[Show abstract][Hide abstract] ABSTRACT: MicroRNAs (miRNAs) are a class of small RNAs that play significant roles in regulating the expression of the post-transcriptional skin and hair follicle gene. In recent years, extensive studies on these microRNAs have been carried out in mammals such as mice, rats, pigs and cattle. By comparison, the number of microRNAs that have been identified in goats is relatively low; and in particular, the miRNAs associated with the processes of skin and hair follicle development remain largely unknown. In this study, areas of skin where the cashmere grows in anagen were sampled. A total of 10,943,292 reads were obtained using Solexa sequencing, a high-throughput sequencing technology. From 10,644,467 reads, we identified 3,381 distinct reads and after applying the classification statistics we obtained 316 miRNAs. Among them, using conservative identification, we found that 68 miRNAs (55 of these are confirmed to match known sheep and goat miRNAs in miRBase ) are conserved in goat and have been reported in NCBI; the remaining 248 miRNA were conserved in other species but have not been reported in goat. Furthermore, we identified 22 novel miRNAs. Both the known and novel miRNAs were confirmed by a second sequencing using the same method as was used in the first. This study confirmed the authenticity of 316 known miRNAs and the discovery of 22 novel miRNAs in goat. We found that the miRNAs that were co-expressed in goat and sheep were located in the same region of the respective chromosomes and may play an essential role in skin and follicle development. Identificaton of novel miRNAs resulted in significant enrichment of the repertoire of goat miRNAs.
PLoS ONE 12/2012; 7(12):e50001. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bacterial Artificial Chromosome (BAC) libraries have proven to be effective tools for genomic studies. Here, we report the construction of an Inner-Mongolian Cashmere goat BAC library. The library contains 276,480 BAC colonies, is organized into two grades, and has a 4-dimension structure. The average insert size of the library is 128kb, based on the analysis of 566 randomly selected clones. Assuming a genome size of 3×109 bases, the genome coverage of the library is approximately 11.8-fold. The library was screened by PCR using 20 microsatellite markers and six goat genes associated with the hair follicle and skin development. Positive BACs for all the microsatellite markers were identified and the number of positive clones ranged from 3 to 19, with an average of 11.1. The number of positive BACs for genes ranged from 3 to 15 with an average of 9.2.
Small Ruminant Research 05/2012; · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ghrelin has been implicated in the control of cell proliferation in reproductive tissue. Here, we provide evidence that both ghrelin mRNA and protein are present in ovarian follicles. Persistent expression of ghrelin was also demonstrated in sheep ovary throughout the estrous cycle and pregnancy. In fact, the relative mRNA levels of ghrelin varied depending on the stage of the cycle, with the highest expression during the development of the corpora lutea (CL) and minimal expression in the regressing CL. A similar pattern was seen during pregnancy. Dynamic changes in the profile of ghrelin expression during the estrous cycle and throughout pregnancy suggest a precise regulation of ovarian expression of ghrelin, which could represent a potential role for ghrelin in the regulation of luteal development. In conclusion, the presence of the ghrelin signaling system within the sheep ovary especially in the oocytes opens up the possibility of a potential regulatory role of this novel molecule in reproductive function.