A Comprehensive Expression Profile of MicroRNAs in Porcine Pituitary

Abstract

MicroRNAs (miRNAs) are an abundant class of small RNAs that regulate expressions of most genes. miRNAs play important roles in the pituitary, the “master” endocrine organ.However, we still don't know which role miRNAs play in the development of pituitary tissue or how much they contribute to the pituitary function. By applying a combination of microarray analysis and Solexa sequencing, we detected a total of 450 miRNAs in the porcine pituitary. Verification with RT-PCR showed a high degree of confidence for the obtained data. According to the current miRBase release17.0, the detected miRNAs included 169 known porcine miRNAs, 163 conserved miRNAs not yet identified in the pig, and 12 potentially new miRNAs not yet identified in any species, three of which were revealed using Northern blot. The pituitary might contain about 80.17% miRNA types belonging to the animal. Analysis of 10 highly expressed miRNAs with the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the enriched miRNAs were involved not only in the development of the organ but also in a variety of inter-cell and inner cell processes or pathways that are involved in the function of the organ.We have revealed the existence of a large number of porcine miRNAs as well as some potentially new miRNAs and established for the first time a comprehensive miRNA expression profile of the pituitary. The pituitary gland contains unexpectedly many miRNA types and miRNA actions are involved in important processes for both the development and function of the organ.

Gonadotrope-specific Deletion of Dicer Results in Severely Suppressed Gonadotropins and Fertility Defects

“…Although transcriptional regulation of gonadotropin subunits has been well studied (10, 12, 19 -22) as described above, the post-transcriptional mechanisms that regulate gonadotropin subunits are unknown (23,24). Of the three pituitary glycoprotein hormone subunit-encoding genes (Cga, Lhb, and Fshb), Fshb gene is unique in its organization.…”

“…These include mRNA expression, turnover, stability, and translational control (36 -41). Expression profiling studies have identified several miRNAs differentially regulated in whole pituitary (23,24), various pituitary cell lineages (42), human pituitary tumors (43)(44)(45), and in an immortalized gonadotrope cell line in response to GnRH treatment (46 -48). In addition, specific miRNAs regulating a repressor that selectively regulates LH levels in the female have also been identified (49).…”

A mikro-RNS-ek szerepe az agyalapimirigy-daganatok tumorbiológiájában

“…Elsősorban állatmodellek vizsgálata alapján tudjuk, hogy a miRNS-ek fontosak az agyalapi mirigy fiziológiás működésében, és hiányuk agyalapimirigy-rendellenességhez vezet [16][17][18][19][20], ám konkrét szerepükről kevés adat áll rendelkezésre. Egér esetében a miRNS-ek érésé-hez szükséges Dicer enzim specifikus kiütése a gonadotrop sejtekben csökkentette a gonadotropinok szintjét, és megváltozott reprodukciós funkciókat, csökkent fertilitást okozott hím egereknél [21].…”

A Comprehensive Profile of Mature MicroRNA in the Pig

“…(Table 3) Although most research has hitherto been dedicated to miRNA's roles in meat quality, emerging research has evaluated miRNA in other solid tissues in pigs, including, but not limited to, reproduction. Many miRNAs are enriched in reproductive tissues [4,15,17,44] ( Table 3). Others may play a role in differentiating neurons in brain development [3,13,[70][71][72][73].…”

“…The common research strategy on miRNA may include three aims: (i) characterization of miRNAs (including identification of novel miRNAs), (ii) determination of target genes, and (iii) illumination of function of miRNAs and target genes. These strategies have been widely used to describe the miRNAome in various pig tissues, such as muscle [9][10][11][12], brain [13], fat [14], embryo [3], pituitary [15], intestine [16], ovary [17] and testes [4].…”