Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian 271018 Shandong Province, PR China.
BMC Genomics. 2013 May 26;14:352. doi: 10.1186/1471-2164-14-352.
MicroRNAs have been suggested to play important roles in the regulation of gene expression in various biological processes. To investigate the function of miRNAs in chicken ovarian development and folliculogenesis, two small RNA libraries constructed from sexually mature (162-day old) and immature (42-day old) ovary tissues of Single Comb White Leghorn chicken were sequenced using Illumina small RNA deep sequencing.
In the present study, 14,545,100 and 14,774,864 clean reads were obtained from sexually mature (162-d) and sexually immature (42-d) ovaries, respectively. In total, 202 known miRNAs were identified, and 93 of them were found to be significantly differentially expressed: 42 miRNAs were up-regulated and 51 miRNAs were down-regulated in the mature ovary compared to the immature ovary. Among the up-regulated miRNAs, gga-miR-1a has the largest fold-change (6.405-fold), while gga-miR-375 has the largest fold-change (11.345-fold) among the down-regulated miRNAs. The three most abundant miRNAs in the chicken ovary are gga-miR-10a, gga-let-7 and gga-miR-21. Five differentially expressed miRNAs (gga-miR-1a, 21, 26a, 137 and 375) were validated by real-time quantitative RT-PCR (qRT-PCR). Furthermore, the expression patterns of the five miRNAs were analyzed in different developmental stages of chicken ovary and follicles of various sizes.
The present study provides the first miRNA profile in sexually immature and mature chicken ovaries. Some miRNAs such as gga-miR-1a and gga-miR-21are expressed differentially in immature and mature chicken ovaries as well as among different sized follicles, suggesting an important role in the follicular growth or ovulation mechanism in the chicken.
microRNAs 被认为在各种生物过程的基因表达调控中发挥着重要作用。为了研究 miRNA 在鸡卵巢发育和卵泡发生中的功能，我们构建了两个来自性成熟（162 日龄）和未成熟（42 日龄）白来航鸡卵巢组织的小 RNA 文库，使用 Illumina 小 RNA 深度测序进行了测序。
在本研究中，分别从性成熟（162 天）和未成熟（42 天）卵巢中获得了 14545100 和 14774864 个清洁读数。总共鉴定出 202 个已知的 miRNA，其中 93 个 miRNA 表现出显著的差异表达：与未成熟卵巢相比，成熟卵巢中有 42 个 miRNA 上调，51 个 miRNA 下调。在上调的 miRNA 中，gga-miR-1a 的倍数变化最大（6.405 倍），而下调的 miRNA 中 gga-miR-375 的倍数变化最大（11.345 倍）。鸡卵巢中最丰富的三个 miRNA 是 gga-miR-10a、gga-let-7 和 gga-miR-21。通过实时定量 RT-PCR（qRT-PCR）验证了 5 个差异表达的 miRNA（gga-miR-1a、21、26a、137 和 375）。此外，还分析了这 5 个 miRNA 在鸡卵巢不同发育阶段和不同大小卵泡中的表达模式。
本研究首次提供了性未成熟和成熟鸡卵巢的 miRNA 图谱。一些 miRNA，如 gga-miR-1a 和 gga-miR-21，在未成熟和成熟鸡卵巢以及不同大小的卵泡中表达不同，这表明它们在鸡的卵泡生长或排卵机制中发挥着重要作用。
