Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the Barred Frog Mixophyes fasciolatus (Myobatrachidae)

Reproductive Biology and Endocrinology

Research

Andrew J French¹  Jitong Guo²  Michael Archer³  Michael J Mahony⁴  Simon Clulow⁴  John Clulow⁴ 

[1] Centre for Animal Biotechnology,Faculty of Veterinary Science, The University of Melbourne, 3010, Parkville, VIC, Australia;Inner Mongolia Saikexing Reproductive Biotechnology Co., Ltd. 6 F, Mengniu Dairy R&D Center, Shengle Economic Zone of Helingeer County, 011517, Hohhot,Inner Mongolia, People's Republic of China;School of Biological, Earth and Environmental Sciences, University of New South Wales, 2052, Sydney, Australia;School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, 2308, Callaghan, NSW, Australia;

关键词: Amphibian;    Mixophyes;    Ovulation;    Oviposition;    Assisted reproduction;    hCG;    PMSG;   

DOI  :  10.1186/1477-7827-10-60

 received in 2012-04-04, accepted in 2012-08-03,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundProtocols for the hormonal induction of ovulation and oviposition are essential tools for managing threatened amphibians with assisted reproduction, but responses vary greatly between species and even broad taxon groups. Consequently, it is necessary to assess effectiveness of such protocols in representative species when new taxa become targets for induction. The threatened genus Mixophyes (family Myobatrachidae) has amongst the highest proportion of endangered species of all the Australian amphibians. This study developed and optimised the induction of oviposition in a non-threatened member of this taxon, the great barred frog (Mixophyes fasciolatus).MethodsGravid female M. fasciolatus were induced to oviposit on one or more occasions by administration of human chorionic gonadotropin (hCG) with or without priming with pregnant mare serum gonadotropin (PMSG). Treatments involved variations in hormone doses and combinations (administered via injection into the dorsal lymph sacs), and timing of administration. Pituitary homogenates from an unrelated bufonid species (Rhinella marina) were also examined with hCG.ResultsWhen injected alone, hCG (900 to 1400 IU) induced oviposition. However, priming with two time dependent doses of PMSG (50 IU, 25 IU) increased responses, with lower doses of hCG (200 IU). Priming increased response rates in females from around 30% (hCG alone) to more than 50% (p = 0.035), and up to 67%. Increasing the interval between the first PMSG dose and first hCG dose from 3 to 6 days also produced significant improvement (p<0.001). Heterologous pituitary extracts administered with hCG were no more effective than hCG alone (p = 0.628).ConclusionsThis study found that M. fasciolatus is amongst the few amphibian species (including Xenopus (Silurana) and some bufonids) that respond well to the induction of ovulation utilising mammalian gonadotropins (hCG). The optimal protocol for M. fasciolatus involved two priming doses of PMSG (50 IU and 25 IU) administered at 6 and 4 days respectively, prior to two doses of hCG (100 IU), 24 hours apart. This study is also the first to demonstrate in an amphibian species that responds to mammalian gonadotropins that an increase in the ovulation rate occurs after priming with a gonadotropin (PMSG) with FSH activity.

【 授权许可】

CC BY   
© Clulow et al.; licensee BioMed Central Ltd. 2012