Identification of miRNAs associated with sexual maturity in chicken ovary by Illumina small RNA deep sequencing

Abstract

BackgroundMicroRNAs 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.ResultsIn 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.ConclusionThe 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.

Expression and Regulation of MMP1, MMP3, and MMP9 in the Chicken Ovary in Response to Gonadotropins, Sex Hormones, and TGFB11

“…Hens were killed by cervical dislocation, and the ovaries were collected immediately. The whole ovary was harvested for RNA sequencing [16] or protein extraction for comparing ovarian MMP expression between prepubertal and mature hens. Different follicles, including small white follicles and F4, F3, F2, F1, POF1, and POF2 follicles, were manually dissected out for RNA or protein extractions for analyzing MMP expression in the different follicles.…”

The avian ovary and follicle development: some comparative and practical insights

“…No fewer than 93 MIRs (of as yet unknown function) are differentially expressed within the ovary of immature pullets compared to sexually mature hens, and a subpopulation of these continue to be expressed at different levels during subsequent follicular growth and development (30). The initial, slow growth of follicles measuring 60-100 µm in diameter occurs over several months via the uptake of a lipoprotein-rich yolk by the oocyte, concurrent with the expansion of the single layer of granulosal cells.…”

Association study of a common genetic variant in pre-miR-1596 with chicken performance traits

“…The expression difference of gga-miR-1a and gga-miR-21 in immature and mature chicken ovaries and different sized follicles suggested that they conducted an important effect on chicken follicular growth or ovulation mechanism [24]. A related research promulgated that miRNA-133a and miR-1a were muscle-related, whereas miR-122 was adipose-related miRNA in chickens [25].…”