Liu Jun, Mtango Namdori, Scicluna Emily L, Ord Sara, Pask Andrew J
TIGRR Lab, School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia.
Colossal Biosciences, Dallas, Texas, USA.
Biol Reprod. 2025 May 5. doi: 10.1093/biolre/ioaf104.
The fat-tailed dunnart, Sminthopsis crassicaudata, is a mouse-sized, polyovular, solitary dasyurid marsupial found in central and southern Australia. With the establishment of a chromosome-scale genome assembly, induced pluripotent stem cells, and targeted genetic editing, the dunnart is emerging as the laboratory marsupial model for comparative developmental, reproductive and conservation biology. The development of assisted reproductive technologies (ART) are critical to achieving these goals in this species. ART requires a large number of mature oocytes which are typically collected through stimulated and synchronised female reproductive cycles. While protocols for induced-ovulation or superovulation are standard in many placental mammals, there are no methods to date designed for marsupials. In the present study, prepubertal dunnarts were stimulated with pregnant mare serum gonadotrophin and human chronic gonadotrophin across 6 different treatment regimens. Our best regimen resulted in over 70% of prepubertal dunnarts ovulating with 82% normal oocytes. When the primed females were mated with stud males, 4-cell stage embryos were collected 48 h post-hCG administration. At around 96 h post-hCG, 50% (n = 8) and 78% (n = 9) of the embryos developed to blastocysts. Our results demonstrated successful stimulation of ovulation and mature oocyte collection in prepubertal dunnarts. Furthermore, we confirmed developmental competence of the induced ovulated oocytes through to at least the blastocyst stage. These findings represent the first robust hormonal regimen for predictable oocyte generation in any marsupial and will significantly contribute to the use of the dunnart in developmental and conservation biology.
肥尾袋鼬（Sminthopsis crassicaudata）是一种体型如鼠、多卵、独居的袋鼬科有袋动物，分布于澳大利亚中部和南部。随着染色体水平基因组组装、诱导多能干细胞和靶向基因编辑技术的建立，袋鼬正在成为用于比较发育生物学、生殖生物学和保护生物学研究的实验性有袋动物模型。辅助生殖技术（ART）的发展对于在该物种中实现这些目标至关重要。ART需要大量成熟卵母细胞，这些卵母细胞通常通过刺激和同步雌性生殖周期来收集。虽然诱导排卵或超排卵方案在许多胎盘哺乳动物中是标准操作，但迄今为止尚无专门为有袋动物设计的方法。在本研究中，对青春期前的袋鼬采用孕马血清促性腺激素和人绒毛膜促性腺激素进行刺激，设置了6种不同的治疗方案。我们的最佳方案使超过70%的青春期前袋鼬排卵，其中82%的卵母细胞正常。当经预处理的雌性与种公鼠交配后，在注射hCG后48小时收集到4细胞期胚胎。在注射hCG后约96小时，分别有50%（n = 8）和78%（n = 9）的胚胎发育到囊胚阶段。我们的结果表明成功刺激了青春期前袋鼬排卵并收集到成熟卵母细胞。此外，我们证实了诱导排卵获得的卵母细胞至少在囊胚阶段具有发育能力。这些发现代表了首个可用于在任何有袋动物中可预测地产生卵母细胞的有效激素方案，并将极大地促进袋鼬在发育生物学和保护生物学中的应用。
