27 28The aim of this study was to investigate the effects of Shh (Sonic Hedgehog) 29 protein on caprine oocyte maturation, early embryo development, and 30 developmental competence after embryo transfer of vitrified-thawed in 31 vitro-produced embryos. Cumulus-oocyte complexes (COCs) derived from abattoir 32 were randomly allocated to the in vitro maturation (IVM) medium supplemented with 33 0 (Control), 0.125, 0.25, 0.5, or 1.0 µg·mL −1 recombinant mouse Shh protein. After 34 IVM, COCs were fertilized with frozen-thawed semen and the presumptive zygotes 35 were cultured on goat oviduct epithelial monolayers in M199 medium for 9 days. Our 36 results showed that supplementation of Shh (0.25 or 0.5 µg·mL Introduction 58 59Influenced by macrobiotics and traditional Chinese medicine, goat milk and 60 meat consumption has been popular in Taiwan. Compared to the exotic breeds, 61Taiwan native goats have much better diseases-and coarse diets-resistant despite 62 of their low productivity. In response to the ever-increasing demand, a large number 63 of Nubian goats were imported to cross-breed with Taiwan native goats during the 64 1980s [1,2]. This is one of the main reasons for the decreased population of the pure 65Taiwan native goats, which may soon become endangered. Therefore, reproductive 66 technologies could be an important tool for preserving genetic diversity and rescuing 67 this caprine breeds in Taiwan. 68Generation of high quality goat embryos is an essential step towards further 69 development and application of in vitro-produced embryos [3,4]. Previous studies 70 have demonstrated that the growth of preimplantation embryos can be enhanced by 71 supplementation of cytokines and/or growth factors in the culture medium [5]. 72 Hedgehog (Hh) protein, which attracts considerable attention over the past few 73 years, is a paracrine factor that enhances embryonic development [6]. In vertebrates, so that no downstream signaling occurs [7,8]; whereas in the presence of Hh, the 79 suppression of Smo is lifted, leading to the activation of intracellular transcription 80 effectors Gli1, Gli2 and Gli3 in vertebrates [9]. 81In the mouse, Ihh and Dhh are expressed in the granulosa cells of preantral and 82 antral follicles, with the receptor Ptc and the signal transducer Smo expressed in 83 thecal cells. Previous studies also suggested that paracrine signaling of Hh exist 84 between granulosa and theca cells [10,11]. Similarly, Russell et al. [9] reported that 85Hh ligands, including Ihh, Dhh and Shh, are expressed in both immature and adult 86 mouse ovaries, where the expression of Ptc (Ptc1, Ptc2) and Smo are found in all 87 ovarian tissues. Therefore, the Hh signaling pathway is most likely to be involved in 88 granulosa cell proliferation and oocyte maturation. Spicer et al. [12] Ptch1 mRNA in theca cells may also suggest a potential paracrine role during 97 bovine folliculogenesis. Nguyen et al. [13,14,15] have also reported that the Shh 98 signaling pathway is active or at least partially active in ...