测T. osimensis已演化出可替代SRY的新型性别决定基因。此外，奄美刺鼠为濒危物种，自1972年起便受到日本政府的官方保护。基于上述背景，本研究开展雌雄基因组序列比对，旨在达成两大目标：一是利用相关数据开展性别决定机制与Y染色体演化研究；二是将该基因组序列作为重要科研资源予以留存。